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【Objective】 Flag leaf is an important place for wheat photosynthetic carbon fixation, which plays an important role in wheat yield. The genetic characteristics and the genetic mechanism were analyzed under high and low nitrogen for flag leaf traits of wheat, which will provide a reference for excellent plant-type breeding and high-yield breeding. 【Method】 188 recombinant inbred line (RIL) populations derived from a cross between Kenong9204 and Jing411 was used in this study, which were planted in low nitrogen (LN) and high nitrogen (HN), respectively. The flag leaf traits of 188 RILs were investigated in 6 different environments, then the genetic analysis was conducted to determine the number of genes controlling each trait, and to estimate the genetic effect value and the heritability. In addition, the relationship between flag leaf characters and yield related traits of wheat was also studied.【Result】 Under LN environment: The optimal genetic model of flag leaf length was 2MG-CE (two pairs of interaction major genes) in E3. The additive × additive epistatic interaction value was 1.098, and the heritability of major genes was 31.35%. The flag leaf length was polygenic in another LN environment. The width of flag leaf was polygenic in all the LN environment. The optimal genetic model for flag leaf area (except E5) was 2MG-CE. The additive × additive epistatic interaction value was 1.884 and the heritability of major genes was 36.7%, while it was polygenic inheritance in E5. Under HN environment: The optimal genetic model for flag leaf length (except E4) was 2MG-CE, the additive × additive epistatic interaction value was 1.133, and the heritability of major genes was 32.6%. The optimal genetic model was 2MG-ER (two pairs of recessive epistatic major genes) in E4, which the additive effect value was 1.431 and 1.108 for the first and the second major genes respectively, and the heritability of the major gene was 51.77%. The optimal genetic model for flag leaf width (except E2) was 2MG-CE, the additive × additive epistatic interaction value was 0.119, and the heritability of major genes was 37.29%, while it showed polygenic inheritance in E2. The optimal genetic model for flag leaf area was 2MG-CE, which the additive × additive epistatic interaction value was 3.067 and the heritability of the main gene was 44.42%. The genetic models of flag leaf traits were different in different environments, which the genetic model was more stable under HN than that in LN. The correlation analysis of flag leaf and yield traits showed that flag leaf traits were significantly positively correlated with grain number per spike, grain weight per spike and yield per plant, and the influence degree was different in the 6 environments. 【Conclusion】 Flag leaf traits are easily affected by environment, and the performance of flag leaf traits is different in HN and LN. Flag leaf traits exhibited different major gene inheritance and polygene inheritance in LN, while they showed major gene inheritance which controlled by two pairs of interactions genes in most of HN environment, which might be major QTLs. Yield per plant and grain weight per spike could be increased by improving flag leaf traits.

【Objective】 Maize growth period traits, including flowering time, are the ones of most important in maize breeding. The advancement of heading date, silking time, and the pollen shed can ensure maize kernels fully dehydrated and thus suited to machinery harvesting. Moreover, the saved time can also leave for wheat sowing under the Maize-Wheat farming mode in Huang-Huai-Hai area. Transcription factors are important up-stream trans-action factors of gene expression regulation, which play roles in transcriptional activation or inhibition on target genes by binding to and driving their promoters. It is of great significance to analyze the regulatory effects of transcription factors on maize flowering time at the whole genome scale, it is also emergence to obtain the maize transcription factor haplotypes which associated with earlier flowering and higher yield. The haplotypes, or the haplotype combinations, will be served as excellent germplasm resources for maize breeding. 【Method】 In this study, candidate gene association analysis was performed to analyze maize flowering time related transcription factors and significant SNPs. DAP-seq was carried out to obtain the binding sites and down-stream genes of the key transcription factors. Followed by GO analysis on the down-stream genes to explore the transcription factor dependent gene expression regulatory network. 【Result】 There are 75, 75, and 128 significant SNPs detected in combinations of the traits Silking time and Heading date, the traits Silking time and Pollen shed, and the traits Heading date and Pollen shed, respectively. Altogether, there are 58 significant SNPs associated with all three flowering time traits. These results suggest that the three traits of flowering time may be regulated by the same transcription factors. Flowering time associated transcription factor genes that containing 3 or more significant SNPs were selected for DAP-seq to capture the key motifs and down-stream genes. Down-stream genes bound by flowering time associated transcription factors are significantly enriched in transcription factor activity, DNA binding, RNA binding, organonitrogen compound metabolic process, reproduction-related developmental processes, etc. Different transcription factors have co-regulated downstream genes related to flowering time. The key regulatory transcription factors for flowering time traits are ARF, MYB and NAC. Through haplotype analysis, the optimal TF haplotype combination that shows earlier flowering and no negative impact on yield was selected. 【Conclusion】 In this research, through candidate gene association and DAP-seq, the regulatory network of transcription factors on the flowering time related agronomic traits were established at the whole genome scale. The optimal haplotype combination of transcription factors that not only advances the flowering time, but also has no negative impact on yield was selected for further use in maize breeding.

【Objective】 Sorghum is one of the main raw materials for wine making and feed. The ratio of amylose content to amylopectin content in its grains is closely related to liquor quality and feed quality. Traditional chemical detection methods of sorghum components are no longer suitable for high-throughput testing. Modified PLS is used to perform spectral preprocessing, score processing and result monitoring on the near-infrared spectra of sorghum samples to establish sorghum grain amylose and amylopectin. The prediction model of amylose content aims to obtain a fast, efficient and low-cost detection method, laying the foundation for genetic improvement and quality analysis of sorghum. 【Method】 From 450 sorghum resources, 112 representative varieties were selected as calibration set and verification set. The chemical values of amylose and amylopectin content in 112 sorghum varieties were measured, and near-infrared spectra with wavelengths of 850-1 048 nm were collected, and the spectrum was scanned data matrix and chemical data calculated score (PL1) processing and interpreting the differences between the spectra, and eliminating abnormal species with Global H (GH) greater than 3 to reduce modeling errors. Modified PLS regression technology is used for modeling, and different calibration models are established through different scattering processing and derivative processing methods. Determine the best model according to the cross-validation standard deviation (SECV) and cross-validation correlation coefficient (1-VR), and perform result monitoring and non-parametric testing to evaluate the predictive performance of the model.【Result】 The near-infrared prediction model SECV of amylose is 2.7732, 1-VR is 0.9503, and the correlation coefficient (RSQ) is 0.9688. Bias=0.229<2.7732(SECV)×0.6, that is, the deviation (Bias) is less than 0.6 times of the calibration model SECV; the predicted standard deviation (SEP)=1.266<2.7732(SECV)×1.3=3.60516, that is, the SEP is less than the calibration. The model SECV is 1.3 times, 11.01(SD)-10.81(SD)=0.2<11.02(SD)×0.2=2.204, that is, the difference between the standard deviation (SD) of the chemical data and the near-infrared prediction data is less than 20% of the chemical data SD. The near-infrared prediction model SECV of amylopectin is 1.7516, 1-VR is 0.8818, and RSQ is 0.9127. Bias=-0.014<1.7516(SECV)×0.6 means that Bias is less than 0.6 times of SECV of calibration model, SEP=1.316<1.7516(SECV)×1.3=2.2708 means SEP is less than 1.3 times of SECV of calibration model, 5.30-5.29=0.01<5.30×0.2=1.06, that is, the difference between the chemical data and the near-infrared prediction data SD is less than 20% of the chemical data SD. Using 30 sorghum grains outside the model to conduct a two-pair sample non-parametric test on the validity of the model, the results showed that the difference between the measured and predicted values of amylose content and amylopectin content was not significant (P=0.262>0.05; P=0.992>0.05).【Conclusion】 The established near-infrared model has high accuracy and good stability, can accurately and quickly detect the content of amylose and amylopectin in sorghum, and can be used for the genetic improvement of sorghum and the detection of sorghum quality.

【Objective】 The aim of this study was to clarify the effects of sowing dates on the eating quality of indica hybrid rice in sub-suitable area of ratoon rice, so as to provide the theoretical and practical basis for the adjustment of planting structure and high quality cultivation in sub-suitable area of ratoon rice.【Method】 Field sowing dates experiments were conducted in the two sub-suitable area of ratoon rice in Sichuan (Longchang and Qianwei) with three indica hybrid rice varieties, namely Chuanyou 6203, Yixiangyou 2115, and Fyou 498. The effects of sowing dates on eating quality of indica hybrid rice in sub-suitable area of ratoon rice were studied by the determination of amylose and protein content, and the analysis of rice aroma, appearance, palatability, flavor, cold rice texture, as well as comprehensive score following the national standard sensory evaluation method.【Result】 (1) The eating quality of indica hybrid rice was affected by location, sowing date, variety, and their interactions. (2) The effects of sowing dates on the eating quality of different rice varieties were different to the study locations in the sub-suitable area of ratoon rice. The amylose content, protein content, palatability, taste, and flavor in the two study years, as well as the palatability and comprehensive score in 2018 in Longchang were significantly lower than that in Qianwei. Compared wtih the conventional sowing date, suitably delayed sowing date could improve the amylose content, palatability, and taste of rice by decreasing the temperature stress during grain filling stage, which resulted in the increase in comprehensive score of rice. This made the taste quality of rice closer to that of the ratoon rice. (3) Correlation analysis showed that amylose content, palatability, and flavor had significantly or extremely significantly negative correlation with the average daily maximum, minimum, and average temperatures, and sunshine hours from the 20 days after heading to mature stage, while comprehensive score was significantly and negatively related to the average daily minimum temperature from the 20 days after heading to mature stage. (4) The GGE-bioplot double plot analysis showed that the third sowing date in Longchang and second and third sowing dates in Qianwei had higher score and better stability of comprehensive score. 【Conclusion】 On the basis of ensuring the yield of rice, Longchang ecological point was sowed at the third sowing date (early May), and Qianwei ecological point was sowed at the second sowing date (March 20-March 25), which could avoid high temperature stress during the grain filling period of rice and improve the eating quality of hybrid indica rice. Furthermore, the selection of high-quality eating varieties as Yixiangyou 2115 and Chuanyou 6203 with suitable delaying of sowing date possessed higher taste quality in the sub-suitable area of ratoon rice.

【Background】 Rice (Oryza sativa L.) is the most important cereal crop in China. An importance rice cultivation location in high latitude in China is Northeast region due to its superior production area. This region accounts for over 50% high quality japonica rice production in China. However, for nearly half a century, the annual average temperature of this region has increased by 1.1℃, making it the most obvious region of climate warming in China. 【Objective】 To ensure the continuous production of high-yielding and good quality japonica rice, it is of great significance to assess the impact of climate warming on rice yield and grain quality in the Northeast region of China. 【Method】 A 2-year field warming experiment (1.5℃) with two japonica rice cultivars (Longdao 5 and Longdao 18) employed under a free air temperature increase (FATI) facility was conducted in Harbin city, Heilongjiang province. The aim of this study was to evaluate the effects of elevated temperature (ET) on rice growth period, grain yield, milled quality, appearance quality, nutrient and cooking quality. 【Result】 The results of the study showed that the growth duration of rice under ET was reduced by 6-7 days and 4-5 days when compared with CK in 2017 and 2018, respectively. This was as a result of the shortened duration from the transplanting stage to heading stage. The average yield of Longdao 5 and Longdao 18 for the two-year increased by 5.8% and 14.4%, respectively, mainly due to the increase in effective panicle number per unit area. The ET significantly decreased amylose content in the rice grain, but varied slightly in-terms of brown rice rate, milled rice rate, head rice rate and protein content. The peak viscosity, hot paste viscosity and cool paste viscosity increased under ET, while consistence viscosity decreased. There was no significant influence of elevated temperature on setback viscosity in both Longdao 5 and Longdao 18. 【Conclusion】 Based on the lower background air temperature, increasing temperature by 1.5℃ in the high latitude region of Northeast promoted japonica rice yield and cooking quality, however, the continued warming would increase the uncertainties of rice quality variation in the future.

