Scientia Agricultura Sinica

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 ( 663 )

HTML ( 68 )

PDF (2776KB) ( 591 )

Save

Figures and Tables | References | Related Articles | Metrics

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.

Establishment and Standardization of Event-Specific Real-Time Quantitative PCR Detection Method of Stress-Resistant Soybean IND-ØØ41Ø-5

LI YunJing, XIAO Fang, WU YuHua, LI Jun, GAO HongFei, ZHAI ShanShan, LIANG JinGang, WU Gang

Scientia Agricultura Sinica. 2023, 56(13): 2443-2460. doi:10.3864/j.issn.0578-1752.2023.13.002

Abstract ( 270 )

HTML ( 27 )

PDF (2711KB) ( 2304 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】Stress-resistant soybean IND-ØØ41Ø-5 has been authorized as a safety certificate for imported processed raw materials in China. This study aims to develop a specific, accurate, and sensitive real-time quantitative PCR (qPCR) assay for the quantification of the stress-resistant soybean IND-ØØ41Ø-5 event, providing a precise measurement technique for regulating its safety in China. 【Method】18 pairs of primers and probes were designed using Beacon designer 8.0 software for the 5′ end flanking sequence of the stress-resistant soybean IND-ØØ41Ø-5 event, in combination with one pair of primer and probe providing by Instituto de Agrobiotecnologia Rosario (INDEAR) S.A. Subsequently, the specific screening of the primers and probes was performed using real-time PCR technology, and one pair of candidate primer and probe was selected. The reaction system parameters, such as primer and probe concentration, were optimized during the establishing the qPCR method. A specificity test was performed using different test samples. The pure stress-resistant soybean IND-ØØ41Ø-5 genomic DNA was serially diluted into standard solution templates, and standard curves were plotted to investigate the linear dynamic range of the qPCR method. Test samples with copy number ratios of 5%, 1% and 0.1% were prepared by mixing IND-ØØ41Ø-5 genomic DNA with non-GM counterpart to evaluate the accuracy of the qPCR method. The limit of detection (LOD) was detected by using test samples with copy number ratios of 0.05% and 0.025%. The limit of quantification (LOQ) was determined after 16 tests on samples with a copy number ratio of 0.1%. Finally, the technical parameters of qPCR assay for the stress-resistant soybean IND-ØØ41Ø-5 event were determined. The specificity, LOD, LOQ and accuracy of the qPCR method were validated by eight qualified testing laboratories. The repeatability and reproducibility of the qPCR were evaluated by Cochran′s test and Grubbs' test, and the measurement uncertainty of the accuracy samples were pre-evaluated by linear least-square method. 【Result】The RBORD-F1/RBORD-R1/RBORD-P1 primer and probe combination was selected as a candidate to establish the qPCR for the stress-resistant soybean IND-ØØ41Ø-5 event, with an amplified fragment of 138 bp. The optimized reaction system had a final concentration of 0.4 μmol·L^-1 for the primer and 0.2 μmol·L^-1 for the probe. Standard curves of IND-ØØ41Ø-5 and Lectin gene assay showed good linearity with the dynamic range from 33 to 83190 copies of genomic DNA. The qPCR can accurately quantify 5%, 1%, and 0.1% content of IND-ØØ41Ø-5 test samples with less than 25% bias and relative standard deviation (RSD). The LOD was determined to be 0.05%, and the LOQ was 0.1%. After validation by eight qualified laboratories, the results indicated that the method was stable, specific and had good repeatability and reproducibility, with the LOD of 0.05% and LOQ of 0.1%. After pre-evaluating the measurement uncertainty, the content of IND-ØØ41Ø-5 in the five test samples was found to be (0.10±0.02)%, (0.53±0.09)%, (1.05±0.18)%, (2.05±0.34)% and (5.18±0.87)%, respectively. These results demonstrate the accuracy and reliability of the qPCR method established in this study for the quantification of stress-resistant soybean IND-ØØ41Ø-5 event components. 【Conclusion】This study successfully developed a specific, accurate, and sensitive qPCR assay for the quantification of stress-resistant soybean IND-ØØ41Ø-5 event using real-time PCR technology. The results show that method is capable of achieving precise measurement and reliable quantification of IND-ØØ41Ø-5 event components.

Study on Adaptability of Spring Wheat Yield to Water and Nitrogen Reduction Under Wide-Width Uniform Sowing and Conventional Strip Sowing in Oasis Irrigated Regions

CHEN GuiPing, CHENG Hui, FAN Hong, FAN ZhiLong, HU FaLong, YIN Wen

Scientia Agricultura Sinica. 2023, 56(13): 2461-2473. doi:10.3864/j.issn.0578-1752.2023.13.003

Abstract ( 312 )

HTML ( 40 )

