【Objective】The aim of this study is to explore the characteristics of the EST-SSR sequences of a Dasypyrum villosum accession No.1026 (Dv#4) introduced from the former Soviet Union, and their distributions on chromosomes and polymorphism in different D. villosum accessions and between Dv#4 and common wheat. 【Method】Transcriptome sequences of Dv#4 plants were obtained by Illumina HiSeq sequencing and used to search and analyze the SSR sequences using MISA software and design primers by Primer 3. In total, 238 pairs of primers were selected randomly for synthesis and used to amplify the genomic DNAs of wheat Chinese Spring (CS) and the two different D. villosum accessions. The polymorphisms of the PCR products on agarose gel were evaluated. Further, the features of their chromosome distributions in Dv#4 were studied by using a set of wheat- D. villosum alien chromosome lines (including disomic addition lines and disomic substitution lines). 【Result】 A total sequence length of 62.76 Mb was detected and 10 497 SSR loci were found in the transcriptome data. They are involved in 8 735 unigenes. Repeated unit of mono-, di-, tri- nucleotides are the main type, holding 95.85% of all loci among 1-6 nucleotides repeats, among which tri-nucleotide is the richest component that makes up of 50.33% and contains CCG/CGG motif by 41.66%. The next component is mono-nucleotide tandem repeat, and its occurrence frequency is 18.39%, and A/T repeats occupy 74.58% in this type. Di-nucleotide ranks the 3rd, and it holds 18.39% in the total SSR loci. Among 238 pairs of randomly synthetized EST-SSR primers, 88 pairs amplified polymorphic fragments between CS and D. villosum (including Dv#2 and Dv#4); 8 pairs only had amplifications in D. villosum and some single alien chromosome lines; 4 pairs could specifically amplify bands in D. villosum and multiple alien chromosome lines. But, many primers which had amplification in both D. villosum accessions had no amplification in any alien chromosome lines. Therefore, it can be inferred that variations on the flanking conserved sequences of SSR might occur during the transferring of the exogenous genome or chromosomes into wheat. Additionally, 47 pairs of primers (19.74%) showed polymorphisms between Dv#2 and Dv#4. By using a pair of EST-SSR primer and a PCR marker, respectively, polymorphic amplicons were detected in 48 D. villosum plants, indicating that polymorphic SSR primer can be used to detect the heterogeneity of D. villosum effectively.【Conclusion】 D. villosum Dv#4 has abundant SSR sequences in its transcriptome, of which, CCG/CGG, A/T, AG/CT and other tri-, mono-, and di-nucleotide are the main tandem repeats. The flanking conserved sequences of partial EST-SSR in Dv#4 are associated with a single or several chromosomes specifically, which provides an ideal sequence resource for the development of specific molecular markers to track and detect D. villosum chromosomes or chromosome fragments in wheat background. Some of the EST-SSR polymorphism between Dv#4 and Dv#2 indicates that there is a certain degree of genetic diversity in some of the expressed sequences between the two different origin D. villosum accessions. Therefore, Dv#4 is valuable to be further investigated.

【Objective】 Inheritance and main QTL for α-tocopherol were detected by genetic analysis and QTL mapping. The results lay a genetic foundation for the selection of soybean varieties with high α-tocopherol content in soybean.【Method】The 447 RILs were derived from a cross between Jindou23 of commercial cultivar as the female parent and Huibuzhi of farm variety from Shanxi Province (ZDD02315) as the male parent that construct SSR genetic linkage map. The parent lines and the RILs were cultivated in summer at Yuanyang testing ground of Academy of Agricultural Sciences, and in Winter at Sanya of Hainan province in 2011, 2012, 2015. A complete random design with two replications was used in this study. Each plot of a single genotype provided 15.00 g big-plump seeds with same size in six environmental conditions. α-tocopherol content was detected quantitatively and qualitatively by High Performance Liquid Chromatography (HPLC). Major gene plus polygene mixed inheritance and QTL mapping for α-tocopherol were detected by major gene plus polygene mixed inheritance analysis and composite interval mapping with WinQTLCart 2.5.【Result】The results showed that α-tocopherol was controlled by four pairs of main genes by major gene plus polygene mixed inheritance analysis. and the four pairs of main genes distributed in two parents. Three main genes shared the same direction with positive additive effect and involved novel alleles from the same parent, Jindou23; one main gene has negative additive effects and donated by Huibuzhi of black beans. Three pairs of genes shared the different direction of positive or negative epistatic effects shared the different direction to α-tocopherol contribution. The phenotypic variation explained by QTL by environment interaction ranged from 0.13 to 4.05%, and indicated that α-tocopherol was significantly affected by four pairs of main genes, more than by environment. Seventeen QTLs for α-tocopherol were mapped on 8 chromosomes 1, 2, 5, 6, 8, 14, 16, and 17, separately; the variation accounted for by each of these seventeen QTLs ranged from 8.35% to 35.78%; and QTL showed additive effect. qα-D1a-1 was all located in marker intervals between Satt320-Satt254 (19.79 cM) on chromosomes 1 in four environmental conditions of 2011 at Yuanyang, 2012 at Yuanyang and Sanya, and 2015 at Yuanyang. and explained 12.55%, 12.01%, 11.89%, 12.61% of the phenotypic variation. It had an additive effect of 0.119–0.132 donated by Jinbean23. qα-A2-1 was all located in marker intervals between Sat_129-Satt377 (44.53 cM) on chromosomes 8 in three environmental conditions of 2011 at Yuanyang and Sanya, 2015 at Yuanyang. and explained 23.18%, 22.56%, 23.01% of the phenotypic variation. It had an additive effect of -0.195–-0.180 donated by Huibuzhi. qα-D1a-1 and qα-A2-1 can be stably expressed in different genetic backgrounds.【Conclusion】α-tocopherol was controlled by four pairs of additive epistatic effect major genes genetic model (4MG-AI), and it less affected by environmental factor. The two stable main QTL of Satt320-Satt254 and Sat_129-Satt377 were co-localization marker intervals in soybean.

