Top Read Articles

Published in last 1 year |

In last 2 years |

In last 3 years |

All

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

Seed Germination and Pre-Harvest Sprouting DONG HuiXue, WANG JiRui Scientia Agricultura Sinica    2024, 57 (7): 1215-1219.   DOI: 10.3864/j.issn.0578-1752.2024.07.001 Abstract （1694）   HTML （59）    PDF （302KB）（741）       Knowledge map    Save Reference | Related Articles | Metrics

Select

Physiological and Molecular Effects of Salicylic Acid on Rice Seed Germination at Low Temperature CHEN BingXian, ZHANG Qi, DAI ZhangYan, ZHOU Xu, LIU Jun Scientia Agricultura Sinica    2024, 57 (7): 1220-1236.   DOI: 10.3864/j.issn.0578-1752.2024.07.002 Abstract （1361）   HTML （51）    PDF （5946KB）（1322）       Knowledge map    Save 【Objective】The study investigated the impact of salicylic acid (SA) priming on the germination vigor and physiological response of rice seeds under low temperatures. It aimed to reveal the expression patterns of genes related to abscisic acid (ABA) and gibberellin (GA) metabolic pathways as well as cell wall relaxation genes by SA priming. This research provided a theoretical basis for the study of rice seed germination at low temperatures.【Method】Using indica three-line hybrid rice Taifengyou 208 seeds as materials, the effects of SA on seed germination vigor and physiology responses under low temperature were analyzed through seed priming treatment, and the expression patterns of genes related to ABA, GA and expansin in response to SA were analyzed by qRT-PCR.【Result】Low temperature (15 ℃) significantly delayed the germination process of rice seeds. In seeds germinated at low temperatures for one day, the endogenous SA concentration was 1.7 times higher than that at normal temperatures (28 ℃). However, for five-day-old seedlings, the SA concentration under low temperature was only 0.6% of that at normal temperatures. SA could effectively enhanced germination vigor of seeds at low temperature, with the most significant effects observed at 2 000 μmol·L-1 SA. This concentration significantly increased the germination index, vigor index, shoot length, root length, fresh weight, and dry weight of seeds under low temperature conditions. Notably, the vigor index was three times that of non-primed seeds (CK1) and two times that of water-primed seeds (CK2). In terms of physiological indexes, SA priming increased the contents of soluble sugar, proline and active oxygen, enhanced the activities of total amylase, β-amylase, superoxide dismutase (SOD) and catalase (CAT), and decreased the content of malondialdehyde (MDA). Compared with CK1, 2 000 μmol·L-1 SA decreased the ABA content by 79%, and increased the IAA and GA1 contents by 32.2% and 2.66 times, respectively. In terms of gene expression, the expression levels of ABA synthesizing genes OsNCED2 and OsNCED3 were decreased by 94.26% and 90.24% compared with CK1 in seeds primed by 2 000 μmol·L-1 SA, respectively, whereas the expression levels of ABA decomposing genes OsABA8’ox2 and OsABA8’ox3 were 5.9 and 3.9 times higher than that of CK1, respectively. Compared with CK1, SA priming significantly upregulated the expression of GA synthesizing genes OsCPS1, OsKAO and OsGA20ox1, while it significantly downregulated the expression of GA decomposing genes OsGA2ox2 and OsGA2ox6. In several candidate genes encoding cell wall relaxation protein, e.t. expansin, all but OsEXPB11 were significantly upregulated to some extent by priming. Compared with CK1, 2 000 μmol·L-1 SA increased the expression levels of OsEXPA2, OsEXPB4 and OsEXPB6 to 12.2, 5.9 and 6.1 times, respectively.【Conclusion】SA priming can significantly alleviate the impact of low temperatures on rice seed germination and seedling growth, which is likely due to SA enhancing the activity of antioxidant enzymes such as SOD and CAT, reducing the production of MDA, and increasing the content of soluble sugars and proline, thereby strengthening the tolerance of seeds and seedlings to low temperatures. On the other hand, SA priming decreases endogenous ABA content, increases GA1 content, enhances the activities of total amylase and β-amylase, and promotes the expression of genes related to cell wall relaxation, thus facilitating seed germination and seedling growth at low temperature. Table and Figures | Reference | Related Articles | Metrics

Select

Effect of Flour and Cooking/Baking Qualities by Sprouted Wheat LIANG WangZhuang, TANG YaNan, LIU JiaHui, GUO XiaoJiang, DONG HuiXue, QI PengFei, WANG JiRui Scientia Agricultura Sinica    2024, 57 (7): 1267-1280.   DOI: 10.3864/j.issn.0578-1752.2024.07.005 Abstract （1355）   HTML （27）    PDF （4286KB）（273）       Knowledge map    Save 【Objective】Continuous rainy weather during the wheat harvest season can cause wheat pre-harvest sprouting (PHS) and even germination, thus impacting wheat yield and quality. Evaluating the effect of flour made by blending different proportions of sprouted wheat with regular wheat on the baking/steaming quality of flour processing products can explore the possibility of using a slight degree of sprouted wheat to examine the possibility of reducing food waste. 【Method】In this study, blends of Zhengmai 583 (Zheng 583) and Kechengmai 6 (Ke 6) wheat with 30%, 50%, and 100% sprouted wheat were prepared, respectively. The degradation of wheat flour from blended wheat was evaluated by the falling number, sedimentation value, wet/dry gluten content, dough development time, and dough stability time. The baking/steaming characteristics of bread, dumpling wrapper, Chinese steamed bread (CSB), sponge cake, noodle, and cookie made from blended wheat were evaluated by sensory scores and quality parameters. 【Result】As the proportion of sprouted wheat increased (30%, 50%, and 100%), the dough development time of Zheng 583 flour first increased and then decreased, while the dough stability time gradually reduced. However, the changes in the two parameters of Ke 6 both showed a trend of first decreasing, then increasing, and finally decreasing. The falling number, sedimentation value, wet/dry gluten content, and farinogram parameters of mixed wheat decreased in both cultivars. The specific volume of Zheng 583 CSB increased and then decreased, while the particular volume of Ke 6 CSB gradually reduced. The exact volume of the Zheng 583 sponge cake gradually increased, while the specific volume of the Ke 6 sponge cake remained unchanged. The particular volume of the bread, area of the cookies, cooking loss of the noodles, and turbidity index (A*) of the dumpling soup changed the same trend in both cultivars. Compared to the control (without sprouted wheat), the specific volume of bread decreased by 11.33% and 17.44%, the cookies area increased by 24.10% and 7.49%, the noodles cooking loss increased by 22.99% and 9.69%, and the A* value of the dumpling soup increased by 8.93% and 13.32% in Z583 and Ke 6 of 100% SW, respectively. The bread, Chinese steamed bread, the dumpling wrapper of two cultivars, and the noodles of Zheng 583 showed significant deterioration in the 30% SW gradient. The sponge cake and cookie of the two cultivars showed significant deterioration in the 50% SW gradient. The noodles of Ke 6 showed significant deterioration in the 100% SW gradient. 【Conclusion】The baking/steaming quality of bread, dumpling wrappers, Chinese steamed bread, sponge cake, noodle, and the cookie was seriously affected by PHS. The influence of PHS is different in various wheat cultivars but has the same trend. When the degree of PHS is slight, it has little effect on the baking quality of cookies and sponge cakes. Table and Figures | Reference | Related Articles | Metrics

Select

Research on the Mechanisms of Pre-Harvest Sprouting and Resistant Breeding in Wheat DONG HuiXue, CHEN Qian, GUO XiaoJiang, WANG JiRui Scientia Agricultura Sinica    2024, 57 (7): 1237-1254.   DOI: 10.3864/j.issn.0578-1752.2024.07.003 Abstract （993）   HTML （69）    PDF （692KB）（4758）       Knowledge map    Save Pre-harvest sprouting (PHS) refers to the germination of cereal crops on the spike in high humidity conditions before grain harvest. Wheat PHS is a significant problem that affects both the yield and quality of wheat. Seed dormancy level is a major factor influencing the resistance of wheat PHS, and domesticated crops often exhibit reduced seed dormancy levels, making cultivated wheat more prone to PHS compared to its wild ancestors. Wheat PHS is mainly regulated by external environmental factors such as temperature and humidity, as well as internal plant hormones (GAs, ABA, IAA, MeJA, ET, BR). Researchers have identified a range of materials resistant to PHS, cloned key genes regulating PHS resistance, such as PM19, MFT, MKK3, Myb10-3D, Vp1. New wheat materials resistant to PHS have been successfully developed through molecular marker-assisted selection, artificial synthesis of wheat, and CRISPR/Cas9 gene editing technology. This article reviews the genetic mechanism of PHS resistance in wheat and the latest progress in PHS resistance breeding research. In the future, it is necessary to continue exploring key genes related to PHS resistance, and employ biotechnological breeding methods to cultivate new PHS-resistant wheat varieties. Table and Figures | Reference | Related Articles | Metrics

Select

Utilization Efficiency of Improving the Resistance for Pre-Harvest Sprouting by Synthetic Hexaploid Wheat and Chinese Wheat Landrace LIU ZeHou, WANG Qin, YE MeiJin, WAN HongShen, YANG Ning, YANG ManYu, YANG WuYun, LI Jun Scientia Agricultura Sinica    2024, 57 (7): 1255-1266.   DOI: 10.3864/j.issn.0578-1752.2024.07.004 Abstract （978）   HTML （19）    PDF （774KB）（369）       Knowledge map    Save 【Objective】Pre-harvest sprouting (PHS) is a serious limiting factor for wheat (Triticum aestivum L.) grain yield and end-use quality. Synthetic hexaploid wheats (SHW) and wheat landraces (WL) are important germplasm resources for improving PHS resistance in wheat. The objective of this study is to utilize PHS-resistant loci from SHW and WL for breeding PHS-resistant elite materials, which will provide a theoretical basis for improving PHS resistance of wheat cultivars.【Method】In this study, SYN792 (a synthetic hexaploid wheat from CIMMYT) and Fulingxuxumai (a Chinese wheat landrace) were used as female parents to cross and backcross with Chuanmai 45 (a sensitive variety to PHS), respectively. Two BC1F7 populations including 1 796 lines were established. Seed germination index (GI) and seed germination rate of each spike (SGR) in different environments were used to evaluate PHS resistance. Two germination temperature of 25 ℃ (18GI) and 32 ℃ (19GI) were set to examine seed germinability in 2018 and 2019. 1 796 BC1F7 lines were evaluated preliminarily by SGR phenotype and molecular markers detection in 2017, and the introgression lines with PHS-3D and PHS-A1 resistant loci and SGR less than 35% were screened. Introgression lines with PHS-3D and PHS-A1 resistant loci were used to analyze utilization efficiency of SHW and WL in PHS-resistance breeding by identifying PHS-resistance and yield related traits in 2018 and 2019.【Result】PHS resistance of 1 796 lines was evaluated preliminarily, and 537 lines with SGR value less than 35% were screened for further molecular marker detection. A total of 332 lines with PHS-3D and PHS-A1 were selected by SSR marker, and the frequency of WL introgression lines was significantly higher than that of SHW introgression lines. 332 introgression lines were used to analyze PHS-resistance and yield related traits in 2018 and 2019. There was a significant positive correlation between different PHS indexes in different years, but there was no significant difference in the values of 18GI, 18SGR and 19SGR between SHW and WL introgression lines. The average values of 18SGR, 19SGR and 18GI in SHW and WL introgression lines were lower than 23%. As far as GI value was concerned, there was obvious difference between different germination temperatures. At the germination temperature of 32 ℃, the mean 19GI value of SHW PHS-3D introgression lines was significantly lower than that of WL PHS-A1 introgression lines. Grain color was associated with PHS resistance in SHW introgression lines, and the red-grained SHW introgression lines had lower the mean GI and SGR values than the white-grained lines. Among 73 SHW introgression lines, 11 white-grained lines showed medium or higher resistance to PHS，and the GI values of 14 red-grained lines at different germination temperatures were lower than 35%. According to the data of agronomic traits in 2018 and 2019, thousand grain weight of SHW introgression lines was significantly higher than that of WL introgression lines, but the number of grains per spike was significantly lower than that of WL introgression lines. 23 elite introgression lines including seven SHW introgression lines and 16 WL introgression lines were selected. Two SHW white-grained introgression lines had better resistance to PHS, and the GI values of two red-grained introgression lines at different germination temperatures were lower than 25%.【Conclusion】It is feasible to transfer PHS-3D and PHS-A1 resistance loci to PHS from SHW and WL for improving PHS-resistance of modern wheat cultivars. In this study, the breeding efficiency of WL for PHS-resistance was better than that of SHW. However, the stability of PHS-resistance of SHW introgression lines was better than that of WL introgression lines. 23 SHW and WL elite introgression lines could be used as parents to improve the PHS-resistance and yield traits in wheat. In particular, the white-grained SHW introgression line No.5201 and the red-grained SHW introgression lines No.5497 and No.5505 were very valuable parents for wheat breeding of PHS resistance. Table and Figures | Reference | Related Articles | Metrics

Select

Research Progress on Machine Learning for Genomic Selection in Animals LI MianYan, WANG LiXian, ZHAO FuPing Scientia Agricultura Sinica    2023, 56 (18): 3682-3692.   DOI: 10.3864/j.issn.0578-1752.2023.18.015 Abstract （755）   HTML （67）    PDF （570KB）（5365）       Knowledge map    Save Genomic selection is defined as using the molecular marker information that covered the whole genome to estimate individual’s breeding values. Using genome information can avoid many problems caused by pedigree errors so as to improve selection accuracy and shorten breeding generation intervals. According to different statistical models, methods of estimated genomic breeding value (GEBV) can be divided into based on BLUP (best linear unbiased prediction) theory, based on Bayesian theory and others. At present, GBLUP and its improved method ssGBLUP have been widely employed. Accuracy is the most used evaluation metric for genomic selection models, which is to evaluate the similarity between the true value and the estimated value. The factors that affect the accuracy can be reflected from the model, which can be divided into controllable factors and uncontrollable factors. Traditional genomic selection methods have promoted the rapid development of animal breeding, but these methods are currently facing many challenges such as multi-population, multi-omics, and computing. What’s more, they cannot capture the nonlinear relationship between high-dimensional genomic data. As a branch of artificial intelligence, machine learning is very close to biological mastery of natural language processing. Machine learning extracts features from data and automatically summarizes the rules and use to make predictions for new data. For genomic information, machine learning does not require distribution assumptions, and all marker information can be considered in the model. Compared with traditional genomic selection methods, machine learning can more easily capture complex relationships between genotypes, phenotypes, and the environment. Therefore, machine learning has certain advantages in animal genomic selection. According to the amount and type of supervision received during training, machine learning can be classified into supervised learning, unsupervised learning, semi-supervised learning, and reinforcement learning. The main difference is whether the input data is labeled. The machine learning methods currently applied in animal genomic selection are all supervised learning. Supervised learning can handle both classification and regression problems, requiring the algorithm to be provided with labeled data and the desired output. In recent years, the application of machine learning in animal genomic selection has been increasing, especially in dairy and beef cattle. In this review, machine learning algorithms are divided into three categories: single algorithm, ensemble algorithm and deep learning, and their research progress in animal genomic selection were summarized. The most used single algorithms are KRR and SVR, both of which use kernel tricks to learn nonlinear functions and map data to higher-dimensional kernel spaces in the original space. Currently commonly used kernel functions are linear kernel, cosine kernel, Gaussian kernel, and polynomial kernel. Deep learning, also known as a deep neural network, consists of multiple layers of connected neurons. An ensemble learning algorithm refers to fusing different learners together to obtain a stronger supervised model. In the past decade, the related literature on machine learning and deep learning has shown exponential growth. And its application in genomic selection is also gradually increasing. Although machine learning has obvious advantages in some aspects, it still faces many challenges in estimating the genetic breeding value of complex traits in animals. The interpretability of some models is low, which is not conducive to the adjustment of data, parameters, and features. Data heterogeneity, sparsity, and outliers can also cause data noise for machine learning. There are also problems such as overfitting, large marks and small samples, and parameter adjustment. Therefore, each step needs to be handled carefully while training the model. This paper introduced the traditional methods of genomic selection and the problems they face, the concept and classification of machine learning. We discussed the research progress and current challenges of machine learning in animal genomic selection. A Case and some application suggestions were given to provide a certain reference for the application of machine learning in animal genomic selection. Table and Figures | Reference | Related Articles | Metrics

Select

Function of Maize ZCN7 in Regulating Drought Resistance at Flowering Stage LI Yan, TAO KeYu, HU Yue, LI YongXiang, ZHANG DengFeng, LI ChunHui, HE GuanHua, SONG YanChun, SHI YunSu, LI Yu, WANG TianYu, ZOU HuaWen, LIU XuYang Scientia Agricultura Sinica    2023, 56 (16): 3051-3061.   DOI: 10.3864/j.issn.0578-1752.2023.16.001 Abstract （715）   HTML （157）    PDF （1718KB）（1876）       Knowledge map    Save 【Objective】The main producing areas of maize is mostly located on the arid or semi-arid region that relying on the rainfed farming in China. The maize production losses caused by drought is a great threaten to food security. As a cross-pollinating crop, maize is mostly sensitive to water stress during flowering time. Drought at flowering stage will lead to asynchronous development between the male and female flower and cause massive grain yield loss. Thus, mining drought resistance related genes at flowering stage is important for maize drought resistance improvement and breeding. 【Method】In the present study, the phylogenic tree of 24 ZCN genes in maize genome, which is homologs of Arabidopsis FT gene, was build. The gene expression patterns of ZCN7 were analysis using qRT-PCR and in vivo GFP fluorescence imaging. A maize natural population consisting of 118 diverse inbred lines were planted in three environments, Beijing in 2021 and 2022 and Urumqi in 2022, to identify the flowering time related traits under different water treatments. The genomic variants around ZCN7 were detected by PCR and Sanger sequencing. The candidate gene association analysis was performed based on mixed linear model and the significant associated variants with drought induced anthesis-silking interval was obtained. The gene expression level of ZCN7 in natural population at flowering time was also measured by qRT-PCR. The differences of drought resistance traits and ZCN7 expression were compared between different haplotypes of significant associated variant. The Ubi1:ZCN7 overexpression transgenic maize were obtained, and the phenotypic performance was identified under different water treatments. 【Result】The 24 ZCN genes in maize genome included 15 FT like genes, 6 TFL1 like genes and 3 MFT like genes. The protein sequence of ZCN genes varied from 111 nn to 193 nn. The ZCN7 showed close relationship with ZCN8 and the protein sequence identity was 83.3% between the two genes. ZCN7 showed highest gene expression in the leaf blade at V12 stage. And the ZCN7-promoter:GFP vector was transformed to Arabidopsis and the GFP showed enriched signal at the blade edge of mature leaf. The candidate gene association analysis revealed a SNP variant at 1001 bp upstream of ZCN7 start codon had highest association signal with drought induced anthesis-silking interval under drought. The A/A and G/G haplotypes of SNP-1001 included 78 and 27 inbred lines, respectively. The anthesis-silking interval of A/A haplotype lines were significantly lower than G/G lines. And the ZCN7 gene expression of A/A haplotype lines were significantly higher than G/G lines. In addition, the ZCN7 overexpression transgenic lines showed significantly decreased anthesis-silking interval than wild type lines. Under drought, the anthesis-silking intervals of OE1 and OE2 were 2.3 and 2.6 days shorter than wild type lines. And the grain yield per plant and kernel number per plant of transgenic lines were significantly higher than wild type lines under drought, while the hundred kernel weight, kernel length and kernel width showed no significant difference. 【Conclusion】The maize ZCN7 played positive role in drought resistance and its overexpression improved grain yield by reducing anthesis-silking interval under drought. Table and Figures | Reference | Related Articles | Metrics