PDF (590KB) ( 158 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】Water shortage and high fertilizer input have become the dominant factors restraining spring wheat production in arid oasis irrigated areas. It is urgent to study the technology of the effects of water and nitrogen reduction in different planting modes on dry matter accumulation and yield formation of spring wheat, so as to provide a theoretical and practical basis for efficient production of spring wheat with water and fertilizer saving. 【Method】A field experiment with split-split plot was conducted at arid oasis irrigated areas from 2020 to 2021. Two planting modes, including wide-width uniform sowing (W) and conventional strip sowing (C), were designed, with two irrigation levels on local conventional irrigation (I2, 2 400 m³·hm^-2) and local conventional irrigation reduced by 20% (I1, 1 920 m³·hm^-2), and three levels of nitrogen fertilizer at a local conventional nitrogen (N3, 225 kg·hm^-2), local conventional nitrogen reduced by 20% (N2, 180 kg·hm^-2), and local conventional nitrogen reduced by 40% (N1, 135 kg·hm^-2). The adaptability of spring wheat yield to water and nitrogen reduction under wide-width uniform sowing and conventional strip sowing was studied. 【Result】Compared wtih conventional strip sowing, the wide-width uniform sowing increased the maximum dry matter growth rate (V_max), average dry matter growth rate (V_mean), and dry matter accumulation rate after booting stage of spring wheat, and delayed the time of emergence of the highest dry matter growth rate (T_m). Compared with conventional strip sowing with conventional irrigation and nitrogen levels, the V_max and V_mean values of spring wheat under the wide-width uniform sowing were increased by 13.0%-23.4% and 11.0%-16.9%, respectively, and T_m was delayed by 3.3-3.7 days with the treatment on the reduction of 20% for water and nitrogen, so the growth and development dynamics of spring wheat could be effectively regulated by wide-width uniform sowing. The wide-width uniform sowing had greater grain and biomass yields by 11.0%-17.3% and 4.3%-9.6%, respectively, and the greater harvest index by 6.3%-6.9%, than conventional strip sowing. Furthermore, the grain and biomass yields were 16.0%-22.5% and 5.6%-13.2%, and harvest index was 8.2%-10.9% greater under wide-width uniform sowing with the reduction of 20% in water and nitrogen than those under the conventional strip sowing with conventional irrigation and nitrogen levels. There was no significant difference in grain and biomass yields, and harvest index of spring wheat was found between the reduction 20% of water and nitrogen, and the reduction of 20% irrigation and conventional nitrogen application under wide-width uniform sowing. The increase of spring wheat yield was mainly attributed to the synergistic of grains per ear and 1000-grain weight, which were increased by 3.9%-7.1% and 18.4%-22.7%, respectively, compared with conventional strip sowing with conventional irrigation and nitrogen application, and the 1000-grain weight increased by a greater extent. Path analysis showed that the reduction 20% of water and nitrogen in wide-width uniform sowing enhanced grain yield mainly through increasing harvest index and 1000-grain weight. 【Conclusion】 The wide-width uniform sowing could realize the simultaneous reduction 20% of water and nitrogen in spring wheat production, which was a feasible measure to save water and nitrogen for stable and high yield of spring wheat in oasis irrigation areas.

Integrating Multi-Source Gaofen Images and Object-Based Methods for Crop Type Identification in South China

WANG JiaYue, CAI ZhiWen, WANG WenJing, WEI HaoDong, WANG Cong, LI ZeXuan, LI XiuNi, HU Qiong

Scientia Agricultura Sinica. 2023, 56(13): 2474-2490. doi:10.3864/j.issn.0578-1752.2023.13.004

Abstract ( 379 )

HTML ( 32 )

PDF (12012KB) ( 205 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Due to frequent cloudy and rainy weather, it is challenging to map crop types over South China with fragmented agricultural landscapes. The Gaofen (GF) series satellites developed by China have high spatial-temporal resolution and good image quality. This study exploited the spatial and temporal advantages of multi-source GF images for fine crop classification in heterogeneous agricultural areas with frequent clouds and rain. 【Method】This study characterized the spatial geometry of agricultural fields based on GF-2 data with high spatial resolution, and cooperated with the encrypted observations from GF-1 and GF-6 time series to fully characterize the spectral seasonal variations of crops. By constructing three-dimensional classification features of spectrum-time-space, the crop classification based on random forest classifier were conducted, and the importance scores of different features were calculated. Furthermore, several classification scenarios were set based on different satellite combinations and different classification units, for further analyzing the performances of integrating different GF datasets on crop type mapping. 【Result】The overall accuracy of synergistic GF-1, GF-2 and GF-6 by object-oriented crop classification was 95.49% with Kappa of 0.94 in Qianjiang city; the overall accuracy in Zaoyang city was 93.78% with Kappa of 0.92. The accuracy of crop classification by integrating GF-2 and GF-6 was higher than that by GF-2 and GF-1. In addition, the object-oriented crop classification based on GF-2 outperformed the pixel-oriented one, in which the overall accuracy improved by 1.4% and 1.32% in Qianjiang and Zaoyang, respectively. Compared with the spectral and spatial features of GF-1 and GF-2, the GF-6 spectral bands had the largest contribution to crop type identification, and the cumulative importance score accounted for 82% (Qianjiang) and 77% (Zaoyang) of all spectral bands. Among them, the four new spectral bands of GF-6, namely, red-edge I band (B5), red-edge Ⅱ band (B6), purple band (B7) and yellow band (B8), accounted for 47% (Qianjiang) and 33% (Zaoyang) of all spectral bands for crop type identification. 【Conclusion】Integrating multi-source GF images by taking advantages of their spectral, spatial and temporal features could not only alleviate the "mixed pixel" problem caused by the fragmented agricultural landscape, but also reduce the uncertainty of crop type identification in cloudy and rainy areas, providing great potential for accurate crop mapping in South China.