【Objective】 This study clarified the nitrogen absorption and utilization characteristics in maize-peanut intercropping by studying the nitrogen concentration, nitrogen uptake, nodulation of peanut and nitrogen distribution under different configurations, which provided a basis for regional screening and application of nitrogen efficient model of maize-peanut intercropping system. 【Method】 A field study with 10 treatments was conducted in National Agricultural Experimental Station for Agricultural Environment in Fuxin in 2015 and 2016, including four cropping systems, such as sole maize (M), sole peanut (P), intercropping system of 2 rows maize and 4 rows peanut (M2P4), and intercropping system of 4 rows maize and 4 rows peanut (M4P4). Each maize treatment included three maize planting densities (6, 9 and 12 plants/m²). The characteristics and advantages of nitrogen uptake and utilization in maize-peanut intercropping system with different configurations (row proportion and maize density) were analyzed. 【Result】 Compared with monocropping, the change of nitrogen concentration in maize and peanut plants was not significant, the yield and nitrogen yield of maize and peanut in intercropping was lower than that in monocropping due to the different proportion of land occupy, and was consistent with intercropping biomass performance. Maize-peanut intercropping significantly increased the system nitrogen uptake, nitrogen uptake equivalent ratio (NER)>1, which was mainly due to the nutrient absorption advantage of maize (pNER_m was 0.63-0.80). The NER was increased with the row and density of maize increasing. The nitrogen uptake under M4P4 pattern (NER 1.06-1.22) was significantly higher than that under M2P4 pattern (NER 1.0-1.06). In maize-peanut intercropping system, maize was more competitive than peanut (A_mp>0), and the competitive ability to absorb nitrogen was also stronger (CR_mp>1), and M4P4 pattern and maize densification could enhance maize competition for nitrogen and increase the advantage of nitrogen uptake (△NU>0) and the contribution of intercropping nutrients to yield. Intercropping with maize could promote nodule formation of peanut. The number of nodule, weight of nodule per plant and weight per nodule of peanut under M4P4 pattern were higher than those under M2P4 pattern, and medium and low planting density treatments were better for nodulation. The soil available nitrogen content (N_min) in the intercropping system was higher in the peanut strip than in the maize strip, and the N_min in the sole peanut strip was higher than that in the intercropped peanut strip, while the N_min in the sole maize strip was lower than that in the intercropped maize strip. 【Conclusion】 Maize-peanut intercropping could significantly improve the nitrogen uptake and utilization in the system, and maize contributed more to the system nitrogen uptake. Moderate increase of maize row ratio and density was beneficial to increase the nitrogen uptake equivalent ratio, enhance maize competition for nitrogen nutrition, and the contribution of intercropping nutrients to yield. In this study, M4P4-6 and M4P4-8 were the better pattern for maize-peanut intercropping. The promotion of maize-peanut intercropping on dry matter and peanut biological nitrogen fixation, as well as the competitive ability of maize to absorb nitrogen, were the important reasons for the advantages of maize-peanut intercropping in nitrogen utilization.

【Background】 Citrus Huanglongbing (HLB) is a citrus disease caused by ‘Candidatus Liberibacter asiaticus’ (CLas). The main approaches to control HLB include plant quarantine, establishing disease-free nurseries, removing disease trees, and concentrating on large area joint control of citrus psyllids (Diaphorina citri). The first three methods all rely on accurate HLB diagnosis techniques.【Objective】 The objective of this study is to establishment of a rapid and handy field/laboratory nucleic acid detection method of CLas using loop-mediated isothermal amplification (LAMP) combined with membrane adsorption rapid DNA extraction and Gelgreen fluorescence dye visualization.【Method】 The LAMP primers were designed using the β-operon and the prophage DNA polymerase gene of CLas as templates, including outer primer F3/B3, inner primer FIP/BIP, loop primer LoopF/LoopB and stem primer StemF/StemB. The LAMP primer set was optimized by setting different dosage combinations for loop primers and stem primers to determine the appropriate primer concentration. A total of 188 field citrus leaves were detected using the optimized LAMP primer set, and the receiver operating characteristic (ROC) curves were constructed to analyze the accuracy of real-time fluorescent LAMP (qLAMP) for CLas detection. The qLAMP premixed reaction solution was dried in two steps at room temperature, storage temperature (4, 25 and 35℃) and storage time (1, 2 and 4 weeks) were also set to assess the enzyme activity stability of the dry LAMP reagent. Using dry LAMP reagent, combined with membrane adsorption rapid DNA extraction technique in this study, 71 citrus leaf samples and 35 citrus fruit samples collected in the field were detected, while the detection results of real-time fluorescent quantitative (qPCR) were used as controls to compare the coincidence rates of the two detection methods.【Result】 The addition of loop primer, stem primer or increasing their concentrations in LAMP reaction could promote the increase of reaction rate, and the addition of both loop primer and stem primer at a final concentration of 1.6 μmol·L^-1 could further improve the reaction rate. The reaction activity of LAMP premix could be maintained unchanged by two-step drying at different temperatures for 1-4 weeks, indicating that the two-step drying LAMP reagent prepared in this experiment had good detection performance and fair stability at low and room temperatures, and only at 35℃ storage would slightly increase the reaction time of LAMP reagent. Using 0.1 μm pore size nylon membrane instead of cellulose filter paper as nucleic acid adsorption material could improve the sensitivity of rapid diagnostic techniques. The overall accuracy of rapid DNA diagnosis for HLB established by combining rapid DNA extraction and visual LAMP was high, and the lowest detectable plasmid concentration was 10² copies/μL. The diagnostic results of this method were not significantly different from those of qPCR by paired Chi-square test. The visual LAMP rapid detection was less cost and time-consuming than routine detection, and visual LAMP rapid detection required no expensive instruments such as centrifuges and PCR instruments, requiring only a 65℃ thermostatic device.【Conclusion】 The rapid DNA detection method for CLas established in this study has low cost and can observe detection results in 30 min, easy to operate and high accuracy, which can replace qPCR for rapid identification of HLB in the field.

【Objective】 Grapholitha molesta is an important fruit pest in apple orchards in southern Xinjiang, which seriously affects the yield and quality of apple. The influence of agricultural landscape configuration and composition on the population number of G. molesta in apple orchards was clarified to provide a theoretical basis for the rational design of agricultural landscape that reduces the harm of G. molesta under the adjustment of cropping structure in southern Xinjiang.【Method】 A total of 50 apple orchards were selected as experimental sites in Aksu area from 2017 to 2020. The landscape composition within a radius of 2.0 km of each site was investigated. The insect sex pheromone traps were used to investigate the population dynamics of G. molesta adult. Regression models of Shannon diversity index (SHDI), perimeter area ratio (PARA), edge density (ED), and the area proportion of non-crop habitats, host crops and other (non-host) crops in landscapes at four scales (0.5, 1.0, 1.5 and 2.0 km) were fitted with the number of adults of the first, second and third generations in apple orchards.【Result】 In the study area, the proportion of host crops was highest (45.7%-55.0%), followed by other crops (18.2%-21.0%) and non-crop habitats (13.5%-19.7%). There was a negative correlation between the abundance of the first generation adult and the proportion of other crops at 2.0 km scale (P=0.062). The abundance of the second generation was negatively correlated with other crops at four scales (0.5 km, P<0.001; 1.0 km, P<0.001; 1.5 km, P=0.028; 2.0 km, P=0.043), negatively correlated with the proportion of host crops at 1.0 and 1.5 km scales (1.0 km, P=0.026; 1.5 km, P=0.048), negatively correlated with the proportion of non-crop habitats at 0.5 and 1.0 km scales (0.5 km, P=0.023; 1.0 km, P=0.019), but positively correlated with Shannon diversity index (SHDI) (0.5 km, P<0.001; 1.0 km, P=0.005). The abundance of the third generation was negatively correlated with the proportion of non-crop habitats at 0.5 km scale (P<0.001).【Conclusion】 Increasing the proportion of host crops, other crops, and non-crop habitats within agricultural landscape decreased the occurrence of G. molesta in apple orchards. However, landscape diversity (Shannon diversity index) promoted the population number of G. molesta. Therefore, increasing the area of the other crops and non-crop habitats coupled with no mixed planting of host crops in landscapes could be beneficial to the management of G. molesta.

【Objective】 In order to provide a scientific basis for the efficient utilization of phosphorus in farmland, the effects of different rotation systems on the availability of soil phosphorus were explored to evaluate the potential of soil phosphorus activation in different crop rotation systems. 【Method】 The experiment was conducted at Rugao Institute of Agricultural Sciences, Jiangsu Province from 2018 to 2020. Four paddy-upland rotation systems in the experiment included rice-wheat (R-W), rice-oilseed rape (R-O), rice-cabbage (R-C), and rice-fallow (R-F) rotation. Three fertilization treatments under each rotation system were applied, including no fertilization treatment (CK), no phosphate treatment (NK), and NPK fertilization treatment (NPK). The variation patterns and main influencing factors of soil phosphorus balance and availability under different paddy and upland rotation systems were clarified by analyzing the phosphorus uptake by aboveground crops, soil phosphorus fraction contents, soil microbial biomass and soil alkaline phosphatase activity under different phosphorus application conditions in dry season and rice season maturity. 【Result】 The severe imbalance of soil phosphorus under NK treatment resulted in differences in the supplement of soil available phosphorus in different rotation systems. Under NK treatment, R-O rotation could maintain a higher phosphorus output and promote the replenishment of soil available phosphorus. Specifically, the relative content of soil labile phosphorus in R-O rotation in dry season under NK treatment was 5.7%-7.3% lower than that in other rotations, and the relative content of soil moderately labile phosphorus and stable phosphorus were 4.2%-6.4% and 0.9%-1.9% higher than that in other rotations, respectively. However, the relative content of soil moderately labile phosphorus in R-O rotations under NK treatment in rice season was 0.5%-3.0% higher than that under other rotations, and the soil labile phosphorus and stable phosphorus were 0-1.5% and 0.2%-2.3% lower than that under other rotations, respectively. Under NK treatment, the soil microbial biomass C/P ratios of R-O rotation was relatively small in both dry season and rice season, and it was significantly lower than that under R-W rotation in rice season. The soil microbial biomass N/P ratios also had a similar trend. But the soil alkaline phosphatase activity of R-O rotation maintained a high level in both dry season and rice season. The path analysis model showed that the phosphorus accumulation (-0.53) and the soil alkaline phosphatase (-0.51) had the most contribution to the soil available phosphorus in dry season and rice season, respectively. 【Conclusion】 When the soil phosphorus was relatively imbalance, the rice-oilseed rape rotation released more alkaline phosphatase in dry season and regulated the soil microbial biomass C/P ratio in rice season, which was conducive to promoting the activation of the non-labile phosphorus by microorganisms to supplement the labile phosphorus, so as to ensure the relative stable of soil available phosphorus content without affecting phosphorus output.

【Objective】 The influence of organic carbon on the contents and transformation of soil in organic phosphorus fractions were investigated, which can help to formulate soil managemental strategies whereby to improve phosphorus use efficiency in tier soil.【Method】 The soil samples were collected and selected with a gradient of organic carbon levels but similar in Olsen-P (ranges from 17.41 mg·kg^-1to 18.72 mg·kg^-1) under winter wheat summer maize cropping in the Guanzhong Plain of Shaanxi Province. The organic carbon contents of the selected soil samples were 6.38, 8.34, 10.17, 11.95, 13.64 and 15.74 g·kg^-1, respectively. Then the soil inorganic phosphorus fractions (dicalcium phosphate (Ca₂-P), octa-calcium phosphate (Ca₈-P), apatite (Ca₁₀-P), aluminum bounded phosphate (Al-P), iron bounded phosphate (Fe-P) and occluded phosphate (O-P)) were analyzed with the phosphorus fractionation procedure proposed by Chang & Jackson and modified by Jiang and Gu.【Result】 The results showed that organic carbon played an important role in transformation of soil inorganic phosphorus in the winter wheat-summer maize cropping in Guanzhong Plain of Shaanxi Province. The soil Ca₂-P, Ca₈-P, Al-P, Fe-P, O-P fractions, moderately labile P (Ca₈-P, Al-P and Fe-P), and stable P (O-P and Ca₁₀-P) pools were increased significantly and linearly with increasing soil organic carbon, whereas Ca₁₀-P remained unchanged. The relative contents of labile-P (Ca₂-P), moderately labile P (mainly Al-P) were significantly and positively correlated with SOC content, but stable P (mainly Ca₁₀-P) showed significant negative correlation with SOC. Soil Olsen-P increased significantly and linearly with increasing stable P.【Conclusion】 Under the similar soil Olsen-P and total phosphorus conditions, soil organic carbon improved the availability of soil phosphorus mainly through promoting the conversion of stable P to moderately labile P and labile P in the soil, increasing the ratio of available phosphorus to inorganic phosphorus, and improving the availability of soil phosphorus. The results implied that improvement of soil fertility (SOC) could promote the activation and utilization of legacy phosphorus in soil.