Select

Research Progress on Root System Architecture and Drought Resistance in Wheat ZHANG YuZhou, WANG YiZhao, GAO RuXi, LIU YiFan Scientia Agricultura Sinica    2024, 57 (9): 1633-1645.   DOI: 10.3864/j.issn.0578-1752.2024.09.002 Abstract （683）   HTML （84）    PDF （3342KB）（2287）       Knowledge map    Save Wheat is the most important cereal crop, and drought is the most significant abiotic stress factor that severely affects wheat growth and development. Plant root system, as a primary organ for crops to acquire water and nutrients, directly determines the efficiency of soil water utilization. In recent years, increasing evidence has shown that plant root system architecture (RSA) plays an important role in plant tolerance to drought stress. This review summarizes the current research progress on the regulation of wheat drought tolerance determined by RSA. First, we present how root tropism especially root gravitropism shapes the RSA, summarize the relevant genes and molecular regulatory mechanism involved in root gravitropic growth, and explain how the root tropism-regulated RSA is implicated in wheat adaptation to drought stress. In addition to root tropic growth, the root development also participates in the RSA formation and the plant adaptability to drought stress. Therefore, this review further summarizes how wheat regulates root development to alter its root system morphology (including increasing root length, modifying lateral root number and root hair density, etc.), thereby enhancing its water acqusition from the soil and its adaption to drought environment. The identified genes involved in wheat root development under drought stress conditions are also systematically summarized. Furthermore, as the underground part of plants, the revelation of RSA has always been a challenging task, which hinders our understanding of the relationship between RSA and plant drought tolerance. Therefore, this review also summarized the available techniques used to analyze the RSA at two- and three-dimension levels. These techniques can measure and analyze wheat root length, density, growth direction, and morphology parameters, laying technical support for an insightful understanding of the relationship between wheat RSA and drought resistance. Finally, we discuss the prospect of the improvement of RSA in breeding wheat drought-resistant varieties, as well as provide an outlook for how to identify genes regulating wheat RSA and pinpoint their regulatory mechanism. In summary, the relationship between wheat RSA and drought resistant is closely associated. The continuous development of sequencing techniques, along with the deepening research on the regulatory mechanism of wheat RSA, will provide new means and strategies for the further breeding of drought-tolerance wheat varieties. Table and Figures | Reference | Related Articles | Metrics

Select

Effects of Long-Term Straw Return and Nitrogen Application Rate on Organic Carbon Storage, Components and Aggregates in Cultivated Layers GUO RongBo, LI GuoDong, PAN MengYu, ZHENG XianFeng, WANG ZhaoHui, HE Gang Scientia Agricultura Sinica    2023, 56 (20): 4035-4048.   DOI: 10.3864/j.issn.0578-1752.2023.20.009 Abstract （680）   HTML （40）    PDF （599KB）（625）       Knowledge map    Save 【Objective】The results of carbon sequestration studies on combining straw returning with nitrogen fertilizer are controversial. Aimed at such problem, this experiment was carried out to reveal the effects of combining straw returning with nitrogen fertilizer on Carbon sequestration capacity and mechanism of farmland, so as to provide a reference for the future research. 【Method】Based on 11 years of long-term positioning experiments, this paper adopted split-zone design, the main treatment included straw returning to soil and removal straw from field, and the subplots included three N application rate, which were no nitrogen (N0), 168 kg·hm-2 (N168, nitrogen), and 336 kg·hm-2 (N336, excessive nitrogen application). 【Result】Compared with wheat without nitrogen fertilizer, wheat yield increased by 14.4%-19.5% with nitrogen fertilizer. The effect of straw returning to the field on yield was not significant. Straw returning significantly increased the cumulative input of soil carbon by 70.8% (P<0.05), but had no significant effect on soil organic carbon storage. Compared N0, the nitrogen application significantly increased soil carbon accumulation input and soil organic carbon storage by 7.7%-8.5% (P<0.05) and 4.7%-8.1% (P<0.05), respectively. The application of nitrogen fertilizer significantly increased the carbon fixation rate by 32.7%-56.1% (P<0.05), and N336 significantly increased the soil carbon fixation efficiency by 51.8% (P<0.05); straw returning to the field did not significantly improve the soil carbon fixation rate, but significantly reduced the carbon fixation efficiency by 30.9% (P<0.05). Both nitrogen application and straw returning could improve soil carbon pool capacity, and N0 and N168 have reached carbon saturation. The content of soluble organic carbon (DOC), microbial biomass carbon (MBC) and easily oxidized organic carbon (EO) in the soil increased by 4.6%, 11.2% and 4.5% respectively after returning straw to the field. Compared N0, DOC under N168 and N336 increased by 14.12% and 29.54% respectively; MBC decreased by 14.0% and 28.0% on average, respectively; EO increased by 8.2% and 11.5%, respectively. Straw returning to the field was beneficial to the improvement of soil DOC/SOC and microbial entropy. Applying nitrogen fertilizer was beneficial to the increase of DOC/SOC, but reduced the microbial entropy. Both straw returning and nitrogen fertilizer application had no effect on soil EO/SOC. Both straw returning and nitrogen application were beneficial to the improvement of macroaggregates (>0.25 mm), and straw returning significantly increased the organic carbon content of macroaggregates by 5.2%. The average weight diameter (MWD) and geometric average diameter (GMD) of aggregates under non-return showed a trend of first increasing and then decreasing with the increase of nitrogen level, while under straw returning, it showed an increase with the increase of nitrogen level. Straw returning increased the MWD and GMD of aggregates by 8.8% and 7.5% respectively, and the application of nitrogen fertilizer increased the MWD and GMD by 14.1%-22.7% and 16.8%-23.4% respectively, compared with CK. Both straw returning and nitrogen application could improve the distribution of organic carbon in large aggregates. 【Conclusion】Straw returning with nitrogen fertilizer could increase carbon input, increase activated organic carbon content, reduce microbial activity, and improve the protection of organic carbon by aggregates. Table and Figures | Reference | Related Articles | Metrics

Select

QTL Mapping and Molecular Marker Development of Traits Related to Grain Weight in Wheat ZHANG ZeYuan, LI Yue, ZHAO WenSha, GU JingJing, ZHANG AoYan, ZHANG HaiLong, SONG PengBo, WU JianHui, ZHANG ChuanLiang, SONG QuanHao, JIAN JunTao, SUN DaoJie, WANG XingRong Scientia Agricultura Sinica    2023, 56 (21): 4137-4149.   DOI: 10.3864/j.issn.0578-1752.2023.21.001 Abstract （671）   HTML （59）    PDF （4065KB）（682）       Knowledge map    Save 【Objective】The yield of wheat, the second-highest-yielding food product in the world, has a major impact by grain weight. This research used materials from a recombinant inbred line (RIL) population derived from Heshangtou (HST) and Longchun 23 (LC23). Based on 55K SNP genotype data, QTL mapping was performed for traits related to grain weight of wheat, and co-segregation markers of major grain length QTL were developed and verified to provide reference for molecular marker assisted selection breeding.【Method】The wheat 55K SNP microarray was used to genotype parents and RIL populations, and a high density genetic linkage map was constructed, and its correlation with Chinese spring reference genome IWGSC RefSeq v1.0 was analyzed. QTL mapping of traits related to grain weight in multiple environments based on inclusive composite interval mapping method. The analysis of variance of major effect QTLs were performed to judge the additive interaction effect among different QTLs, and to analyse its effect on traits related to grain weight. At the same time, the corresponding kompetitive allele specific PCR marker was developed according to the closely linked SNP loci of major QTL for grain length, and verified in 242 wheat accessions worldwide.【Result】In this study, a high density genetic map of Heshangtou/Longchun 23 RIL population was constructed, with full length 4 543 cM, including 22 linkage groups, covering 21 chromosomes of wheat, and the average genetic distance was 1.7 cM. There was a significant correlation between genetic map and physical map, and the Pearson correlation coefficient were 0.77-0.99 (P<0.001). A total of 51 QTLs related to grain weight were detected, among them, 4 stable major QTLs were found in multi-environments (three or more environments) and distributed on 2D, 5A, 6B and 7D chromosomes. According to the physical interval and functional markers, it is inferred that stable major QTLs Qtkw.nwafu-2D.1 and Qtkw.nwafu-7D are photoperiod gene Ppd-D1 and flowering gene FT-D1, respectively. The analysis of variance shows that there is a significant interaction between them. The favorite alleles polymerization of Qtkw.nwafu-2D.1 and Qtkw.nwafu-7D can significantly increase thousand grain weight and grain width of wheat. In addition, the corresponding KASP molecular detection marker AX-111067709 was developed based on the co-segregated SNP of the major locus Qgl.nwafu-5A for grain length, which was significantly correlated with grain length and grain weight traits in a diversity panel comprising of 242 wheat accessions, and could increase grain length by 3.33% to 4.59% and grain weight 5.70% to 10.35% in different environments (P<0.001).【Conclusion】There are several genetic loci that affect traits linked to grain weight in Heshangtou (HST) and Longchun 23 (LC23), and Qtkw.nwafu-2D.1 and Qtkw.nwafu-7D dramatically increased thousand grain weight and grain width through additive interaction effects. Qgl.nwafu-5A is significantly correlated with grain weight and grain length, and its co-segregated molecular marker AX-11106770 can be used in molecular marker assisted selection breeding. Table and Figures | Reference | Related Articles | Metrics

Select

The Genetic Basis of Flavonoid Contents in Wheat and Its Application in Functional Wheat Variety Breeding CHEN Jie, CHEN Wei Scientia Agricultura Sinica    2023, 56 (13): 2431-2442.   DOI: 10.3864/j.issn.0578-1752.2023.13.001 Abstract （653）   HTML （68）    PDF （2776KB）（486）       Knowledge map    Save Accompanying the elevated expenses on consumption, people’s urge upon food has been gradually changed from “eat to be fed” to “eat to be satisfied” and further to “eat to gain nutrition” and “eat to be healthy”. Accordingly, breeders considered the wheat breeding goals should be set as breeding wheat with better quality along with higher yield, wherein the phrase “functional wheat variety” was recently raised. Flavonoids comprise one of the most widely reported categories of metabolites, the contents of which have been included within the “functional wheat variety” breeding program for its connection with plant phenotypes and its contribution to human health. The combination of metabolomics approach and genetics design has been proved to be efficient in identifying the candidates that responsible for metabolite contents, that said its application in wheat was lagged behind due to the lately released wheat reference genome. Further, the deficient knowledge upon the genetic basis of metabolites has in turn constrained the application of breeding “functional wheat variety”. In the current manuscript, the research progresses on genetic basis of flavonoids are briefly summarized, and its application for wheat breeding is highlighted. Meanwhile, the metabolomics-assisted breeding frame is concepted. Ultimately, the “functional wheat variety” breeding program will be achieved through the combination of the fundamental researches and breeding applications. Table and Figures | Reference | Related Articles | Metrics

Select

Epidemiological Investigation of Respiratory Pathogens in Deceased Fattening Pigs in Major Pig Farming Area of Middle and Eastern China and Characterization of Pasteurella multocida LUO SuXian, ZHOU Hong, LIN HuiXing, FAN HongJie Scientia Agricultura Sinica    2024, 57 (11): 2254-2264.   DOI: 10.3864/j.issn.0578-1752.2024.11.016 Abstract （628）   HTML （13）    PDF （1165KB）（141）       Knowledge map    Save 【Objective】This study aims to isolate and identify prominent bacterial respiratory pathogens from samples collected from fattening pigs that have died from respiratory diseases in major domestic pig farming area of middle and eastern China. And identifying these bacterial pathogens will offer valuable evidence for preventing and controlling the significantly prevalent respiratory diseases in recent years. Moreover, the characteristics of Pm were identified, providing reference for the development of Pm vaccines.【Method】The lungs of pigs died from respiratory disease were collected from large-scale farms in major pig farming area of middle and eastern China from 2021 to 2023. Blood agar and TSA were employed for the isolation of pathogens, which were then identified through microbiological and molecular biology methods. Additionally, MLST typing and virulence testing in mice were conducted on Pm isolates. The primers for PCR against seven housekeeping genes of adk, est, gdh, mdh, pgi, pmi and zwf of Pm were designed. Then the productions of amplicons were sequenced and submitted to perform MLST typing. The capsule and lipopolysaccharide typing were detected by PCR. The virulence factor genes were detected by PCR. Single isolates of A type and selected D and F types of Pm were evaluated for virulence in ICR mice. LD50 of JS-65, JS-51 and JS-34 were detected in ICR mice.【Result】A total of 73 Pm isolates were obtained, with an isolation rate of 15.53%. Additionally, 71 SS isolates, 29 APP isolates, and 10 GPS isolates were obtained, with isolation rates of 15.11%, 6.17%, and 2.13% respectively. The typing results indicated that the prevailing subtype among Pm isolates was A:L3, accounting for 55%. Among SS isolates, subtype 9 was the prevailing type, accounting for 38.03%. Among APP isolates, subtype 15 was the prevailing type, accounting for 51.72%. Among GPS isolates, subtype 5/12 was the prevailing type, accounting for 60.00%. Co-infection included Pm+SS, Pm+APP, SS+APP and Pm+APP+GPS, accounting for 16.67% of the total pig population. Three capsule types were isolated: A (67%), D (30%), and F (3%). Two lipopolysaccharide types were found: L3 (56%) and L6 (44%). Nine ST genotypes were identified: ST79, ST50, ST7, ST74, ST13, ST27, ST9, ST287, and ST370, with proportions of 33%, 26%, 16%, 10%, 4%, 4%, 3%, 3%, and 1%, respectively. The results of virulence gene detection showed that the positivity rates of ptfA, fimA, hsf-2, exbB, exbD, tonB, fur, nanH, sodA, and sodC genes were greater than 95%. The positivity rates of hsf-1, pfhA, tadD, hgbA, hgbB, pmHAS, ompA, ompH, oma87, and plpB genes ranged from 40% to 90%. The positivity rates of tbpA and nanB genes were between 10% and 30%; the toxA gene was not detected. The virulence test results indicated that all mice died when exposed to less than 102 CFU of strain A, the mortality rate of mice was between 60% and 100% when exposed to 103 CFU of strain D, and the mortality rate of mice was 60% when exposed to 5×103 CFU of strain F. LD50 of JS-65, JS-51, and JS-34 were detected in ICR mice, and the results showed that JS-65 LD50<10 CFU, and JS-51 LD50=6.3 × 102 CFU, JS-34 LD50=3.98 × 103 CFU.【Conclusion】Based on the bacterial pathogen isolates from 2021 to 2023, the primary pathogen bacterium of the respiratory tract in dead fattening pigs were Pm, SS, APP, and GPS. Pm had the highest number of isolates and isolation rate from lung tissue. The RIRDC identified a Pm strain of ST370 and extended MLST typing data in pigs. PCR typing results showed that the dominant serotype of Pm was A:L3:ST79, which exhibited the highest virulence in ICR mice with a minimum lethal dose of less than 10 CFU. These results serve as the foundation for the development of an inactivated Pm vaccine. Table and Figures | Reference | Related Articles | Metrics

Select

Screening of Mycobacterium Avium Subsp. Paratuberculosis Immunogenic Proteins and Its Evaluation of Immunological Effect CHEN FanRuo, ZHANG JiaJun, LU Ping, CUI Ning, CUI YingYing, CUI ZiYin, DANG GuangHui, LIU SiGuo Scientia Agricultura Sinica    2024, 57 (6): 1204-1214.   DOI: 10.3864/j.issn.0578-1752.2024.06.014 Abstract （615）   HTML （12）    PDF （3113KB）（300）       Knowledge map    Save 【Background】 Paratuberculosis (PTB) is a chronic, wasting infectious disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) in ruminants. PTB causes huge economic losses to the livestock industry and poses a serious threat to public health safety. Since the current clinical methods for the detection and control of PTB are inadequate, and the PTB vaccine used is ineffective and interferes with the diagnosis of bovine tuberculosis, there is a need for developing a vaccine with strong immunogenicity, good safety, and excellent protection for the prevention and control of PTB. 【Objective】 The immunogenic protein of MAP was screened and its immunoprotective effect was evaluated, so as to provide the data support for the prevention and control of PTB. 【Method】 Five recombinant plasmids were constructed based on six genes of MAP: p22, map1272c, map3531c, map3783, map3701c, and map3527. The five recombinant proteins were combined with MONTANIDE ISA 61 VG adjuvant to immunize mouse by subcutaneous injection, and the best immunogen was screened by IFN-γ ELISPOT assay. The best immunogen was then mixed with the reported 66NC fusion protein. Mouse were immunized by subcutaneous multi-point injection. At 3 weeks after the second immunization, mice were immunized with 1×108 CFU of the MAP K-10 strain intraperitoneally. The immunogenicity and immunoprotective effect of the candidate subunit vaccine were comprehensively evaluated by IFN-γ ELISPOT assay, monitoring antibody titers and serum cytokines, as well as detecting weight changes, liver pathological and histopathological observations and charge count differences of infected mouse. 【Result】 Five recombinant proteins, such as 58F, 62F, 69F, 46F, and 52F, were expressed based on the genes p22, map1272c, map3531c, map3783 and map3701c. 58F produced the highest level of IFN-γ after immunization and was the most promising candidate immunogen. The fusion protein combination 66NC+58F induced persistent high titers of IgG, IgM, IgG1 and IgG2a, and also induced specific release of IFN-γ, TNF-α, and IL-17A. In the evaluation of protective effects, the fusion protein combination 66NC+58F resisted the weight loss caused by MAP infection, significantly reduced pathological damage in the liver, and decreased MAP colonization in the liver. 【Conclusion】 The fusion protein combination 66NC+58F induced Th1 and Th17-type immune responses in mouse, provided immune protection against MAP infection and was an important candidate subunit vaccine for PTB. Table and Figures | Reference | Related Articles | Metrics