Response and Function of the Transcription Factor CncC in Cnaphalocrocis medinalis Infected with Baculovirus CnmeGV

ZHANG Nan, HAN GuangJie, LIU Qin, LI ChuanMing, QI JianHang, LU YuRong, XIA Yang, XU Jian

Scientia Agricultura Sinica. 2023, 56(13): 2491-2503. doi:10.3864/j.issn.0578-1752.2023.13.005

Abstract ( 251 )

HTML ( 15 )

PDF (4947KB) ( 1356 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】The objective of this study is to research the role of transcription factor CncC (Cap ‘n’ Collar Isoform C) of Cnaphalocrocis medinalis and its regulation of antioxidant enzyme genes in the infection of Cnaphalocrocis medinalis granulovirus (CnmeGV), and to further enrich the study of immune regulation mechanism of insects against baculovirus.【Method】The full-length cDNA sequence of CncC in C. medinalis (CmCncC) was cloned by RT-PCR, and its protein structure was analyzed. Third instar larvae of C. medinalis were fed with 10⁶ OB/mL concentration of CnmeGV or a mixture of the same concentration of CnmeGV and 1 mmol·L^-1 CncC inhibitor ML385. Samples were taken 6-48 h after infection to analyze the effect of ML385 on the change of malondialdehyde (MDA) content induced by CnmeGV, and viral DNA replication levels, the expression levels of CmCncC, glutathione peroxidase-3 (GPx-3), manganese superoxide dismutase (Mn-SOD), and thioredoxin peroxidase (TPx) were analyzed by RT-qPCR. The number of larval deaths was counted every 24 hours, and the Kaplan-Meier survival analysis of the larvae within 10 d was conducted. Infected larvae were fed with 1 mmol·L^-1 ML385 or a mixture of 1 mmol·L^-1 ML385 and 200 μg·mL^-1 antioxidant N-acetyl-L-cysteine (NAC), and viral DNA replication levels at different times were analyzed using RT-qPCR.【Result】The full length cDNA of CmCncC was 3 404 bp, including a 321 bp 5′-UTR, an 847 bp 3′-UTR, and a 2 211 bp ORF that encoded a protein of 736 amino acids. The predicted molecular weight of the protein was 75.8 kDa. The MDA content in C. medinalis significantly increased within the first 12 h of CnmeGV infection and returned to normal levels at 24 h, but was lower than the control group at 48 h. The expression of CmCncC was significantly up-regulated at 12, 24, and 48 h after viral infection, by 1.56, 2.16, and 2.63 folds of the control group, respectively. NAC treatment significantly reduced the fold increase of CmCncC expression induced by CnmeGV, to 48.12%, 59.83%, and 56.32% of the control group, respectively. Treatment with the ML385 caused an increase in viral gene copy number to 1.79 and 1.76 folds of the control group at 12 and 24 h, respectively, and significantly increased the mortality rate of C. medinalis infected with CnmeGV 10 d after treatment, from 73.33% to 94.14%. NAC treatment partially alleviated the up-regulation of viral gene copy number caused by CncC inhibition. CnmeGV infection led to a 3.68-fold increase in GPx-3 expression level at 48 h after infection, and 1.73-, 2.62-, and 2.77-folds increase in Mn-SOD expression level at 12, 24, and 48 h after infection, respectively. The expression level of TPx increased by 1.76 and 2.10 folds at 12 and 24 h after infection, respectively, but returned to the control group level at 48 h, and treatment with NAC or the CncC inhibitor significantly weakened the responses of GPx-3, Mn-SOD, and TPx to CnmeGV infection.【Conclusion】CmCncC mediates the CnmeGV infection-induced up-regulation of GPx-3, Mn-SOD and TPx mRNA levels and reduces oxidative stress caused by CnmeGV infection, thereby limiting virus replication, and reducing oxidative damage.

Identification, Cloning and Expression Profiles of Gustatory Receptor Genes in Chilo suppressalis

HUANG YuXuan, SHEN Chen, JU JiaFei, YANG Lei, LUO GuangHua, FANG JiChao

Scientia Agricultura Sinica. 2023, 56(13): 2504-2517. doi:10.3864/j.issn.0578-1752.2023.13.006

Abstract ( 260 )

HTML ( 18 )

PDF (11314KB) ( 111 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】The rice striped stem borer, Chilo suppressalis, is one of the important rice pests in China. The gustatory receptors (GRs) play important roles in insect feeding, oviposition, and so on.【Objective】Based on transcriptomic and genomic data, the gustatory receptor gene sequences of C. suppressalis were identified and cloned in this study. Then, their expression characteristics at different developmental stages and in different tissues of adults were clarified. These results will lay a foundation for further study on the function of gustatory receptor genes in C. suppressalis.【Method】Combined with the transcriptome data of C. suppressalis and the GR sequences of other insects, the GR genes in C. suppressalis were identified by multiple sequence alignment. The complete open reading frame (ORF) sequences of the GR genes in C. suppressalis were cloned by RT-PCR, and the molecular biological characteristics and domains of the amino acid sequences encoded by the GR genes in C. suppressalis were analyzed by bioinformatics analysis tools. The phylogenetic tree of GR gene protein sequences of C. suppressalis and other insect GR genes was constructed based on the maximum likelihood method. The expression patterns of GR genes at different developmental stages (1-6 instar larvae, female and male adults) and in different adult tissues (antennae, head, wing, abdomen and leg) of C. suppressalis were determined by real-time quantitative PCR (RT-qPCR).【Result】Five gustatory receptor genes were identified and named as CsupGR1-5. The complete ORFs of these GR genes were between 1 122 and 1 428 bp in length, encoding 373-475 amino acids. Among them, CsupGR2, CsupGR4, CsupGR5 had seven transmembrane domains, CsupGR1, CsupGR3 had eight transmembrane domains. Phylogenetic analysis showed that CsupGR1 and CsupGR2 were closely related to DmelGR63a in Drosophila melanogaster, PxylGR7 and PxylGR8 in Plutella xylostella, belonging to the CO₂ receptor family. CsupGR3 was closely related to DmelGR43a in D. melanogaster, BmorGR9 and BmorGR10 in Bombyx mori, belonging to the fructose/inositol receptor family. CsupGR4 and CsupGR5 were closely related to DmelGR64 in D. melanogaster and BmorGR5-8 in B. mori, belonging to the sugar receptor family. The expression profile analysis showed that the five GR genes were all expressed at different developmental stages in C. suppressalis. Among them, CsupGR1 and CsupGR4 were highly expressed in male adults, CsupGR2 had the highest expression level in the 1st instar larvae and male adults, CsupGR3 was highly expressed in adults, and CsupGR5 had the highest expression level in the 4th instar larvae. Tissue expression profile analysis showed that these five GR genes were expressed in all tissues of male and female adults. CsupGR1 and CsupGR5 were highly expressed in the head of adults, and CsupGR2-4 were highly expressed in the antennae of adults.【Conclusion】The five GR genes of C. suppressalis identified in this study have the typical characteristics of insect gustatory receptors and are highly expressed in the antennae or heads of adults. It is speculated that these five genes may be related to the recognition and adaptation of C. suppressalis to host plants.