【Objective】 The massive ammonia (NH₃) volatilization from excessive nitrogen (N) fertilization is a common issue in greenhouse cultivated vegetable production in China. To alleviate this problem, a field experiment was conducted to study the effects of different fertilization methods on NH₃ volatilization of greenhouse vegetable fields.【Method】 The study was carried out with 6 fertilization treatments via one-time basal fertilization and two-time topdressings, including N fertilizer-blank treatment (Control), conventional fertilization treatment (CF), 20% N-reduced slow-release fertilizer treatment (SF), 20% N-reduced organic fertilizer treatment (OF), 20% N-reduced microbial fertilizer treatment (MF) and integrated management of water and fertilizer treatment (IM). Except for the Control treatment, an identical application ratio of N, P and K fertilizers was employed to each treatment throughout the whole vegetable growing season. The NH₃ volatilization fluxes under different fertilization methods were observed by using venting absorption method. The potential influencing factors of NH₃ volatilization were also investigated synchronously.【Result】 The dynamics of NH₃ volatilization under different fertilization treatments were similar, and the occurrence of the peaks of NH₃ flux was highly associated with fertilization time. During basal fertilization period, for the most of treatments, the NH₃ fluxes peaks appeared 3-days after the application of basal fertilizer, while it was only 1-day under IM treatment. The maximum fluxes of NH₃ ranged from 0.12 to 0.26 kg NH₃·hm^-2·h^-1 during basal fertilization period. The occurrence of the peaks of NH₃ fluxes were ahead by 1-2 days during topdressing periods. The maximum fluxes of NH₃ volatilization were 0.08-0.19 kg NH₃·hm^-2·h^-1 during the first topdressing period, and 0.13-0.18 kg NH₃·hm^-2·h^-1 during second topdressing period. Significant differences were found among different fertilization treatments in the seasonal cumulative NH₃ volatilizations. The seasonal cumulative NH₃ volatilizations in the decreasing order of different treatments were CF, MF, OF, SF, IM, Control. Compare with CF treatment, the treatments of SF and IM markedly reduced NH₃ volatilization from greenhouse vegetable field by 24.2% and 42.4% (P<0.05), and reduced by 10.1% and 8.3% (P>0.05) under MF and OF treatments, respectively. The NH₃ volatilization-induced N losses in the decreasing order of different treatments were MF, OF, CF, SF, IM. Compare with the rest of the applied treatments, the IM treatment consistently showed lower NH₃-N loss rate during the whole season. However, the NH₃-N loss rates under MF and OF treatments were different during basal fertilization and topdressing periods. In the basal fertilization period, the MF and OF treatments showed lower NH₃-N loss rates compare with CF treatment, however, during topdressing period, the NH₃-N loss rates under MF and OF treatments were higher than that under CF treatment. 【Conclusion】 Compare with CF treatment, both of the SF and IM treatments could significantly reduce the NH₃ volatilization that derived from applied N fertilizer. The IM treatment reduced NH₃-N-induced N fertilizer loss in both basal fertilization and topdressing periods, while the SF treatment mainly reduced the NH₃ volatilization during basal fertilization period. On balance, both the application of slow-release fertilizer and the technique of integrated management of water and fertilizer were the effective ways in the reduction of NH₃ volatilization from greenhouse vegetable field, and were worthy for recommendation.

【Objective】 The aim of this study was to analyze the genes involved in the regulation of ABA induced grape coloring, and to explore the molecular mechanism of ABA induced anthocyanin accumulation in grape. 【Method】 In present study, Benibalado was used as the experimental material. In the early stage of veraison, the grape clusters were treated with 300 mg·L^-1ABA, water treated as control. The grape phenotypes were observed and anthocyanins were determined by UPLC-MS. The mechanism of ABA promoting anthocyanin accumulation was analyzed by transcriptome sequencing. 【Result】 After 3 days of exogenous ABA treatment, the grape berries were obviously colored, and the variety and content of anthocyanins were also increased. Among them, Peonidin 3-O-glucoside and Malvidin 3-O-glucoside increased most significantly. By KEGG enrichment analysis, 11 DEGs related to ABA signaling and 52 DEGs that related to anthocyanin biosynthesis, and transportation were identified, all of which were up-regulated. After exogenous ABA treatment, the DEGs from RNA-seq were searched by using BLAST against the grape TF database, and 297 transcription factors were identified. Through the further analyzing of the expression patterns of identified TFs, 15 members of MYB, bHLH, bZIP, NAC, Dof, and HD-ZIP families were observed to regulate anthocyanin biosynthesis. The analyzing of cis-acting elements in promoters showed that ABREs were identified in most of the promoters. The accuracy of RNA-seq was validated by qRT-PCR analysis of some candidate genes. 【Conclusion】 Overall, ABA promoting anthocyanin accumulation in grape was a complex process, including 11 DEGs related to ABA signal transduction, 52 DEGs that related to anthocyanin biosynthesis, modification and transportation, 15 transcription factors. This study provided a basis for revealing the molecular mechanism of ABA promoting anthocyanin accumulation in grape fruits.

【Objective】 This study aimed at analyzing both expression patterns and regulatory pathways of tea plants in response to glyphosate stressing, which could revealed the effect of glyphosate herbicides on tea plants at transcriptional level and identify key genes of tea plants. 【Method】 C. sinensis cv Jin-guanyin was applied as material plant. A recommended concentration of glyphosate was irrigated to test plants. The leave samples were collected at different time intervals (0, 0.25, 1, 3 and 7 d). The samples were sequenced by transcriptome, the content of shikimic acid was also quantified. The WGCNA method was used to jointly analyze transcriptome and shikimic acid content data, to identify co-expressed gene modules related to glyphosate response, and to screen out key regulatory genes. 【Result】 The content of shikimic acid in tea leaves reduced gradually during first 3 days. However, it suddenly reached a peak on the 7th day (6.99 times compared with no glyphosate treated sample). A total of 12 568 differential expression genes (DEGs) were also identified, which mainly enriched in phenylpropane, flavonoid biosynthesis and plant hormone signal transduction pathways. In addition, the glyphosate treatment induced 24, 52, 31 and 69 genes respectively which related to shikimic acid metabolism, phenylpropane, flavonoid biosynthesis and hormone signal transduction pathways. A total of 19 modules were screened out by WGCNA method. The correlation analysis of transcriptome and shikimic acid content indicated two key modules, including 2 024 and 2 305 genes, respectively. The top 50 genes with the highest connectivity in the key modules were selected for co-expression analysis, and 6 key response genes were obtained, including 2 resistance genes (SHMT and RPM), 1 drug resistance gene (PDR), 1 ion transport gene (At), 1 membrane transport gene (GPT), and 1 transcription factor gene (ERF).【Conclusion】 Glyphosate could affect downstream genes transcription of phenylpropane, flavonoid biosynthesis and hormone signal transduction pathways by interfering shikimic acid metabolism of tea plants. In addition, this study also identified two co-expression modules closely related to glyphosate response, and found that multiple potential candidate genes and transcription factors could resist glyphosate stress, such as SHMT, RPM, At, PDR, ERF and GPT.

【Objective】 Tea saponin is a naturally active substance with wide application prospective, and its purity is the key factor limiting its application and value. In this study, the optimal conditions for ultrasonic-assisted two-phase extraction (UAATPE) of tea saponin from camellia meal were explored, and the possible extraction mechanism was discussed in order to develop an efficient, high-purity extraction technology, so as to provide a technical guidance for high-value utilization of camellia meal. 【Method】 On the basis of the single factor experimental results, the key factors affecting the yield of tea saponin were screened by Plackett Burman design, and the extraction process was optimized by Box-Behnken design. The extraction efficiency of tea saponin using the UAATPE method was evaluated by comparing the extraction yield and purity to the traditional ethanol extraction method and water extraction method. Scanning electron microscopy (SEM) was employed to analyze the microstructure of camellia meal, and the possible mechanism of extraction by the UAATPE method was discussed. 【Result】 The key factors affecting the yield of tea saponin were mass fraction of ethanol, mass fraction of ammonium sulfate, and ultrasonic time. The process parameters optimized by Box-Behnken design were as follows: an ethanol content of 27.50% (W/W), an ammonium sulfate content of 19.60% (W/W), a liquid-solid ratio of 50﹕1, an ultrasonic time of 32 min, an ultrasonic power of 300 W and an extraction temperature of 60℃, and the yield of tea saponin at (26.21±0.54)% was achieved under the optimized conditions. Compared with the traditional method of ethanol extraction, the purity of tea saponin extracted by the UAATPE method increased by 6.57% (P<0.05), although the difference of the yield of tea saponin extracted by these two methods was not significant. Compared with the traditional method of water extraction, the yield and purity of tea saponin extracted using the UAATPE method were increased by 17.74% and 40.23%, respectively (P<0.01). The microstructure showed that owing to the effect of the camellia meal treated by the UAATPE method, the ultrasonic cavitation accelerated the tissue damage of the camellia meal, producing a large number of voids and strong surface shrinkage, which effectively promoted the release of tea saponin in the camellia meal. In the process of the UAATPE extraction, the tea saponin first entered the bottom phase with high electrical conductivity through solid-liquid extraction in the two-phase water system, and then moved to the top phase with high polarity through liquid-liquid extraction, achieving primary purification and improving the purity of tea saponin. 【Conclusion】 The UAATPE method could significantly improve the yield and purity of tea saponin, thus providing a new novel method for the efficient utilization of camellia meal.

【Background】Subcutaneous adipose tissue (SAT) under the skin is an important factor affecting the taste of meat. Exploring the molecular regulation mechanisms of SAT deposition is very important for breeding improvement and the development of animal husbandry. Krüppel-like factors 12 (KLF12) is a conserved transcription factor that evolutionarily conserved, and it was found that it could be expressed in a variety of cell types and control a wide range of cellular processes. 【Objective】 This study aimed to obtain the coding sequence (CDS) of goat KLF12 and to explore its molecular characteristics. Moreover, the study also intended to clarify the expression pattern of KLF12 in goat tissues and subcutaneous adipocytes, and to explore the role of KLF12 in goat subcutaneous preadipocytes differentiation via interference KLF12, so as to provide a theoretical basis for further research on the potential role of KLF12 in the process of fat deposition. 【Method】 In this study, the goat KLF12 CDS sequence was cloned by Reverse Transcription PCR ( RT-PCR) method, and the nucleotide sequence and amino acid sequence of goat KLF12 were analyzed on online bioinformatics analysis software. The Quantitative Real-time PCR (qRT-PCR) technology was used to detect the expression levels of KLF12 in goat heart, liver, abdominal fat, subcutaneous fat, triceps brachii, longissimus dorsi and other 14 tissues. Furthermore, the expression level of KLF12 in subcutaneous preadipocytes in different differentiation periods was investigated. Then, the goat KLF12 small interfering RNA (si-KLF12) was chemically synthesized and transfected into goat subcutaneous preadipocyte in vitro by using Lipofectamine RNAiMAX transfection reagent. Subsequently, 100 µmol·L^-1 oleic acid induced adipocyte differentiation. Oil red O and Bodipy staining methods and qRT-PCR techniques were used to clarify the effects of interference KLF12 on the accumulation of lipid droplets in subcutaneous preadipocytes and the mRNA expression levels of adipose differentiation marker genes from the perspectives of morphology and molecular biology. 【Result】 The goat KLF12 (1 315 bp) were successfully obtained, which contained an Open Reading Frame (ORF) (1 209 bp) and encoded 402 amino acids. The subcellular localization results showed that KLF12 was mainly located in the nucleus. In addition, KLF12 had no transmembrane domain and signal peptide but 3 typical zinc finger domains (ZnF_C2H2) at amino acids 317-341, 347-371 and 377-399. Tissue expression profile showed that the expression level of KLF12 in goats’ heart and spleen were significantly higher than that in other tissues (P<0.01). Moreover, during subcutaneous preadipocytes differentiation, the expression level of KLF12 was peaked at 60 h. After transfection of si-KLF12 into goat subcutaneous preadipocytes, the results of oil red O and Bodipy saining showed that accumulation of lipid droplets in adipocytes were significantly increased. At the same time, the results of qRT-PCR showed that the expression levels of key adipogenic regulatory genes like lipoprotein lipase (LPL) and peroxisome proliferator-activated receptor γ (PPARγ) were significantly increased (P<0.05), while the expression level of preadipocyte growth factor (Pref-1) was extremely significantly reduced (P<0.01). Combined with the morphological observation results and the changes in the expression levels of key adipogenic regulatory genes, it was speculated that KLF12 played a negative regulatory role in the differentiation of subcutaneous adipocytes. 【Conclusion】 By investigating the basic molecular biological characteristics and its expression pattern between tissues and cells of goat KLF12 and analyzing the potential regulatory effects of KLF12 on differentiation process of goat subcutaneous adipocytes, the results suggested that KLF12 played a negative role in goats subcutaneous preadipocytes differentiation, and this effect achieved by regulating LPL, PPARγ and Pref-1, which laid a foundation for further exploring the molecular mechanism of KLF12 in regulating the differentiation of adipocytes.

