Loading...

Table of Content

    16 February 2023, Volume 56 Issue 4
    CONTENTS
    CONTENTS
    Scientia Agricultura Sinica. 2023, 56(4):  0. 
    Abstract ( 133 )   PDF (318KB) ( 121 )   Save
    Related Articles | Metrics
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Construction of A High-Density Genetic Map and QTL Mapping for Yield Related Traits in Upland Cotton
    JIA XiaoYun, WANG ShiJie, ZHU JiJie, ZHAO HongXia, LI Miao, WANG GuoYin
    Scientia Agricultura Sinica. 2023, 56(4):  587-598.  doi:10.3864/j.issn.0578-1752.2023.04.001
    Abstract ( 350 )   HTML ( 67 )   PDF (1855KB) ( 215 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】By constructing a high-density SNP genetic map, QTL mapping for cotton yield related traits of multiple populations was carried out to obtain stable and accurate QTL. It will provide references for the excavation of yield trait regulatory genes and the development of effective molecular markers. 【Method】Jifeng 1271 with high and stable yield and Jifeng173 with super fiber quality were used to construct an F2 population composing of 200 plants. A high-density SNP genetic map was constructed by GBS (Genotyping by sequencing), and QTL mapping was carried out for lint percentage, seed index and boll weight of F2, F2:3 and F2:4 populations. Genes in major and stable QTL were annotated, and the expression patterns in different tissues were analyzed for candidate genes selection. 【Result】A total of 383.07 Gb data was obtained by GBS, including 26.93 Gb for the maternal cultivar Jifeng 1271, 27.30 Gb for the paternal inbred line Jifeng 173 and 328.84 Gb for the 200 F2 plants, and Q30 scores were 90.55%, 89.95% and 95.77%, respectively. And 1 305 642 SNP markers were developed in the F2 population, including 410 726 aa×bb type SNP that were used for genetic map construction. A high-density genetic map containing 16 088 SNP and spanning 4 282.81 cM was constructed, and the average genetic distance between adjacent SNP was 0.27 cM. Collinearity analysis proved high quality of the genetic map. A total of 108 yield related QTL were mapped, including 34 lint percentage QTL, 36 seed index QTL and 38 boll weight QTL. 30 QTL overlapped with or were close to the published QTL, and the other 78 QTL were new. 10 major QTL and 16 stable QTL were found, and 5 major QTL could be mapped in 2 or 3 populations. qLP-A13-4 could be mapped in 3 populations, and the R2 reached 13.78%. qLP-A13-6 could be mapped in 2 populations, and the R2 reached 10.01%. qLP-D10-2 could be mapped in 2 populations, and the R2 reached 10.92%. qSI-D10-1 could be mapped in 2 populations and the R2 reached 12.31%. qBW-D5-3 could be mapped in 2 populations and the R2 reached 15.54%. A total of 3 415 genes were annotated in these major and stable QTL. By KEGG and GO analysis, the annotated genes are mainly involved in plant hormone signal transduction, TCA cycle, biosynthesis of secondary metabolites and amino acids, carbon fixation in photosynthetic organisms. Using the transcriptome data of TM-1 and NDM8, 8 genes were highly expressed in fiber, ovule or seed, which may be important candidate genes for boll weight and yield by regulating lint percentage or seed index. 【Conclusion】An intra-specific high-density genetic map was constructed for upland cotton. 108 yield related QTL were mapped, 5 major QTL could be mapped in at least 2 populations, and 8 candidate genes with high expression level in fiber, ovule or seed were identified.

    Correlation Between Stomatal Characteristics and Cold Resistance of Brassica napus L.
    FAN JunQiang, WU JunYan, LIU LiJun, MA Li, YANG Gang, PU YuanYuan, LI XueCai, SUN WanCang
    Scientia Agricultura Sinica. 2023, 56(4):  599-618.  doi:10.3864/j.issn.0578-1752.2023.04.002
    Abstract ( 330 )   HTML ( 42 )   PDF (2779KB) ( 203 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The characteristics of the stomatal movement of winter Brassica napus with different cold resistance in northern China in a low-temperature environment were analyzed, and the relationship between cold resistance and stomatal movement was clarified, which provided a basis for analyzing the cold resistance mechanism of winter Brassica napus and cultivating strong cold resistance varieties. 【Method】 The physiological indexes of 14 winter Brassica napus varieties under semi-lethal temperature and low temperature were determined to judge the difference in cold resistance. At the same time, 12 stomatal indexes of the lower epidermis of the leaves of the plants treated at 24℃ for 12 h, 0℃ for 1 h, and 0℃ for 12 h were determined. Stomatal evaluation indexes significantly related to cold resistance evaluation indexes were screened by correlation analysis. 【Result】 (1) According to the results of semi-lethal temperature determination, the cold resistance of the tested varieties was identified as gau-1 (-8.06)>gau-24 (-7.83)>gau-30 (-7.58)>gau-39 (-7.44)>ts309 (-7.28)>ts312 (-7.08)>nts158 (-6.81)>npz269 (-6.62)>Tianyou 14 (-5.98)>16-2444 (-5.4)>17-2251 (-5.13)>Tianyou 2266 (-4.8)>Tianyou 2238 (-4.6)>Tianyou 2288 ( -4.38 ). According to the comprehensive evaluation value of physiological indexes, the results of cold resistance were gau-1 (0.990)>gau-24 (0.876)>gau-30 (0.693)>gau-39 (0.644)>ts309 (0.534)>ts312 ( 0.463)>nts158 (0.439)>npz269 (0.388)>Tianyou 14 (0.352)>16-2444 (0.307)>17-2251 (0.282)>Tianyou 2266 (0.236)>Tianyou 2238 (0.126)>Tianyou 2288 ( 0.000). The cold resistance measured by semi-lethal temperature was consistent with the comprehensive evaluation results of physiological indexes. (2) 12 stomatal movement-related indicators changed significantly after low-temperature treatment. The correlation analysis showed that there was no significant correlation between the 12 stomatal indexes and the semi-lethal temperature at room temperature and 0℃ after 1 h treatment. After 12 h treatment at 0℃, the stomatal pore length, area of stomatal pore, circumference of stomatal pore, stomatal apparatus length, area of stomatal apparatus, Circumference of stomatal apparatus, and stomatal closure rate were significantly correlated with cold resistance. The semi-lethal temperature was significantly correlated with the comprehensive evaluation value (Z) of stomata, and the correlation coefficient was-0.572. 【Conclusion】 Low-temperature treatment can significantly affect the stomatal movement of winter Brassica napus, and the characteristics of stomatal closure tend to be more obvious with the extension of low-temperature treatment time. At the same time, the relative changes of stomata of different temperature-sensitive varieties were different, and the varieties with strong cold resistance had stronger ability to keep stomata open after low-temperature treatment.