Changes in Topsoil Organic Matter Content and Composition of a Gleyic Stagnic Anthrosol Amended with Maize Residue in Different Forms from the Tai Lake Plain, China

CHEN ShuoTong, XIA Xin, DING YuanJun, FENG Xiao, LIU XiaoYu, Marios Drosos, LI LianQing, PAN GenXing

Scientia Agricultura Sinica. 2023, 56(13): 2518-2529. doi:10.3864/j.issn.0578-1752.2023.13.007

Abstract ( 292 )

HTML ( 31 )

PDF (1130KB) ( 5146 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】This study was to explore the changes in topsoil organic matter content and composition of a rice paddy with crop residue return in different forms, in order to provide the useful information for crop residue utilization and paddy soil carbon sequestration.【Method】 In June, 2015, compared with no straw amendment (CK), untreated (CS), manured (CM) and pyrolyzed (CB) maize residue were returned at 10 t C·hm^-2 to a paddy topsoil in Tai Lake Plain, China. Topsoil (0-15 cm) samples were collected at rice harvest in November respectively of 2015, 2017 and 2019, and the changes in soil organic carbon (SOC) content and molecular composition were analyzed using ¹³C isotope and biomarker assays. 【Result】Compared with CK, topsoil OC was significantly increased by 8%-36% in 2015 and 2017 with all the residue amendment treatments, but increased by 24% only under CB in 2019, with the SOC increases mainly from the input biochar. The abundance of lignin phenols in the topsoil under CS and CM peaked after 2-year amendment, and increased by 115% and 66% relative to CK, respectively. After 4 years, molecular abundance of plant-derived lipids increased significantly under all the amendments and the abundance ratio of plant- to microbe-derived lipids (PL/ML) and Shannon diversity of biomarkers (H’) were significantly enhanced. 【Conclusion】Compared with untreated and manured residue, pyrolyzed residue returning enhanced SOC sequestration and the molecular diversity of organic matter, through the retention of plant-derived components in the paddy soil.

Origin, Present Situation and Development Trend of Green Fertilizer

WU ZhiJie, ZHANG LiLi, SHI YuanLiang, WEI ZhanBo, LI DongPo, GONG Ping, LI Jie, ZHANG Lei, WANG LingLi, WU KaiKuo, XUE Yan, SONG YuChao, CUI Lei

Scientia Agricultura Sinica. 2023, 56(13): 2530-2546. doi:10.3864/j.issn.0578-1752.2023.13.008

Abstract ( 445 )

HTML ( 25 )

PDF (558KB) ( 1217 )

Save

References | Related Articles | Metrics

The new development concept of "innovation, coordination, green, openness and sharing" is the centralized reflection of China's development concept, direction and focus in the 14th Five-Year Plan and even in the longer term. The green development of agriculture is an important part of the implementation of the new development concept, which plays an important role in forming a harmonious coexistence between human beings and nature, ensuring food safety and creating a livable environment. Fertilizer, as the largest exogenous input and production material, plays a significant role and has a profound impact on the quantity and quality of agricultural products and the agricultural ecological environment, and plays a pivotal role in the green development of agriculture. However, the improper application of traditional fertilizers has caused the degradation of soil quality, environmental pollution and degradation of agricultural products, which urgently requires the transformation and upgrading of fertilizer products, and the development of green inputs has come into being. Green fertilizer concept and definition is: the application of quality and safety of raw materials, low-carbon environmental protection process, the use of physical - chemical - biological modification and efficiency technology production and use, with efficient and balanced nutrients, emission reduction and environmental protection, fertilization of fertile soil function of a class of fertilizers. The types of green fertilizers are mainly divided into the following five categories: nutrient-efficient green fertilizers, carbon-fixing and fertilizing green fertilizers, efficiency-enhancing and nutrient conversion efficiency green fertilizers, nutrient-balanced green fertilizers, and value-added green fertilizers. How to realize the green transformation of chemical fertilizers and the efficient and low-cost utilization of organic fertilizer resources? there are four main suggestions: (1) Rely on market mechanisms, strengthen top-level design, and build a new system of green fertilizer manufacturing; (2) Take the integrated management of nutrient resources as the core, and promote the balanced and coordinated development of organic-mass-element-micro-element fertilizers; (3) Fully play the role of scientific research platforms, and greatly develop intelligent green fertilizer products; (4) Integrate modern sensing and information technology to thoroughly promote green and efficient precision fertilization. This paper provided an overview of the background, concept, types and characteristics of green fertilizers proposed, and discussed the future development direction, in order to provide insight into the green transformation of China's fertilizer industry and the green development of agriculture in the future.