Select

QTN Mining and Candidate Gene Screening of Upland Cotton (Gossypium hirsutum L.) Seed-Related Traits BAI BingNan, QIAO Dan, GE Qun, LUAN YuJuan, LIU XiaoFang, LU QuanWei, NIU Hao, GONG JuWu, GONG WanKui, ELAMEER ELSAMMAN, YAN HaoLiang, LI JunWen, LIU AiYing, SHI YuZhen, WANG HaiZe, YUAN YouLu Scientia Agricultura Sinica    2024, 57 (15): 2901-2913.   DOI: 10.3864/j.issn.0578-1752.2024.15.001 Abstract （597）   HTML （119）    PDF （3621KB）（564）       Knowledge map    Save 【Objective】Exploring the genetic loci and related genes that control cottonseed size traits to lay a foundation for subsequent study on the molecular mechanism cottonseed size formation. 【Method】The upland cotton recombinant inbred line (RIL) population composed of 300 lines was used as the research material. Seven phenotypic traits including cottonseed index (SI), seed length-cutting acreage (SLA), seed length-cutting perimeter (SLP), seed length (SL), seed width (SW), length-width ratio (LWR) and seed roundness (SR) were evaluated in four environments. The RIL population was genotyped by liquid phase chip strategy. The high-quality single nucleotide polymorphism (SNP) markers and phenotypic data were subjected to perform genome-wide association study (GWAS), and quantitative trait nucleotides (QTNs) associated with cottonseed size-related traits were mined. The genetic effects of QTNs were analyzed to identify candidate genes. 【Result】Seven cottonseed size-related traits showed a continuous normal distribution in four environments, which expressed a sizable phenotypic variation. The coefficient of variation ranged from 1.82% to 10.70%. The influencing effect on trait formation were basically as genotype>environment>genotype × environment, indicating suitability for GWAS analysis of these results. Correlation analysis showed that the seed index was significantly correlated with SLA, SLP, SL and SW, and LWR was significantly correlated with SR, indicating the possible existence of pleiotropic loci. GWAS was performed using the 3VmrMLM model, and a total of 47 QTNs were associated with these seven traits. A total of 11 QTNs were associated on chromosome A07, of which three physical loci in the region of 71.99-72.87 Mb, A07:71993462, A07:72067994 and A07:72198802 were very close and simultaneously associated with SI, SLA, SLP, SL and SW in four environments. The average value of R2 between markers was>0.8 (P<0.001), showing a large linkage disequilibrium. Genetic effect analysis showed that there were two haplotypes in this region. Among these cottonseed size relating traits, haplotype Ⅱ and haplotype I were significantly different, indicating that these loci directly affected cottonseed size traits and could be used for molecular marker-assisted selection. The expression patterns of the genes in the interval were analyzed using TM-1 transcriptome data. The results revealed that Gh_A07G1767 was preferentially expressed and Gh_A07G1766 specifically expressed at the stage of cottonseed development. These results speculated that these genes may play an important role in the growth and development of cottonseed.【Conclusion】47 QTNs were identified, and two candidate genes related to cottonseed development were screened. Table and Figures | Reference | Related Articles | Metrics

Select

Research Progress of PPR Protein in Plant Abiotic Stress Response LI Cheng, LU Kai, WANG CaiLin, ZHANG YaDong Scientia Agricultura Sinica    2023, 56 (24): 4801-4813.   DOI: 10.3864/j.issn.0578-1752.2023.24.001 Abstract （579）   HTML （81）    PDF （499KB）（5781）       Knowledge map    Save Abiotic stress is one of the main factors causing global grain yield reduction. It is of great significance to study the function and response mechanisms of plant stress-related proteins to improve crop stress resistance. Pentatricopeptide repeat (PPR) proteins, belong to the largest family of nuclear coding proteins in higher plants and are named because they contain highly specific PPR motifs. Depending on motif type and arrangement, PPR proteins can be classified as P and PLS, and PLS proteins can be further classified as PLS, E, E+, DYW, and other subclasses based on their carboxyl-terminal domains. PPR proteins are widely distributed in terrestrial plants, mainly in chloroplasts and mitochondria, and a few in the nucleus. As sequence-specific RNA binding proteins, PPR proteins are involved in multiple aspects of plant RNA processing, including RNA editing, splicing, stabilization, and translation. PPR protein plays a variety of important roles in the whole life process of plants, but the mechanism of its action in plant stress resistance is not well understood. Based on the localization and function of PPR proteins related to abiotic stress reported, the mechanism of PPR proteins involved in regulation of abiotic stress, including post-transcriptional regulation and retrograde signaling, was reviewed and discussed in this paper. Post-transcriptional regulation is related to the role of PPR proteins in the modification of RNA after transcription. It is generally believed that PPR affects stress resistance in plants by regulating the expression of stress-related genes via binding RNA and by regulating the metabolism of organelle RNA. In terms of retrograde signaling, damage to PPR proteins can lead to impaired mitochondrial or chloroplast function, and then produce various retrograde signals (such as ROS), thereby regulating the expression of related genes and resisting adversity. However, since plastid signaling is affected by many environmental factors, some of which are still unclear, the mechanism of the PPR protein in retrograde signaling remains to be clarified. In addition, PPR proteins are pleiotropic and some have important effects on plant growth and reproduction while acting on stress resistance. Finally, this paper further analyzed the current research status of PPR protein as an RNA editing tool, discussed the remaining problems and research prospects of PPR protein in the direction of abiotic stress, and pointed out the key points and difficulties that need to be paid attention to in future research, to provide references for further research on PPR protein and crop abiotic stress resistance breeding. Table and Figures | Reference | Related Articles | Metrics

Select

Non-Destructive Monitoring of Rice Growth Key Indicators Based on Fixed-Wing UAV Multispectral Images WANG WeiKang, ZHANG JiaYi, WANG Hui, CAO Qiang, TIAN YongChao, ZHU Yan, CAO WeiXing, LIU XiaoJun Scientia Agricultura Sinica    2023, 56 (21): 4175-4191.   DOI: 10.3864/j.issn.0578-1752.2023.21.004 Abstract （577）   HTML （43）    PDF （2299KB）（3920）       Knowledge map    Save 【Background】In recent years, with the rapid development of remote sensing technology, real-time and non-destructive monitoring of crop growth status has become a research hotspot. Remote sensing-derived agricultural information will provide guidance for the precise management of large-scale crops. Among various remote sensing monitoring platforms, unmanned aerial vehicles (UAVs) have attracted wide attention due to their simple operation and low cost. UAVs equipped with multispectral cameras can quickly obtain crop growth conditions.【Objective】This study attempted to combine texture information and spectral information of multispectral images of fixed-wing UAVs to explore the monitoring effect of “atlas” information on rice growth indicators.【Method】A two-year rice field experiment involving different sowing dates, varieties, planting methods and nitrogen levels was conducted. During the key growth stages of rice, remote sensing images of the rice canopy were obtained using a Sequoia multispectral camera mounted on a fixed-wing UAV. Shoot destructive sampling was conducted simultaneously to obtain leaf area index (LAI), aboveground biomass (AGB), plant nitrogen content (PNC) and other agronomic indexes of rice. Simple regression, partial least squares regression and artificial neural network algorithms were used to construct rice growth index monitoring model based on multispectral images of fixed-wing UAV. The monitoring effects of spectral texture information in different models were compared and analyzed.【Result】The quantitative relationship between vegetation index (VI), single-band texture features and rice LAI, AGB, and PNC was explored using simple linear regression. The results showed that vegetation indexes had strong correlations with LAI and AGB, with the best-performing indexes being CIRE and NDRE, with R2 values of 0.80 and 0.76, respectively. However, for PNC monitoring, vegetation indexes did not achieve ideal results, with the best-performing RESAVI and NDRE having R2 values of only 0.13 with PNC. Further analysis using simple linear regression revealed that single-band texture features did not perform well in monitoring rice growth indicators. In order to further analyze the monitoring effect of image texture on the above three indexes, normalized texture indexes (NDTI), ratio texture indexes (RTI), and difference texture indexes (DTI) were constructed by referring to the construction method of VI. Correlation analysis showed that the newly constructed texture index (TI) improved the monitoring accuracy of rice growth indicators compared to single-band texture feature but did not perform better than vegetation indexes. To combine spectral and texture information, partial least squares and artificial neural network modeling methods were adopted in this paper. VI and VI+TI were used as different input parameter combinations to construct rice LAI, AGB and PNC monitoring models. The results showed that both partial least squares and artificial neural network modeling methods significantly improved the monitoring accuracy compared to simple linear regression. The best performance was achieved using VI+TI as input variables and an artificial neural network model for validation, with validation R2 values for LAI, AGB, and PNC models increasing from 0.75, 0.72, and 0.26 to 0.86, 0.92, and 0.86, respectively, while RMSE values were significantly reduced.【Conclusion】The monitoring accuracy of rice LAI, AGB and PNC can be effectively improved by using the fixed-wing UAV to collect multispectral images of rice canopy and using the texture features and reflectance information as input parameters of the model through the model construction method of artificial neural network. The research results will provide a theoretical basis for rapid monitoring of large area crop growth. Table and Figures | Reference | Related Articles | Metrics

Select

Effects of Sowing Date Adjustment on Yield and Quality of Winter Wheat and Summer Maize in Northern Area of North China ZHAO HuaRong, ZHOU GuangSheng, QI Yue, GENG JinJian, TIAN XiaoLi Scientia Agricultura Sinica    2024, 57 (15): 2964-2985.   DOI: 10.3864/j.issn.0578-1752.2024.15.005 Abstract （572）   HTML （38）    PDF （698KB）（1959）       Knowledge map    Save 【Objective】Based on the field staging experiments, this study revealed the different responses of winter wheat and summer maize sowing date adjustments in growth and development, photosynthetic physiological characteristics, grain filling, yield formation and quality to climate warming in northern area of North China, providing scientific basis for agricultural production measures to cope with climate change in North China Plain.【Method】Different sowing date experiments of winter wheat and summer maize have been conducted at Hebei Gucheng Agricultural Meteorology National Observation and Research Station in northern area of North China from 2017 to 2023, which were set up in four sowing dates, including 10 d early sowing, 10 d late sowing, 20 d late sowing, and control. The growth process, above-ground dry matter accumulation and distribution, photosynthetic characteristics of leaves, grain filling rate, yield agronomic traits, and grain nutrients of winter wheat and summer maize were observed. 【Result】 The whole growth period of winter wheat was shortened with the delay of sowing date, mainly because of the shortening of seedling stage before winter. There was a parabolic relationship between the whole growth period and sowing date of summer maize. The seedling stage was shortened by 1.3 d, and the flowering stage and grain formation-filling stage were extended by 1.5 d and 1.6 d for every 10 d delay of sowing date. The grain filling characteristics of winter wheat and summer maize were not sensitive to sowing date adjustments, and the grain filling rate of summer maize was little different during different sowing dates, but the grain formation period, the filling end date and the peak date were successively delayed due to the delay of sowing date, and the duration of filling days was shortened by 4.0 d for every 10 d delay of sowing date. Under the background of warm autumn and winter in northern wheat region, the sowing duration of winter wheat was extended, while its influence on the yield was obviously weakened. The delay of sowing date with the increase of sowing seed amount would result in yield increase slightly. The yield of summer maize decreased significantly with the delay of sowing date, and the decline rate of theoretical yield was 1 381.50 kg·hm-2 for every 10 d delay of sowing date, but the yield of winter wheat and summer maize showed a jumping decease for 20 d late sowing. The grain distribution rate increased by 1.67% for winter wheat, decreased by 1.57% for summer maize with every 10 d delay of sowing date. As a result, the harvest index increased by 0.017 for winter wheat, and decreased by 0.016 for summer maize with every 10 d delay of sowing date. The leaf photosynthetic rates (Pn) of winter wheat and summer maize were also different in response to sowing date, they were similar for winter wheat during different sowing dates, while decreased by 1.21 μmol·m-2·s-1 for summer maize for every 10 d delay after sowing date. Sowing date adjustments had no significant effects on grain quality of winter wheat and summer maize in northern area of North China. 【Conclusion】Extending suitable sowing date range and sowing date delay of winter wheat in North China Plain were positive and effective measures to adapt to climate warming. The early sowing of summer maize in North China Plain might avoid the negative effects of high temperature and heat damage, and would promote the increase of yield. Table and Figures | Reference | Related Articles | Metrics

Select

Meta-Analysis of Yield Effects and Influencing Factors of Cover Crops on Main Grain Crops in China MA JiaYu, WANG Tao, LIU XiaoLi, WANG Li, ZHANG XueCheng, WANG WenTao, KONG FanSheng, HUANG XueJun, WANG ZiYi, WANG YanDong, ZHEN WenChao Scientia Agricultura Sinica    2023, 56 (10): 1871-1880.   DOI: 10.3864/j.issn.0578-1752.2023.10.005 Abstract （563）   HTML （49）    PDF （2214KB）（418）       Knowledge map    Save 【Objective】The objective of this study was to clarify the effect of cover cropping on the yield of main grain crops in China, and to investigate the significant influencing factors, so as to provide a scientific basis for the promotion and application of cover crops in China.【Method】A Meta-analysis including data from 903 pairwise observations from 137 publications from 1980 to 2022 was conducted to elucidate the effect of “fallow” versus “cover cropping” on yield of main grain crops. Meta regression was also conducted to explore the factors influencing the effect of cover crops on grain crops yield.【Result】Under cover crops, grain crop yields increased significantly by 12.2% compared to fallow, with wheat, rice and maize yields increasing significantly by 9.5%, 11.9%, and 19.6%, respectively. In addition, grain crop yields increased by 9.5% and 12.4% for winter and summer cover crops, respectively. Among the different types of cover crops, leguminous cover crops increased grain crop yields by 12.9% (February orchid 14.2%, Chinese milk vetch 11.8%, vetch 9.5%, pea 7.8%, soybean 7.4%), while cruciferous and gramineous cover crops increased grain crop yields by 9.3% and 8.3% (rape 7.0%, ryegrass 7.9%), respectively. However, compared with pure stands, cover crop mixtures more markedly increased grain crop yield by 17.3%. Furthermore, cover cropping years and sunshine hours significantly increased the effect of cover crops. High precipitation and temperature increased the effect of cover crops at high latitudes, while high precipitation and temperature decreased the effect of cover crops at low latitudes.【Conclusion】During the fallow period, cover crops mixtures contribute to increase grain crops yields, reduce surface exposure and make full use of solar, thermal, water and soil resources, especially during the northern summer and southern winter. Table and Figures | Reference | Related Articles | Metrics

Select

Physiological Changes and Integrity of ATP Synthase Subunits mRNA in Naturally Aged Cotton Seeds SONG Ci, GU FengXu, XING ZhenZhen, ZHANG JunMing, HE WenXue, WANG TianBo, WANG YuLu, CHEN JunYing Scientia Agricultura Sinica    2023, 56 (10): 1827-1837.   DOI: 10.3864/j.issn.0578-1752.2023.10.001 Abstract （557）   HTML （119）    PDF （769KB）（344）       Knowledge map    Save 【Objective】Seed aging is a complex biological process, previous studies have been used to elucidate the events. However, the mechanism of seed aging is still unclear. The naturally aged cotton seeds were used as experimental materials, and the physiological and biochemical changes as well as the changes in ATP synthase mRNA integrity that occurred in cotton seed during storage were investigated in order to provide a foundation for further illuminating the aging mechanism of cotton seeds.【Method】In this study, a collection of seeds (cultivar Xinluzao 74) that had been stored for 3 and 5 years served as the experimental materials, the newly harvested seeds were used as the control (CK). The germination percentage, water absorption and viability of cotton seeds were valued by germination test between paper, low constant temperature over method, and TTC staining method, respectively; The acid value and respiratory rate of cotton seeds were determined by the acid-base titration method, and the ATP synthase activity was detected with plant ATP synthase ELISA Kit. The mRNA integrity of ATP synthase subunit α, β, γ, ε, and δ in cotton embryo was analyzed by reverse transcription blocking-double primer amplification method.【Result】Our data suggest that seed vigor dramatically decreased over storage time. After 3 and 5 years of storage, the germination percentage of cotton seeds was significantly decreased from 98.7% to 84.0% and 58.0%, respectively (P<0.05). At the initial stage of seed imbibition (the first 4 h), the water absorption rate of seeds was significantly decreased by 11.0% and 26.9%, respectively. The results of TTC staining showed that only the radicle was slightly stained in seeds preserved 5 years but not the cotyledons and other organs stained; The acid value of seeds was significantly increased by 28.4% and 40.0%, respectively (P<0.05), this indicated that severe hydrolysis of lipid occurred in seeds. Seed respiration rate and ATP synthase activity showed an increasing trend during imbibition, but the increasement was significantly decreased (P<0.05); The respiration rate of seeds was reduced by 33.3% and 49.2% after 24 hours of imbibition, and the activity of ATP synthase was decreased by 17.9% and 73.4% after 12 hours of imbibition, respectively. The results of reverse transcription blocking-double primer amplification showed that the R value of ATP synthase subunits α, β, γ, and δ mRNAs stored in seeds were significantly decreased, but the subunit ε mRNA was significantly increased. These results indicated that the integrity of the ATP synthase subunits mRNA decreased to varying degrees during the natural storage process.【Conclusion】These results showed that a prolonged storage time could reduce seed vigor; The integrity loss of ATP synthase subunit mRNAs stored in seed embryos would cause ATP synthase subunit to be impaired and ATP synthase activity declined, thus lead to a decreased production of ATP and affect seed germination capacity. This might be one of the important reasons for cotton seed aging. Table and Figures | Reference | Related Articles | Metrics