    Effects of Cultivation Patterns on Grain Yield, Nitrogen Uptake and Utilization, and Population Quality of Wheat Under Rice-Wheat Rotation
    DING JinFeng, XU DongYi, DING YongGang, ZHU Min, LI ChunYan, ZHU XinKai, GUO WenShan
    Scientia Agricultura Sinica. 2023, 56(4):  619-634.  doi:10.3864/j.issn.0578-1752.2023.04.003
    Abstract ( 366 )   HTML ( 64 )   PDF (665KB) ( 285 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】This study aimed to provide the theoretical and technical support for the synergic cultivation of good-quality, high-yield, and high-efficiency of wheat under the rice-wheat rotation. 【Method】 In 2017-2018 and 2018-2019, the cultivation patterns of tradition (TCP), high yield (HCP), reducing fertilizer (RFCP), and reducing fertilizer and increasing planting density (IDCP) were conducted in Suining (northern Jiangsu) and Hanjiang and Yangzhou (middle area of Jiangsu) to study the differences in grain protein content, grain yield, nitrogen efficiency, and economic benefits. The excepted results could clarify the patterns achieving high yield and high efficiency and the characteristics of their wheat population qualities and nitrogen absorption and transportation, explore the relationship between yield, nitrogen efficiency and agronomic physiological traits, and then reveal the approaches to realize high yield and high-efficiency synergy. 【Result】 The effects of cultivation patterns on wheat grain yield, net economic benefit, and nitrogen efficiency were different depending on the ecological conditions in the various years and sites. The wheat grain protein content under different cultivation patterns was more than 12.5%, but which under HCP and RFCP was 13%-14%. In 2018, IDCP achieved the highest grain yield and economic net benefit with 31.5%-33.5% and 104.4%-239.1% higher than TCP, respectively, followed by HCP and RFCP. In 2019, the grain yield under HCP was the highest, which was 8.1%-13.2% higher than that under TCP, followed by RFCP and IDCP. In addition, IDCP could obtain stable or increased net economic benefits compared with TCP because of less fertilizer inputs. The above results indicated that compared with other patterns, grain yield, nitrogen efficiency, and economic benefits under TCP were relatively lower. HCP could achieve more stable and higher grain yield as well as higher protein content, and IDCP achieved the highest yield potential, economic benefits, and nitrogen efficiency but had a low grain protein content. High yield was achieved by increasing single-spike yield based on enough spike number, and the high yielding HCP mainly increased grains per spike, but IDCP achieved high grain weight. HCP achieved high spike number mainly depended on tiller fertility, and IDCP depended on the synergistically increasing tiller number and tiller fertility. The suitable range of the ratio of tiller number at the beginning of wintering stage to spike number was 0.9-1.1 for high yield population. Further analysis showed that the high yield patterns could improve the leaf photosynthetic rate and maintain a high photosynthetic area after anthesis, indicating high-level coordination of the source-sink relationship and enlarged source level. The results also indicated that improving nitrogen absorption efficiency based on high nitrogen physiological efficiency was the key for realizing high nitrogen use efficiency. The nitrogen accumulation in the HCP population was low at the early growth stage, but the absorption capacity was gradually increased at the middle and late growth stage, finally promoting nitrogen transportation. The IDCP population also had strong nitrogen absorption capacity during the middle and early growth stage and also showed a sufficient transportation level. The relationships of grain yield and nitrogen use efficiency with agronomic and physiological traits under different ecological conditions and cultivation patterns were analyzed, and it was found that increasing tiller fertility of the crop population contributed to a higher photosynthetic area per stem and leaf photosynthetic rate at the grain-filling stage, which increased single-spike yield and wheat production. Besides, the high tiller fertility also promoted nitrogen absorption capacity before anthesis increasing nitrogen transportation and use efficiency. 【Conclusion】 In conclusion, the synergistic approach to achieve high yield and high efficiency of wheat under the rice-wheat rotation was to develop large spikes especially increase grain weight based on obtaining sufficient spikes and to establish the population with sufficient quantity and high quality. The latter included that the tiller number of the population before wintering stage met the expected spike number with improving tiller fertility, the nitrogen absorption and transportation level was high before the anthesis stage, and the photosynthetic area and intensity of single stem could maintain a high level after the anthesis to promote the grain filling. The present study also indicated that technologies realizing high-yield and high-efficiency production needed to emphasize moderately increasing planting density, limitedly reducing nitrogen application, increasing topdressing nitrogen with reducing base fertilization, and precisely applying fertilization.

    Effects of Potassium Application on Root and Nodule Characteristics, Nutrient Uptake and Yield of Peanut
    LIU Na, XIE Chang, HUANG HaiYun, YAO Rui, XU Shuang, SONG HaiLing, YU HaiQiu, ZHAO XinHua, WANG Jing, JIANG ChunJi, WANG XiaoGuang
    Scientia Agricultura Sinica. 2023, 56(4):  635-648.  doi:10.3864/j.issn.0578-1752.2023.04.004
    Abstract ( 317 )   HTML ( 77 )   PDF (1453KB) ( 195 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】According to the current situation such as low content of available potassium and insufficient application of potassium fertilizer of peanut production in Liaoning province, this study explored the effects of different potassium levels on peanut root system, nodule characteristics, main nutrient absorption rate and yield, so as to determine the optimal application rate of potassium fertilizer and provide the theoretical basis and reference for local peanut production. 【Method】 This study was conducted in Shenyang Agricultural University from 2018 to 2019. Under the condition of normal application of nitrogen and phosphorus fertilizer needed for peanut field production, four potassium fertilizer (potassium sulfate) treatments of 0 (CK), 112.5 kg·hm-2 (T1), 225 kg·hm-2 (T2) and 337.5 kg·hm-2 (T3) were used to study the effects of different potassium application rates on root morphology of plough layer, nodule characteristics, nutrient absorption and yield of peanut. 【Result】Potassium application had little effect on root dry weight of peanut, and there was no significant indigenous difference in root dry matter accumulation treatments. Compared with CK, the total root length, total root surface area and total root volume in plough layer of peanut were significantly increased under T2. Root nodules were more sensitive to potassium concentration, and the number and dry weight of nodules reached the maximum at all stages when the amount of potassium application was 112.5 kg·hm-2. The increase of potassium application might also accelerate the formation and senescence of nodules. The application of potassium fertilizer increased the maximum accumulation rate, average accumulation rate and maximum accumulation of nitrogen, phosphorus and potassium, prolonged the active accumulation period of nitrogen and potassium. The yield components such as pods per plant and yield under T2 were higher than that under other treatments. 【Conclusion】 When the potassium application rate was 225 kg·hm-2 ( T2 ), it was most conducive to peanut root growth and nutrient absorption, and the yield increase effect was the best. When the potassium application rate was 112.5 kg·hm-2, the growth of nodules was the best, however, the yield increase effect was weaker than that of T2.