Spatial-Temporal Pattern, Influencing Factors and Spatial Spillover Effect of Rural Energy Carbon Emissions in China

TIAN Yun, YIN Minhao, ZHANG Huijie

Scientia Agricultura Sinica. 2023, 56(13): 2547-2562. doi:10.3864/j.issn.0578-1752.2023.13.009

Abstract ( 293 )

HTML ( 10 )

PDF (666KB) ( 4399 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】In the context of the “dual carbon” strategy, clarifying the current characteristics, spatial-temporal pattern and influencing factors of rural energy carbon emissions can provide important support for effectively promoting rural low-carbon development. 【Method】Carbon emission factor method is used to measure rural energy carbon emissions in China effectively, and analyze its temporal and spatial characteristics. Then, the autocorrelation model is used to explore its spatial correlation pattern. Finally, the introduction of STIRPAT extended model is used to analyze the main factors affecting its intensity changes and the spatial spillover effect. 【Result】China's total rural energy carbon emissions are in a continuous upward trend, with an increase of 77.55% in 2019 compared with 2005, which is mainly attributed to the increase in rural residents' domestic energy consumption. Rural energy carbon emission intensity has increased slightly during the investigation period. Although there are some inter-annual fluctuations, the overall fluctuations are small. In 2019, there were significant inter-provincial differences in rural energy carbon emissions, with Hebei leading the way and Ningxia at the bottom. Compared with 2005, only 5 provinces were in a downward trend. In 2019, Beijing ranked first in rural energy carbon emission intensity, while Hainan ranked last, with the latter even less than one tenth of the former. Since 2008, China's rural energy carbon emissions have shown obvious and stable spatial dependence, as well as local spatial clustering, with a small and relatively stable number of high-high concentration provinces and a lager and growing number of low-low concentration provinces. Among the social factors, the increase of rural affluence can lead to an increase of rural energy carbon emission intensity, while agricultural technology progress and rural labor force structure variables have a dampening effect, with only rural affluence showing a spatial spillover effect in a negative direction. Among the economic factors, the increase in the rural financial agglomeration and the improvement of agricultural development level both lead to the increase of rural energy carbon emission intensity, and both have spatial spillover effects, with the former positive and the latter negative. While agricultural financial investment does not have a direct effect but shows a negative spatial spillover effect. Among the industry-level factors, the increase of agricultural industry agglomeration leads to the increase of rural energy carbon emission intensity, but at the same time, it also presents a negative spatial spillover effect. 【Conclusion】The total amount and intensity of rural energy carbon emissions in China are on the rise, with significant inter-provincial differences. China's rural energy carbon emissions show obvious spatial dependence and spatial heterogeneity. Rural energy carbon emissions are affected by a combination of social, economic and industrial factors.

Response Characteristics of Rhizosphere and Root Endosphere Bacteria and Rhizosphere Enzyme Activities to Soil Compaction Stress in Young Apple Tree

LI JiaQi, XUN Mi, SHI JunYuan, SONG JianFei, SHI YuJia, ZHANG WeiWei, YANG HongQiang

Scientia Agricultura Sinica. 2023, 56(13): 2563-2573. doi:10.3864/j.issn.0578-1752.2023.13.010

Abstract ( 296 )

HTML ( 23 )

PDF (756KB) ( 2006 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】The aim of this study was to identify the main factors causing bacterial abundance changed in the apple roots microenvironment under compaction stress, so as to provide a reference for further revealing the biological characteristics of apple rhizosphere and orchard soil management under soil stress.【Method】The experimental materials were potted young apple (Malus domestica Borkh.cv. Red Fuji) tree with the rootstocks of Malus hupehensis Rehd. and Malus robusta Rehd., respectively. After pressing the potted soil to form compaction stress, the rhizosphere mineral nutrient content, soil enzyme activity and the bacterial abundance of rhizosphere and root endosphere were measured.【Result】In both M. huphensis and M. robusta, the soil compaction stress significantly increased rhizosphere available phosphorus content, available potassium content and catalase activity, however, significantly decreased rhizosphere alkaline-hydrolyzed nitrogen content, sucrase activity, urease activity, acid phosphatase activity and root endosphere bacterial abundance. Furthermore, the soil compaction stress also changed the composition and structure of rhizosphere microorganisms. Under soil compaction stress, the amount and abundance of rhizosphere bacterial and the activity of fluorescein diacetate (FDA) hydrolase changed with different rootstocks; however, which were significantly decreased in Red Fuji/M. hupehensis, with the reduction rates were 46.88%, 50.50% and 29.13%, respectively, and significantly increased in Red Fuji/M. robusta, with the increases were 51.41%, 20.22% and 13.76%, respectively. In compacted soil, rhizosphere alkali- hydrolyzed nitrogen content, hydrolase (sucrase, urease, acid phosphatase) activities and the bacterial abundance of root endosphere in Red Fuji/M. hupehensis decreased more than that in Red Fuji/M. robusta. Compared with Red Fuji/M. hupehensis, Red Fuji/M. robusta had stronger FDA hydrolase activity and recruited more rhizosphere bacteria. Redundancy analysis showed that rhizosphere available potassium, alkali-hydrolyzed nitrogen, and FDA hydrolase activities had the highest explanatory rate for variation of bacterial abundance in rhizosphere and root endosphere of apple under soil compaction stress.【Conclusion】The soil compaction stress significantly affected rhizosphere microbial composition, then changed soil enzyme activity and mineral nutrient content in apple rhizosphere. Rhizosphere bacteria and FDA hydrolase activity were different with rootstock, and highly inhibited by soil compaction stress in Red Fuji/M. hupehensis. Under soil compaction stress, the content of rhizosphere available potassium and alkali-hydrolyzed nitrogen, and the activity of rhizosphere FDA hydrolase were more closely related to the abundance of rhizosphere and root endosphere bacteria.