【Objective】Wheat ears number is a major factor of yield composition and plays an important role in yield estimation and genetic improvement. Using image processing technology to accurately identify and count wheat ears in the field, a new method for obtaining agricultural information was proposed in this paper, which provided a reliable reference for the yield estimation and crop growth monitoring. 【Method】In this paper, wheat with different growth conditions after treatment with nitrogen fertilizer gradient was the research object. Firstly, the simple linear iterative cluster (SLIC) was used to segment the wheat image, and the unit of an image was transformed from pixels to superpixel block. After analyzing the color histograms, the classifiers were trained to identify wheat ears. Then, we performed a simple morphological treatment on the classification results to segment the wheat ears and performed binarization. We obtained the main body of wheat and conducted regional statistics through a series of morphological calculations, such as corrosion and expansion. The wheat ear skeleton was extracted to detect the skeleton corner points to calculate the number of wheat ears. Lastly, the results of counting wheat ears under different nitrogen levels (no nitrogen, low nitrogen, normal nitrogen, high nitrogen) were verified by linear regression analysis. 【Result】 (1) Super green value (Eg) and normalized red green index (Dgr) could be used as classification features to effectively identify wheat ears after color histogram analysis. (2) Compared to directly identifying the field image, the main body of wheat identified after superpixel segmentation was more explicit and complete in shape. (3) By comparison, wheat with better growth situation had better ear counting results, which approached 94.4% in high nitrogen level. However, the wheat ear count accuracy was low at a poor nitrogen level, which was only 81.9%. After eliminating the nitrogen-free condition, the overall growth of the mixed sample was uniform, and the wheat ear count accuracy reached 92.9%. The accuracy was improved by 8.3% compared to mixed samples with large differences in growth.【Conclusion】In the general environment, the automatic counting method of wheat ears using superpixels and color features could quickly and accurately calculate the number of wheat ears in field. While the growth vigor was too weak and the difference was too large, this method was not recommended. The research results provided a new reference for wheat field estimation.