    PLANT PROTECTION
    Identification of Antagonistic Bacterium Strain KRS022 and Its Inhibition Effect on Verticillium dahliae
    LUO WanZhen, WANG Dan, QI HongYue, WANG Tong, LIU Zheng, TIAN Li, DAI XiaoFeng, CHEN JinYin, MIJITI Maihemuti
    Scientia Agricultura Sinica. 2023, 56(4):  649-664.  doi:10.3864/j.issn.0578-1752.2023.04.005
    Abstract ( 309 )   HTML ( 44 )   PDF (4539KB) ( 184 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】To clarify the taxonomic status of antagonistic bacterium KRS022 and its inhibitory effect on a variety of pathogenic fungi, and to focus on the control efficacy on Verticillium dahliae, and this study will provide important resources for the research and development of biocontrol preparations against V. dahliae. 【Method】The classification of KRS022 was determined by morphological, physiological and biochemical tests, and 16S rDNA-gyrB gene sequence tandem analysis. The inhibitory effects of KRS022 on various fungi were tested by confrontation and fumigation methods. The effect of KRS022 on the morphology of V. dahliae hyphae and conidia was determined by co-culture of cell-free supernatant and fumigation. The control efficacy of KRS022 on Verticillium wilt of cotton and tobacco was determined by pot experiment and biomass measurement. The RT-qPCR method was used to detect the expression levels of plant resistance-related genes. 【Result】The strain KRS022 was gram-negative bacterium, and it was identified as Pseudomonas alcaligenes. KRS022 has the characteristics of phosphorus and potassium solubilization, nitrogen fixation and siderophore production, and the function of protease, amylase and catalase activities. KRS022 belongs to aerobic alkali-producing bacterium, and 100 μg·mL-1 ampicillin can be used as the screening condition for natural resistance of this strain. KRS022 showed different degrees of antifungal activity against a variety of pathogenic fungi (such as Verticillium dahliae, Fusarium oxysporum, Fusarium graminearum, Magnaporthe oryzae, Botrytis cinerea, Colletotrichum gloeosprioides, Colletotrichum fructicola). The inhibitory rates of confrontation and fumigation against V. dahliae were 75.19% and 99.78%, respectively. The inhibition rates of PDA plates with fermentation liquid, spreading plates and fumigation against Vd991 were 96.21%, 99.72% and 99.44%, respectively. The co-culture of KRS022 cell-free supernatant with conidia of Vd991 completely inhibited spore germination. The hyphae of Vd991 were enlarged and thickened after fumigation treatment of KRS022. The results of pot experiment showed that KRS022 could significantly inhibit the occurrence of Verticillium wilt of cotton and tobacco. After treatment of KRS022 bacterial solution, the biomass of V. dahliae was significantly reduced. The biomass of V. dahliae in the control group (Vd991 alone) was 1.75 and 2.57 folds higher than that in the treatment group (KRS022+Vd991), respectively. Moreover, KRS022 could also promote plants growth, and the leaf dimension and single leaf area of the tobacco treated with KRS022 fermentation broth increased by 65.7% and 146.4%, respectively. At the same time, KRS022 could stimulate the plants resistance-related genes expression. Cotton treated with KRS022 fermentation broth, the salicylic acid (SA) pathway marker gene GhPR1, jasmonic acid (JA) pathway marker gene GhAOC4 and ethylene (ET) pathway marker gene GhEIN2 were significantly up-regulated, the up-regulation folds were 7.23, 1.69 and 15.05 that of water treatment, respectively. Cotton treated with KRS022 fermentation broth and inoculated with V. dahliae, the expression of GhAOC4 and GhEIN2 was significantly induced, and the up-regulation folds were 68.09 and 11.87 that of cotton plants inoculated with V. dahliae, respectively. The up-regulated expression folds of NbHSR203, NbHIN1, NbPR1, NbPR2, NbPR5, NbRbohA and NbRbohB after KRS022 cell-free supernatant injection were 1.98, 2.79, 2.52, 1.25, 1.70, 3.28 and 3.44 that of LB treatment, respectively. 【Conclusion】The antagonistic bacterium KRS022 was identified as P. alcaligenes. It has the characteristics of siderophore production, phosphorus and potassium solubilization, and nitrogen fixation, which suggested KRS022 may have the function of plant growth promotion. It can inhibit the conidia germination and hyphae growth of V. dahliae. In addition, KRS022 can protect plants from V. dahliae infection and trigger plant immunity response. Together, KRS022 is a potential biocontrol microbial resource with development prospect for the prevention and control of Verticillium wilt and other fungal diseases.

    Function of MBF2 Transcriptionally Regulating Glutathione S-transferase Metabolizing Chlorantraniliprole in Plutella xylostella
    GE TianCheng, YIN Fei, HU QiongBo, PENG ZhengKe, LI ZhenYu
    Scientia Agricultura Sinica. 2023, 56(4):  665-673.  doi:10.3864/j.issn.0578-1752.2023.04.006
    Abstract ( 209 )   HTML ( 47 )   PDF (526KB) ( 99 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this study is to explore the regulation function of transcription regulation factor MBF2 (multiprotein bridging factor 2) on glutathione S-transferase (GST) in Plutella xylostella and its role in resistance to chlorantraniliprole, and to provide a theoretical basis for clarifying the metabolic mechanism of P. xylostella to detoxify chlorantraniliprole. 【Method】The resistance level of P. xylostella to chlorantraniliprole in three populations, susceptible (SS), Lianzhou (LZ) and Tonghai (TH), was determined by leaf dipping method and the GST activity of three populations was measured by enzyme kinetic method. Real-time quantitative PCR (RT-qPCR) was used to analyze the expression difference of MBF2 in different P. xylostella populations. After induction for 12 h under the LC50 of chlorantraniliprole, the induced expression level of MBF2 in different populations was analyzed. The regulatory role of MBF2 on specific GST genes was confirmed by RNA interference (RNAi) and the GST activity of MBF2-silenced P. xylostella was analyzed. Susceptibility variations of MBF2-silenced P. xylostella populations to chlorantraniliprole were conducted by leaf dipping method, which support that MBF2 influenced the resistance of P. xylostella to chlorantraniliprole. 【Result】The TH population was moderately resistant and LZ population was highly resistant to chlorantraniliprole when respectively compared to susceptible population (SS), with the resistance ratio of 54.27 and 289.58. The GST activity of TH and LZ populations was significantly higher than that of SS population. Compared with SS population, MBF2 was significantly up-regulated in resistant populations, and the expression level of MBF2 in the moderately resistant and highly resistant populations was 4.6 and 9.4 times that of susceptible population, respectively. When P. xylostella was exposed to chlorantraniliprole at LC50 for a short time, the expression levels of MBF2 in susceptible, moderately resistant and highly resistant populations were significantly increased within 8 hours, and the highest expression was 10 times that of the control. After RNAi treatment for 24 hours, the expression levels of 9 GST genes in MBF2-silenced P. xylostella were significantly decreased, and GSTZ1 as well as GSTU1 decreased by more than 90%. Compared with the negative control (dsGFP), the GST activity in the treatment group (dsMBF2) decreased by 57.76%. After treatment with 75 mg·L-1 chlorantraniliprole, the mortality in the treatment group increased by 23.34% compared with the control group. 【Conclusion】It is speculated that MBF2 improves the metabolism of chlorantraniliprole by regulating the transcription of GSTs, thereby participating in the detoxification effect of P. xylostella to chlorantraniliprole. The results can provide experimental basis for further analysis of P. xylostella resistance mechanisms to insecticides and research as well as development of new insecticides.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Spatio-Temporal Variations of Fertilizer Contribution Rate for Rice in China and Its Influencing Factors
    LI YaZhen, HAN TianFu, QU XiaoLin, MA ChangBao, DU JiangXue, LIU KaiLou, HUANG Jing, LIU ShuJun, LIU LiSheng, SHEN Zhe, ZHANG HuiMin
    Scientia Agricultura Sinica. 2023, 56(4):  674-685.  doi:10.3864/j.issn.0578-1752.2023.04.007
    Abstract ( 274 )   HTML ( 45 )   PDF (512KB) ( 186 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Spatio-temporal variations and driving factors of fertilizer contribution rate were conducted for the paddy soil in China, so as to provide a theoretical basis for the sustainable development of rice and scientific recommended application of fertilizers in rice cultivation areas. 【Method】 Data was cited from a total of 338 long-term paddy soil monitoring sites located in rice-producing provinces of China for this study. The effects of fertilizer contribution rate for cropping system, climate, regions, soil texture and its driving factors were evaluated. 【Result】 In the past 30 years (1988-2017), the fertilizer contribution rate for rice increased first and then levelled off in China in the condition of same rice variety and cultivation techniques both in fertilization and none-fertilization plots. The variable range of fertilizer contribution rate for rice was from 41.20% to 51.89%. The fertilizer contribution rate for rice was 38.58%-55.49%, 41.96%-51.05%, and 42.34%-53.43% in single, double rice, and rice and other cropping systems, respectively. After 30 years, the fertilizer contribution rate for rice from high to low was as follows: Southwest China (55.82%), Middle of Yangtze River (46.73%), North China (46.27%), North east China (45.90%), South China (45.83%) and Lower of Yangtze River (44.25%). According to the fitting equation, it was found that the stable fertilization years of fertilizer contribution rate for rice was 15.2 a, 18.5 a, 19.0 a, 15.3 a, 15.3 a and 14.5 a in the Northeast China, North China, Southwest China, Middle of Yangtze River, Lower of Yangtze River and South China, respectively. The fertilizer contribution rate for rice in subtropical monsoon (49.23%) was much higher than temperate monsoon (45.90%) and tropical monsoon (34.57%). The fertilizer contribution rate for rice with different soil texture was 43.25%-64.80% for clay soil, 40.65%-48.46% for loam soil, and 26.20%- 45.98% for sand soil. Among the fertilization factors, nitrogen and phosphate fertilizer were the main factors affecting fertilizer contribution rate. Among the climatic factors, frost-free period, mean annual rainfall and mean annual temperature were the main factors and soil organic matter was the most important one among the soil factors. 【Conclusion】 The fertilizer contribution rate for rice was increased first and then levelled off in 1988-2017, and there was different for fertilizer contribution rate for rice under different rice cropping systems, regions, climate and texture. Nitrogen and phosphate fertilizers were main factors of fertilizer contribution rate for rice in China. Moreover, the soil organic matter in paddy soil was the most important to fertilizer contribution rate for rice in soil fertility indexes.