【Objective】 After the first outbreak of African Swine Fever (ASF) in Shenyang, China in 2018, it has rapidly spread to the whole country, severely hitting the pig industry. This study aimed to establish an optimized nucleic acid testing technique for African Swine Fever Virus (ASFV), so as to provide a fast and accurate method for early diagnosis and accurate treatment of ASF outbreaks. 【Method】 Appropriate primers and probes were designed and screened for the conserved gene B646L (p72) of ASFV, and a real-time fluorescent RPA assay based on recombinase polymerase amplification (RPA) was established. The reaction system, reaction conditions and sample treatment steps were optimized. Specificity and sensitivity of the optimized detection method were evaluated by using quality controls. In addition, 1 009 clinical samples were tested by the optimized real-time RPA, after which the results were further confirmed by the real time PCR recommended by OIE and through virus isolation. 【Result】 A pair of primers-probe combinations was successfully screened, and a real-time fluorescence RPA for detection of ASFV p72 gene was developed. The total volume of optimized reaction system was 25 μL. The reaction conditions were set as 39℃ 10 s, 39℃ 20 s, 40 cycles on the fluorescence quantitative PCR instrument, and the whole amplification reaction needs about 20 min. The analysis method at room temperature could replace the traditional nucleic acid extraction method, thus the whole process of sample treatment, nucleic acid amplification and result reading could be completed in 30 min. Specific evaluation showed that the real-time RPA was negative for porcine parvovirus (PPV), pseudorabies virus (PRV), circovirus type1/2 (PCV1/2), classical swine fever virus (CSFV) and porcine reproductive and respiratory syndrome virus (PRRSV); the sensitivity evaluation showed that the assay could detect type I/II/IX ASFV samples, and could detect 10 copies/μL of ASFV positive simulated blood samples and 1﹕10^3.0 dilution of positive clinical samples, which was as sensitive as the OIE-recommended qPCR method. Seventeen out of 1 009 clinical samples were tested positive using the real-time RPA, with the same results as by qPCR, 17 positive cultures were obtained from virus isolation. 【Conclusion】 A real-time RPA diagnostic method for ASF was developed, which was proved to be simple, less time consuming with high sensitivity and specificity, providing a new, simple, specific and rapid diagnostic method for ASF.

【Objective】 In this study, transcriptome-wide identification and analysis of miRNAs in the larval guts of Apis cerana cerana was conducted using a combination of small RNA-seq (sRNA-seq) technology and bioinformatic method, aiming to enrich the information of A. c. cerana miRNAs and offer a basis for further investigation of miRNA-regulated molecular mechanism underlying A. c. cerana larval gut development.【Method】 Gut samples of A. c. cerana 4-, 5-, and 6-day-old larvae (Ac1, Ac2, and Ac3 ) were sequenced using sRNA-seq technology, and clean tags were obtained after quality control. By using Blast tool, clean tags were continuously mapped to Apis cerana genome and miRBase database to identify known miRNAs and novel miRNAs. TPM method was used to perform normalization of miRNAs’ expression. The ratio of sRNAs, length distribution of miRNAs and first base bias were calculated with GraphPad Prism 7 software. Using related software, target mRNAs of above-mentioned miRNAs were predicted followed by GO and KEGG database annotation. Further, regulatory networks between genes associated with development and immune-related pathways and corresponding target miRNAs were constructed and analyzed, followed by visualization of regulatory networks with Cytoscape software. The authenticity of miRNA expression and sequence was verified by using Stem-loop RT-PCR, molecular cloning and Sanger sequencing.【Result】 In total, 371 known miRNAs and 64 novel ones of A. c. cerana were identified; their length was distributed among 18-25 nt, and the first base had an U bias. The aforementioned miRNAs could target 14 750 mRNAs, involving 2 270 GO terms such as ion binding, metal ion binding, membrane, membrane part and single-organism process, as well as 332 KEGG pathways including endocytosis, apoptosis, mTOR signaling pathway, RNA transport and insect hormone biosynthesis. Further investigation suggested that 156 miRNAs could target 67 genes relative to development-associated pathways such as Wnt, Hippo, Notch and mTOR signaling pathways, while 145 miRNAs could target 21 genes relevant to immune-associated pathways such as Toll, Imd/JNK, Jak-STAT signaling pathways and antimicrobial effectors. Stem-loop RT-PCR result indicated that specific fragments with expected sizes could be amplified from miR-8-y, miR-9-z, miR-14-y, miR-281-y, miR-283-x and miR-306-x; Sanger sequencing result demonstrated that sequences of above-mentioned six miRNAs were in accordance with those in deep sequencing result.【Conclusion】 Our findings provide number, structural characteristics and expression profile of A. c. cerana miRNAs, and unraveled that miRNAs in A. c. cerana larval gut potentially regulate a lot of life processes and cellular activities, part of miRNAs can participate in regulation of development-related and immune-related pathways by targeting corresponding mRNAs.

【Objective】 Genome-wide association studies (GWAS) were performed using multi-locus random-SNP-effect mixed linear (mrMLM) model to identify the significantly associated SNPs and candidate genes with yield traits, and lay a foundation for molecular marker-assisted selection breeding for sesame high yield.【Method】 In this study, 363 diverse sesame lines were assembled into an association-mapping panel. Eight yield-related traits, including seed yield per plant, capsule number per plant, seed number per capsule, 1000-seed weight, plant height, capsule axis length, first capsule height and apparent harvest index, were investigated. Genome-wide association studies were performed using mrMLM to detect significantly associated SNPs and predict important candidate genes related to yield traits.【Result】 Eight yield-related traits measured in four environments exhibited extensive phenotypic variation with 1.63%-17.29% of phenotypic variation coefficients. The seed yield per plant was positively correlated with capsule number per plant, plant height, capsule axis length, and apparent harvest index respectively. Analysis of variance indicated that significant variations were observed across environment, genotype, and the genotype × environment interaction. GWAS were performed and a total of 210 SNPs were detected for yield traits. Among these SNPs, 47, 35, 35, 53, and 75 SNPs were detected in 2018NY, 2019NY, 2018PY, 2019PY and BLUP, explaining 1.63%-17.29%, 1.94%-11.90%, 2.15%-15.90%, 1.25%-11.13% and 1.44%-13.58% of phenotypic variation, respectively. These 210 SNPs corresponded to 175 loci, and 10 loci were detected in more than 3 environments. A total of 214 candidate genes were identified, including 156 genes involved in metabolism, biological regulation, and developmental and growth process. Among these genes, 4 genes were selected as important candidate genes. SIN_1006338, encoding 1-aminocyclopropane-1-carboxylate synthase 3-like protein, was involved in ethylene biosynthesis. SIN_1024330, encoding transcription factor IBH1-like 1, was involved in regulating cell and organ elongation. SIN_1014512, encoding indole-3-acetic acid-amido synthetase GH3.6, was involved in shoot and hypocotyl cell elongation. SIN_1011473, encoding protein DA1-like, was involved in restricting the period of cell proliferation.【Conclusion】 One hundred and seventy-five loci were identified by mrMLM, and 4 important genes related to yield traits were selected.

【Objective】As one of the largest transcription factor families in plants, MYB genes play an important role in resisting stress. The MYB transcription factor GhMYB108 was cloned and analyzed to verify its role in drought stress response, which laid a foundation for further study on the molecular mechanism of GhMYB108 regulating drought tolerance in G. hirsutum.【Method】Through the analysis of unpublished drought transcriptome data, GhMYB108 was identified to drought response. The target gene was amplified from the root cDNA by polymerase chain reaction (PCR). Through bioinformatics analysis of gene structure characteristics, the sequence information and phylogenetic relationship of these genes were predicted. The obtained gene promoter sequences were analyzed by Plant Care website. The genes expression characteristics under different stress conditions were analyzed using Real time fluorescence quantitative PCR (qRT-PCR). The location of GhMYB108 protein was determined by subcellular localization. The transcriptional activity was tested in yeast cell; The GhMYB108 gene was silenced using Virus induced gene silencing (VIGS), and the gene silencing efficiency was detected by qRT-PCR. The phenotypic changes before and after drought treatment were observed and the survival rate was counted. The relevant physiological and biochemical indexes were measured by Solarbio Kit; The relationship between GhMYB108 and ABA was analyzed by spraying ABA and Fluridone on cotton leaves.【Result】GhMYB108 (Gh_A10G1563) was cloned from G. hirsutum, with 879 bp length and 292 amino acids. Its protein relative molecular weight and isoelectric point is 33.288 kD and 6.037, respectively. Multiple sequence alignment and conserved domain analysis showed that GhMYB108 contains two highly conserved MYB binding domains, which belongs to a typical R2R3 MYB transcription factor. Phylogenetic analysis of different species showed that GhMYB108 was highly homology with ATMYB108, ATMYB78 and ATMYB2, belonging to the same subfamily. Previous studies found that ATMYB108, ATMYB78 and ATMYB2 were related to drought and ABA signaling pathway. GhMYB108 located in the nucleus and had transcriptional activation activity. The expression level of GhMYB108 was the highest in roots and the lowest in stems, and was induced by abiotic stresses including natural drought, 18% PEG 6000 simulated drought, salt stress and low temperature. The GhMYB108 silenced plants showed a critical phenotype under natural drought conditions. Compared with the control, the silenced plants showed more serious wilting and decreased survival rate. Some physiological and biochemical indexes also changed significantly, such as accelerated leaf water loss rate, increased malondialdehyde content, decreased leaf relative water content and proline content, and decreased CAT and POD activities. Through DAB and NBT staining, the hydrogen peroxide (H₂O₂) and superoxide anion (O₂^-) were significantly accumulated in plants. By spraying the hormone ABA or Fluridone on cotton leaves, we found that GhMYB108 could be positively regulated by ABA signal.【Conclusion】GhMYB108 positively regulates cotton drought resistance and is positively regulated by ABA signal.