Select

Genome-Wide Association Analysis of Yield Traits in Xinjiang Winter Wheat Germplasm MA YanMing, LOU HongYao, ZHANG ShengJun, WANG Wei, GUO Ying, NI ZhongFu, LIU Jie Scientia Agricultura Sinica    2023, 56 (18): 3487-3499.   DOI: 10.3864/j.issn.0578-1752.2023.18.001 Abstract （545）   HTML （49）    PDF （1989KB）（927）       Knowledge map    Save 【Objective】To discover new high yield genes in wheat by association analysis, which can provide technical supports for the innovation and genetic improvement of high yield germplasm resources in wheat.【Method】Totally 188 bread wheat cultivars in Xinjiang were genotyped using the wheat 55K genotyping assay. GWAS was carried out to identify the signifcant single nucleotide polymorphisms (SNPs) which were associated with 9 wheat yield traits in 6 environments. The MLM algorithm in TASSEL5.0 was used to analyze the nine traits related to wheat yield traits.【Result】Totally 1309 SNPs explained 7.259%-70.792% of the phenotypic variation. 38 SNP loci were identifed, which were significantly correlated with 5 plant height weight SNP loci, 10 spike length weight SNP loci, 10 spikelet number SNP loci, 6 fertile spikelet number SNP loci, 6 spike grain number SNP loci, and 1 thousand grain weight SNP loci. These loci can explain 9.10%-23.81% of phenotypic variations. Comparing these 38 loci with the published wheat genome loci, only 3 functional genes were found, which annotated with gene function. There genes are: TraesCS2A01G448800 on chromosome 2A, which is close to the plant height associated site AX-108794050 and is related to the metabolic synthesis of transcription factor bHLH71; TraesCS2A01G448800, located on chromosome 1A at a distance similar to the spike length associated site AX-110689765, is related to protein coding; TraesCS4B01G031100, located on the 4B chromosome at a distance similar to the 1000 grain weight associated site AX-110399975, is associated with the encoding serine/threonine protein kinase SD1-8 and is involved in regulating cell proliferation and differentiation. 【Conclusion】38 QTL loci associated with wheat yield traits were detected. After verification, it was found that the associated excellent alleles have the effect of reducing plant height, increasing spike length, spikelet number, fertile spikelet number, grain number per spike, and thousand grain weight. Table and Figures | Reference | Related Articles | Metrics

Select

The Construction and Application of SSR and SNP Molecular ID for Maize Germplasm Resources of Jilin Province ZHANG MingQi, WANG Rui, ZHANG ChunXiao, SUN Bo, REN Jie, LI ShuFang, WANG Lu, ZHU ShaoXi, ZHANG JiangBin, SHI XinChen, WANG HaiJie, ZHANG YunLong, TIAN HongLi, ZHAO YiKun, KUANG Meng, WANG YuanDong, YI HongMei, LI XiaoHui, WANG FengGe Scientia Agricultura Sinica    2024, 57 (2): 236-249.   DOI: 10.3864/j.issn.0578-1752.2024.02.002 Abstract （544）   HTML （46）    PDF （9255KB）（715）       Knowledge map    Save 【Objective】 Crop germplasm resources hold a crucial strategic position. The Maize Germplasm Resources Bank in Jilin Province safeguards a collection of germplasm resources distinctively representative of the Northern Spring Maize Region. Traditional germplasm resource management faces challenges in ascertaining accurate identity information. To address this issue, molecular marker technology has been employed to establish a process for the construction and classification of molecular IDs for germplasm resources, thereby enabling precise identification and bolstering categorical management. Thorough exploration of the exceptional resources within Jilin Province's Maize Germplasm Resources Bank is intended to advance the shared utilization of these valuable germplasm resources. 【Method】 A total of 2 918 maize germplasm resources were utilized from the Jilin Provincial Maize Germplasm Resources Bank as subjects of the study, the molecular IDs were constructed by using 40 pairs of SSR markers and 61 214 SNP markers recommended in maize variety identification standards. Based on the molecular ID information, the germplasm resources were categorized into core, closely related, heterogeneous, and population groups for management purposes. Furthermore, the core germplasms were analyzed on genetic diversity. 【Result】 In this investigation, the SSR molecular IDs were constructed for 2 918 maize germplasm resources, while the SNP molecular IDs were constructed for 2 502 maize germplasm resources, excluding heterogeneous germplasm. The standards for the construction of SSR and SNP molecular IDs were established for maize germplasm resources. The SSR molecular ID is composed of a combination of three-digit numbers and one-letter code converted from 40 SSR loci fingerprints, stored in the form of a QR code. The SNP molecular ID converts the fingerprints of 61 214 SNP loci into visual barcodes. Based on the features of sample homozygosity and fingerprint specificity, the samples were categorized into 1 561 cores, 705 closely related, 416 heterogeneous, and 236 population types of germplasm resources. Genetic diversity analysis indicates that domestic germplasm resources, represented by Lüdahonggu and Huanggai groups, constituting the main germplasm resources in the Jilin Provincial Maize Germplasm Resources Bank, accounting for 64.38% of all core germplasm resources. 【Conclusion】 This research outlines a methodology for constructing molecular IDs for maize germplasm resources. The SSR molecular IDs were constructed for 2 918 accessions stored in the Jilin Provincial Maize Germplasm Resources Bank and the SNP molecular IDs were constructed for 2 502 among them. The germplasm resources were categorized into core, closely related, heterogeneous, and population types to achieve the classification management. Table and Figures | Reference | Related Articles | Metrics

Select

CRISPR/Cas9-Mediated Editing of MODD Enhances Rice Dormancy GUO NaiHui, ZHANG WenZhong, SHENG ZhongHua, HU PeiSong Scientia Agricultura Sinica    2024, 57 (2): 227-235.   DOI: 10.3864/j.issn.0578-1752.2024.02.001 Abstract （540）   HTML （71）    PDF （2256KB）（1078）       Knowledge map    Save 【Objective】 Dormancy is an important agronomic trait of rice. Proper dormancy can inhibit the preharvest sprouting of rice and is a key factor to ensure yield and quality. However, the genes and regulatory networks of rice dormancy regulation still need further study. The MODD encoded a protein with unknown function, and it negatively regulate rice abscisic acid signaling and drought resistance, but its function in regulating rice dormancy is unknown. Studying the function of MODD in regulating rice dormancy will help to improve the rice dormancy regulatory network, and at the same time provide a new theoretical basis and germplasm resources for genetic breeding of preharvest sprouting resistance.【Method】 Based on the gene sequences published in the RGAP database, a CRISPR-Cas9 knockout vector for MODD was constructed, and the calli of Zhonghua 11 was transformed through agrobacterium mediated genetic transformation to obtain transgenic rice plants. The MODD knockout homozygous lines were screened and identified using PCR amplification, sequencing technology, and qRT-PCR technology. The amino acid sequences of the two mutant lines (KO-1 and KO-2) were obtained according to the CDS of the two mutant lines, and then the protein sequences of ZH11 and the two mutant lines (KO-1 and KO-2) were compared by DNAMAN. The homologous genes of MODD in rice were screened using Linux system. Take the seeds 35 days after heading and investigated the germination rate of ZH11 and knockout lines. The yeast hybridization and LUC experiments were used to verify the upstream gene of MODD. 【Result】 Six MODD homologous genes were found in rice, which were LOC_Os07g41160, LOC_Os03g30570, LOC_Os03g53630, LOC_Os04g35430, LOC_Os03g17050, LOC_Os06g01170. The knockout vector was successfully constructed and transferred it into ZH11, two homozygous mutant lines (KO-1 and KO-2) were obtained. The qRT-PCR results showed that the expression level of MODD in the two mutant line (KO-1 and KO-2) was significantly reduced. Protein sequence analysis showed that the frameshift mutations of KO-1 and KO-2 caused the early termination of protein translation. The germination rate of the two mutant lines (KO-1 and KO-2) was significantly lower than that of ZH11 by 15% and 15% respectively on the third day after water absorption; After that, the difference gradually expanded and reached the maximum on the 6th day, which was significantly lower than that of ZH11 by 35% and 35% respectively. The preharvest sprouting of two mutant lines (KO-1 and KO-2) was significantly lower than that of ZH11. The results of Y1H experiment showed that ABI5 could bind to the promoter region of MODD in yeast, and the binding range was further reduced to less than 300bp. LUC results showed that the fluorescence value of ABI5 was 2.6 times that of none alone, indicating that ABI5 could activate the expression of MODD.【Conclusion】 Knocking out MODD could increase seed dormancy, and MODD may regulate seed dormancy through ABA signaling pathway. Table and Figures | Reference | Related Articles | Metrics

Select

Effects of Long-Term Synergistic Application of Organic Materials and Chemical Fertilizers on Bacterial Community and Enzyme Activity in Wheat-Maize Rotation Fluvo-Aquic Soil ZHANG LingFei, MA Lei, LI YuDong, ZHENG FuLi, WEI JianLin, TAN DeShui, CUI XiuMin, LI Yan Scientia Agricultura Sinica    2023, 56 (19): 3843-3855.   DOI: 10.3864/j.issn.0578-1752.2023.19.011 Abstract （532）   HTML （42）    PDF （1745KB）（4185）       Knowledge map    Save 【Objective】This experiment studied the effects of long-term synergistic application of organic materials and chemical fertilizers on soil bacterial community and enzyme activity, and revealed the relationship between soil nutrients, extracellular enzyme activity and bacterial community, so as to provide a theoretical basis for formulating long-term and reasonable fertilization strategies under wheat-maize rotation system in fluvo-aquic soil. 【Method】 Based on a 10-year located experiment, five treatments were set up, including no fertilization (NF), chemical fertilizer (NPK), chemical fertilizer with straw return (NPKS), 50% chemical fertilizer with 6 000 kg·hm-2 pig manure (NPKP), and 50% chemical fertilizer with 6 000 kg·hm-2 cow manure ( NPKC ). 【Result】 (1) The combined application of organic materials and chemical fertilizers ( NPKS, NPKP and NPKC ) could significantly improve soil fertility and extracellular enzyme activity, among which NPKC treatment had the most significant effect. Compared with NPK treatment, the contents of organic matter, total nitrogen, available nitrogen, available phosphorus and alkaline phosphatase activity were increased by 13.8%-15.4%, 9.7%-15.5%, 7.2%-15.9%, 13.6%-38.5%和2.5%-13.1%. (2) Long-term combined application of organic and inorganic fertilizer significantly changed the bacterial community structure and composition. In the wheat season, compared with NPK treatment, NPKS treatment significantly increased the abundance of Aggregatilinea and Parachlamydia, NPKP treatment significantly increased the abundance of Pseudomonas, Nonomuraea and Flexilinea, while NPKC treatment only significantly increased the abundance of Luteitalea. In the maize season, compared with NPK treatment, NPKS treatment significantly increased the abundance of Phycisphaera and Syntrophothermus, NPKP treatment significantly increased the abundance of Gemmatimonas, and NPKC treatment significantly increased the abundance of Aquipuribacter and Desulfosoma. (3) The results of functional prediction showed that combined application of organic and inorganic fertilizers could promote soil carbon and nitrogen cycling compared with long-term single application of chemical fertilizer. In particular, the NPKC treatment had a strong effect on nitrification, ureolysis, aromatic compound degradation, xylanolysis and cellulolysis. (4) Mental analysis showed that soil pH was the main factor regulating bacterial community structure and ecological function in fluvo-aquic soil. 【Conclusion】 Long-term application of organic and inorganic fertilizers (especially chemical fertilizers combined with cow manure) could improve soil fertility and extracellular enzyme activity, increase the abundance of beneficial bacteria, significantly change the structure and composition of bacterial communities, and promote the circulation of carbon, nitrogen and phosphorus, thus construct an environment suitable for crop and bacterial growth in fluvo-aquic soil. Table and Figures | Reference | Related Articles | Metrics

Select

Analysis of Genetic Effect of Fruit Color Controlled by Epistatic Genes in Eggplant CHEN JinRong, LÜ ZiJian, FAN LiSha, YOU Qian, LI Tao, GONG Chao, SUN GuangWen, LI ZhiLiang, SUN BaoJuan Scientia Agricultura Sinica    2023, 56 (23): 4729-4741.   DOI: 10.3864/j.issn.0578-1752.2023.23.014 Abstract （530）   HTML （17）    PDF （3332KB）（1302）       Knowledge map    Save 【Objective】Fruit color is an important trait that affects the commercial value of eggplant fruit. By analyzing the causes for the special segregation ratio of individual plants with purple red peel and with white peel in the F2 population constructed by crossing between two white-fruit parents, this paper could lay the foundation for elucidating the mechanism of epistatic gene interaction on regulating eggplant fruit coloration.【Method】The white-flower and white-peel female parent 19141 with mutation at the structural gene ANS involving in the anthocyanin biosynthesis pathway, white-flower and white-peel male parent 19142 with unknown mutation genes involving in the anthocyanin biosynthesis pathway, and their F1 population with purple red peel and F2 population with separate peel colors were used to explore the epistatic inheritance of eggplant fruit coloration. Genes and their mutation patterns were studied by cloning the known genes, D (SmMYB1) and Y (SmDFR) related to peel color in male parent 19142. Molecular basis of peel color-controlling epigenetic genes was analyzed by developing molecular markers based on genetic variations of peel color genes, analyzing the relationship between genotype and phenotype in E4450F2 population, and crossing with other eggplant parents without anthocyanin pigmentation in peel.【Result】The segregation ratio of plants with purple red fruit and white fruit in E4450 F2 progeny was consistent with the segregation ratio of 27:37 controlled by three pairs of epistatic genes, that is, mutations occurred at the P gene locus in 19141, with genotype DDppYY, and mutations occurred at both D and Y gene loci in 19142, with genotype ddPPyy. The results of cloning and sequencing showed that alternative splicing occurred in SmMYB1 of 19142, which led to the second exon skipping. In 19142, SNP (C→G) in the promoter region’s -326 bp upstream of the start codon resulted in the absence of a CAAT-box cis-acting element in SmDFR gene. An SNP, G to C, at the last base of the second exon, was annotated as splicing mutation, which might cause abnormal function of SmDFR gene in 19142, resulting in the eggplant peel’s inability to synthesize anthocyanin. Based on the genetic variation of SmMYB1, SmANS and SmDFR, the functional molecular markers were developed, and the progenies of E4450F2 were genotyped. The results showed that genotype and phenotype were completely consistent. D_P_Y_ corresponded to phenotypes of purple flower and purple red peel, ddP_Y_ corresponded to phenotype of purple flower and white peel, D_ppY_, D_P_yy, D_ppyy, ddppY_, ddP_yy and ddppyy genotypes corresponded to white flower and white peel phenotypes. When 19142 was crossed with white-peel inbred line 19147 (dtdtPPYY), and green-peel inbred line 19144 (DDPPyy), it was found that the fruit color of the two F1 progenies were white and green, respectively, and there was no anthocyanin pigmentation in the peel, which further proved that 19142 was a double mutant in SmMYB1 and SmDFR.【Conclusion】When two eggplant parents without anthocyanin pigmentation in the peel were crossed, the peel of the F1 generation had anthocyanidin pigmentation, and the segregation ratio of plants with anthocyanin pigmentation and non-anthocyanin pigmentation in F2 population was 27:37, it was because one of the parents had a mutation at a gene locus in the anthocyanin biosynthesis pathway, and the other parent had mutations at two other loci in the anthocyanin biosynthesis pathway. When two parents without anthocyanin pigmentation were crossed, the peel of F1 was able to synthesize anthocyanin and present purple red color, which was due to the simultaneous dominance of three epistatic gene loci D, P and Y, and anthocyanin biosynthesis was restored. Mutation of the structural gene of SmANS or SmDFR inhibited anthocyanin biosynthesis in all parts of the plant. The regulation of transcription factor mutation SmMYB1 was tissue specific, and its mutation inhibited anthocyanin biosynthesis in the peel, but did not inhabit anthocyanin biosynthesis in the flower. Table and Figures | Reference | Related Articles | Metrics