    Effects of Maize Shoot and Root Residues Added on Microbial Residue Carbon and Nitrogen in Different Fertility Levels of Black Soil
    MA Nan, AN TingTing, ZHANG JiuMing, WANG JingKuan
    Scientia Agricultura Sinica. 2023, 56(4):  686-696.  doi:10.3864/j.issn.0578-1752.2023.04.008
    Abstract ( 251 )   HTML ( 42 )   PDF (519KB) ( 141 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Maize shoot and root residues are the significance sources of soil organic matter (SOM). Exogenous carbon (C) and nitrogen (N) are assimilated by soil microorganism, accumulated as microbial necromass and contributed to relatively stable SOM. The objectives of this study were to clarify the accumulation of microbial residue C and N in different fertility levels of soil with shoot and root residues addition, and to qualify the contributions of microbial residue C and N to soil organic C (SOC) and total N (TN), respectively, so as to provide a basis for increasing the storage and stability of SOC and TN. 【Method】 Based on a long-term experiment of black soil with different fertility levels, this study used the 13C15N isotope labeling and amino sugar biomarkers methods, and mixed the labeled maize shoot and root residues with black soil samples. Then the mixture samples were incubated in lab, and sampled in 30 and 180 days. The percentages of exogenous C (shoot C and root C) and N (shoot N and root N) remaining in soil, contents of microbial residues C and N, and their contributions to SOC and TN were analyzed. 【Result】On the 180th day, the percentages of shoot C and root C remaining in soil were, on average, 36.3% and 31.7%, respectively, and those of shoot N and root N remaining in soil were, on average, 95.8% and 79.3%, respectively. On the 180th day, the ratio of the SOC derived from exogenous C (13C-SOC) to TN derived from exogenous N (15N-TN) were, on average, 17.6 and 28.5 in the soils with shoot and root residue addition, respectively. The ratio of 13C-SOC to 15N-TN was decreased by 47.9% and 28.2% in the soils with shoot and root residue addition on the 180th day compared with the 30th day, respectively. During the incubation, the contents of fungal and bacterial residue in the high fertility soil were, on average, 1.17 and 1.31 times those in the low fertility soil, respectively. On the 180th day, the content of microbial residue C and N (fungal and bacterial) was, on average, 8.5% higher in the soil added with shoot than that in the soil added with root. On the end of incubation, the average percentage of fungal residue C contributed to SOC was 37.0% and 33.8%, respectively, and that of bacterial residue C contributed to SOC was 11.2% and 9.2% in the high and low fertility level soils, respectively. The average percentage of fungal residue C contributed to SOC was 36.0% and 34.7%, and that of bacterial residual C contributed to SOC was 10.8% and 9.6% on the end of incubation, respectively. The average percentage of bacterial residue C contributed to SOC was 55.2% and 16.3% in the soil added with shoot and root on the 30th day, respectively. The average percentage of fungal residue N contributed to TN was 63.5% and 60.5%, and that of bacterial residue N to TN was 16.4% and 17.5% in low and high fertility level soils on the 180th day, respectively. The percentage of bacterial residue C and N contributed to SOC and TN was increased by 4.8% and 7.4% in the high fertility soil and by 20.3% and 32.5% in low fertility soil on the 180th day compared with the basic soil without shoot and root addition, respectively. 【Conclusion】 The accumulation of fungal residue was of great significance for the storage and stability of SOC and TN. Maize shoot addition promoted the accumulation of microbial residues C and N in soil compared with root addition. Low fertility soil with the addition of shoot and root improved the transformation of bacterial residue C and N to SOC and TN.