【Objective】The objective of this article was to establish a low-N tolerance evaluation system for sweetpotato varieties, to screen low-N-tolerant genotypes and evaluate different N efficiency categories and to provide a theoretical basis for studying the low-N-tolerant physiological mechanism of sweetpotato varieties and mining N-efficient genes.【Method】Under the treatment of low N stress (0 mmol·L^-1) and normal N application (14 mmol·L^-1) of hydroponic experiment. Selected 126 sweetpotato varieties from different sweetpotato areas at home and abroad, we collected eleven indicators, including the shoot biomass, shoot biomass increase, root biomass increase, plant biomass increase ratio, root-to-shoot ratio, vine length, root length, leaf number, CCI, nitrogen accumulation, nitrogen physiological utilization efficiency, and calculated the low-N tolerance index of all indicators. The study carried out principal component analysis by using the comprehensive membership function method, regression analysis and cluster analysis to comprehensively evaluate the low-N-tolerant sweetpotato varieties and N efficiency types.【Result】1) Under low N level, the average of the shoot biomass, shoot biomass increase, root biomass increase, plant biomass increase ratio, vine length, root length, leaf number, CCI, and N accumulation of 126 tested sweetpotato varieties was lower than that under normal N level, while the average of root-to-shoot ratio and nitrogen physiological utilization efficiency were higher than that under normal N level; 2) The variation coefficient of shoot biomass, shoot biomass increase, root biomass increase, plant biomass increase ratio, root-to-shoot ratio, vine length, root length, leaf number, nitrogen accumulation, nitrogen physiological utilization efficiency at low-N stress was higher than that at normal N level, and the amplification of them were ranked as shoot biomass increase>plant biomass increase ratio>root biomass increase>leaf number>shoot biomass>nitrogen physiological utilization efficiency>nitrogen accumulation>root length> root-to-shoot ratio>Vine length; 3) The principal component analysis was carried out on the low-N-tolerant index of eleven indicators, extracted three principal components, the cumulative variance contribution rate of which was 72.67%, and calculated the comprehensive evaluation Y-value; 4) The correlation between the low-N-tolerant index of shoot biomass, shoot biomass increase, root biomass increase, plant biomass increase ratio, leaf number, vine length, root length, root-to-shoot ratio, nitrogen accumulation, nitrogen physiological utilization efficiency and the Y-value were highly significant(P<0.01), among them, the correlation of shoot biomass increase, root biomass increase, plant biomass increase ratio, nitrogen accumulation and shoot biomass was higher, with the correlation coefficients of 0.85, 0.86, 0.81, 0.79 and 0.73, respectively; 5) The regression equation of the Y-value screened eight indicators to evaluate low-N tolerance of sweetpotato varieties, and the cluster analysis on eight indicators showed that the sweetpotato genotypes were classified into three types, low-N-tolerant, intermediate, and low-N-sensitive. The agronomic traits and N efficiency traits of three sweetpotato categories were analyzed by variance analysis.【Conclusion】Shoot biomass, shoot biomass increase, root biomass increase, root length, vine length, leaf number, nitrogen accumulation and nitrogen physiological utilization efficiency were selected as the low-N tolerance evaluation indicators of sweetpotato; The study screened 7 low-N-tolerant sweetpotato varieties: 13104-2/Zishu1, Yibinhongxinshu, Zhezishu 2, Yuzi 3, Yuzi 6, Luozi 1 and Yuzixiang 10; The results of variance analysis showed that the low-N-tolerant varieties performed better than the intermediate and the low-N sensitive varieties, and there are significant difference in five traits: shoot biomass, shoot biomass increase, root biomass increase, vine length and nitrogen accumulation.

【Objective】The purpose of this study was to explore the effects of interspecific distance on soil environment and root spatial distribution of maize-soybean intercropping, so as to provide a theoretical basis for crop roots to regulate the efficient utilization of nutrients.【Method】The field experiments were used one-factor randomized block design with 5 root interaction modes: maize-soybean intercropping spacing 30 cm (MS30), 45 cm (MS45), 60 cm (MS60), maize monoculture row spacing 100 cm (MM100), and soybean monoculture row spacing 100 cm (SS100). The changes of soil oxygen content, soil respiration rate, soil nutrient content, soil aggregate and root distribution were investigated.【Result】From dough stage (R4) to maturity stage (R6) of maize, as well as from the beginning seed (R5) to full maturity (R8) of soybean, the daily average soil oxygen content and soil respiration rate of intercropping treatment initially increased and then decreased later with the increase of interspecific distance; The soil oxygen content of maize was the highest in MS45, the lowest under MS30, while the soil respiration rate of intercropping was significantly lower than the monoculture. The soil respiration rate of soybean was the highest under MS45, which was 130.00% higher than that under SS100, while the soil oxygen content of intercropping was lower than that of monoculture. Compared with monoculture, the content of water-stable aggregates >5 mm in the soil of intercropping maize, the content of water-stable aggregates of 5-2 mm in the soil of intercropping soybean and the soil NO- 3-N were significantly increased, by 19.26%, 4.49%, and 18.07%, respectively; Among which, those contens under MS45 was the highest. During the co-growing period, compared with monoculture, the spatial distribution of maize and soybean roots under each intercropping treatment was asymmetrical, and the intercropping maize roots could extend horizontally below the space of soybean rows and grow deeper vertically. The root system of intercropping soybean was obviously inclined to the growth of soybean belt, and the total root length, root surface area, root volume and root dry weight of intercropping maize and soybean were lower than that of monoculture. After the maize was harvested, the intercropping soybean root system resumed growth and further extended in the horizontal and vertical directions. The root volume of MS45 was higher than those of monoculture. PCA analysis showed that soil nutrient content and water stable aggregate index were positively correlated with root morphological parameters.【Conclusion】Reasonable interspecific distance promoted the formation of soil large aggregates, increased soil oxygen content, improved soil aeration environment and soil nutrient, optimized the spatial distribution of crop roots, and promoted root growth and development.

【Objective】 In order to provide the important scientific reference for optimizing the layout of staple crops in Inner Mongolia, the adaptability of staple crops (maize, potato, oats, canola, oil and edible sunflower) was evaluated in four ecological regions of Inner Mongolia under different precipitation year types.【Method】Four typical sites in four ecological regions were selected. The validated APSIM model was used to quantify the potential yields, rainfed yields and yield gaps of six crops. Yield reduction rates of rainfed yields relative to potential yields under different precipitation year types were calculated to evaluate the adaptability of staple crops. Crop water production functions were conducted to analyze crop water sensitivity. 【Result】RMSE between simulated and observed vegetative growth period, reproductive growth period, dry yield was 10.1 d, 8.9 d, and 1 322.4 kg·hm^-2, respectively. NRMSE between observed and simulated vegetative growth period, reproductive growth period, and dry yield was 14.6%, 19.2%, and 22.6%, respectively. The validation results showed that APSIM could effectively simulate the growth, development, and yield of each crop in different regions. The potential dry yields of maize, potato, oats, canola, oil sunflower, and edible sunflower were 12 024±4 874, 7 315±806, 6 611±906, 2 424±326, 2 721±205, and 4 905±428 kg·hm^-2, respectively. The potential yields of oats and edible sunflower reached the maximum values in the north foot of Yinshan Mountains while potential yields of other four crops reached the maximum values in the Loess Plateau. The rainfed dry yields of maize, potato, oats, canola, oil sunflower, and edible sunflower were 3 056±2 902, 3 337±1 608, 2 974±1 677, 912±511, 869±618, and 1 508±984 kg·hm^-2, respectively. Average rainfed yields of the six crops increased from west to east and reached the maximum values in Da Hinggan Mountains. Yield gaps of maize, potato, oats, canola, oil sunflower, and edible sunflower were 8 968±5 844, 3 978±2 358, 3 637± 2 122, 1 512±832, 1 852±749, and 3 397±1 328 kg·hm^-2, respectively. Except maize and oats, the yield gaps of four crops decreased from west to east and reached the minimum values in Da Hinggan Mountains. Taking the yield reduction rate from potential to rainfed conditions as the drought index under the rainfed condition and considering the variation coefficients of rainfed yields, it was not suitable to plant crops in any years in the Loess Plateau. In the north foot of Yinshan Mountains, crops were not suitable for planting in dry years. Potato was suitable for planting in normal years, while potato and oats were suitable for planting in wet years. At the foothills of Yanshan hilly area, crops were not suitable for planting in dry years. Potato and oats were suitable for planting in normal years while six crops were all suitable for planting in wet years. In Da Hinggan Mountains, potato, oats, canola, and edible sunflower were suitable for planting in dry years, while six crops were all suitable for planting in normal and wet years. The linear correlations between the relative evapotranspiration and the relative yield of the six crops were all significant (P<0.01) with R² ranging from 0.84 to 0.99. The sensitivity of crop to water stress was in the order of oil sunflower, edible sunflower, maize, oats, canola, and potato.【Conclusion】This study revealed the adaptability of staple crops under different precipitation year types in the four ecological regions of Inner Mongolia. There was a large difference in water sensitivity of six crops. Under rainfed condition, potato were suitable for planting in normal and wet years in the north foot of Yinshan Mountains and the foothills of Yanshan hilly area, and in all year types in Da Hinggan Mountains. Oats were suitable for planting in wet years in the north foot of Yinshan Mountains, in normal and wet years in the foothills of Yanshan hilly area and in all year types in Da Hinggan Mountains. Canola and edible sunflower were suitable for planting only in wet years in the foothills of Yanshan hilly area and in all year types in Da Hinggan Mountains. Maize and oil sunflower were suitable for planting only in wet years in the foothills of Yanshan hilly area and in normal and wet years in Da Hinggan Mountains.

【Objective】Plasmodiophora brassicae is an obligate endoparasite that causes clubroot disease, which is the most devastating soil-borne disease in brassica crops. The propidium monoazide xx (PMAxx) could selectively bind to the chromosomal DNA of dead spores and therefore block DNA amplification by real-time fluorescent quantitative PCR (qPCR). In the present study, a strategy involving a PMAxx pre-treatment followed by the qPCR (PMAxx-qPCR) assay was developed for quantifying viable spores of P. brassicae, so as to provide a basis for early detection and prevention measurement of cloobroot disease. 【Method】 PMA and PMAxx with concentrations of 0, 5, 10, 20, 40 and 60 µmol·L^-1 were prepared, respectively, and were used to pre-treat P. brassicae prior to DNA extraction, followed by qPCR. The inhibitory effects of PMA and PMAxx on DNA amplification of P. brassicae dead spores were compared, and the optimal nucleic acid dye and concentration to distinguish between live and dead spores were determined. The illumination time was set as 0, 2, 5, 10, 15 and 20 min, respectively, and the optimal exposure time was optimized to establish a PMAxx-qPCR assay for selectively detection of viable spores of P. brassicae. The mixed suspensions with different ratios of dead and viable spores (0, 0.01%, 0.1%, 1%, 10%, 25%, 50%, 75% and 100% viable spores) were prepared to determine the suitability of PMAxx-qPCR assay for distinguishing viable and dead spores. The assay was also applied to quantitative detection of viable spores of P. brassicae in 25 field soil samples. 【Result】 PMAxx showed a better discrimination effect than PMA on the viable and dead spores of P. brassicae. When the concentration of P. brassicae was 1×10⁸ spores/mL, the optimal PMAxx concentration and light exposure time were 4 μmol·L^-1 and 10 min, respectively. The amplification of dead spores could be inhibited effectively, and only the DNA of living spores was targeted for selective amplification. For pre-defined ratio of viable spores, there was a good linear relationship between the lg of the P. brassicae DNA concentration assessed by PMAxx-qPCR and the theoretical viability (R²=0.992). For soil samples, viable P. brassicae was quantified in 11 of 25 samples, with infestation levels of approximately 32.35-6.97×10³ fg·g^-1. 【Conclusion】 The established method could quantitatively detect the viable spores of P. brassicae, with advantages of rapid, efficiency and sensitivity, which could be useful for avoiding the inability of qPCR method to distinguish between viable and nonviable spores. Application of the assay may potentially improve P. brassicae control and disease management.

【Background】As a major migratory insect pest putting the whole world on alert, the fall armyworm Spodoptera frugiperda warned by Food and Agriculture Organization of the United Nations (FAO) poses a serious threat to the agriculture production (including maize) of China from the end of 2018. Taking advantages of the long-distance transport of seasonal monsoons and its self-powered migratory capacity, S. frugiperda performs two migration pathways to fly across the eastern and western China separately, which has caused regional dispersal and severe infestation. According to 2-year systematic investigation in China, the west migration route of S. frugiperda ends in Northwestern China, especially in Ningxia and Alxa Left Banner of Inner Mongolia. However, little is known about the source areas of S. frugiperda population invading Northwestern China, and few reports explore the migration route of this devastating pest through the whole western China.【Objective】The objective of this study is to accurately analyze on the key atmospheric factors driving the immigration of S. frugiperda into the Northwestern China, source regions of the first populations to arrive, and Asian monsoon-induced migration pathways of S. frugiperda, which can provide fundamental evidence for the early warning and regional management and control of this invasive pest in China.【Method】Based on the invasion dynamics of S. frugiperda in Ningxia of the Northwestern China and meteorological data, a meso-scale numerical model, insect’s flight trajectory calculating program, and Geographic Information System (GIS) were used to identify the atmospheric transport backgrounds, simulate the succussive 1-3 night migration routes and trace their source regions of S. frugiperda in the Northwestern China.【Result】The southerly summer monsoon from July to September each year was the key factor for the successive and successful immigration of S. frugiperda into Ningxia and other regions of Northwestern China, of which their major source populations of S. frugiperda were located in southeastern Gansu and eastern Sichuan, while some were from western Shaanxi. In addition, southwestern Chongqing, northeastern Yunnan and part of western Shanxi could possibly provide population source of S. frugiperda.【Conclusion】Under the influence of southerly Asian summer monsoons, S. frugiperda can fly towards the north for 1-3 successive nights via its west migration pathway “Yunnan-Sichuan and Chongqing-Shaanxi and Gansu-Ningxia” in China, which originates from Myanmar and ends in Inner Mongolia, China. In particular, the government should be vigilant against the occurrence and damage of this devastating pest in the maize-cropping regions of Northwestern China while the preponderance of early southerly wind is advanced and wind speed gets strong during July to September.