Select

QTL Identification and Genetic Analysis of Plant Height in Wheat Based on 16K SNP Array YAO QiFu, CHEN HuangXin, ZHOU JieGuang, MA RuiYing, DENG Liang, TAN ChenXinYu, SONG JingHan, LÜ JiJuan, MA Jian Scientia Agricultura Sinica    2023, 56 (12): 2237-2248.   DOI: 10.3864/j.issn.0578-1752.2023.12.001 Abstract （530）   HTML （61）    PDF （829KB）（1617）       Knowledge map    Save 【Objective】There is a close relationship between plant height (PH) and yield. The aim of this study is to further explore quantitative trait loci (QTL) of PH with breeding value in wheat and analyze the genetic effects of major QTL for PH on other yield related traits toward to providing a theoretical basis for molecular breeding. 【Method】A recombinant inbred line population (MC) derived from a cross between the natural mutant msf and Chuannong 16 (CN16) was used for QTL analysis. During 2020 to 2022, planting and PH phenotype identification were conducted at five environments in Wenjiang, Chongzhou, and Ya’an of Sichuan Province. The high-quality genetic linkage map constructed using the 16K SNP array was used for QTL mapping of PH. Genotypes of flanking markers of major QTL for PH were used to analyze the genetic effects of positive alleles on yield related traits and evaluate the potentiality of QTL for yield improvement. 【Result】Eight QTL controlling PH were identified on chromosomes 1A, 3D, 4D, 5A, and 7B, respectively. Among them, two stable and major QTL, QPh.sau-MC-1A and QPh.sau-MC-5A, were located, which explained 9.09% to 25.56% and 3.91% to 13.09% of the phenotypic variation rate, respectively. Their positive alleles were all from CN16. The additive effect analysis showed that PH of the lines carrying positive alleles from QPh.sau-MC-1A and QPh.sau-MC-5A was significantly higher than that of the lines carrying only a single positive allele or none. Correlation analysis showed that PH has a significantly positive correlation with effective tiller number (ETN), a significantly negative correlation with flag leaf width (FLW), and no significant correlation with kernel number per spike (KNPS), kernel weight per spike (KWPS), thousand kernel weight (TKW), flag leaf length (FLL) and anthesis date (AD). Genetic effects analysis showed that positive allele of QPh.sau-MC-1A had a significant effect on improving ETN (56.51%), a significant effect on decreasing KNPS (-11.26%), KWPS (-13.04%), TKW (-5.47%), and FLW (-2.85%), and a significant effect on advancing AD (-0.61%). Positive allele of QPh.sau-MC-5A had a significant effect on improving ETN (10.57%), KNPS (4.32%), and TKW (2.92%), and a significant effect on delaying AD (1.07%). 【Conclusion】A major QTL QPh.sau-MC-5A for PH was mapped on chromosome 5A, and its positive allele significantly increased ETN, KNPS, and TKW, indicating that it may have a positive impact on yield. Table and Figures | Reference | Related Articles | Metrics

Select

China Urgently Needs to Transform from Mainland Agriculture to Cross-Sea Agriculture REN JiZhou, JIAO Hong, YANG RuiXue, XU Gang, ZHAO An Scientia Agricultura Sinica    2024, 57 (13): 2698-2702.   DOI: 10.3864/j.issn.0578-1752.2024.13.016 Abstract （528）   HTML （78）    PDF （407KB）（389）       Knowledge map    Save Relying on its special geographical advantages, China has established a continental agricultural country. Chinese land area was nearly 10 million square kilometers, while its population had never exceeded 80 million from the Qin and Han Dynasties to the Ming Dynasty, so known as “a vast territory with abundant resources”. However, during the Qianlong period in the 19th century, its population suddenly increased to 400 million, and the land area was already insufficient. In the early days of the founding of the People’s Republic of China, the population reached 650 million, and further reached 1.41 billion in 2020 based on The Seventh Census. The per capita water and soil resources are only about 1/3 to 1/4 of the world level, which making it a resource-poor country. It is not easy to obtain enough food and even more difficult to achieve a moderately prosperous lifestyle relying solely on domestic resources. The shortage of water and soil resources is an urgent problem despite the huge potential for technological innovation. In nearly a century and a half, the historical tragedy of the collision between China’s agricultural civilization and the world’s industrial civilization has reminded us to break through the mentality of “domestic is the world” fostered by land-based agriculture and to set sail to the sea. China needs to transform from “self-sufficient” mainland agriculture to “shared supply and common sustenance” cross-sea agriculture, establishing itself as the main base, utilizing the world’s agricultural resources, and building world agriculture. It is an urgent need to set up a long-term national policy in order to transform mainland agriculture into cross-sea agriculture, to build a global agricultural database in order to respond to the demand of the international food market, to adjust accurately and timely the domestic agricultural structure in order to reduce international trade risks, and to make a global strategic deployment as soon as possible for China’s agriculture. Reference | Related Articles | Metrics

Select

Current Status and Strategies for Utilization of Stripe Rust Resistance Genes in Wheat Breeding Program of China LIU ZhiYong, ZHANG HuaiZhi, BAI Bin, LI Jun, HUANG Lin, XU ZhiBin, CHEN YongXing, LIU Xu, CAO TingJie, LI MiaoMiao, LU Ping, WU QiuHong, DONG LingLi, HAN YuLin, YIN GuiHong, HU WeiGuo, WANG XiCheng, ZHAO Hong, YAN SuHong, YANG ZhaoSheng, CHANG ZhiJian, WANG Tao, YANG WuYun, LIU DengCai, LI HongJie, DU JiuYuan Scientia Agricultura Sinica    2024, 57 (1): 34-51.   DOI: 10.3864/j.issn.0578-1752.2024.01.004 Abstract （524）   HTML （42）    PDF （6853KB）（1282）       Knowledge map    Save Wheat stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating disease threaten food security in China and worldwide. Epidemics of wheat stripe rust have been under control through applying resistant cultivars and crop protection approaches. However, due to climate change, innovation of cropping system, improvement of breeding technology, yield level enhancement of wheat cultivars, variation in structure and frequency of virulence genes in Pst populations in the new era, the current status of stripe rust resistance genes in wheat breeding programs need to be evaluated. The results could provide useful information for applying stripe rust resistance genes to develop new wheat cultivars with broad-spectrum and durable rust resistance. After multiple year’s stripe rust resistance survey, genetic analysis, molecular tagging and mining of stripe rust resistance genes in wheat cultivars and advanced breeding lines, the current status of major stripe rust resistance genes utilization was reviewed. We summarized the present situations of major stripe rust resistance gene discovery and germplasm innovation, the most frequently used stripe rust resistance genes, new strategy for pyramiding adult plant partial resistance and all stage resistance, and molecular marker assisted selection for developing wheat cultivars with broad spectrum and durable resistance in China. This review also proposes the major research areas in wheat stripe rust resistance breeding in the new era. Table and Figures | Reference | Related Articles | Metrics

Select

Seedling Characterization and Genetic Analysis of Low Phosphorus Tolerance in Shanxi Varieties WEI NaiCui, TAO JinBo, YUAN MingYang, ZHANG Yu, KAI MengXiang, QIAO Ling, WU BangBang, HAO YuQiong, ZHENG XingWei, WANG JuanLing, ZHAO JiaJia, ZHENG Jun Scientia Agricultura Sinica    2024, 57 (5): 831-845.   DOI: 10.3864/j.issn.0578-1752.2024.05.001 Abstract （515）   HTML （44）    PDF （5434KB）（396）       Knowledge map    Save 【Objective】In arid and semi-arid regions, the water and nutrients are scarce in the soil. The phosphorus use efficiency between different wheat genotypes varies greatly. Therefore, identification of low phosphorus-tolerant germplasm and mapping of related loci is helpful for genetic improvement of wheat. 【Method】Using 282 Shanxi wheat varieties as materials, twelve seedling morphological indicators were investigated under three phosphorus concentrations, including SDW, RDW, DW, SFW, RFW, FW, MRL, TRL, RS, RV, RD, and RN. Principal component analysis, membership function analysis, and cluster analysis were used to comprehensively evaluate the low phosphorus tolerance characteristics of different varieties at the seedling stage. On this basis, the trait evolution trend and biomass allocation at seedling stage were analyzed. At the same time, GWAS was used to identify significant loci related to the low phosphorus-related traits. 【Result】The response of different traits to low phosphorus at the seedling stage was different. Lower phosphorus concentrations led to changes in biomass allocation strategy, and shoot growth was less affected by change in phosphorus concentrations than root growth. The decrease in phosphorus concentration inhibited the growth of shoot, and SDW and SFW were significantly reduced. In contrast, low phosphorus promoted root growth, and the indicators of RDW, RFW, MRL, TRL, RV and RN increased significantly. According to the correlation analysis between D-value and morphological indicators, it was found that MRL and RD could be used as selection indicators for low phosphorus tolerance at seedling stage. Based on D-value clustering analysis, 9 low phosphorus tolerant varieties were selected, including Jinmai 46, Jinmai 61, Youmangdahongjing, Hongtumai, Hongheshang, Baikehong, Baixianmai, Huoshaotou, Baishanmai. Analysing trends in trait evolution showed that cultivars were not directly selected for their ability to tolerate low phosphorus. The ability to tolerate low phosphorus decreased first and then increased over time. Before 2010, there was a decreasing trend in the ability of varieties to tolerate low phosphorus, and after 2010, there was an increase in the ability of varieties to tolerate low phosphorus. GWAS stably detected eight loci with R2>10% in three environments, in which 1A_545074550, 2B_489279799, 6A_166899658 and 6A_273060644 were not reported previously.【Conclusion】The MRL and RD can be used as selection indicators for low phosphorus tolerance at seedling stage. A total of nine varieties were selected through comprehensive evaluation of ability in Shanxi wheat to tolerate low phosphorus during seedling stage. Association analysis detected four novel loci associated with low phosphorus tolerance on chromosomes 1A, 2B and 6A, and the results provide germplasm resources and QTL for future low phosphorus tolerance wheat breeding. Table and Figures | Reference | Related Articles | Metrics

Select

Application Status and Development Suggestion of Direct-Seeding Rice Cultivation in China LIAO Ping, WENG WenAn, GAO Hui, ZHANG HongCheng Scientia Agricultura Sinica    2024, 57 (24): 4854-4870.   DOI: 10.3864/j.issn.0578-1752.2024.24.003 Abstract （513）   HTML （43）    PDF （728KB）（335）       Knowledge map    Save With the continuous improvement in rice cultivation techniques, China has maintained a high rice production level of about 210 million tons over the past decade. Direct-seeding rice cultivation technology, recognized for its efficiency and simplicity, has been favored by Chinese farmers. However, controversies persist regarding direct-seeding rice compared to transplanted rice in national-scale production. Thus, this study employed meta-analysis techniques to quantify disparities in grain yield, economic benefit, rice quality, lodging characteristic, and greenhouse gas emissions between direct-seeding rice and transplanted rice. Our results indicated that direct-seeding rice significantly reduced grain yield by an average of 6.3% relative to transplanted rice, which was main due to the reduced total spikelet (-3.8%) and filled-grain percentage (-1.8%). In different planting systems in China, the yield of direct-seeding rice had significantly decreased compared to transplanted rice, and the direct-seeding rice-induced reductions in yield of single rice (-10.9%) and late rice (-13.1%) were higher than those of middle rice (-4.8%) and early rice (-4.4%). The grain yield reductions for direct-seeding rice were from 10% to 20% in Jilin, Liaoning, Xinjiang, Ningxia, Shandong, Jiangsu, and Zhejiang provinces, meanwhile Heilongjiang and Jiangxi provinces saw reductions of 5% to 10%, but it had no significant effect in other provinces. Direct-seeding rice resulted in comparable net economic return relative to transplanted rice (p> 0.05). Direct-seeding rice reduced milled rice rate (-3.1%) and gel consistency (-3.5%), improved appearance quality (chalkiness percentage and chalkiness degree, which decreased by 25.3% and 22.5%, respectively), whereas no significant effects were observed on nutrition quality and taste value. Direct-seeding rice increased lodging index at base of the first (+12.4%) and third (+10.3%) internodes, but not at the second internode, indicating an increase in risk of lodging relative to transplanted rice. In terms of greenhouse gas emissions, direct-seeding rice fields showed reductions in methane emissions (-42.8%), global warming potential (-36.2%), and greenhouse gas intensity (-41.1%) compared to transplanted rice fields, while promoting nitrous oxide emissions (+29.1%). In addition, a review was recounted on nitrogen utilization and its loss, water and energy use efficiency, and weed incidence. Finally, the recommendations for the future advancement of direct-seeding rice were proposed, main focusing on rice variety breeding, rice cultivation technique optimization, rice planting area layout, as well as policies and services with the goal of technological innovation and regionalized application of direct-seeding rice cultivation technology in China. Table and Figures | Reference | Related Articles | Metrics

Select

Research Progress of Southern Corn Rust and Resistance Breeding WANG Shuai, ZHANG RuYang, WANG RongHuan, SONG Wei, ZHAO JiuRan Scientia Agricultura Sinica    2024, 57 (14): 2732-2743.   DOI: 10.3864/j.issn.0578-1752.2024.14.003 Abstract （497）   HTML （34）    PDF （1827KB）（1602）       Knowledge map    Save Maize is the most widely cultivated, used and highest yield crop in the world and China. Southern corn rust (SCR) is an air borne disease caused by Puccinia polysora Underw., which mainly occurs in tropical and subtropical maize growing areas. In recent years, SCR has become one of the major diseases in the Huang-Huai-hai maize production region due to the climate change, which directly leads to compromised grain quality and poor yields in maize and significantly jeopardizes maize production in China. At present, SCR usually spreads in a large area within a short period of time once occurred because most maize varieties promoted in China are susceptible, and conventional chemical measures is usually in vain. Therefore, cultivating resistant cultivars by exploiting resistance genes in maize germplasm resources is the most effective and economical strategy for controlling SCR. The highly resistant germplasm is scarce in maize resources, mainly from tropical and subtropical regions, and barely no temperate germplasm can be directly used in breeding practice. Compared with foreign maize germplasm, the highly resistant maize germplasms of China were much less, mainly from local landraces or P group materials containing tropical origins with relatively limited genetic variation. The identification and cloning of SCR resistance genes in maize is essential for promoting molecular marker-assisted breeding, as well as accelerating the breeding process of new varieties with desired resistance. At present, several SCR resistance genes have been identified and cloned, laying a foundation for molecular marker-assisted selection. Over the years, Chinese breeders have developed a number of elite maize inbred lines resistant to SCR with limited resistance germplasm resources, and successfully created disease-resistant hybrids. Recent studies on the genome of SCR pathogens revealed that pathogens have differentiated into highly toxic lineages in China, thus escaping the recognition of resistance genes. Therefore, the exploration and utilization of extensive genetic resources in resistant germplasm still need to be further strengthened. In this paper, we outlined the biological characteristics and hazards of SCR, systematically summarized the research progresses in the identification and utilization of maize germplasm resources resistant to SCR, the mapping and cloning of SCR resistant genes and the breeding of resistant varieties, and prospect the future research direction of SCR. This review will provide references for the prevention and control of SCR, as well as the breeding of resistant maize varieties. Table and Figures | Reference | Related Articles | Metrics

Select

Molecular Marker Assisted Identification and Application of Maize Germplasms for Maize Rough Dwarf Disease Resistance WANG JiangHao, WANG LiWei, ZHANG DongMin, GUO Rui, ZHANG QuanGuo, LI XingHua, WEI JianFeng, SONG Wei, WANG BaoQiang, LI RongGai Scientia Agricultura Sinica    2023, 56 (10): 1838-1847.   DOI: 10.3864/j.issn.0578-1752.2023.10.002 Abstract （489）   HTML （64）    PDF （2438KB）（305）       Knowledge map    Save 【Objective】Molecular markers tightly linked to three maize rough dwarf disease (MRDD) resistant loci were employed to identify resistant inbred lines, then the classification of heterotic groups and analysis of combining ability of these inbred lines were carried out, which proved a highly efficient way for maize MRDD resistance breeding.【Method】A recombinant inbred lines (RILs) population consisting of 263 F9 lines was developed through single seed descent method from a segregating F2 population by crossing a resistant inbred line K36 to a susceptible inbred line S221. The MRDD resistances of the RILs were identified in different growing environments. Meanwhile the RILs were genotyped by employing three pairs of molecular markers, 5FR, 6W53 and IDP25K which were closely linked to the three resistant loci, qMrdd2, Rmrdd6 and qMrdd8. The excellent lines with disease resistance and good agronomic traits were selected out after field evaluation. Totally 24 maize inbred lines including the elite lines were genotyped using Maize 56K SNP array, then the genetic distances between the selected lines and other elite inbred lines were calculated according to Roger's algorithm and cluster analysis was conducted to classify the heterotic groups. Meanwhile, hybrid combinations were generated and the combining abilities were tested to screen the combinations with strong disease resistance and heterosis.【Result】The inbred line K36 were homozygous resistant at the three loci, qMrdd2, Rmrdd6 and qMrdd8 while S221 were homozygous susceptible. All the 263 RILs were genotyped into 21 patterns in terms of genetic composition of the three resistant loci. The lowest DSI (0.281) appeared when all the three loci were homozygous resistant while the highest DSI (0.776) appeared when the three loci were homozygous susceptible, which were consistent with the resistant and susceptible parents (0.257, 0.623). The order of DSI from low to high value for one homozygous resistant locus was Rmrdd6 (0.396), qMrdd8 (0.478) and qMrdd2 (0.654) when the other two loci were homozygous susceptible, which showed that Rmrdd6 and qMrdd2 performed the strongest and the weakest resistance while qMrdd8 was in the middle. The variation range of genetic distance between JR2136 with the genotype of three homozygous resistant loci and other 23 inbred lines was 0.2234-0.2895, with an average value of 0.2612. The inbred line with the smallest genetic distance was C413, and the largest was Chang7-2. According to the results of cluster analysis, JR2136 was classified into Reid group, hybrid combinations with inbred lines H92 and H521 belonging to Huanggai group performed strong disease resistance and heterosis.【Conclusion】The resistance of K36 to MRDD was controlled by three loci, qMrdd2, Rmrdd6 and qMrdd8, and it had quantitative genetic characteristics and gene additive effect. Maize varieties with homozygous resistant genotypes demonstrated the strongest disease resistance. The developed molecular markers closely linked with the three resistant loci have proved valuable tools in disease-resistant breeding and screening of resistant germplasm resources. It is feasible to use molecular markers for assisted selection and gene aggregation to select highly heterotic combinations with strong disease resistance. Table and Figures | Reference | Related Articles | Metrics