    Effects of Control Irrigation on Grain Yield and Greenhouse Gas Emissions in Ridge Cultivation Direct-Seeding Paddy Field
    XIE Jun, YIN XueWei, WEI Ling, WANG ZiFang, LI QingHu, ZHANG XiaoChun, LU YuanYuan, WANG QiuYue, GAO Ming
    Scientia Agricultura Sinica. 2023, 56(4):  697-710.  doi:10.3864/j.issn.0578-1752.2023.04.009
    Abstract ( 188 )   HTML ( 34 )   PDF (1033KB) ( 119 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Paddy fields are one of the important sources of greenhouse gas emissions, while farming practices and water management can reduce greenhouse gas emissions from field to a certain extent. Ridge cultivation and direct-seeding is a new kind of rice planting pattern that saves costs and increases economic efficiency. The impact of water management of ridge cultivation and control irrigation on grain yield and greenhouse gas emissions were explored for increasing grain yield and reducing greenhouse gas emissions, so as to provide a theoretical basis and technical approaches for the innovation of high-yield and emission-reduction. 【Method】In this study, a rice-radish rotation system under the ridge cultivation from 2019 to 2021 was conducted to use as the research object. Four treatments were set up, including traditional flooded furrow irrigation (TFI: the height of irrigation was about 5 cm above the ridge), controlled furrow irrigation 1 (CFI1: the height of irrigation was about 5 cm below the ridge), controlled furrow irrigation 2 (CFI2: the height of irrigation was about 10 cm below the ridge), and control furrow irrigation 3 (CFI3: the height of irrigation was about 15 cm below the ridge). The greenhouse gas emissions and global warming potential (GWP) of rice-radish season were investigated by airtight static box-gas chromatography, and the rice yield, soil reducing substances, ammonium nitrogen and nitrate nitrogen were measured. Finally, the optimal irrigation patterns were identified with both reducing the GWP and increasing the rice yield. 【Result】Based on the three-year experimental results, compared with TFI treatment, controlled irrigation could significantly reduce the cumulative emission of CH4 by 22.81%-78.47% in the rice season, of which CFI3 had the most significant effect; CFI2 treatment significantly increased the cumulative emission of N2O by 20.45%-59.90%, CFI3 significantly reduced the cumulative N2O emissions by 12.08%-68.64%, and CFI1 had no significant effect on the cumulative N2O emissions. For radish season, compared with TFI controlled irrigation could significantly reduce the cumulative emission of CH4 by 34.87%-53.31%, among which CFI2 and CFI3 had the most significant effects; CFI1, CFI2 and CFI3 treatments could significantly increase the cumulative emission of N2O by 35.00%-120.00%. The results of two-way ANOVA showed that control irrigation, the interaction of control irrigation and year had an extremely significance on the cumulative emission of CH4 (P<0.01). The control irrigation, year, the interaction of control irrigation and year had an extremely significance on cumulative N2O emissions (P<0.01). Compared with TFI, controlled irrigation treatment could significantly reduce GWP by 20.24%-74.87% in rice season; CFI1 and CFI2 treatments increased rice yield by 12.34%-33.97%, CFI3 treatment had no significant effect on yield. Controlling irrigation reduced GHGI by 29.37%-75.92%. Controlled irrigation affected CH4 emissions by reducing the total amount of reducing substances, active reducing substances and reducing Fe2+ by 15.00%-30.84%, 53.45%-71.65% and 60.47%, respectively. It also affected N2O emissions by reducing NH4+ by 7.51%-9.87% and increasing NO3- by 5.81%-8.55%. 【Conclusion】Controlled irrigation affected GHG emissions through soil properties such as NO3-, NH4+, and reducing substances. Therefore, CFI1 and CFI2 had the best effects in terms of reducing GWP and increasing rice yield. Under the conditions of ridge cultivation and direct-seeding in paddy field, the depth of irrigation with two-thirds or half of the depth of traditional furrow irrigation flooding was the best water management method to alleviate greenhouse gas emissions and increase rice production.

    HORTICULTURE
    Genome-Wide Identification and Expression Analysis of DIR Gene Family in Cucumber
    ZHANG KaiJing, HE ShuaiShuai, JIA Li, HU YuChao, YANG DeKun, LU XiaoMin, ZHANG QiAn, YAN CongSheng
    Scientia Agricultura Sinica. 2023, 56(4):  711-728.  doi:10.3864/j.issn.0578-1752.2023.04.010
    Abstract ( 368 )   HTML ( 108 )   PDF (9399KB) ( 253 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Based on the cucumber (Cucumis sativus L.) genome information and transcriptome sequencing big-data, the DIR gene family in cucumber was identified with bioinformatics methods, and the expression pattern analysis of DIR family genes in different tissues and stresses response were analyzed. It would lay an important foundation for further study on the biological function of cucumber DIR genes. 【Method】 With the reported HMM model file of DIR gene, the probable DIR genes ID from the cucumber protein database was firstly identified using HMMSearch program in the HMMER software package. The cucumber DIR genes were ultimately verified using online tools Pfam and SMART. The tools of ExPASy, TBtools, GSDS, MEME, MEGA, MCScanX and Circos were used to analyze the physicochemical characteristics, chromosomal distributions, gene structure, phylogenetic tree and synteny of cucumber DIR genes. Based on cucumber transcriptome sequencing big-data of different tissues and under different stresses, transcriptome sequencing analysis was re-analyzed using cucumber V3 version genome information. The data of cucumber DIR genes in different transcriptome sequencing analysis were retrieved. The expression heatmaps of DIR gene family were drawn using TBtools software, and the expression patterns of cucumber DIR genes in different tissues and stresses response were analyzed. 【Result】 Total of 23 DIR genes were identified from cucumber genome, which distributed to 7 chromosomes. The number of amino acids of these DIR genes ranged from 78 to 684, and the molecular weight ranged from 8.70 to 73.82 kD. Phylogenetic analysis divided the cucumber DIR genes into 3 subgroups, the structure and motif of the genes in each subgroup were similar. Synteny analysis showed that the 12 cucumber DIR genes were collinearity with 19 Arabidopsis DIR genes and with 27 kinds of linear relationships, and 12 cucumber DIR genes were collinearity and with 11 rice DIR genes with 19 kinds of linear relationships. While only 8 cucumber DIR genes were conservative, which were not collinearity with any DIR gene in Arabidopsis and rice. Tissue-specific expression analysis revealed that some cucumber DIR genes had low or no expression levels in all tissues including root, stem, flower, fruit, leaf and so on, some cucumber DIR genes had high expression levels in all tissues, and some DIR genes had specific expression levels in some tissues, but no or low expression levels in other tissues. This suggested that different cucumber DIR genes had tissue specific expression patterns. The expression profiles analysis of cucumber DIR genes under biotic and abiotic stresses conditions revealed that cucumber DIR gene, CsaV3_4G023490, were up-regulated expression in response to all stresses, which meant this gene played an important role in the process of cucumber growth and development. 【Conclusion】 Total of 23 DIR genes were identified in cucumber, which were divided into 3 subgroups. The gene members in each subgroup were highly conserved, and the gene structure and protein conserved domain were different among 3 subgroups. The expression patterns of cucumber DIR genes in different tissues and stresses response were different, which coordinately regulated the growth and development of cucumber.