The Function of PmABCG9 Transporter Related to the Volatilization of Benzyl Alcohol in Prunus mume

HAO RuiJie, QIU Chen, GENG XiaoYun, JIA HaoTian, ZHANG YaJing, CHANG Jun, FENG XinXin

Scientia Agricultura Sinica. 2023, 56(13): 2574-2585. doi:10.3864/j.issn.0578-1752.2023.13.011

Abstract ( 220 )

HTML ( 11 )

PDF (2638KB) ( 1620 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】The aim of this study was to improve the volatilization mechanism of floral scent by exploring the gene related to the transmembrane transport of important aromatic components in P. mume. 【Method】The P. mume Caizhiwufen was applied as material plant. Based on the analysis of volatile and endogenous contents of benzyl alcohol at different blooming stages, the ABC transporters (ATP-binding cassette transporter) involved in the transmembrane transport of benzyl alcohol were identified by weighted gene co-expression network analysis (WGCNA), phylogenetic analysis, and gene expression profiles. Finally, the functions of PmABCG9 were validated by subcellular localization, transgenic technology and incubation assay with substrates. 【Result】The flowering process of P. mume was divided into seven blooming stages, and the total relative content of benzaldehyde, benzyl alcohol and benzyl acetate reached more than 80% at the initial blooming stage, indicating that they were the key aromatic components of Caizhiwufen. The quantitative analysis showed that the endogenous content of benzaldehyde was the highest among the above three, while its volatile content was only 13.17 ng·g^-1·h^-1 at the highest level. The endogenous and volatile content of benzyl alcohol reached the highest at wither stage, up to 82.28 ng·g^-1·h^-1 of the volatile content. The highest volatile content of benzyl acetate was at full blooming stage and up to 280.21 ng·g^-1·h^-1. WGCNA between the transcriptome data of different blooming stages and the volatile content of aromatic components showed that the turquoise module highly correlated with the volatile content of benzyl alcohol, importantly. 11 ABCG subfamily genes were identified. Moreover, based on the expression patterns of PmABCG9 in different flower organs and blooming stages of P. mume, it was inferred that PmABCG9 was related to the transmembrane transport of benzyl alcohol in P. mume. Therefore, PmABCG9 gene was cloned, and the typical NBD-TMD domain of PmABCG9 gene was confirmed. Subcellular localization showed that PmABCG9 was localized on the cell membrane. The leaves of transgenic PmABCG9 Nicotiana benthamiana and wild-type plants were incubated with benzyl alcohol solution, and the volatile content of benzyl alcohol from each line were analyzed by GC-MS. It was noted that the volatile content of benzyl alcohol from transgenic tobaccos was significantly higher than that of wild-type ones, demonstrating that PmABCG9 had the function of transporting benzyl alcohol. 【Conclusion】 Benzaldehyde, benzyl alcohol and benzyl acetate were the key aromatic components at florescence of P. mume Caizhiwufen. PmABCG9 belonged to the semi-molecular transporters type from ABCG subfamily, PmABCG9 was closely related to volatile content benzyl alcohol, furthermore, it could effectively transport benzyl alcohol into the air through cell membrane.

Aroma Characteristics of Foxtail Millet Varieties from Different Ecological Regions by Analysis of SDE-GC-MS Combined with OPLS-DA

LI ShaoHui, ZHAO Wei, LIU SongYan, LI PengLiang, ZHANG AiXia, LIU JingKe

Scientia Agricultura Sinica. 2023, 56(13): 2586-2596. doi:10.3864/j.issn.0578-1752.2023.13.012

Abstract ( 237 )

HTML ( 17 )

PDF (1889KB) ( 4184 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】The foxtail millet production areas in China are divided into four regions: the Northeast China region, the North China region, the Inner Mongolia plateau region, and the Northwest China region. The regional trials aimed to screen germplasm resources with good genetic traits. However, good growth genetic traits and foxtail millet grain appearance phenotypes do not necessarily have good culinary quality and aroma characteristics, especially the aroma characteristics largely affect its production and downstream industries. Simultaneous distillation extraction (SDE) is a pretreatment method that simulates the cooking process of porridge and is suitable for the aroma analysis of foxtail millet.【Objective】The aim of this study was to clarify the aroma characteristics of cereal germplasm resources in different ecological regions, so as to promote sensory-oriented breeding-processing industrial practices.【Method】Simultaneous distillation extraction-gas chromatography-mass spectrometry (SDE-GC-MS) combined with odor activity value (OAV) method was used to analyze the differences in aroma components of foxtail millet in different regions of China.【Result】 A total of 81 volatile substances were detected in 12 foxtail millet varieties from four ecological regions, 25 aldehydes, 6 alcohols, 4 phenols, 11 ketones, 11 hydrocarbons, 13 benzene-containing derivatives, 4 acids, and 7 others. The comparison of the results showed that the volatile substance subclasses were similar in different regions, but the contents of the components were different. Thirty-seven volatile components with literature-accessible odor characterization were labeled, and 23 contributing aroma compounds with OAV > 1 were identified in the 12 foxtail millet varieties. The effective discrimination model of the cereal regional test was established by orthogonal partial least squares discrimination analysis (OPLS-DA). Then, the 12 foxtail millet varieties were classified into three categories, and 18 compounds with VIP>1 were screened out: hexanal, heptanal, (Z)-2-heptenal, benzaldehyde, (E,E)-2, 4-decadienal, 2,4-decadienal, nonane, tetradecanoic acid, (Z,Z)-9, 12-octadecadienoic acid, pentadecanoic acid, n-hexadecanoic acid, 2-methoxy-4-vinylphenol, 2, 4-bis(1, 1-dimethylethyl)-phenol, 2, 5-bis(1, 1-dimethylethyl)-phenol, 1-heptanol, nerolidol, 2-pentyl-furan, and hexadecanoic acid methyl ester, which could be used to distinguish the differences between different samples.【Conclusion】 SDE-GC-MS combined with OAV identification analyzed the flavor components and characteristics of key aroma compounds of foxtail millet from different ecological regions, and the OPLS-DA model screened 18 VIP compounds that distinguished the flavor differences of foxtail millet from different samples and ecological regions. The results of the study provided data references for understanding the differences in flavor characteristics of foxtail millet grown in different regions of China, and for a basis of flavor-oriented foxtail millet variety selection, breeding, and processing.