Select

The Effect of indica/Xian Pedigree Introgression in japonica/Geng Rice Breeding in China XU HAI, LI XIUKUN, LU JIAHAO, JIANG KAI, MA YUE, XU ZHENGJIN, XU QUAN Scientia Agricultura Sinica    2023, 56 (22): 4359-4370.   DOI: 10.3864/j.issn.0578-1752.2023.22.001 Abstract （483）   HTML （65）    PDF （4344KB）（496）       Knowledge map    Save 【Objective】To demonstrate the impact of indica/Xian (XI) pedigree introgression on the yield and quality of japonica/Geng (GJ) rice varieties, providing a theoretical basis and genomic resources for optimizing XI pedigree introgression breeding programs in northern GJ rice.【Method】In this study, the whole genome sequence on Illumina platform was employed to elucidate the effects of XI pedigree introgression on the yield and quality of rice in Northeast China were analyzed using recombinant inbred lines (RIL) derived from the cross between XI and GJ varieties, and 74 major GJ varieties grown from Heilongjiang, Liaoning, Shandong, and Jiangsu provinces as test materials. Using CRISPR/Cas9 gene editing technology to knock out the unfavorable genes introduced by XI pedigree introgression. 【Result】Analysis of RIL revealed a significant positive correlation between XI pedigree introgression and panicle length, grain length, and a negative correlation with head rice ratio. XI pedigree introgression was significantly negatively correlated with Amylose content, and significantly positively correlated with protein content in Jiangsu. With the increase of latitude, the correlation efficiency between XI pedigree introgression and grain shape increased, while the correlation between XI pedigree introgression and panicle length and head rice ratio decreased. The genomic fragments of XI pedigree introgression are unevenly distributed across different chromosomes and are more abundantly present on chromosomes 1, 10, 11, and 12. The XI pedigree introgression of the major cultivars in Jiangsu and Liaoning provinces is significantly higher than that in Heilongjiang and Shandong provinces, and the XI pedigree introgression of the cultivars after 2000 is significantly higher than that before 2000. The XI pedigree introgression includes multiple resistance and fertility-related genes. The project identified an XI pedigree introgression fragment on chromosome 5 of YF47, including the XI type grain regulatory gene GS5 and XI type chalkiness regulatory gene Chalk5, which increased the 1000 grain weight of YF47 but affected its chalkiness-related traits. The project uses CRISPR/Cas9 technology to knock out the Chalk5 gene of YF47. The grain shape of the homozygous gene editing plants is similar to those of YF47, and its chalkiness character has been significantly improved. 【Conclusion】The XI pedigree introgression mainly increases the yield potential of GJ rice by increasing the number of grains per panicle, but has a negative impact on milling quality. Exploring the unfavorable alleles in varieties through high-throughput genome sequencing, combined with CRISPR/Cas9 gene editing, to break the genetic drag in breeding using the cross between XI and GJ, is an efficient breeding strategy that can quickly and accurately improve target traits. Table and Figures | Reference | Related Articles | Metrics

Select

Effect of Phytochlorin Iron on Stress Tolerance to Waterlogging in Wheat CHU YanMeng, MAO YingChao, CAI Jian, ZHOU Qin, DAI TingBo, WANG Xiao, JIANG Dong Scientia Agricultura Sinica    2023, 56 (10): 1848-1858.   DOI: 10.3864/j.issn.0578-1752.2023.10.003 Abstract （476）   HTML （38）    PDF （509KB）（256）       Knowledge map    Save 【Objective】Waterlogging stress is one of the main limiting factors for wheat production, especially in the middle and lower reaches of the Yangtze River in China. Improving the waterlogging tolerance of wheat is an important goal to achieve stable and increased yield in this region. In this study, by exploring the suitable use period and concentration of phytochlorin iron, its role in improving waterlogging stress tolerance was further evaluated mainly from the perspectives of plant photosynthesis and plant antioxidant capacity. The research results could provide the theoretical and technical support for waterlogging-resistant cultivation of wheat.【Method】Using Yangmai 16 as material, three concentrations (0.0875, 0.126, and 0.194 mmol·L-1) of phytochlorin iron were set at anthesis and grain filling stages to screen the appropriate period and concentration for achieving a significant increase in wheat yield. Based on this, the effect of phytochlorin iron on wheat tolerance to waterlogging stress at anthesis stage was further evaluated.【Result】Compared with control, treatment with a concentration of 0.126 mmol·L-1 phytochlorin iron at anthesis stage (A2) could significantly increase wheat grain yield by increasing the grain weight. Waterlogging stress at anthesis stage significantly reduced the chlorophyll content, net photosynthesis rate, and post-flowering dry matter accumulation and translocation to grain, resulting in grain yield reduction. However, compared with non-spraying treatment, AW2 treatment showed a higher photosynthetic pigment content, photosystem II stability, net photosynthetic rate. Meantime, the raised activities of antioxidant enzymes, reduced O2- production rate and H2O2 content, which showed correspondence with the reduced accumulation of malondialdehyde content, thus alleviated the damage of cell membrane lipid peroxidation and the yield reduction caused by waterlogging stress.【Conclusion】Spraying a concentration of 0.126 mmol·L-1 phytochlorin iron at anthesis stage could significantly increase wheat yield. Phytochlorin iron could alleviate the plant senescence, reduce damage to PSII, enhance the activity of antioxidant enzymes, reduce the damage of cell membrane lipid peroxidation, maintain higher photosynthetic rate, reduce the degree of yield reduction, and enhance wheat tolerance to waterlogging stress. Table and Figures | Reference | Related Articles | Metrics

Select

Genetic Diversity Analysis and Comprehensive Evaluation of Sorghum Breeding Materials Based on Phenotypic Traits ZHANG YiZhong, ZHANG XiaoJuan, LIANG Du, GUO Qi, FAN XinQi, NIE MengEn, WANG HuiYan, ZHAO WenBo, DU WeiJun, LIU QingShan Scientia Agricultura Sinica    2023, 56 (15): 2837-2853.   DOI: 10.3864/j.issn.0578-1752.2023.15.001 Abstract （476）   HTML （70）    PDF （644KB）（892）       Knowledge map    Save 【Objective】 The present study analyzed the genetic variation of phenotypic traits and genetic diversity of sorghum breeding materials. Additionally, the study explored a comprehensive method for the evaluation of germplasm materials and screening of excellent sorghum germplasm to provide an important basis for sorghum germplasm innovation and variety selection.【Method】 In total, 263 sorghum germplasms from different sources were used as the test materials, and 17 phenotypic traits were identified under different environments for two years. Genetic diversity of the phenotypic traits was calculated based on the Shannon-Wiener information diversity index. The sorghum germplasms were comprehensively evaluated using the correlation analysis, principal component analysis, cluster analysis, and stepwise regression. Excellent sorghum germplasms were screened according to the phenotypic comprehensive evaluation value (F value) and target traits.【Result】 Sorghum breeding materials exhibited high genetic diversity. The diversity index distribution of different traits ranged from 0.497 to 2.075, with the diversity index of spike shape being the smallest and that of spike stalk length being the largest. The coefficient of variation of seven plant height, stem diameter, panicle length, panicle stalk length, grain weight per spike, thousand grain weight, period of duration varied in different years; the smallest variation was observed in the period of duration, followed by the panicle length, whereas the largest variation was observed in grain weight per spike, followed by stem diameter. A comprehensive evaluation of the breeding materials showed that when the cumulative contribution percentage was >80%, the number of the total principal components was 11. F value of the sorghum breeding materials was calculated using the membership function method. The average F value was found to be 0.464, with the restorer line L28 having the highest F value (0.581) and the maintainer line 72B/DORADO having the lowest the F value (0.330). Through stepwise regression, a regression equation was established, with 12 traits (main vein color, ear type, ear shape, awn character, glume coating degree, grain shape, plant type, stem diameter, ear length, grain weight per ear, 1000-grain weight, and growth period) as independent variables. The equation could be used for a comprehensive evaluation of the phenotypic traits of breeding materials of sorghum breeding materials. Based on F value clustering, 263 materials were divided into six groups. Among these, 33 materials in group Ⅳ exhibited excellent agronomic characteristics and high F value, which could be used as parent materials for material innovation and cross breeding.【Conclusion】 Sorghum phenotypic traits exhibit rich genetic variation and high genetic diversity. A total of 33 excellent germplasms were obtained. Using multivariate statistical analysis is a feasible approach to comprehensively evaluate sorghum germplasm. Table and Figures | Reference | Related Articles | Metrics

Select

Progress on Genetic Transformation of Sorghum HAN LiJie, CAI HongWei Scientia Agricultura Sinica    2024, 57 (3): 454-468.   DOI: 10.3864/j.issn.0578-1752.2024.03.003 Abstract （473）   HTML （37）    PDF （539KB）（229）       Knowledge map    Save Sorghum is the fifth largest grain crop in the world and can be used for food, feed, brewing and bioenergy. Sorghum genetic transformation technology is an essential and important tool in the research of sorghum functional genomics and can also serve as an important complement to traditional breeding methods. In this review, we summarize the research progress of sorghum transformation in recent years, analyze the problems in sorghum genetic transformation and propose strategic solutions to them in order to provide a reference for further improvement of sorghum genetic transformation technology. By summarizing more than 50 literatures on sorghum tissue culture and genetic transformation in recent years, we introduced the current research status of sorghum genotypes, explant sources, and regeneration system construction for genetic transformation, and compared the advantages and disadvantages of four commonly used methods for sorghum genetic transformation: electroporation, pollen-mediated transformation, particle bombardment and Agrobacterium-mediated transformation, summarized the effects of the main components of genetic transformation vectors, including promoters, target genes, selective marker genes and reporter genes, on transformation efficiency, explained the current application status of sorghum genetic transformation, analyzed the main bottleneck problemns in sorghum genetic transformation technology, and studied countermeasures. Sorghum genotypes have a significant influence on tissue culture and P898012 and Tx430 are the most widely used. Gene bombardment and Agrobacterium-mediated transformation are the most commonly used methods for sorghum genetic transformation, and the advantages of Agrobacterium-mediated transformation are gradually emerging. In vector construction, CaMV35S and ubi1 are the most commonly used promoters, and antibiotic resistance genes (nptII, hpt), herbicide resistance genes (bar), and nutrient assimilation genes are the three commonly used selection markers. With the development of sorghum genetic transformation technology and CRISPR/Cas9-mediated gene editing technology, some genes with important agronomic traits have been successfully transferred into sorghum. However, strong genotype dependence, long tissue culture cycle, and poor genetic transformation stability are the main bottlenecks that limit the genetic transformation of sorghum. By introducing morphogenesis regulatory factors, somatic cell generation can be directly performed, which shortens the tissue culture cycle, improves the transformation efficiency, and expands the source of explants. This has become a major breakthrough in sorghum genetic transformation technology. The use of morphogenesis regulatory factors and adoption of cut-dip-budding (CDB) delivery system can further improve the sorghum genetic transformation technology. Combined with the application of CRISPR/Cas9 gene editing technology, they will surely provide an important technical basis for the sorghum molecular breeding and gene function identification. Table and Figures | Reference | Related Articles | Metrics

Select

Identification of Drought Resistance of 244 Spring Wheat Varieties at Seedling Stage ZHOU Quan, LU QiuMei, ZHAO ZhangChen, WU ChenRan, FU XiaoGe, ZHAO YuJiao, HAN Yong, LIN HuaiLong, CHEN WeiLin, MOU LiMing, LI XingMao, WANG ChangHai, HU YinGang, CHEN Liang Scientia Agricultura Sinica    2024, 57 (9): 1646-1657.   DOI: 10.3864/j.issn.0578-1752.2024.09.003 Abstract （472）   HTML （50）    PDF （1415KB）（269）       Knowledge map    Save 【Objective】Drought is a major environmental factor limiting global wheat production, and breeding drought-tolerant varieties is a key challenge faced by wheat breeders worldwide. Spring wheat, which has a short growth period, plays a vital role for national food security and planting structure, therefore, it is of great importance to identify and select drought tolerance of spring wheat varieties for breeding of high-yielding and drought-tolerant wheat.【Method】In this study, 244 spring wheat varieties (lines) from 10 different regions were used to assess the drought tolerance of spring wheat varieties during the seedling stage, this study used the controlled water content method to impose drought stress during the seedling stage, 5 seedlings with uniform and consistent growth were selected during the trefoil stage. Thirteen seedling stage indicators including maximum root length (MRL), first leaf length (FLL), first leaf width (FLW), coleoptile length (CL), shoot fresh weight (SFW) and root fresh weight (RFW) were measured. Comprehensive evaluation of drought resistance of various spring wheat varieties (lines) was conducted through methods such as using descriptive statistics, membership function, principal component analysis, cluster analysis, and correlation analysis. 【Result】The drought tolerance of spring wheat varieties (lines) exhibits a large variation. The coefficient of variation of the measured traits under drought treatment conditions ranges from 2.1% to 32.9%, while the coefficient of variation of the control group ranges from 1.0% to 29.3%. Compared with the control, the coleoptile length, root dry weight, fresh weight root to shoot ratio, and dry weight root to shoot ratio under drought treatment were all greater than those under the control treatment. The original 13 indexes were summarized into 5 principal components, and the contribution rate reached 79.56%, and the D value of the comprehensive drought resistance coefficient was calculated according to the characteristic vector of each principal component and the drought resistance coefficient of each trait index, then the D value was clustered and analyzed, which could be divided into 5 subgroups. Therefore, the root biomass (underground fresh weight and dry weight) was screened as an effective comprehensive index for the identification of drought resistance at the seedling stage. We conducted correlation analysis between the seedling stage drought index and the agronomic traits of maturity stage showed that the coleoptile length, first leaf length was significantly positively correlated with flag length, plant height, spike length, the number of spike and grain length. Additionally, and the seedling biomass was significantly positively correlated with thousand-grain weight.【Conclusion】Twenty-two highly drought-tolerant varieties were screened, and root biomass (both fresh and dry weight of the underground part) was identified as an effective comprehensive indicator for evaluating seedling stage drought tolerance. Table and Figures | Reference | Related Articles | Metrics

Select

Analysis of Maize Phenylalanine Ammonia-Lyase (PAL) Family Genes and Functional Study of ZmPAL5 CAO LiRu, YE FeiYu, KU LiXia, MA ChenChen, PANG YunYun, LIANG XiaoHan, ZHANG Xin, LU XiaoMin Scientia Agricultura Sinica    2024, 57 (12): 2265-2281.   DOI: 10.3864/j.issn.0578-1752.2024.12.001 Abstract （465）   HTML （62）    PDF （6268KB）（304）       Knowledge map    Save 【Objective】 Mining the key drought-resistant genes of maize, revealing its drought-resistant molecular mechanism, and providing genetic resources and theoretical guidance for the cultivation of new drought-resistant maize varieties.【Method】Transcriptome data combined with weighted gene co-expression network (WGCNA) and screening methods for physiological and biochemical indicators of drought resistance were used to identify ZmPAL genes associated with drought resistance and rewatering. Genome-wide analysis of the genes encoding PAL was performed using bioinformatics methods. Quantitative real-time fluorescence PCR (qRT-PCR) was used to detect the expression of ZmPAL genes under drought treatment conditions, as well as the expression characteristics of ZmPAL5 among different inbred lines and the expression patterns in different tissues. Finally, genetic transformation was used to analyze the drought resistance function of ZmPAL5 in maize, and the deletion-type Arabidopsis mutant was analyzed for drought resistance with the help of CRISPR/Cas9 technology for the PAL5 homologous gene.【Result】Nineteen maize ZmPAL genes were identified, six of which were clustered on chromosome 5 and encoded proteins that were mostly hydrophilic acidic proteins and relatively evolutionarily conserved in the PAL family of genes. The promoter region of ZmPAL genes contained a large number of cis-acting elements associated with hormonal and abiotic stress responses. Six core genes were identified, four of which were significantly up-regulated for expression after drought treatment. In particular, ZmPAL5 showed an 8.57-fold increase in expression after drought stress. The expression level of ZmPAL5 was found to be significantly higher in the drought-resistant inbred line Zheng 8713 than in the drought-sensitive inbred line B73 under both drought stress and rewatering treatments. Meanwhile, ZmPAL5, a constitutively expressed gene, showed a high level of expression in young stems. Overexpressed ZmPAL5 maize grew well under drought stress, and its relative water content, lignin, chlorophyll, soluble protein, proline content, and activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase were 1.52, 1.49, 1.47, 1.43, 1.44, 1.41, 1.53, 1.41, and 1.35 times, but the malondialdehyde content was 0.65 times that of the wild type. The PAL5-deficient Arabidopsis mutant was sensitive to drought. Under drought stress, its physiological and biochemical indexes showed the opposite trend to those of overexpression of ZmPAL5 maize. 【Conclusion】 Six core genes (ZmPAL3, ZmPAL5, ZmPAL6, ZmPAL8, ZmPAL11, and ZmPAL13) were screened in response to drought stress, in which the expression of ZmPAL5 was positively correlated with drought resistance. ZmPAL5 positively regulated the drought resistance and resilience of the plant by influencing the content of osmotically regulated substances and antioxidant enzyme activities. Table and Figures | Reference | Related Articles | Metrics

Select

Effects of Changing Normal and Extreme Climate States on Maize Meteorological Yield in Northeast China ZHANG WenJing, ZHAO Jin, CUI WenQian, LI ManYao, LI E, GONG XiaoYa, YANG XiaoGuang Scientia Agricultura Sinica    2023, 56 (10): 1859-1870.   DOI: 10.3864/j.issn.0578-1752.2023.10.004 Abstract （464）   HTML （42）    PDF （2016KB）（276）       Knowledge map    Save 【Objective】Northeast China is the main grain production base in China, which has been significantly affected by climate change in recent years. It was of great significance to understand the impact of normal and extreme climate states changes on crop yield in Northeast China for regional crop production and national food security.【Method】In this study, the maize in Northeast China was used as research object, and the main climate factors affecting maize yield were screened to analyze the effects of normal and extreme climate states changes on maize yield in 81 counties in Northeast China from 1980 to 2018.【Result】(1) The average temperature, growing degree-days (GDD), and heat degree-days (HDD) during the maize growth period showed an increasing trend, and the rising rates were 0.34 ℃·(10 a)-1, 47.07 ℃·d·(10 a)-1, and 5.15 ℃·d·(10 a)-1, respectively. The precipitation showed a decreasing trend, with the rate of 7.0 mm·(10 a)-1; the average temperature, GDD, and HDD increased from northeast to southwest, while the precipitation increased from northwest to southeast. (2) The meteorological yield of maize in Northeast China showed an increasing trend from 1980 to 1999, with a rate of 80.93 kg·hm-2·a-1, while it showed a decreasing trend of 46.25 kg·hm-2·a-1 from 2000 to 2018. In terms of spatial distribution, it showed an increasing trend from the middle to the surrounding areas. The area with high yield was concentrated in the eastern part of Heilongjiang. The change of Liaoning was the most stable, and the fluctuation range was stable in the middle area. (3) By the multiple linear regression model, HDD contributed the most to meteorological yield from 1980 to 2018, and the effect was negative, which meant extreme high temperature had the greatest impact on maize yield in Northeast China and caused maize yield reduction; GDD had a positive effect, that is, the average temperature increased maize yield, and the greater GDD, the more yield increased; the precipitation had a negative effect; the interaction between temperature and precipitation had a positive impact on maize yield in Northeast China.【Conclusion】Normal and extreme climate states changes and its impact on maize meteorological yield in Northeast China from 1980 to 2018 were as follow: the normal and extreme temperature showed an overall increasing trend, while the normal precipitation showed a decreasing trend. Extreme high temperatures and normal precipitation led to a decrease in maize yield, but the average temperature increased maize yield, and the extreme high temperature had the greatest impact. In the future, it was necessary to make full use of the average temperature state and minimize the harm caused by extreme high temperature to ensure a high-stable maize production. Table and Figures | Reference | Related Articles | Metrics