    Effects of Different Color Fruit Bags on Quality of Ruixue Apple Fruits
    WANG ZiDun, WANG Hui, FENG YuChen, ZHANG XueLiang, YAN LeiYu, LIU XiaoJie, ZHAO ZhengYang
    Scientia Agricultura Sinica. 2023, 56(4):  729-740.  doi:10.3864/j.issn.0578-1752.2023.04.011
    Abstract ( 281 )   HTML ( 33 )   PDF (1431KB) ( 156 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The aim of this study was to explore the effects of different color of fruit bags on the fruit quality of Ruixue apple (Malus × domestica Ruixue), so as to provide the theoretical guidance and technical support for the production of high-quality Ruixue apples. 【Method】The experimental materials were five-year-old trees of Ruixue using M26 as rootstock, bagged with red, orange, yellow, green, blue, indigo and purple single-layer fruit bags at 70 days after full bloom, with white bags as control. The fruits were harvested at 190 days after full bloom. The transmitted light spectrum of bags was measured by spectrometer. The indicators of fruit quality were determined, such as peel chlorophyll, ascorbic acid, soluble sugar and aroma compounds contents. To explore the effects of different light qualities on fruit quality, the relationship between light and fruit quality was analyzed by correlation analysis. 【Result】The difference in the color of the fruit bags changed the composition of the light quality and had a positive correlations between light quality and fruit bags. Compared with white bag control, the transmittances of purple in purple bag were the highest, which were 1.15 times than that in white bag; meanwhile, the transmittances of red in red bag were the highest (1.13 times). The external quality of fruits was significantly improved after the treatment of different color fruit bags. Among the indicators, the L* and b* values of the peel were higher than white bag control, while the a* value, fruit point index and coloration index were lower. Compared with other color fruit bags, some indicators of purple fruit bags were significantly improved (P < 0.05), such as chlorophyll (0.0548 mg·g-1), total phenolic (1.325 mg·g-1), and total flavonoid content of fruits (1.361 mg·g-1). Under different light quality environments, there were significant differences in fruit firmness, and the fruit firmness of the red fruit bag was significantly lower, which was 16.1% lower than white bag control. In addition, other internal quality measurements showed that the indigo fruit bags significantly improved the flavor of the fruits, which improved mainly soluble solids, sugar components and sweetness value. The detection of aroma compounds showed that the blue fruit bag significantly increased the total amount of fruit aroma compounds, which was significantly increased by 2.89 times compared with white bag control. Based on the above indicators, a correlation analysis between light quality and various quality indicators was conducted, and found that there was a close correlation between fruit external quality and light quality. The correlation coefficients between the purple/indigo, orange, and purple/blue values and the L*, a*, and b* values of the peel were 0.901, 0.810, and 0.854, respectively. The internal quality of fruit, such as chlorophyll, total flavonoid, total phenolic and total aroma compounds, were most closely related to blue light, and the correlation coefficients of them with blue light were 0.947, 0.822, 0.851 and 0.757, respectively. 【Conclusion】 According to the comprehensive analysis, purple and blue light were beneficial to improve the external and internal quality of Ruixue apple. Therefore, the transmission amount of purple and blue light could be appropriately increased in the fruit bag during Ruixue bagging cultivation to further improve fruit quality.

    FOOD SCIENCE AND ENGINEERING
    Effects of Pulsed Electric Field on Gelation Properties of PSE-Like Chicken Myosin: A Molecular Dynamics Simulation Analysis
    GUO YuChen, DONG Ming, ZENG XianMing, TIAN HuiXin, YIN JiaQi, HOU YuKe, BAI Yun, TANG ChangBo, HAN MinYi, XU XingLian
    Scientia Agricultura Sinica. 2023, 56(4):  741-753.  doi:10.3864/j.issn.0578-1752.2023.04.012
    Abstract ( 170 )   HTML ( 24 )   PDF (2666KB) ( 66 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】In the present study, the effects of pulsed electric field (PEF) on pale soft exudative-like (PSE-like) chicken myofibrillar protein gel properties and conformational modification were investigated by molecular dynamics simulation. The potential mechanism of gel properties change was explored, so as to broaden the industrial application of this emerging food processing technology and to provide a novel method for enhancing abnormal meat products economic benefit in poultry processing. 【Method】Myofibrillar protein was extracted from PSE-like chicken. Effect of PEF under 8, 18 and 28 kV·cm-1 electric field intensity (800 Hz, duty cycle 47%) were compared with untreated samples of PSE-like chicken myofibrillar for turbiscan stability index (TSI) and rheological properties, and the PEF simulation system of 18 kV·cm-1 electric field strength was established by molecular dynamics simulation technology. The root mean square deviation (RMSD), root mean square fluctuation (RMSF) and the overall conformational changes of proteins were collected to explore the mechanism of PEF treatment on the molecular conformational changes of myofibrillar proteins in PSE-like chicken, and the effects of PEF on the conformational stability, water holding capacity (WHC) and rheological properties of myofibrillar protein extracted from PSE-like chicken were also evaluated. 【Result】The TSI of the PSE-like chicken myofibrillar protein system treated by PEF with various field strengths had a smaller slope, which indicated that the protein system was more stable than the untreated sample. The results of WHC of protein gel were 18 kV·cm-1 (81.42%)>28 kV·cm-1 (79.46%)>8 kV·cm-1 (77.82%)>0 kV·cm-1 (76.15%). The rheological properties demonstrated that the changes of storage modulus (G') and loss modulus (G") had the same trend as that of WHC, and the treatment of 18 kV·cm-1 significantly improved the G 'and G" of myofibrillar protein gel (P<0.05). The molecular dynamics simulation result of 30 ns under 18 kV·cm-1 PEF revealed the polymer protein model acted higher RMSD value and more obvious RMSF fluctuation after treatment, which reflected that the secondary structure of protein molecule was uncoiled and unfolded, α-helix was transformed into irregular crimp, protein polypeptide chain was expanded, amino acid residues were exposed, and protein molecules displayed higher flexibility. Interactions of protein-protein and protein-water have been modified, such as electrostatic interaction, hydrogen bond, disulfide bond, hydrophobic interaction. However, when the electric field intensity increased to 28 kV·cm-1, myosin aggregated due to the enhancement of protein-protein interaction, which reduced the effect of PEF on protein property. 【Conclusion】The 18 kV·cm-1 PEF changed the inherent spatial structure of PSE-like chicken myofibrillar protein, the exposure of hydrophobic groups and the formation of hydrogen bonds enhanced the binding of protein and water molecules and the interaction between protein molecules, thus improving the stability and rheological properties of PSE-like chicken myosin gel, which contribute to better gel WHC and elastic network structure.

    ANIMAL SCIENCE·VETERINARY SCIENCE
    Effects of Anemoside B4 on Growth Performance, Nutrition Digestion and Rumen Fermentation of Calves
    LU Meng, HU FengMing, TU Yan, DIAO QiYu
    Scientia Agricultura Sinica. 2023, 56(4):  754-765.  doi:10.3864/j.issn.0578-1752.2023.04.013
    Abstract ( 207 )   HTML ( 30 )   PDF (524KB) ( 79 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this experiment was to investigate the effects of Anemoside B4 on growth performance, digestion and metabolism, and rumen fermentation parameters of calves, so as to provide a theoretical basis for developing new feed additives. 【Method】In this experiment, sixty newborn Holstein male calves were randomly divided into 4 groups (15 calves in each group) and fed 0 (group C), 15 (group A1), 30 (group A2), and 45 (group A3) mg/d of Anemoside B4, respectively. The test period was 56 days. The calves were weighed before morning feeding at the ages of 14, 28, 42 and 56 days, and rumen fluid was collected two hours after morning feeding at the ages of 28, 42 and 56 days. Two stages of digestion and metabolism tests were carried out at 42 and 63 days, respectively, and the apparent digestibility of nutrients and the indexes of energy and nitrogen metabolism were measured. 【Result】(1) Anemoside B4 had no significant effect on the body weight (BW) and dry matter intake (DMI) of suckling calves (P>0.05), but the average daily gain (ADG) of calves aged 14-28 days was significantly positively correlated with Anemoside B4 (P<0.05), and the feed conversion ratio was significantly negatively correlated with the addition amount (P<0.05). The ADG of calves in group A3 was significantly higher than that in group C (P<0.05), and the feed conversion ratio was significantly lower (P<0.05). (2) The fecal score and diarrhea incidence of calves aged 7-56 days and 7-14 days in group A3 were significantly lower than those in group C (P<0.05), and the fecal score and diarrhea incidence of calves aged 15-28 days in group A2 were significantly lower (P<0.05). There was a significant negative correlation between the effect of Anemoside B4 and the dosage (P<0.05). There was no significant difference in fecal score and diarrhea incidence between 29-42 and 43-56 days of age (P>0.05). (3) Before weaning, the dry matter intake of calves in group A3 was significantly lower than that in group C (P<0.05), and the dry matter intake of calves in group A2 was lower than that in group C (0.05≤P<0.10). The dry matter intake of calves decreased significantly with the increase of Anemoside B4 (P<0.05). There were no significant differences in apparent digestibility of dry matter (DM), crude protein (CP), crude fat (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF) of calves (P>0.05). After weaning, the apparent digestibility of DM and NDF in group A2 tended to be higher than that in group A1 (0.05≤P<0.10), and the apparent digestibility of ADF was significantly higher than that in group A1 (P<0.05). The apparent digestibility of EE in group A2 calves had a trend to increase with the increase of Anemoside B4 (0.05≤P<0.10). (4) Before weaning, total energy intake of calves in group C was significantly higher than that in group A3 (P<0.05) and had a trend higher than that in group A2 (0.05≤P<0.10). Total energy intake of calves in group A1 was also significantly higher than that in group A3 (P<0.05). After weaning, the fecal energy in group C was higher than that in group A2 (0.05≤P<0.10), while the gross energy digestibility in group A2 was higher than that in group A1 (0.05≤P<0.10), and the gross energy metabolic rate was significantly higher than that in group A1 (P<0.05) and had a higher trend than that in group C (0.05≤P<0.10). (5) Before weaning, there were no significant differences in fecal nitrogen, urinary nitrogen, nitrogen digestibility and nitrogen deposition rate among all groups (P>0.05), and the total nitrogen intake in group C was significantly higher than that in group A3 (P<0.05). After weaning, there was no significant difference in nitrogen metabolism indexes among all groups (P>0.05). (6) There was no significant difference in rumen fermentation parameters among four groups (P>0.05). 【Conclusion】 The addition of Anemoside B4 could significantly increase the average daily gain of suckling calves at 14-28 days, reduce the feed conversion ratio and diarrhea incidence, improve the feed conversion efficiency, improve the apparent digestibility of dry matter, neutral detergent fiber and acid detergent fiber of suckling calves, promote the digestibility and metabolic rate of total energy, and had no adverse effect on the rumen fermentation index of calves. Considering comprehensively, the recommended amount of additive was 45 mg/d.