【Objective】The yellow peach moth, Conogethes punctiferalis, as an agricultural insect pest, its damage to maize ears has become more and more serious in Huang-Huai-Hai maize-producing areas of China in recent years, threatening the safe production of maize and the food safety. The spatial distribution pattern is an important ecological attribute of insect population, the objective of this study is to research the spatial distribution pattern of C. punctiferalis larvae in maize fields, clarify the spatial distribution characteristics of the pest, and to provide scientific bases for formulating field sampling program of C. punctiferalis larvae in maize fields, forecasting and effective management of the insect pest on maize.【Method】The spatial distribution pattern of the population of C. punctiferalis larvae in maize fields was studied by traditional statistical method (aggregation indexes, Taylor’s power law and Iwao’s regression model) and geostatistical method. Based on the Iwao’s regression model, the theoretical sampling number of C. punctiferalis larvae in fields was determined, and the maximum theoretical sampling number with different admissible errors (D=0.1, 0.2, 0.3) and the putative economic thresholds (m₀=0.5, 1, 1.5, 2 larvae per plant) was also determined by the sequential sampling.【Result】The results of the two kinds of statistical methods showed that the spatial distribution pattern of C. punctiferalis larvae belonged to aggregation distribution. The analysis of some aggregation indexes showed that spatial distribution pattern of C. punctiferalis larvae belonged to aggregation distribution. The results of Taylor’s power law showed that the spatial distribution pattern of C. punctiferalis larvae belonged to aggregation distribution, and the aggregation intensity increased with the population density. The Iwao’s regression model proved that the spatial distribution pattern of C. punctiferalis larvae belonged to negative binomial distribution in aggregation distributions. The parameters of semivariogram models indicated that the optimal fitting models of C. punctiferalis larvae were the spherical, exponential and linear models. The three-dimensional and two-dimensional maps from Kriging interpolations showed that the aggregation centers of C. punctiferalis larvae were located at the edges of the fields. Based on sampling technique from the Iwao’s regression model, the theoretical sampling number of C. punctiferalis larvae in maize fields was determined when the confidence probability t=2 and different mean densities m=0.5, 1, 2, 3, 4, 5, 10 and 15. The maximum theoretical sampling number was also determined by the sequential sampling. Assuming t=2, D=0.1, 0.2, 0.3, when m₀=0.5 larva per plant, the maximum theoretical sampling numbers were 3 417, 854 and 380, respectively; when m₀=1 larva per plant, the maximum theoretical sampling numbers were 1 717, 429 and 191, respectively; when m₀=1.5 larvae per plant, the maximum theoretical sampling numbers were 1 150, 287 and 128, respectively; when m₀=2 larvae per plant, the maximum theoretical sampling numbers were 867, 217 and 96, respectively.【Conclusion】The spatial distribution pattern of C. punctiferalis larvae belongs to the negative binomial distribution in aggregation distributions, and the aggregation centers were located at the edges of the fields. The maximum theoretical sampling number based on the sequential sampling in maize fields can be used for monitoring and management of C. punctiferalis larvae.

【Objective】 Foliar zinc (Zn) application is an effective agronomic biofortification strategy to realize Zn enrichment of wheat grains and to combat the human Zn malnutrition. The aim of this study was to investigate the effects of spraying Zn with different nitrogen (N) inputs on Zn enrichment and content of protein and protein components in wheat whole grain and flour.【Method】 Based on the long-term positioning experiment, the spraying experiment of Zn in wheat for two consecutive seasons was conducted during 2018-2020. A split plot design was used with soil N rates of 0 (N₀), 120 (N₁₂₀) and 240 ∙hm^-2 (N₂₄₀) as the main plot factor, and the foliar application of distilled water (Zn₀) and 0.4% ZnSO₄·7H₂O (Zn₁) as subplot. The indexes were analyzed for this study, including Zn content of various nutritional organs, Zn mobilization and distribution from leaf and other vegetative organs to grain, and protein and protein component content in grains and flour at the early filling stage and maturation stage. 【Result】Compared with N₀, the grain yield under N₁₂₀ and N₂₄₀ treatments was significantly increased by 88%-114%, but there was no significant difference between N₁₂₀ and N₂₄₀. Regardless of the N inputs, the foliar Zn application could significantly increase the Zn concentration in grains and flour and the grain Zn content reached the biofortification standard. Among those treatments, the Zn concentration of wheat grains under N₁₂₀ and N₂₄₀ was increased by 0.95 and 1.12 times than that under N₀, respectively. Compared with N₀, the N inputs increased the translocation of N and Zn transferred from leaf and other vegetative organs to grain at early grain filling stage, but reduced the transfer ratio of N and Zn: N decreased from 60.2% to 48.6% and Zn decreased from 42.3% to 26.5%. A significant positive linear correlation was found between the amount of N and Zn mobilization and the content of N and Zn in grain at maturity, and the synergistic effect of N and Zn was more significant at Zn₁. Compared with the early filling stage, the content of storage protein (gliadin and glutenin) in grains and flour at the mature stage increased significantly, accounting for about 80%-84% of the protein content. The content of gliadin and glutenin in grain and flour was increased by N application more than that of albumin and globulin, and the gluten was the largest. The content of protein and protein components in grain and flour were not affected by spraying Zn. However, in terms of Zn₁, the increase of gluten content in grain and flour was higher than that under the condition of Zn₀ with the increase of N dosage, which was 37.5% and 38.1%, respectively.【Conclusion】Foliar Zn application could achieve Zn-rich grains but did not affect the content of protein and protein components in grains and flour, indicating that there was sufficient protein pool for Zn storage in grains and flour. Therefore, a reasonable amount of soil N combined with foliar Zn application could increase the N, Zn content and nutritional quality of the grains by ensuring high and stable yield on potentially Zn-deficient calcareous soils.

【Objective】By studying the spatial-temporal variation characteristics of tobacco-planting soil nutrients in Erhai Lake Basin (ELB), the objective of grading evaluation and spatial visualization of tobacco-planting soil fertility in this region was achieved, so as to provide a scientific basis for the nutrient management, balanced fertilization, and the control of agricultural non-point source pollution of tobacco-planting areas in ELB.【Method】Based on the 964 tobacco-planting soil samples in ELB collected in 2011-2013, 2018 and 2020, this study explored the spatial-temporal variability of nutrients and regional distribution patterns by using Geostatistics, Geographic Information Systems (GIS) technology, and Fuzzy integrated fertility index method to quantify the soil fertility in tobacco-planting areas. 【Result】The average values of soil pH, soil organic matter (SOM), total nitrogen (TN), Olsen-P (AP) and available potassium (AK) of tobacco-planting soil in ELB were 7.3, 59.6 g·kg^-1, 3.5 g·kg^-1, 54.4 mg·kg^-1, and 192.0 mg·kg^-1, respectively, all of which belonging to moderate variation. Tobacco-planting soil was rich in SOM, TN, AP and AK, and the proportions of areas within the upper-middle level accounted for 85.2%, 93.8%, 94.5% and 78.8%, respectively, showing obvious variation at regional scale. The area of tobacco-planting soil fertility were graded to five levels (from high to low: I to V), which accounted for 8.4%, 25.0%, 40.3%, 23.3% and 3.0%, respectively. The pH of tobacco-planting soil was relatively alkaline in ELB, which was higher in the northern than in the southern; the highest concentrations of SOM and TN occurred in the northern and the western region; the areas with high AP concentration were distributed in patches in the northern, eastern and western region of Erhai Lake; the areas with high AK concentration were distributed in flakes in the northern and eastern of Erhai Lake. 【Conclusion】Collectively, the fertility of the tobacco-growing soil in ELB was in high level, and the high-quality soil areas above grade III were mainly distributed in the northern and eastern region. Meanwhile, the tobacco-planting soil in the northern and western Erhai Lake were rich in nitrogen and phosphorus, and there was a risk of agricultural non-point source pollution in the region.

【Objective】 The aim of this study was to understand the mechanism of arbuscular mycorrhizal fungi (AMF) on soil nitrous oxide (N₂O) emissions, so as to provide the theoretical basis for increasing maize yield, improving nitrogen (N) use efficiency and reducing greenhouse gas emissions. 【Method】 A 2-factorial greenhouse experiment was established during maize growth periods in 2016 and 2017. The factors were as follows: (1) N fertilizer rates (180 kg N·hm^-2 (N1) and 360 kg N·hm^-2 (N2)), and (2) three mycorrhizae treatments, including a control (M0, neither roots nor AMF could enter the hyphal chamber from the growth chamber), an AMF treatment (M1, only AMF can enter the hyphal chamber from the growth chamber), and a root treatment (M2, both roots and AMF can enter the hyphal chamber from the growth chamber). Maize grain yield, plant biomass and their N accumulation, and soil N₂O flux were measured. Soil bacterial community structure and diversity at maize maturity stage was determined by using the high throughput sequencing technique on Hiseq 2500 PE250. 【Result】 Both N fertilizer rates and mycorrhizae treatments significantly affected maize yield, plant N accumulation and soil N₂O flux. Compared with M0, maize yield under M1 and M2 under the conditions of N1 input increased by 38% and 82%, by 30% and 52% for aboveground N accumulation, respectively, and reduced by 26% and 65% for soil inorganic N, respectively. However, under the conditions of N2 input, the maize yield under M1 and M2 increased by 16% and 48%, by 9% and 33% for aboveground N accumulation, and reduced by 34% and 55% for soil inorganic N, respectively. Compared with the M0, the total N₂O emission of M1 and M2 treatments reduced by 17% and 40% under the conditions of N1 input, and by 41% and 67% for the N₂O emission intensity, respectively; while under the conditions of N2 input, the total N₂O emission reduced by 26% and 45%, and by 28% and 57% for the N₂O emission intensity, respectively. Nonmetric multidimensional scaling analysis showed that both N fertilizer rates and mycorrhizae treatments had significant effects on bacterial communities’ composition. Compared with N1, the relative abundance of Proteobacteria and Gemmatimonadetes under N2 treatment on phyla level reduced by 6% and 15%, increased by 32% for Actinobacteria, while on genera level, the Streptomyces increased by 27%, and reduced by 8% for Gemmatimonas. Compared with M0 under the conditions of N1 input, the relative abundance of Streptomyces under M1 and M2 increased by 64% and 205%, by 31% and 53% for Gemmatimonas; however, under the conditions of N2 input, the relative abundance of Streptomyces under M1 and M2 increased by 10% and 93%, respectively, the Gemmatimonas for M1 reduced by 2%, and increased by 56% for M2. Moreover, the relative abundance of soil Streptomyces and Gemmatimonas was negatively related with soil N₂O emission, but positively related with maize yield. 【Conclusion】 Arbuscular mycorrhizal fungi could reduce soil N₂O emission under both higher and lower N fertilizer application rate by increasing the maize N uptake, and regulating the bacterial composition, especially increasing the relative abundance of Streptomyces and Gemmatimonas.