Select

Identification and Evaluation of Stripe Rust Resistance in 153 Wheat Collections ZHOU JingWei, YE BoWei, ZHANG PengFei, ZHANG YuQing, HAO Min, YIN YuRuo, YUAN Chan, LI ZhiKang, LI ShunDa, XIA XianChun, HE ZhongHu, ZHANG HongJun, LAN CaiXia Scientia Agricultura Sinica    2024, 57 (1): 18-33.   DOI: 10.3864/j.issn.0578-1752.2024.01.003 Abstract （457）   HTML （50）    PDF （1623KB）（235）       Knowledge map    Save 【Objective】Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), significantly reduced wheat production worldwide. Breeding resistant wheat varieties is currently considered to be one of the most economical and effective ways to control this disease. Understanding the resistance level of Chinese and International Maize and Wheat Improvement Center (CIMMYT) wheat breeding materials and the distribution of known disease resistance genes will greatly helpful for discovering the new resistance resources and improving the utilization efficiency of disease resistance genes. 【Method】In the present study, we phenotyped 153 wheat breeding lines derived from China and CIMMYT at both seedling against prevalent Chinese Pst races CYR33 and CYR34. In 2018-2019, 2019-2020 and 2020-2021, using the Pst races CYR33 and CYR34 to identify the materials at the adult plant stages in Ezhou, Hubei. In addition, we used the gene-based or closely linked molecular markers of known stripe rust resistance genes Yr5, Yr9, Yr10, Yr15, Yr17, Yr18, Yr26, Yr29 and YrSP to genotype the whole set of wheat collections. 【Result】We found 10 lines immune against CYR33 at the seedling stage (IT: 0), including seven Chinese cultivars (Shannong 28, Luomai 163, Shimai 13, Zhongyi 6, Tanmai 98-2, Zhongmai 175, Taishan 21) and three CIMMYT lines (CIM-53, CIM-60 and CIM-71). However, only two cultivars, Tanmai 98-1 and Shannong 102, showed immune to CYR34 at the seedling stage. Based on the three years field tests, we found 64 lines showed highly resistance to stripe rust (final disease severity, FDS≤5%), including seven Chinese cultivars and 57 CIMMYT lines. The molecular marker analysis of known stripe rust resistance genes showed that there were 31, 23, 73, 2, 4, 50 and 2 lines carrying resistance genes Yr9, Yr10, Yr17, Yr18, Yr26, Yr29 and YrSP, respectively. None of any lines had Yr5 and Yr15. Based on the phenotype, only CIM-53 showed immune against two races at both seedling and adult plant stages (IT=0, FDS=0) and it might carry the known stripe rust resistance gene combination of Yr17+Yr29 based on the genotype. 【Conclusion】A total of 153 wheat collections from China and CIMMYT were showed adult plant resistance to the prevalent Pst races. Among these, Chinese wheat varieties mainly carry Yr9, Yr10 and Yr26, while CIMMYT wheat line mainly carry Yr17, Yr18 and Yr29, indicating that near-immunity resistance of CIMMYT wheat lines due to combinations of 1-2 moderate seedling resistance gene and 2-3 adult plant resistance genes resulting in durable resistance. Therefore, it is very urgent to expand the resistance sources and identify new resistance genes for pyramiding more genes biotechnology methods to develop new wheat varieties with durable rusts resistance and good agronomic traits. This plays an important role for controlling stripe rust in China by improving the resistance level of wheat variety overall. Table and Figures | Reference | Related Articles | Metrics

Select

Construction of ms1 Basic Recurrent Populations Adapted to Different Ecological Regions Using Maturity Genes E1 and E2 in Soybean HU XueJie, LIU LuPing, WANG FengMin, HAN YuHua, SUN BinCheng, MA QiBin, HUANG ZhiPing, FENG Yan, CHEN Qiang, YANG ChunYan, ZHANG MengChen, ZHANG Kai, QIN Jun Scientia Agricultura Sinica    2024, 57 (17): 3305-3317.   DOI: 10.3864/j.issn.0578-1752.2024.17.001 Abstract （457）   HTML （47）    PDF （1730KB）（361）       Knowledge map    Save 【Objective】Soybean is a short day crop that is sensitive to photoperiod, and it maybe lead to premature or late flowering when it is planted in different ecological areas. Therefore, in the application of ms1 (male sterility 1) basic population for recurrent selection in different ecological regions, there are problems such as the flowering time unsynchronization between local donor parents and acceptor sterile plants and low introduction rate. The purpose of this study is to construct ms1 basic recurrent population adapted to three ecological regions for improving the probability of flowering time synchronization between donor parents and acceptor sterile plants and reveal the changes of maturity genes E1 and E2 genotypes and phenotype of each population after two rounds of cross-fertilize for providing evidence for improvement of the flowering and maturity time of soybeans.【Method】We used 528 donor parents from different ecological regions and the ms1 basic population as materials. The donor parents were genotyping with the KASP markers of maturity genes E1 and E2 reported by previous research. The donor parents were classified according to E1 and E2 genotypes and mixed with seeds of ms1 basic population respectively, and these populations were planted in different ecological areas according to the suitable genotypes of each region for two rounds of cross-fertilize in two years. Northeast ecological region population was planted in Hulunbuir, Inner Mongolia and Chengde, Hebei, respectively. Huang-Huai-Hai ecological region population was planted in Shijiazhuang, Hebei and Xuchang, Henan. South ecological region population was planted in Guangzhou, Guangdong. Seeds harvested from different ms1 populations were planted in Sanya, Hainan every winter. The flowering and maturity time of donor parents and ms1 basic population were investigated, and the proportions of E1 and E2 genotypes in populations of different region were calculated.【Result】According to genotypes of maturity genes E1 and E2, the donor parents were divided into four groups E1E1/E2E2, E1E1/e2e2, e1e1/E2E2 and e1e1/e2e2 with ratios of 12.1%, 65.0%, 19.3%, and 3.6%, respectively. In the ms1 basic population, the late flowering genotype E1E1/E2E2 had the highest proportion (48.6%), and the flowering time of the population was late, mainly concentrated in 45-51 days. After two rounds of import by cross-fertilize, the percentage of target genotype e1e1/e2e2 increased from 33.0% to 51.6% in Hulunbuir of Northeast China, and the percentage of the e1e1/e2e2 genotype increased from 1.6% to 8% in Chengde. The percentage of target genotype e1e1/E2E2 increased from 18% to 23.1% in Shijiazhuang of Huang-Huai-Hai ecological area, and the percentage of E1E1/e2e2 increased from 12.5% to 30% in Xuchang, respectively. The percentage of E1E1/E2E2 remains above 80% in Guangzhou of South ecological region. The proportion of heterozygous genotypes of target imported genotypes was also increasing in the population. After two rounds of cross-fertilize, there were significant differences in flowering time among ms1 populations of different ecological regions, indicating that phenotypes of different populations also changed with the change of genotype of flowering genes.【Conclusion】Importing genotype of donor parents into the ms1 population based on their genotypes of flowering genes can increase the frequency of suitable genotypes in each ecological region, construct ms1 basic recurrent populations adapted to different ecological regions, increase the probability of flower time synchronization of local donor parents and acceptor ms1 sterile plants, achieve open pollination, gene aggregation and accumulation in soybean, and enrich the genetic diversity of the population, further improve breeding efficiency. Table and Figures | Reference | Related Articles | Metrics

Select

Current Situation of Breeding and Popularization of Short-Growth- Period Winter Rapeseed Varieties for Rice-Rice-Rapeseed Mode LI RongDe, HE Ping, LUO LiXia, SHI MengYa, HOU Qian, MA ZhenGuo, GUO RuiXing, CHENG HongTao Scientia Agricultura Sinica    2024, 57 (5): 846-854.   DOI: 10.3864/j.issn.0578-1752.2024.05.002 Abstract （456）   HTML （24）    PDF （449KB）（673）       Knowledge map    Save The self-sufficiency rate of edible vegetable oil is less than 31 percent in China, with a high degree of import dependence. Rapeseed is the only winter oilseed crop with a wide range of suitable planting region, and it is an important source of edible vegetable oil in China. Planting more rapeseed is an important measure to guarantee national edible oil supply security. Making full use of the winter fields in the southern double cropping rice area to promote “rice-rice-rapeseed” production is an important approach to expand the planting area of rapeseed. The area suitable for the “rice-rice-rapeseed” production mode is mainly distributed in the double cropping rice area of Hunan, Jiangxi, Guangxi and Hubei provinces in China, with a potential area of about 1.87 million hm2. According to the conditions of temperature and light resources, three suitable areas for the “rice-rice-rapeseed” production include the ample area, tightly balanced area and the constrained area. All the areas require early-maturing rapeseed varieties with a growth period of around 180 days, which are suitable for being sown in mid- to late October and harvested in mid- to late April. Among a total of 75 new rapeseed lines participated in the early-maturity group of the national rapeseed variety trials from 2013 to 2022, the average growth period ranged from 169.3 to 185.5 days, and the average yield was 1 635.90-2 228.55 kg·hm-2, with 22 varieties out yielded the check variety. There are 72 early-maturing winter oilseed rape varieties with a growth period less than 190 days were registered by the end of May 2023. These varieties are suitable to be used in the “rice-rice-rapeseed” mode, and most of them are hybrid varieties with low erucic acid and low glucosinolate quality. 11 varieties, Yangguang 131, Fengyou 730, Fengyou 320, Fengyou 847, Ganyouza 906, Shengguang 127, Xiangyou 420, Jingyou 69, Fengyou 112, Huayouza 652, Ganyouza 1009, are the most promoted and applied early-maturing winter rapeseed varieties in the “rice-rice-rapeseed” production area, with more than 135 hm2 each in 2022. The present varieties can basically meet the early-maturation demand in the ample area. In the tightly balanced and constraint areas, however, the growth period of these varieties is too long. To expand the production and efficiency of rapeseed industry, it is urgently needed to strengthen the policy and financial security in the future, carry out joint breeding projects for short-growth-period winter rapeseed varieties to further improve the yield in the ample area and shorten the growth period in the tightly balanced and constrained areas. Meanwhile, to strengthen the research and promotion of supporting cultivation technology for elite varieties, match well early rice, late rice, and rapeseed varieties are also good measures to support the expansion of rapeseed production in the “rice-rice-rapeseed” production area. In addition, improving agricultural socialized services, expanding agricultural insurance and increasing subsidies for rapeseed planting to ensure production benefit will enhance the farmers’ enthusiasm for the “rice-rice-rapeseed” production. Table and Figures | Reference | Related Articles | Metrics

Select

Leaf Area Index Inversion of Cotton Based on Drone Multi-Spectral and Multiple Growth Stages SHI HaoLei, CAO HongXia, ZHANG WeiJie, ZHU Shan, HE ZiJian, ZHANG Ze Scientia Agricultura Sinica    2024, 57 (1): 80-95.   DOI: 10.3864/j.issn.0578-1752.2024.01.007 Abstract （452）   HTML （28）    PDF （2398KB）（1646）       Knowledge map    Save 【Objective】The leaf area index (LAI) is a vital indicator for evaluating crop growth, photosynthesis, and transpiration. The objective of this study is to explore the cotton LAI estimation models based on multi-spectral data from drones at different growth stages and multiple growth stages, clarify the variation patterns of cotton LAI estimation models during different growth stages, and to provide a basis for real-time understanding of cotton growth and scientific field management tailored to local conditions. 【Method】The DJI Elf 4 multi-spectral UAV was used to acquire multi-spectral images and RGB images of cotton at budding stage, initial flowering stage, boll setting and open-boll stages. Five multi-spectral indices, namely normalized difference vegetation index (NDVI), normalized green difference vegetation index (GNDVI), normalized difference red-edge index (NDRE), leaf chlorophyll index (LCI), optimized soil adjusted vegetation index (OSAVI), and five color indices, namely modified green-red vegetation index (MGRVI), green-red vegetation index (GRVI), green leaf algorithm (GLA), excess red index (EXR), and visible atmospherically resistant vegetation index (VARI), were selected to build a data set for each growth stage of cotton and multiple growth stages of cotton growth, respectively. Combined with the punching method to obtain actual ground LAI data, the machine learning algorithms of partial least squares regression (PLSR), ridge regression (RR), random forest (RF), support vector machine (SVM) and back propagation (BP) were used to construct a cotton LAI prediction model. 【Result】The LAI of cotton exhibited an increasing and then decreasing pattern during the growth stage. Notably, the mean LAI values of cotton at the inner side of the budding stage, initial flowering stage, and boll setting stage were significantly greater than those at the lateral side (P<0.05). The selected indices exhibited significant correlations with each other across the periods (P<0.05). In general, the correlation between multi-spectral index and color index showed a decreasing trend as the growth stage progressed, and the selected indices were significantly correlated with cotton LAI in all stages (P<0.05), the correlation coefficients of multi-spectral index ranged from 0.35 to 0.85, and the correlation coefficients of color index ranged from 0.49 to 0.71, and those with a larger absolute value of the correlation coefficients were mostly multi-spectral indices, while those of the correlation coefficients of color index and cotton LAI were smaller. The estimated model performance results showed that the multi-spectral index was better than the color index in the cotton growth models, the predictive performance of the index models showed certain regularity with the change of growth, and NDVI was the optimal index for predicting cotton LAI. From the model results, the RF model and BP model obtained higher estimation accuracy under each growth stage. The LAI inversion model at the initial flowering stage had the highest accuracy, with the optimal model validation set R2 of 0.809, MAE of 0.288, and NRMSE of 0.120. The optimal model validation set for the multiple growth stages had the R2 of 0.386, MAE of 0.700, and NRMSE of 0.198. 【Conclusion】There are significant differences in LAI between the inner and lateral sides of cotton during the budding stage, initial flowering stage, and boll setting stage. NDVI emerged as the optimal index for predicting cotton LAI at all growth stages, with the RF and BP models demonstrating superior performance. The effectiveness of the multiple growth stages model was notably lower compared to that of the single-growth model, with the optimal index identified as GNDVI and the optimal model as BP. The initial flowering stage appeared to be the optimal window for predicting cotton LAI. These findings can provide theoretical basis and technical support for utilizing UAV remote sensing to monitor cotton LAI. Table and Figures | Reference | Related Articles | Metrics

Select

Effects of Soil Film Tillage on Soil and Crop in Farmland YANG ShiQi, YAN Xin, HAN Yu Scientia Agricultura Sinica    2024, 57 (15): 3010-3022.   DOI: 10.3864/j.issn.0578-1752.2024.15.008 Abstract （451）   HTML （47）    PDF （1317KB）（222）       Knowledge map    Save 【Objective】To make clear the agricultural productive value of soil film tillage, the effects of soil film tillage on soil moisture, temperature and nutrient changes in farmland were explored, and the effects of soil film on crop root growth and yield were revealed too, so as to provide the theoretical basis and technical methods for the application of soil film.【Method】Soil film was induced by spraying a 1.0% concentration of carboxymethyl cellulose ammonium (CMC-NH4) aqueous solution, and the field experiment was conducted with five treatments, including 0 (CK), 50.0 (T1), 100.0 (T2), 200.0 (T3), and 300.0 kg·hm-2 (T4). The effects of CMC-NH4 application rate on soil moisture, temperature, nutrients, microorganisms, crop roots and yield in multiple cropping of spring wheat and summer maize were studied.【Result】Soil film treatment of spring wheat and summer maize could increase average daily soil moisture content by 3.3%-7.0% (P<0.05, the same as below) and 1.9%-6.1%, average daily temperature by 7.9%-12.6% and 5.6%-11.7%, contribution of soil accumulated temperature of growth period by 88.98-141.94 ℃ and 60.25-136.65 ℃, root length of 0-30 cm soil layer by 37.5%-17.1% and 11.2%-1.7%, root surface area of 0-30 cm soil layer by 15.3%-4.5% and 12.5%-9.2%, respectively, and root biomass (dry weight) in 0-30 cm soil layer were enhanced by 17.0%-41.5% and 30.9%-36.7%, respectively. Finally, the grain yield of spring wheat per unit area was increased by 7.3%-18.8% and above-ground dry weight of summer maize per unit area was increased by 33.6%-49.0%. and the soil nitrogen, phosphorus and potassium content as well as soil microbial diversity were improved too. 【Conclusion】As a novel type of soil tillage, soil film had the function of farmland coverage, which greatly contributed to improve soil hydrothermal environment, and promote nutrient absorption and utilization, root growth and crop yield. At the same time, soil film produced the important technique and method to make the better plough layer structure that is “compact surface, loose top and tight bottom of plough layer”, which would support the improvement of crop productivity, farmland soil amendment and agricultural high-quality development. In this study, the recommended application rate was 100.0 kg·hm-2 in Ningxia Yellow River irrigation area. Table and Figures | Reference | Related Articles | Metrics