    Effects of Guanidinoacetic Acid and Betaine Supplementation on Growth Performance, Rumen Fermentation and Blood Metabolites in Lambs
    REN GuoDong, HAO XiaoYan, ZHANG XuanZi, LIU Sen, ZHANG HongXiang, TIAN GuangYuan, ZHANG JianXin
    Scientia Agricultura Sinica. 2023, 56(4):  766-778.  doi:10.3864/j.issn.0578-1752.2023.04.014
    Abstract ( 266 )   HTML ( 28 )   PDF (547KB) ( 100 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】This study was conducted to investigate the effects of dietary guanidinoacetic acid (GAA) and betaine (BT) on growth performance, rumen fermentation and blood metabolites in lambs, so as to provide a support for applying GAA and BT on ruminants. 【Method】Forty-eight 3-month-old Dorper×Thin-tailed Han F1 hybrid male lambs with similar body weight (22.03±1.3 kg; mean±SD) were randomly divided into 4 groups with a 2×2 factorial arrangement, and the experimental factors were GAA (0 or 900 mg/kg) and BT (0 or 5 g/day). Lambs in four groups were control group, GAA group, BT group and GAA+BT group, respectively. The feeding experiment lasted for 75 days with 15 days of adaptation. On the first day of the formal experiment period, the body weight (BW) before morning feeding was weighed as the initial BW, and each lamb were recorded accurately the amount of feed and residual of weight every day; at the end of the trial period, the blood samples were collected from the jugular vein, and final body weight (FBW) was weighed before morning feeding to calculate average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency (FE). The blood serum was used for the determination of creatine metabolism indexes, homocysteine and lactate content. The rumen fluid was collected from all lambs at 3 hours after feeding at the end of the experiment, which were used to measured rumen fermentation parameters, digestive enzyme activity, and functional microorganisms. 【Result】(1) Compared to the control group, the addition of GAA in the diet did not significantly increase ADG (P>0.05), while the addition of BT increased ADG significantly (P<0.05). The addition of GAA or BT in the diet increased FE significantly (P<0.05), and GAA and BT had significant interaction on ADG and FE (P<0.05). (2) The rumen pH was decreased by addition of GAA or BT (P<0.05), and the concentration of propionic acid and total volatile fatty acid were increased by GAA or BT (P<0.05). There was no significant interaction between GAA and BT on rumen fermentation in lambs (P>0.05). (3) The addition of GAA or BT increased the populations of R. flavefaciens, F. succinogenes, B. fibrisolvens, and P. ruminicola (P<0.05), and decreased the populations of total protozoa (P<0.05). The addition of BT decreased the populations of total methanogens and had a tendency to increase the populations of Rb.Amylophilus (P<0.05, P=0.098). GAA had a tendency to decrease the populations of total methanogens (P=0.088). The addition of GAA and BT had no significant interaction effect on ruminal main functional microflora in lambs (P>0.05). (4) The activity of protease was increased by addition of GAA and BT (P<0.05). The addition of BT increased carboxymethyl-cellulase, xylanase and α-amylase activities (P<0.05), and had a tendency to increase cellobiase activity (P=0.075). GAA increased pectase activity (P<0.05), and had a tendency to increase α-amylase activitiy (P=0.056). The significant interaction effect between GAA and BT was observed on pectase (P<0.05). (5) The addition of GAA or BT increased the content of creatine in blood serum (P<0.05). The addition of GAA had a tendency to increase the concentration of homocysteine (Hcy) and to decrease L-arginine-glycine amidinotransferase (AGAT) (P=0.053, P=0.056). BT decreased the content of Hcy in blood serum, and had a tendency to increase creatine kinase (P=0.063). GAA and BT had no interactive significant effects on blood metabolites (P>0.05). 【Conclusion】In conclusion, the addition of GAA or BT promoted rumen fermentation, increased the populations of functional rumen microflora and microbial enzyme activity, elevated serum creatine levels, and decreased the content of homocysteine. However, the combination addition of GAA and BT did not further increase the performance of lambs when compared with the addition of GAA or BT alone.