Effects of Smad7-Mediated TGF-β Signaling Pathway on Proliferation of Sheep Granulosa Cells

GUO ZeYuan, DU ZhangSheng, ZHANG YaQi, CHEN ChunLu, MA XiaoYan, CHENG Ying, WANG Kai, LÜ LiHua

Scientia Agricultura Sinica. 2023, 56(13): 2597-2608. doi:10.3864/j.issn.0578-1752.2023.13.013

Abstract ( 225 )

HTML ( 18 )

PDF (1695KB) ( 94 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】Follicle development is a complex regulatory process, in which the proliferation and differentiation of ovine follicular granulosa cells (Granulosa Cells, GCs) will directly affect the development of follicles. TGF-β signaling pathway plays an important role in sheep ovarian development and follicle growth, and Smad7 also plays an important role as a key inhibitor of TGF-β signaling pathway. 【Objective】In this study, the effect of Smad7-mediated TGF-β signaling pathway on the proliferation and apoptosis of ovine follicular GCs was explored to provide a basis for further research on the regulatory role of Smad7 in the process of follicular GCs proliferation and apoptosis. 【Method】20 non-pregnant Jinzhong Duhu hybrid ewes aged 4-6 months were selected. After slaughtering, bilateral ovaries were collected, and GCs were isolated and cultured in vitro. And then, FSHR cell and expression localization of Smad7 cells was identified by immunofluorescence, the cell proliferation was measured by CCK8 method, and the growth curve was drawn. After the cells were passaged, different concentrations of Smad7 agonist Asiaticoside AS (0, 100, 200, 400, 600 ng·mL^-1) were added exogenously, and the optimal concentration of AS was selected to treat the second generation GCs. The expression levels of key genes as well as apoptosis and cycle-related genes in the TGF-β signaling pathway were detected using qRT-PCR and Western blotting. Three siSmad7s were synthesized and transfected into follicular GCs, and the one with the best interference effect was selected. The expression levels of key genes in the TGF-β signaling pathway, apoptosis and cycle-related genes were detected by qRT-PCR and Western blotting. 【Result】Smad7 was expressed in ovine follicular GCs; 200 ng·mL^-1 AS could significantly up-regulate the expression of Smad7 in GCs (P<0.01), siSmad7-1 could effectively transfected ovine follicle GCs (P<0.01); Up-regulation of Smad7 could significantly increase the expressions of Smad4, TFDP-1 and EP300 in the TGF-β signaling pathway (P<0.05), extremely significantly increase the expression of SP1 in the TGF-β signaling pathway (P<0.01), and significantly increase the expression of apoptosis-related gene Caspase8 (P<0.05), extremely significantly increased the expressions of apoptosis-related genes Caspase3 and Bim (P<0.01), significantly increased the expressions of cell cycle-related genes P21 and P27 (P<0.05), extremely significantly increased the expression of cell cycle-related gene CCND2 (P<0.01), while the expression of CCND1 was significantly decreased (P<0.05); Smad7 siRNA significantly decreased the expressions of Smad4, TFDP-1 and EP300 in the TGF-β signaling pathway (P<0.05), extremely significantly decreased the expression of SP1 in the TGF-β signaling pathway (P<0.01), and significantly decreased the apoptosis-related gene Caspase8 (P<0.05), extremely significantly decreased the expressions of apoptosis-related genes Caspase3 and Bim (P<0.01), extremely significantly decreased the expressions of cell cycle-related genes P21, P27 and CCND2 (P<0.01), extremely significantly increased the expression of CCND1 (P<0.01); CCK8 analysis demonstrated into that when Smad7 was up-regulated, the proliferation rate of GCs was significantly down-regulated at 24 h and 48 h (P<0.01). Smad7 siRNA significantly increased the proliferation rate of GCs at 24 h and 72 h (P<0.05), which also extremely significantly increased the proliferation rate of GCs (P<0.01).【Conclusion】In summary, it was suggested that Smad7 mediated TGF-β signaling pathway to inhibit the proliferation of ovine follicular GCs and to promote cell apoptosis.

Effects of Different Caging Regimes on Egg Yolk Flavor of Laying Hens

GAO LiBing, CHEN Gang, WANG Jing, QI GuangHai, ZHANG HaiJun, QIU Kai, WU ShuGeng

Scientia Agricultura Sinica. 2023, 56(13): 2609-2619. doi:10.3864/j.issn.0578-1752.2023.13.014

Abstract ( 325 )

HTML ( 26 )