Select

Screening Regulatory Genes Related to Luffa Fruit Length and Diameter Development Based on Transcriptome and WGCNA CHEN MinDong, WANG Bin, LIU JianTing, LI YongPing, BAI ChangHui, YE XinRu, QIU BoYin, WEN QingFang, ZHU HaiSheng Scientia Agricultura Sinica    2023, 56 (22): 4506-4522.   DOI: 10.3864/j.issn.0578-1752.2023.22.012 Abstract （450）   HTML （62）    PDF （3099KB）（3890）       Knowledge map    Save 【Objective】 The aim of this study was to identify the co expression modules of luffa fruit length and diameter development and to screen key regulatory genes, so as to provide the theoretical basis for subsequent research on the molecular mechanism of fruit shape control in luffa. 【Method】 The luffa fruits in 9 fruit development stages (2 days before anthesis, and 0, 2, 4, 6, 8, 10, 15, and 20 days after anthesis) were applied as research materials. The fruit length and diameter of each stage were measured. The WGCNA method was used to jointly analyze transcriptome and fruit length and diameter data, to identify co-expressed gene modules of fruit length and diameter development, and to screen out key regulatory genes.【Result】A total of 14 co expression modules were identified by WGCNA, among which two modules (Turquoise and Lightpink4) were significantly correlated with fruit length and diameter (absolute value of correlation coefficient=0.9); Turquoise module was significantly positively correlated, while Lightpink4 module was significantly negatively correlated. KEGG enrichment analysis found that the Turquoise module was significantly enriched in endocytosis and phenylpropanoid biosynthesis pathways, which were closely related to fruit enlargement and growth regulation, and could be used as a key gene module for studying fruit length and diameter in luffa. According to the connectivity and functional annotation of genes in Turquoise module, ten key regulatory genes were screened, including xyloglucan endotransglucosylase/hydrolase gene XTH23, actin-depolymerizing factor gene ADF2, chaperone protein gene DnaJ10, expansin gene (EXPA1, EXPA4 and EXLA5), kinesin gene kinesin-13A, auxin response genes SAUR21, and Aux/IAA11. The RT-qPCR results showed that the expression levels of ten regulatory genes significantly increased after the fruit entered the rapid growth period (8 day after anthesis), with an increase of 2-50 times approximately. Through constructing a gene interaction network, it was found that some candidate genes interacted with the WRKY, bHLH, and HSF transcription factor families.【Conclusion】The Turquoise module, an important co expression module of luffa fruit length and diameter was obtained, and ten potential candidate genes for luffa fruit shape control were screened. It was found that luffa fruit length and diameter development regulation mainly involved the processes of cell wall reconstruction, cell development and differentiation, and auxin regulation. Table and Figures | Reference | Related Articles | Metrics

Select

Genetic Inheritance and Breeding of Stripe Rust and Powdery Mildew Resistance in Wheat LI ShunDa, LAN CaiXia Scientia Agricultura Sinica    2024, 57 (1): 1-3.   DOI: 10.3864/j.issn.0578-1752.2024.01.001 Abstract （449）   HTML （70）    PDF （251KB）（400）       Knowledge map    Save Reference | Related Articles | Metrics

Select

Comprehensive Fruit Quality Evaluation and Suitable Areas Selection of Newhall Navel Orange in China CHEN ZhiMin, CHEN XiaoLin, TAN ZhenHua, CHEN ZhaoXing, SHEN DanDan, MA YanYan, ZHENG YongQiang, YI ShiLai, LÜ Qiang, XIE RangJin Scientia Agricultura Sinica    2023, 56 (10): 1949-1965.   DOI: 10.3864/j.issn.0578-1752.2023.10.011 Abstract （443）   HTML （43）    PDF （1220KB）（262）       Knowledge map    Save 【Objective】This study aimed to establish a comprehensive evaluation model in fruit quality, clarify the comprehensive grade of fruit quality and their corresponding meteorological characteristics from different Newhall Navel orange (Citrus sinensis [L.] Osb. cv. Newhall) orchards in China, so as to provide a reference for the ecological environment adaptability and suitable planting.【Method】Twenty three Newhall orchards in different ecological environments of China were selected to measure fruit external and internal quality indicators. Correlation analysis, principal component analysis and cluster analysis were used to identify the core indicators, and the comprehensive evaluation models of fruit quality were established by analytic hierarchy process (AHP), principal component analysis (PCA) and fuzzy comprehensive appraisal (FCA), respectively. The optimal algorithm model and fruit grade classification threshold were determined and verified with sensory quality evaluation. Meanwhile, the comprehensive quality grades and the characteristics of corresponding ecological factors of Newhall navel orange fruit from different producing areas were explored.【Result】The fruit comprehensive quality of 23 Newhall orchards showed obvious regional characteristics. The fruit in southern Jiangxi and southern Hunan had higher total soluble solid and solid acid ratio, while the fruit in western Hunan and the upper and middle reaches of the Yangtze River had better fruit external color indexes and higher titratable acid. The quality indexes were correlated to varying degrees. Five core indexes were selected by principal component analysis combined with cluster analysis, including comprehensive color index, fruit weight, soluble solids, solid acid ratio, and vitamin C content. At the same time, AHP model was determined as the comprehensive evaluation model of fruit quality with the best fitting degree of sensory quality index: Y (comprehensive value) = 0.06× comprehensive color index + 0.26× single fruit weight +0.16× soluble solid content +0.42× solid acid ratio +0.11× vitamin C content (standardized value). The comprehensive fruit quality indicators of different Newhall orchards were ranked, and the classification threshold was determined as follows: ≥0.60 was the first-class orchards, mainly concentrated in southern Jiangxi, southern Hunan and eastern Guangdong, with active accumulated temperature, effective accumulated temperature, maximum sunshine hours and surface temperature; 0.45-0.60 was the second-class orchards, mainly concentrated in northern Guangxi and western Fujian, characterized by higher temperature accumulation and rainfall; 0.30-0.45 was the third-class orchards, mainly concentrated in western Hunan and the middle and upper reaches of the Yangtze River, with relatively lower rainfall and temperature accumulation; <0.30 was the fourth-class orchards, mainly distributed in southern Zhejiang, with the highest rainfall.【Conclusion】The core indicators of the comprehensive quality of citrus fruits were identified by PCA, and the AHP model with the optimal for the Newhall fruit comprehensive evaluation by combining the eigenvalues of each principal component to achieve automatic assignment of AHP judgment matrix. The ecological factors of different grades of orchards were significantly different. These results provided algorithms and data support for the development of the decision system based on "suitable planting" of citrus varieties in different ecological environment. Table and Figures | Reference | Related Articles | Metrics

Select

Cloning and Functional Characterization of the Promoter of GhSLD1 Gene That Predominantly Expressed in Cotton Fiber LIU Fang, XU MengBei, WANG QiaoLing, MENG Qian, LI GuiMing, ZHANG HongJu, TIAN HuiDan, XU Fan, LUO Ming Scientia Agricultura Sinica    2023, 56 (19): 3712-3722.   DOI: 10.3864/j.issn.0578-1752.2023.19.002 Abstract （442）   HTML （42）    PDF （2559KB）（872）       Knowledge map    Save 【Objective】Cotton fiber is the main economic product of cotton. It is the epidermal cells of the ovule outer integument through polar elongation and secondary wall thickening. As one of the longest plant cells, the cotton fiber cells are regarded as an ideal material in the study of plant cell growth and development. Identification of promoters specifically or preferentially expressed in fiber cells is of great significance for basic research on fiber development and molecular breeding for improving fiber traits. 【Method】In this study, we cloned the promoter of GhSLD1 gene, which is predominantly expressed in fiber cells. Through the PlantCARE website for promoter sequence analysis, we identified the important cis-regulatory elements contained in the cloned sequence. According to the distribution of some important cis-regulatory elements, the cloned promoter fragments were deleted at 5′- end. A total of 4 promoter fragments were obtained and the corresponding plant expression vector was constructed. The constructed plant expression vectors were used for genetic transformation of tobacco and cotton. The transgenic plants were identified through molecular identification of transgenic tobacco and cotton. GUS activity in different tissues, organs and fiber cells of transgenic plants at different development stages was also investigated. 【Result】The longest promoter cloned was 2 900 bp in length. In addition to a lot of transcription regulatory elements in the promoter, the sequence also contained multiple abscisic acid response elements, the elements essential for the anaerobic induction, methyl jasmonate response elements, brassinolide response elements, the elements involved in seed-specific regulation, the elements involved in defense and stress responsiveness, and MYB transcription factor binding sites. Four promoter fragments with a length of 2 900 bp (GhSLD-P1), 2 178 bp (GhSLD1-P2), 1 657 bp (GhSLD1-P3) and 1 232 bp (GhSLD-P4) were obtained by the 5′-terminal deletion, respectively. The transgenic tobacco plants were generated after confirmed by molecular identification. GhSLD-P1, GhSLD1-P2 and GhSLD1-P3 did not express in transgenic tobacco, while GhSLD-P4 is widely expressed, and the expression level of GhSLD-P4 was similar to that of CaMV 35S promoter. The different sequence between GhSLD1-P3 and GhSLD-P4 contained four abscisic acid response elements, two brassinolide response elements, and three MYB binding sites. These cis-regulatory elements may be associated with the non-expression of GhSLD1-P1, GhSLD1-P2, and GhSLD1-P3 promoters in transgenic tobacco. The transgenic cotton plants of GhSLD1-P2 were obtained after confirmed by molecular identification. GhSLD1-P2 predominantly expressed in transgenic cotton fibers, and its expression level was higher at the elongation stage (10-15 DPA) of fiber cells while lower in the early developmental stage (5 DPA) of fiber cells and the stage of secondary cell wall deposition (20-30 DPA). 【Conclusion】The GhSLD1-P4 promoter was a widely expressed promoter, and the GhSLD1-P2 promoter was a fiber predominant expression promoter, which was highly expressed during the elongation of fibers. It could be applied to the study on the gene function involved in cotton fiber development and molecular breeding for improving fiber traits. Table and Figures | Reference | Related Articles | Metrics

Select

Integrated Aanalysis of Genome and DNA Methylation for Screening Key Genes Related to Pork Quality Traits ZHAO ZhenJian, WANG Kai, CHEN Dong, SHEN Qi, YU Yang, CUI ShengDi, WANG JunGe, CHEN ZiYang, YU ShiXin, CHEN JiaMiao, WANG XiangFeng, TANG GuoQing Scientia Agricultura Sinica    2024, 57 (7): 1394-1406.   DOI: 10.3864/j.issn.0578-1752.2024.07.014 Abstract （441）   HTML （23）    PDF （1869KB）（190）       Knowledge map    Save 【Background】 The meat quality traits of pigs are important economic traits. Studying the molecular mechanisms that affect various meat quality traits and discovering key genes can guide genetic improvement of pigs and have significant implications for improving pork quality. Currently, those researches on meat-related mechanisms were mainly based on DNA genomics, while studies on DNA methylation related to meat quality traits, as well as integrated analysis of combining genomics and methylation, are scarce. 【Objective】 The potential key genes affecting pork meat quality were screened and identified by combined analysis of genome and DNA methylome, so as to provide a reference for the genetic improvement of pork quality. 【Method】 In this study, 28 meat quality traits of the ongissimus dorsi muscle of 140 Large White pigs were examined. Epigenome-wide association analysis (EWAS) and genome-wide association analysis (GWAS) were performed to identify CpG and SNP sites significantly associated with each trait. Subsequently, the conditional association analysis was performed by using SNPs as covariates on the significantly associated sites overlapping between GWAS and EWAS to further identify CpG sites with independent effects. Association analysis was then conducted to identify methylation quantitative trait loci (meQTL) by using the methylation levels of CpG sites as the dependent variable and SNPs as the independent variable. Finally, the cis-methylation quantitative trait loci (cis-meQTL) were used as instrumental variables for Mendelian randomization analysis to infer the causal relationship between cis-meQTL and phenotypes, while potential key genes at the loci were annotated and identified. 【Result】 (1) The significant associated sites were identified in the same genomic regions for the meat quality traits, namely yellowness value at slaughter 45 minutes postmortem (b45min), drip loss (DL), and docosahexaenoic acid (C22:6n-3), by both EWAS and GWAS. (2) After conditional association analysis, seven CpG sites for b45min and one CpG site for DL remained significant, while the three sites for C22:6n-3 were no longer significant after using SNPs as covariates, indicating that the significant associations of the seven CpG sites for b45min and one CpG site for DL identified by EWAS were not influenced by nearby significant SNPs. (3) A total of ten meQTL were identified for the seven CpG sites for b45min and one CpG site for DL, but the majority were trans-meQTL, with only one CpG site (SSC12:44 254 675 bp) identifying a cis-meQTL, suggesting that this site might be regulated by nearby SNPs. (4) Mendelian randomization analysis showed a causal relationship between the CpG site (SSC12:44 254 675 bp) and the b45min phenotype. (5) annotation of the locus revealed that the nearest gene to the CpG site (SSC12:44 254 675 bp) and its cis-meQTL was NOS2, and the CpG site was located within the NOS2 gene. 【Conclusion】 Based on the integrated analysis of DNA methylation and genomics data, this study proposed that the NOS2 gene might be a key candidate gene for meat color traits. DNA methylation and SNP jointly regulated gene expression, thereby affecting the expression of genes related to meat color traits. Table and Figures | Reference | Related Articles | Metrics

Select

Development and Application of Specific Molecular Markers for Six Homologous Rice Blast Resistance Genes in Pi9 Locus of Rice YANG Hao, HUANG YanYan, YI ChunLin, SHI Jun, TAN ChuTian, REN WenRui, WANG WenMing Scientia Agricultura Sinica    2023, 56 (21): 4219-4233.   DOI: 10.3864/j.issn.0578-1752.2023.21.007 Abstract （439）   HTML （31）    PDF （4029KB）（297）       Knowledge map    Save 【Objective】The Pi9 resistance gene locus, conferring a broad-spectrum resistance against Magnaporthe oryzae, is consist by several tandem homologous genes. Over 10 resistance genes have been cloned from this gene locus. This study aims to clarify the R gene composition at Pi9 locus in rice resource materials and promote the application of those genes in rice resistance breeding.【Method】Comparing the DNA sequence of cloned R genes at Pi9 locus, the specific nucleotide polymorphism sites were screened as the candidate sites. Subsequently, each R gene was blasted with 155 rice genomes in the database of Rice Resource Center. The most specific nucleotide polymorphism sites were picked out from the candidate site in each gene to develop primer pair of molecular markers. The PCR product of primer pairs was used to mark indicated R gene in tested rice materials via parameter optimization. To verify the results, the R genes were cloned from indicated rice variety randomly and examined by Sanger sequencing, or analyzed the R genes from the genome database if the genome sequence of indicated rice variety exists in Rice Resource Center. The R genes in Pi9 locus have high homology, which cause same specific nucleotide polymorphism sites existing in different R genes. Therefore, some R genes are hardly identified by one molecular marker. For this case, several molecular markers were employed to identify the indicated R gene simultaneously. Moreover, some specific nucleotide polymorphism sites are single nucleotide polymorphism (SNP), in where the primers of molecular markers have a mismatched base. In order to improve the specificity of PCR amplification, the adjacent base of SNP was mutated to generate two mismatched bases at 3′ site of primer.【Result】Finally, the valid molecular markers were developed for each R gene and identified 32.09% tested materials containing R genes at Pi9 locus. Pi9, Pid4, PigmR, Piz-t, Pi2 and Pi9-type5 are present in 1, 7, 8, 14, 23 and 33 tested materials, respectively. The Pi9 only presents in monogenic line but not in rice parent lines. The other genes are usually present in two or more gene combinations in rice parent lines. The Pi9-type5 often presents in pair with Pi2 and Piz-t, and presents alone in three rice parents, Chenghui 993, HR2168 and Mianhui 365. Yuhui 38 contains the most R genes at Pi9 locus, including Pi2, Pi9-type5, PigmR and Pid4. Chuangu B, Chuannong 4B, Neixiang 6B and Shuang 1B contain Piz-t, PigmR and Pid4. Qianxiang 654B contains Piz-t and Pid4.【Conclusion】This study successfully developed specific molecular markers for six homologous rice blast resistance genes in Pi9 locus and identified the R gene composition in Pi9 locus for 110 rice parent lines that used in rice breeding in Sichuan basin. It also discovered different types of R genes combination at Pi9 locus and provided a clear reference for choosing the resistance source in rice breeding. Table and Figures | Reference | Related Articles | Metrics

Select

Rational Design and Innovative Application Strategy for the Insecticidal Protein Based on Bt Toxin XU ChongXin, JIN JiaFeng, SUN XiaoMing, SHEN Cheng, ZHANG Xiao, CHEN ChengYu, LIU XianJin, LIU Yuan Scientia Agricultura Sinica    2024, 57 (1): 96-125.   DOI: 10.3864/j.issn.0578-1752.2024.01.008 Abstract （436）   HTML （32）    PDF （802KB）（1567）       Knowledge map    Save Bt toxin is a macromolecular protein derived from Bacillus thuringiensis with special insecticidal function. Its preparation and transgenic crops have been widely used in pest control, and have produced huge economic and social ecological benefits. Exploiting and improving the application value of Bt toxin is a hot spot of continuous research. In particular, as the structure and function of Bt toxin and its mechanism of action appear clearer, it has created conditions for its functional modification and innovative application. As a result, the related research has flourished and achieved remarkable results. A large number of studies have shown that strategies such as site directed mutagenesis, domain replacement or fusion, and anti-idiotype antibody simulation are effective means to rationally design novel insecticidal proteins with higher activity, greater stability, wider insecticidal spectrum and higher non-target biosecurity. Those novel insecticidal proteins are different from parent Bt toxins, of which are mutants, structural heterozygotes and even functional effector antibodies. In addition, it is also an important approach to promote the application value of Bt toxin by use of innovative synergistic strategies such as catalytic toxin activation, driving toxin-targeted receptor binding, promoting toxin expression and the synergistic effect of combination or co-expression of homologous or heterologous insecticidal materials. This paper summarizes the structure and function of Bt toxin and its mechanism of action. It also reviews the research progress in rational design of novel insecticidal proteins such as mutants, structural heterozygotes and functional effector antibodies based on Bt toxin function modification, and innovative application strategies based on Bt toxin function enhancement. The future development trend and potential shortcut of rational design and innovative application strategy for insecticidal protein based on Bt toxin were discussed. Furthermore, the author’s team combined it with the latest achievements in targeting design and development of the insecticidal function effector antibodies simulating Bt toxin. This paper is expected to provide more comprehensive and valuable literature information and enlighten ideas for the related research based on Bt toxin. Table and Figures | Reference | Related Articles | Metrics