    Effects of TBHQ on Pyroptosis, Necroptosis and Inflammatory Damage of Chicken Embryonic Lung Tissues Induced by PM2.5 from Chicken Houses
    XI MengXue, SHEN Dan, SHI YiFan, LI ChunMei
    Scientia Agricultura Sinica. 2023, 56(4):  779-787.  doi:10.3864/j.issn.0578-1752.2023.04.015
    Abstract ( 189 )   HTML ( 31 )   PDF (10548KB) ( 96 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The aim of this study was to investigate the protective effect and mechanism of tert-butylhydroquinone (TBHQ) on chicken embryo lung injury induced by fine particulate matter (PM2.5) in chicken house, so as to provide a theoretical basis for prevention and mitigation of chicken respiratory health problems caused by PM2.5 pollution in chicken house. 【Method】 14-day-old chicken embryos were selected as the research model in this study. Firstly, a model of lung tissue damage induced by PM2.5 from chicken houses was established, and then the alleviating effects of TBHQ on lung injury of chicken embryos was studied. In the experiment of establishing the model of chicken embryo lung tissue injury induced by PM2.5 from chicken houses, different concentrations of PM2.5 (0, 0.25, 0.5, and 1 mg·mL-1) were injected into egg albumens. After 5 days, the survival rate and lung tissues of chicken embryos were observed, and the appropriate concentration of PM2.5 (0.25 mg·mL-1) was selected to establish the model of chicken embryo lung injury. In the experiment of the effects of TBHQ on PM2.5-induced lung injury of chicken embryos, chicken embryos were divided into control group (saline), PM2.5 group (0.25 mg·mL-1 PM2.5), TBHQ group (0.1 μg·mL-1 TBHQ) and PM2.5+TBHQ group (0.25 mg·mL-1 PM2.5+0.1 μg·mL-1 TBHQ). The experiment lasted for 5 days. The lung tissues were collected and the egg weight, embryo weight and lung tissue weight were recorded. The expressions of MDA, T-SOD, T-AOC and pyroptosis-related genes (NLRP3, Caspase-1, IL-18, IL-1β) and necroptosis-related genes (RIPK1, RIPK3, MLKL) in lung tissues of chicken embryos were detected. 【Result】 The results suggested that in the experiment to establish a model for PM2.5-induced lung tissue damage in chicken embryos, different concentrations of PM2.5 (0, 25, 50, and 100 μg·mL-1) from chicken houses did not significantly affect the survival of chicken embryos, but the lung tissues of chicken embryos in the 0.25 mg·mL-1 PM2.5 group showed inflammatory cell infiltration. The lung tissues of chicken embryos in 0.5 mg·mL-1 and 1 mg·mL-1 PM2.5 groups showed pulmonary edema. In the experiment on the effects of TBHQ on PM2.5-induced lung damage in chicken embryos, there was no effect on embryo weight, lung tissue weight and related indices in all groups. Compared with the PM2.5 group, the inflammatory cell infiltration and MDA levels were reduced in the lung tissues of chicken embryos co-treated with TBHQ and PM2.5. RT-PCR results showed that the expression of the Caspase-1 gene in the TBHQ group was significantly increased compared with the control group (P<0.01), as were the expressions of IL-1β (P<0.01) and RIPK1 (P<0.01) genes in the PM2.5 group. Compared with the PM2.5 group, the expressions of IL-18 (P<0.01), IL-1β (P<0.01), RIPK1 (P<0.01), and MLKL (P<0.01) genes were significantly down in the TBHQ and PM2.5 co-treatment groups. On the contrary, the expressions of Caspase-1 (P<0.01), RIPK3 (P<0.05) genes in the TBHQ and PM2.5 co-treatment groups were significantly increased compared with the PM2.5 group. 【Conclusion】TBHQ could alleviate inflammatory damage in chicken embryo lung tissues induced by PM2.5 from chicken houses by inhibiting oxidative stress and reducing the gene expressions of pyroptosis and necroptosis.

    RESEARCH NOTES
    Effects of Seed Soaking with Chitooligosaccharide on the Growth of Sprout and Endogenous Phytohormone Content in Potato Minitubers
    YE Nan, ZHU Yan, ZHAO YuanShou, ZHU JianNing, MEN JiaWei, CHEN Fu, KONG DeYuan, ZHANG WeiBing, ZONG YuanYuan, LI YongCai
    Scientia Agricultura Sinica. 2023, 56(4):  788-800.  doi:10.3864/j.issn.0578-1752.2023.04.016
    Abstract ( 248 )   HTML ( 34 )   PDF (1691KB) ( 125 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Seed soaking treatment is commonly used in potato production to promote tuber germination and bud growth. However, the improper use of seed soaking agents can trigger an imbalance of endogenous plant hormone levels, leading to the emergence of potato high-legged seedlings. In this study, the immersion effects on the growth and endogenous hormone content of potato minitubers were studied, so as to provide a theoretical basis for the safe use of chitooligosaccharide as a seed dressing agent for potato minituber. 【Method】The minitubers of Favorita were soaked with chitooligosaccharide solution at different concentrations of 10, 50, and 200 mg∙L-1 (w/v), respectively, and the most effective concentration for promoting bud growth was screened. Seeds treated with 50 mg∙L-1 (w/v) chitooligosaccharide for 15 min was the treatment group (COS50), and the negative and positive control groups were treated with distilled water (Con) and 15 mg∙L-1 gibberellin (GA3), respectively. The germination rate, germination energy, bud length and bud diameter of tubers after seed soaking treatment were determined. The content of endogenous hormones in bud tissue was analyzed by ELISA before treatment (BT), before germination stage (BGS), germination stage (GS), and vigorous growth period (VG), respectively, and the morphology of terminal bud cells of GS was observed by paraffin section staining. Pearson correlation analysis was used to determine the intrinsic differences between shoot growth and endogenous hormone content. 【Result】Seed soaking with 50 mg∙L-1 (w/v) chitooligosaccharide effectively promoted the germination and growth of tuber buds of the potato minitubers. The bud length and bud diameter of the treated samples were significantly higher than that of Con group (74.7%) and GA3 group (37.2%). On the 5th day after soaking, the tuber germination rate reached 100%, which was 40.0% and 17.0% higher than the negative and the positive control, respectively. The germination energy of the minitubers was significantly enhanced. On the 5th day after treatment, the germination energy of minituber increased by 80.0% and 28.6% compared with Con and GA3 groups, respectively. Different seed soaking treatments also showed significant differences in the endogenous hormone contents in the terminal bud meristem of minitubers. Compared with the negative control, COS50 treatment elevated the levels of auxin, cytokinin, and gibberellin in the tubers during VG period, and the contents of these hormone increased by 11.4%, 2.7%, and 2.5%, respectively, while the content of abscisic acid decreased by 3.2% (P<0.05). The positive control treatment promoted the highest levels of endogenous gibberellin, cytokinin and auxin, and COS50 treatment group had significantly lower levels of auxin, cytokinin and gibberellin than the positive control group by 5.1%, 8.4%, and 2.0%, respectively (P<0.05). No significant reduction was observed in the level of abscisic acid. However, the contents of endogenous polyamines in the apical bud meristems of the minitubers treated with COS50 was 7.0% and 2.8% higher than those in the Con and GA3 treatment groups, respectively. The results of paraffin section staining revealed that the morphological differences between the minitubers terminal bud cells was attributed to the different seed soaking treatments. The cells of the terminal bud meristem expanded resulting in elongated and flat shape in GA3 treatment, while the cells of COS50 treatment group showed a uniform shape, similar to the negative control. Furthermore, the sprouts growth, sprouts diameter, germination rate and energy of minitubers were positively correlated with the increase of cytokinin, gibberellin and polyamines contents induced by COS50 treatment (P<0.05), while abscisic acid and ployamines content were significantly negatively correlated (r=-0.785, P<0.01). 【Conclusion】Seed soaking with chitooligosaccharide increased the contents of auxin, cytokinin, gibberellin, and polyamines in sprouts of minitubers. The treatment also increased the germination rate, sprouts length and sprouts diameter of potato minitubers. Uniform enlargement of meristematic cells in the sprouts of minitubers observation showed that COS50 treatment did not affect the longitudinal elongation of apical bud meristematic cells during the expansion process, causing the bud to grow wildly. However, gibberellin content decreased significantly in seed soaked with 50 mg∙L-1 (w/v) chitooligosaccharide compared with the treatment with exogenous gibberellin 3.