【Objective】Flavonoids are important metabolites of wine grapes, which have important effects on the qualities of the grape fruits and their wines. In this study, the effects of different rootstocks on the physicochemical parameters and flavonoid substances of Tannat (Vitis vinifera L.) grapes were studied to provide the theoretical basis for the selection and utilization of rootstocks.【Method】In the present research, Tannat shoots were used as scions and were greenwood grafted on four different kinds of rootstocks, including 1103P, 101-14, SO4, and Beta. On the bases of the analysis of the basic physicochemical parameters (total soluble solid content, titratable acid, pH, and 100-berry weights) of the commercial mature grape berries of these grapevines grafted on different rootstocks, the compositions and contents of the flavonoids in the corresponding grape berries were detected by using high performance liquid chromatography-mass spectrometry (HPLC-MS), in the three vintages of 2016, 2017 and 2019.【Result】 The rootstocks had little effect on the 100-berry weights of the Tannat grapes; the contents of the total soluble solids were higher in the combination of Tannat/101-14, as well as the own-rooted Tannat; the titratable acids of the grape juice of the Tannat/101-14 and the Tannat/Beta combinations were higher than the own-rooted Tannat grapes. In the part of flavonoids, the contents of anthocyanins and flavonols in the Tannat/SO4 combination was the lowest in all of these combinations; the concentrations of anthocyanins and flavonols in the Tannat/101-14 combination and the own-rooted Tannat were higher than those of other combinations; the concentrations of flavanols in the skins of the Tannat/101-14 combination was higher. In addition, the concentrations of anthocyanins and flavonols in the Tannat/ 11103P combination was lower, but the content of flavanols in the skins of the Tannat/1103P combination was relatively high. Besides, the results of two-factor ANOVA of the year and the rootstock showed that the rootstocks had significant effects on all types of anthocyanins. All the four rootstocks showed a tendency of reducing the anthocyanins of peonidin, petunitin, malvidin, non-acylation, acetylation and coumaric acylation. In the mature fruits, the quercetins were the most abundant flavonols, followed by myricetins, while syringetins and laricitrins accounted for a smaller proportion. Rootstocks had a significant effect on the myricetins and laricitrins, which reduced the contents of myricetin and laricitrin to different degrees. Through the establishment of OPLS-DA (Orthogonal Partial Least Squares Discrimination Analysis) model, it was found that the Tannat/101-14 combination was mainly distinguished by the malvidin anthocyanin compared with the own-rooted grapes. The main difference compounds of Tannat/Beta combination were anthocyanins of malvidin, delphinidin and acetylation, the total flavanols and quercetin compounds. The difference compounds of the Tannat/SO4 combination were anthocyanins of malvidin, delphinidin, acetylation, and quercetins. The Tannat/1103P combination mainly consisted of acetylated anthocyanins and quercetins.【Conclusion】 In Beijing region, all the four rootstocks (1103P, SO4, Beta, and 101-14) showed a tendency of reducing the flavonoid concentrations, including anthocyanins of peonidin, petunitin, malvidin, non-acylation, acetylation, coumaric acylation quercetins, and laricitrins. The rootstock '101-14' was beneficial to the accumulation of anthocyanins, flavonols and flavanols in fruit skins, which was conducive to the improvement of the wine quality, so it was recommended to be used. However, Tannat grapes grafted with SO4 had less flavonoid accumulation, which was not recommended to be used.

【Objective】 The objective of this study was to conduct a systematical analysis of the lactone volatile compounds in different types of ripe peach fruit (Prunus persica L.) and to evaluate the contributions of each lactone compound to peach fruit aroma. 【Method】 Multiple peach cultivars with different flesh textures, flesh colors and fruit growth periods were used in this study. The gas chromatography-mass spectrometry system was employed to identify and quantify the lactone volatile compounds in peach fruit, and the odor activity value was used to evaluate the contributions of each lactone compound to the fruit aroma of respective cultivars. 【Result】 Lactone volatile compounds were detected in ripe fruit of all peach cultivars, and a total of ten lactone volatile compounds were identified in peach fruit, including γ-hexalactone, γ-octalactone, γ-heptalactone, γ-decalactone, δ-deca-2, 4-dienolactone, δ-decalactone, γ-undecalactone, δ-octalactone, jasmine lactone, and cis-4-hydroxydodec-6-enoic acid lactone. Each lactone compound was of specific odor notes, and the lactone compounds predominantly emit fruity (reminiscent of coconut and peach), sweet, dairy, caramel, floral, and herbaceous smells. The common lactone compound shared by all cultivars was γ-hexalactone, the frequently detected lactone compounds were γ-decalactone and δ-decalactone, and some lactone compounds were specific to individual cultivars, such as cis-4-hydroxydodec-6-enoic acid lactone in Shenzhoumitao. Relatively higher numbers of lactone volatile compounds were detected in ripe fruit of melting peach cultivars, including Baihuashuimi, Shenzhoumitao, Chengxiang, Fenghuayulu (wan), and Feichenghonglidatao, while the lower numbers of lactone volatile compounds were present in stony hard peach cultivars including Xiacui, Qinwang and Huayu. The analysis of the odor activity values of the lactone volatile compounds revealed the universal contribution of γ-decalactone to the aroma of the majority of cultivars due to its low odor threshold value and high concentrations in fruit. γ-Decalactone conferred the strong characteristic peach-like odor to melting peach cultivars, including Shenzhoumitao, Chengxiang, Fenghuayulu (wan), and Baihuashuimi, while plain peach-like odor was observed in melting peach Achutao and stony hard peach Huayu due to the lower odor activity values of γ-decalactone, and the characteristic peach-like odor note was absent in stony hard peach Qinwang and Xiacui fruit as no γ-decalactone was detected. Besides, γ-octalactone contributed to the coconut and very sweet odors of specific cultivars, such as Chengxiang and Shenzhoumitao. 【Conclusion】 Lactones constituted an essential chemical group of the volatile compounds of peach fruit, and the mature peach fruit presented at least ten lactone volatile compounds. Various lactone volatile compounds and their different concentrations showed the aroma characteristics of different types of peach cultivars, especially the cultivars of different flesh textures, while not the ones of different flesh colors or fruit growth periods. γ-Hexalactone was the common lactone shared by all cultivars, γ-decalactone and δ-decalactone were frequently detected lactone compounds, and cis-4-hydroxydodec-6-enoic acid lactone and other lactones were specific to individual cultivars. γ-Decalactone, γ-octalactone and other lactones made important contributions to the characteristic peach-like odor and other unique odor notes in different peach cultivars.

【Objective】Based on the freeze-thaw stability of quinoa stabilized Pickering emulsion, it was incorporated evenly into surimi to generate surimi gels in this study, and its feasibility to improve the freeze-thaw stability of fish protein gel was evaluated. This research aimed to prevent the deterioration of fish protein gel, caused by the temperature fluctuation during storage and transportation.【Method】Quinoa protein Pickering emulsion was prepared and distributed in surimi, followed by heating process to generate surimi gels. The surimi gels with different contents of Pickering emulsion and without emulsion were subjected to three freeze-thaw cycles, and then, the texture, color, water and ice crystal distribution and drip loss of surimi gels were measured. 【Result】The quinoa protein Pickering emulsion improved the lightness and whiteness of fish surimi gel, and inhibited the changes of color after freeze-thaw cycles. Meanwhile, the Pickering emulsion addition delayed the changes of hardness and chewiness of surimi gels during freeze-thaw cycles. It was found that quinoa protein Pickering emulsion had no effect on the moisture distribution of surimi gels before freeze-thaw cycles, but significantly increased the proportion of immobile water and decreased free water content in surimi gels after freeze-thaw cycles. Therefore, the drip loss of surimi gel was decreased by emulsion addition. Furthermore, the emulsion addition decreased the diameter of ice crystals formed in surimi gel, reduced the damage to muscle tissues, and decreased the free water content. 【Conclusion】The Quinoa protein Pickering emulsion weakened the adverse impact of freeze-thaw cycles on the color and textural properties, maintained the gel structure, and improved the freeze-thaw stability of fish surimi gel, which maintained its quality and nutritional value. Quinoa protein Pickering emulsion was promising to become an innovative antifreeze to be applied in frozen food.

【Background】MicroRNAs (miRNA) are a type of small RNAs (18-23 nt) that are widely involved in the regulation of mammogenesis and milk traits in livestock animals. In our previous research, the expression level of miR-221 in non-lactating mammary gland was found to be 3.6-time higher than in mammary gland at lactation period in Small-Tailed Han sheep by using RNA-Seq. However, the regulatory mechanism of miR-221 on ovine mammary gland development is still unclear. 【Objective】The aim of this study was to investigate the inhibition of miR-221 on the viability and proliferation of ovine mammary epithelial cells by targeting insulin receptor substrate 1 (IRS1) gene, so as to provide a theoretical reference for revealing the molecular regulation mechanism of miR-221 on ovine lactation performance.【Method】In the study, mammary gland, heart, liver, kidney, spleen, lung, Longissimus dorsi muscle and ovary tissues were collected in Small-Tailed Han sheep, and the expression profiles of miR-221 were constructed in ovine eight tissues by using reverse transcription-quantitative PCR (RT-qPCR). The effects of miR-221 on the viability and proliferation of ovine mammary epithelial cells (OMECs) were investigated by using cell transfection, CCK-8 and Edu assays. The miRDB and miRanda were used to predict the target genes of miR-221. Based on functional enrichment analysis, an investigated target gene was screened. The target relationship between miR-221 and the predicted target gene was investigated by constructing wild-type and mutant-type report vectors for the target gene by using dual luciferase reporter assay. Finally, the effects of over-expressed and silenced miR-221 on expression levels of the target gene and other functional genes in downstream signaling pathways were detected.【Result】The miR-221 was expressed in ovine eight tissues including mammary glands, with the highest expression levels in lung and spleen, and the lowest expression levels in Longissimus dorsi muscle and kidney. The CCK-8 assay result revealed that miR-221 mimic inhibited the viability of OMECs, whereas miR-221 inhibitor promoted the viability of OMECs. The Edu result found that miR-221 mimic reduced the number of Edu-labeled positive OMECs. On the contrary, miR-221 inhibitor increased the number of Edu-labeled positive OMECs. The result from dual luciferase reporter assays showed that the miR-221 mimics reduced the luciferase activity of the 3′UTR region of IRS1, while miR-221 inhibitor increased the luciferase activity. This suggested that IRS1 was a target gene of miR-221. The results from RT-qPCR further found that over-expressed miR-221 reduced expression levels of IRS1 and PIK3R1 in OMECs (P<0.05), while silenced miR-221 enhanced the levels of the two genes in expression (P<0.05). No effect on IGF1R was found for over-expressed and silenced miR-221 in OMECs (P>0.05).【Conclusion】The miR-221 inhibited the viability and proliferation of OMECs by reducing IRS1 expression.

【Background】 The Steroids synthesis capacity of ovarian granulosa cells plays the important roles in the development and maturation of follicles, however, the key regulators were involved in this process remains largely unknown. Our previously research reported that Liver kinase B1 (LKB1) influenced the cellular lipid metabolism, which is close associated with steroids synthesis. Further, another study showed that knockout of LKB1 caused premature ovarian failure in mice. 【Objective】 The aim of this study was to study the expression pattern of LKB1 in bovine follicle and its regulation on steroid synthesis related genes expression in granulosa cells (GCs),and provided a theoretical basis for the research of the reproductive physiological regulation in the cow.【Method】The expression pattern of LKB1 in follicle was detected by immunohistochemically assay. Then the primary follicular granulosa cells were isolated and identified by immunofluorescence staining incubated by follicle stimulating hormone receptor (FSHR) antibody. Next, these verified granulosa cells were used as the cell model. On one hand, LKB1 loss-of-function was mediated by siRNAs. qRT-PCR was performed to measure LKB1 regulation of steroid hormone synthesis related genes expression. On the other hand, LKB1 gain-of-function was mediated by adenovirus. qRT-PCR and ELISA analysis were carried out to confirm the changes of above detected genes influenced by LKB1 and estradiol (E2) secretion, respectively. 【Result】 The data showed that: 1) LKB1 protein expressed in all cell types of follicles and the positive signal in granulosa cells is significantly higher than that of theca cells, which is verified by quantitative analysis. 2) The morphology of isolated bovine follicular granulosa cells was shape of round, which were specifically labeled by follicle stimulating hormone receptor (FSHR) using immunofluorescence staining, with 95% of positive cells. 3) The interference efficiency of LKB1 treated by siRNA1 and siRNA2 was respectively 48% (P<0.05) and 52% (P<0.05) to that of control. Knockdown of LKB1 significantly down-regulated mRNA levels of STAR (P<0.01), CYP11A1 (P<0.01) and CYP19A1 (P<0.05), with the 60%, 80% and 50% decrease to those of the control. 4) The highly infected efficiency was observed infected by LKB1-OE and control adenovirus. In contrast, overexpression of LKB1 dramatically increased mRNA levels of STAR (P<0.01), CYP11A1 (P<0.01) and CYP19A1 (P<0.05), which was associated with elevation of E2 secretion. 【Conclusion】In summary, LKB1 was highly expressed in follicular granulosa cells, which promoted the expression of steroids synthesis related genes and E2 secretion. This result provides directly theoretical evidence for the LKB1 regulation of steroids hormone synthesis in bovine.