PDF (2168KB) ( 580 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】In this study, sensory evaluation, electronic nose detection, electronic tongue detection and texture analyzer detection were used to determine the differences in egg yolk flavor between traditional caging regime and furnished caging regime, to provide basic data on the egg yolk flavor. 【Method】The eggs were produced by Jing Tint 6 laying hens that were 55 weeks old and healthy in traditional caging regime and furnished caging regime that was used as the test objects. The aroma, flavor and texture of egg yolk were detected by sensory evaluation, electronic nose detection and electronic tongue detection, and texture analyzer. Linear discriminant analysis (LDA) analysis, support vector machine (SVM) analysis, K-nearest neighbor method (KNN) analysis and decision tree analysis were used to distinguish the yolk flavor of the two caging regimes to explore the influence of different caging regimes on the flavor of egg yolk.【Result】The yolk color was significantly increased in traditional caging regime compared with furnished caging regime (P<0.05). The milky flavor scores of egg yolk in furnished caging regime were significantly higher than that in traditional caging regime (P<0.05), and the seaweed flavor scores and stickiness scores of egg yolk in traditional caging regime were higher than those in furnished caging regime (P<0.05). The results of correlation analysis showed that the overall preference score of the yolk was significantly correlated with the acceptance of flavor scores and texture scores (P<0.05). Egg flavor was significantly negatively correlated with fishy flavor and sweet flavor (P<0.05), and the fishy flavor was significantly positively correlated with sweet flavor (P<0.05). There was a significant positive correlation between egg yolk lumpy and egg yolk adhesive dentition (P<0.05). The responses of W2W, W2S, W1W and W1S of electronic nose sensors in furnished caging regime were significantly higher than those in traditional caging regime (P<0.05), and the responses of SRS, STS and UMS of egg yolk electronic tongue sensors in furnished caging regime were significantly lower than those in traditional caging regime (P<0.05). The hardness and chewiness of egg yolk in furnished caging regime were significantly higher than that in traditional caging regime (P<0.05). The KNN method could discriminate the differences in egg yolk aroma in the different caging regimes based on the responses of the electronic nose, and the accuracy was 94.5%. The SVM, KNN method and decision tree could distinguish the differences in egg yolk flavor in the different caging regime based on the responses of the electronic tongue, with 100% accuracy rate. 【Conclusion】In conclusion, the milky flavor of egg yolk was increased in furnished caging regime, and seaweed flavor and stickiness were reduced. The instrument detected the increased responses of the electronic nose sulfide sensor and the decreased responses of the electronic tongue umami and salty sensors in furnished caging regime. According to the responses of electronic nose and electronic tongue, the differences in egg yolk flavor in two different caging regimes could be effectively distinguished by KNN analysis, SVM analysis and decision tree analysis.

Establishment of a Canine Experimental Infection Model with a H3N2 Subtype Canine Influenza Virus

HUANG Cheng, YANG LongFeng, SUN Peng, CHENG HuiMin, YANG ZhiYuan, LIN Jian, ZHU HongWei, LIU LiXin, SUN HouMin, LI JiaFeng, ZHAO JiCheng, DUAN HuiJuan, PAN Jie, LIU YueHuan

Scientia Agricultura Sinica. 2023, 56(13): 2620-2628. doi:10.3864/j.issn.0578-1752.2023.13.015

Abstract ( 228 )

HTML ( 10 )

PDF (5796KB) ( 416 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 In this research, an experimental animal infection model of canine influenza virus (CIV, H3N2 subtype) was established to better understand the pathogenesis of canine influenza, so as to lay the foundation for vaccine efficacy evaluation. 【Method】 26 beagles aged 6-13 months with negative CIV Haemagglutination Inhibition (HI) antibody (HI<1﹕10) were selected, three beagles of which were challenged by 1mL nasal spray of PBS, and 23 beagles of which were challenged by 1mL nasal spray of H3N2 CIV (A/canine/China/Huabei-170607/2017(H3N2), HB strain for short) with 5 groups (10, 10³, 10⁵, 10⁶, and 10⁷ 50% EID₅₀) as 3, 5, 5, 5, and 5 beagles each group, respectively_. Clinical symptoms, lung lesions, histopathological changes of lung, calculating the proportion of consolidation mass, HI antibody titer and virus shedding were examined at 14 days after virus challenge together with three control beagles. 【Result】 3 beagles inoculated with a dose of 10 EID₅₀ H3N2 CIV did not show any clinical symptoms, gross lesions in lungs and histopathological changes, the consolidation rate was 0%, and the virus shedding was not detected. The geometric mean titer (GMT) of HI antibodies was 1﹕15.9. However, 4/5 of beagles inoculated with a dose of 10³ EID₅₀ H3N2 CIV showed the clinical symptoms and virus shedding, such as puffing, runny nose and cough. 2/5 of beagles showed light lung consolidation, whose rate was 1.4%. The GMT of HI antibodies was 1:320. All beagles (5/5) infected with a dose of 10⁵ EID₅₀ H3N2 CIV showed clinical symptoms at day 5 after challenge, such as runny nose and cough, virus shedding, lung consolidation, and widened alveolar septum, and the consolidation rate was 4.2%. The GMT of HI antibodies was 1﹕2 940.7. 5/5 of beagles infected with a dose of 10⁶ EID₅₀ all showed severe clinical symptoms at day 4 after challenge, such as cough and elevated body temperature, virus shedding, obvious pathological features in the lungs, and the GMT of HI antibodies was 1﹕2 228.7. The clinical symptoms appeared earlier 1 day than that in 10⁵ EID₅₀dose infection group, and the degree of lung consolidation increased. The lung consolidation ratio was 17.9%. 5/5 of beagles infected with doses of 10⁷ EID₅₀ all showed severe clinical symptoms at day 3 after challenge which appeared earlier 1 day than that in 10⁶ EID₅₀dose infection group, virus shedding and widened alveolar septum in the lungs, the GMT of HI antibodies was 1﹕2 940.7, and the consolidation rate of lung was 29.0%. The control beagles did not show any clinical symptoms, gross lesions and histopathological changes in lungs, the virus shedding was not detected, and GMT of HI antibodies was <1﹕10. 【Conclusion】 The dose of 10⁶ EID⁵⁰ was the minimum virus inoculation dose that could cause obvious pathogenesis in beagles. An experimental animal infection model of CIV subtype H3N2 in beagles was established.

Table of Content