【Objective】Influenza virus is a zoonotic pathogen that often causes a pandemic and poses a great threat to human health, and the influenza viruses are prone to variants and can constantly escape the host cell immune response and develop resistance to existing anti-influenza drugs, so the search for new ways to fight influenza is imminent. This study aimed to explore the effect of NMRAL1 (NmrA-like family domain-containing protein 1) on influenza virus replication, and to reveal the molecular mechanism by which it functioned, so as to provide a potential target for anti-influenza drugs development. 【Method】In this study, siRNA interference technology was used to down regulate the expression of NMRAL1 in A549 cells, and the expression levels of NMRAL1 were detected by Western Blot. Virus titers in cell supernatants at 24 h and 48 h after infection with two different subtypes influenza viruses, including a/Anhui/ 2/2005(AH05)(H5N1) and a/WSN/33(H1N1), were detected using the plaque assay. To determine the specific stage at which NMRAL1 affected influenza virus replication, NMRAL1 was overexpressed by transiently transfecting NMRAL1-Myc-pCAGGS plasmid in HEK293T cells, and the effect of overexpressing NMRAL1 on influenza virus polymerase activity was examined by luciferase reporter system. The influenza virus NP protein was stained by using immunofluorescence, and the down-regulated expression of NMRAL1 on the localization of NP protein at 3, 4, 5, 6 and 8 h post infection was assessed respectively by confocal assay to determine whether down-regulated expression of NMRAL1 affected the process of influenza virus vRNP import and export. Western Blot was used to detect the effect of NMRAL1 knockdown on the expression of viral proteins and on the expression of IFN stimulated genes (ISGs) downstream of type I interferon pathway activated by influenza virus. Indirect immunofluorescence assay was utilized to further verify the effect of NMRAL1 on influenza virus replication. 【Result】Western Blot assay showed that NMRAL1 siRNA could significantly down regulate NMRAL1 expression in A549 cells. With the down-regulated expression of NMRAL1, A549 cells were infected with H5N1 and H1N1 viruses, respectively. Then the virus titers in the cell supernatant were measured by plaque assay, which showed that the virus titers in the supernatant of cells at 24 and 48 h after infection with H5N1 or H1N1 were significantly decreased, meaning that NMRAL1 could promote the replication of different subtypes influenza viruses. To further explore the specific mechanism by which NMRAL1 regulated influenza virus replication, a luciferase reporter system was used to detect influenza virus polymerase activity, and it was found that the overexpression of NMRAL1 had no effect on influenza virus polymerase activity. The results of confocal assay showed that the down-regulated expression of NMRAL1 did not affect the process of NP nuclear import and export, meanwhile Western Blot assay indicated that down-regulated expression of NMRAL1 did not affect the expression of each viral protein. However, the results of the fluorescence quantitative PCR assay showed that down-regulated expression of NMRAL1 was able to promote the up-regulation of IFN-β mRNA levels induced by influenza virus infection, and Western Blot assay found that down expression of NMRAL1 promoted the expression of MxA and IFITM3 antiviral proteins downstream of type I interferon pathway. Meanwhile, the indirect immunofluorescence assay showed that the down expression of NMRAL1 could significantly inhibit influenza virus replication. 【Conclusion】 Those results demonstrated that, during influenza virus infection, NMRAL1 did not affect the process of influenza virus invasion as well as transcription translation, but rather inhibited the expression of antiviral factors, such as MxA and IFITM3, by inhibiting type I interferon pathway activation, which ultimately promoted influenza virus replication. This study confirmed that the host factor NMRAL1 positively regulated influenza virus replication and enriched the network of host factors involved in influenza virus replication.

【Objective】 The objective of this study is to evaluate the application value of the high temperature adult plant (HTAP) resistance gene Yr52 in wheat production for improving stripe rust resistance. And wheat lines with good agronomic characters and high disease resistance were developed and selected. It laid a foundation for making full use of the existing HTAP resistance resources and improving the yield related traits.【Method】 The stripe rust resistance gene Yr52 was introgressed to Lunxuan 987 (LX987), Bainong Aikang 58 (AK58) and Han 6172 (H6172) by backcrossing and self-crossing combined with marker-assisted selection breeding. Adult-plant resistance of donor parent, receptor cultivars and their progeny lines were evaluated in the disease nursery fields at Mianyang, Sichuan and Yangling, Shaanxi by mixed endemic physiological races CYR32, CYR33 and CYR34. In comparison to the Chinese Spring reference genome, the flanking SSR markers Xcfa2040 (6.8 cm-Yr52) and Xbarc182 (1.2 cm-Yr52) of Yr52 were combined to search for markers of 35K SNP chip in the physical interval of target genes, and developed into derived cleaved amplified polymorphic sequences (dCAPS) and kompetitive allele specific PCR (KASP) markers. The resistance gene Yr52 was detected in BC₂F_5:6 progeny lines.【Result】 The evaluation of adult plant resistance and agronomic traits indicated that nineteen BC₂F_5:6 lines with LX987 background was obtained: Among of them, 11 were high resistance (IT=0-3, DS=1%-20%), 8 were moderate resistance (IT=4-6, DS=15%-30%), the average thousand kernel weight (TKW), kernels per spike (KPS), productive tiller number per line (PTN), plant height (PH) and spike length (SL) was 45.33 g, 46, 7, 113.26 cm and 10.05 cm, respectively. Four BC₂F_5:6 families with AK58 background: all showed high resistance (IT=0-3, DS=5%-25%); the average TKW, KPS, PTN, PH and SL were 44.67 g, 48, 7, 96.54 cm and 10.17 cm, respectively. Five BC₂F_5:6 lineages with H6172 background showed high resistance to stripe rust (IT=0-3, DS=5%-20%). The average TKW, KPS, PTN, PH and SL were 43.74 g, 49, 8, 109.72 cm and 10.06 cm, respectively. The detection rate of three simple sequence repeat (SSR) molecular markers Xbarc182, Xcfa2040 and Xwmc557 linked to Yr52, in offspring population were 78.57%, 66.67% and 66.67%, respectively. One dCAPS marker Xdcaps-Yr52-1 and one KASP marker Xkasp-Yr52-1 were successfully developed, and the detection rates were 73.68% and 41.67%, respectively. The agronomic traits of lines with high (IT=0-3) and medium (IT=4-6) resistance levels were compared. The results showed that the average TKW (P>0.05), PTN (P>0.05) and KPS (P<0.05) of lines with IT=0-3 were higher than those of families with moderate resistance level lines (IT=4-6). Five lines with disease resistance and stable agronomic traits were selected by evaluated of PH=80-105 cm, PTN≥6,KPS≥45, TKW≥42 g, SL≥8 cm.【Conclusion】 Yr52 was found to be resistant to all of the present predominant races in the adult plant stage. After introgression Yr52 into the main susceptible Chinese wheat varieties, the progeny lines with good disease resistance and agronomic characters could be used for breeding resistance varieties with multi-gene polymerization, it is enriching for the diversity of disease resistance genes and achieving durable utilization. The development of molecular markers will facilitate detect the utilization of Yr52 gene in resistance identification of germplasm in the future.

【Objective】 Through the research on the phenotypic diversity and genetic variation of the sorghum germplasm resources in the panicle, we will screen for superior sorghum germplasm, enrich the genetic information of sorghum panicle-related traits, and provide a reference for the conservation and efficient use of existing germplasm resources and the selection and breeding of new varieties.【Method】 Using 320 sorghum accessions from different parts of China as test materials, we accurately identified 12 panicle traits (grain length, grain width, thousand-grain weight, grain hardness, grain density, corneous endosperm rate, kernel weight per panicle, main panicle length, panicle neck length, panicle neck diameter, primary branches length, primary branches number) in two different ecological environments. A comprehensive evaluation of sorghum germplasm resources using correlation analysis, principal component analysis, cluster analysis, and other methods. We screened elite sorghum germplasms with different outstanding characteristics according to the comprehensive evaluation value F and target traits. 【Result】 The frequency distribution of each quantitative trait showed a trend of high in the middle and low on both sides. The two-year frequency distribution and curve trend of grain hardness, kernel weight per panicle and grain density, and corneous endosperm rate were similar at the Baoding and Jinzhong test sites. Most of the traits only showed normal distribution in one year or a single location. Except for the main panicle length and number of primary branches, the other traits differed between the two test sites in the same year. The mean diversity index (H') distribution of the 12 panicle traits ranged from 1.72 to 2.11, among which the average diversity index of grain hardness was the highest, and the average diversity index of primary branches length was the lowest. The coefficients of variation of grain hardness, corneous endosperm rate, kernel weight per panicle, primary branches length, and the number of primary branches were all higher than 30.00%. The cumulative contribution rate of the extracted four principal components was 65.39%. Cluster analysis classified the 320 accessions into three groups, class I can be used as the germplasm for screening process (broom) sorghum; class II is suitable for selecting excellent germplasm for grain (brewing) sorghum; class III was the germplasm with poor panicle traits. We screen 29 superior germplasm with outstanding characteristics according to the comprehensive score value F and target traits. 【Conclusion】 The variability of sorghum germplasm resources in panicle traits was rich and diverse; the coefficient of variation of corneous endosperm rate and primary branches length was high; grain length, grain width, grain hardness, grain density, and kernel weight per panicle were significantly affected by environmental conditions. We screened 29 superior germplasm.

【Objective】 Establish an efficient extraction and detection technology for sesamin content evaluation in sesame seeds, then apply it to examine sesamin content variation and identify high-sesamin content materials in sesame germplasm, which will lay the foundation for advancing basic research and breeding of sesame with high sesamin content. 【Method】 Using sesame seeds as raw materials, the single factor tests, including diameters of steel balls, crushing time, crushing amplitude, and seeds weight, were investigated. The seeds were extracted with 80% ethanol via ultrasonic mechanical crushing and cavitation, and the sesamin content was determined by High Performance Liquid Chromatography (HPLC). Based on the Box-Behnken center combined test design principle, we carried out the response surface test with four factors and three levels and established the quadratic polynomial regression equation model with sesamin content as response value. We drew the response surface diagram and contour diagram and determined the main factors affecting sesamin content and the interaction between factors. Finally, the optimal extraction conditions of sesamin were determined, and 1 151 local resources and innovative germplasm were analyzed. The accessions with high sesamin content≥9 g·kg^-1 were selected and identified at the Oil and Product Quality Supervision and Testing Center of the Ministry of Agriculture and Rural Affairs. 【Result】 The regression model established in this experiment was extremely significant (P<0.05), and the lack of fit was insignificant (P=0.1768). The model had a good fitting degree and could be used to predict sesamin content. The influence of the four factors on sesamin content was as follows: crusher amplitude>diameters of steel balls>crushing time>seeds weight. The interaction between the crusher amplitude and diameters of steel balls was significant, while that between crusher amplitude and crushing time was close to the significance level. The optimal conditions for ultrasonic-assisted extraction of sesamin were as follows: steel ball diameter of 6.5 mm, crushing time of 225 s, crushing amplitude of 1 335 r/min, and seeds weight of 0.20 g. Under these conditions, the sesamin content detected was 4.601 g·kg^-1, which was consistent with the predicted value of 4.633 g·kg^-1. Fifteen varieties with specific high sesamin content were identified from 1 151 sesame germplasm for breeding purposes. The highest content was 14.36 g·kg^-1, and the average content was 12.35 g·kg^-1.【Conclusion】 An efficient extraction technology of sesamin was established,compared with the traditional method, the method only needed 0.2 g seeds, which improved the extraction efficiency and reduced sample consumption, the operation was simple, and the sesamin content in sesame seeds could be accurately detected.