【Objective】 The frequent spring drought has severely negative impacts on seed emergence and seedling growth in the maize production of Northeast China. It is necessary to understand the coupling effects of soil water condition and nitrogen (N) rate on maize plant and root growth at the seedling stage, and further to provide reference for optimizing water and N management in maize production of Northeast China. 【Method】In this study, two pot experiments were conducted in 2016 and 2017, with a two factor factorial design of soil water and N rates. The soil water condition included 30%, 50%, 70% and 90% of field capacity, respectively, representing severe water-stress (W0), moderate water-stress (W1), well-watered (W2) and over-watered (W3), respectively. The N rates included 0, 0.12 and 0.24 g·kg ^-1 soil, representing N-omission (N0), low N (N1) and high N (N2), respectively. 【Result】 Soil water and N rate had significant individual effects on maize plant and root growth at the seedling stage, and showed interactive effects on dry matter (DM), root morphology, N uptake, and N fertilizer use efficiency (NUE). Both soil water deficit and excess had negative impacts on maize plant growth, DM accumulation, root development, and N uptake at the seedling stage, and was especially serious under W0 treatment. Compared with W2 treatment, on average in two years, shoot and root DM and plant N uptake under W0 treatment decreased by 55.5%, 60.1% and 45.8%, respectively, NUE decreased by 7.8 percentage points. And root length (RL) and root surface area (RSA) decreased by 58.2% and 59.5%, respectively. The N fertilization improved significantly maize plant growth and N uptake but reduced root/shoot ratio at the seedling stage. Moreover, the plant and root growth responses of N fertilizer differed obviously with the different soil water conditions. The N fertilization improved root growth in terms of higher RL, RSA and root volume (RV) under W2 treatment, and therefore showed the highest plant DM and N uptake. However, N fertilization limited root growth and decreased significantly RL and RSA under W0 and W1 treatments. The N fertilization also improved root growth under W3 treatment, but the N fertilizer response was still lower than that under W2 treatment. Across all the soil water conditions, maize plants showed higher RL and RSA under N1 treatments than that under N2 treatments, but the RV was equal or smaller, indicating that low N supply induced fine root development at the seedling stage. Soil water and N rate not only affected significantly maize root morphology, but also had great effects on root system spatial distribution. The water-stress induced deeper root growth and RL distribution in subsoil. Compared with W2 treatment, on average, the distribution ratio of RL in 0-12 cm soil layer decreased by 11.0 percentage points under W0 treatment and 8.3 percentage points under W1 treatment, but their distribution ratio in 24-36 cm soil layer increased by 9.5 and 6.9 percentage points, respectively. In contrast to soil water-stress condition, maize root system showed a concentrated trend in topsoil under over-watered condition. The N fertilization improved significantly root distribution in topsoil. Compared with N0 treatment, the RL distribution ratio increased by 16.3 and 13.7 percentage points higher in 0-12 cm soil layer under N1 and N2 treatments, respectively, and the distribution ratio decreased by 11.5 and 12.5 percentage points lower in 24-36 cm soil layer, respectively. Across all the soil water-N treatments, maize root system showed the more balanced spatial distribution under the W1N1 treatment.【Conclusion】Soil water condition and N rate had significant coupling effects on maize seedling growth and root development. The appropriate soil water and N management could optimize root morphology and spatial distribution, and improve plant DM accumulation and N uptake. Therefore, we suggested reducing basal N rate to stimulate deeper root growth with more fine root by inducing the water-N coupling effect, and further to enhance plant resistance to drought stress and to improve NUE in spring maize production of Northeast China.

【Objective】Cryptochrome (Cry) and iron-sulfur cluster protein IscA (iron-sulfur cluster assembly, MagR) are potential magnetic receptor proteins in organisms. In this study, key magnetic response genes of the brown planthopper (Nilaparvata lugens) were knocked-down by RNA interference (RNAi), including NlCry1, NlCry2 and NlMagR. The objective of this study is to investigate the role of these three magnetic response genes in the longevity mediation of N. lugens in near-zero magnetic field (NZMF). Thus, the response of these three genes to magnetic field could be studied indirectly.【Method】Newly emerged brachypterous female and male adults of N. lugens fed in the lab magnetic field were chosen as the experimental material, and RNAi technology was used to inhibit the key magnetic response genes’ (NlCry1, NlCry2 and NlMagR) expression by injection of double stranded RNA, respectively. Then the RNAi treated adults were immediately transformed into the geomagnetic field (GMF) and NZMF respectively to observe their longevity. The total RNA of the RNAi treated adults under GMF was extracted by using the RNAiso Plus method on the 1st, 2nd and 3rd day after the microinjection, respectively. And then the gene expressions of NlCry1, NlCry2 and NlMagR were measured by using the RT-qPCR (real-time quantitative polymerase chain reaction) after the reverse transcription synthesis of first strand DNA in order to test the efficiency of RNAi. 【Result】There was no significant difference in the longevity of female and male adults after the injection of dsNlCry1 between the treatments of NZMF and GMF, while after the injection of dsNlCry2, the longevity of female (27.78%) and male (50.04%) adults under NZMF was significantly longer than that of the individuals under GMF, respectively. Moreover, the longevity of female adults injected with dsNlCry2 was shorter under GMF while longer under NZMF than that of individuals injected with dsGFP, even if the difference was not significant. The longevity of male adults injected with dsNlCry2 was shorter than that of individuals injected with dsGFP under NZMF (25.41%) and GMF (10.73%), respectively, and the difference under GMF reached the significant level. Furthermore, the longevity of female adults injected with dsNlMagR was significantly shorter (16.48%) than that of individuals injected with dsGFP under the NZMF. 【Conclusion】There is a difference in the regulation of the key genes of magnetic susceptibility (NlCry1, NlCry2 and NlMagR) on the female and male longevity for N. lugens under the change of magnetific field. Hereinto, the NlCry2 susceptibly responses to the changes of magnetic fields, which shows that the gene knock-down and its interaction with magnetic field changes can significantly influence the longevity of female and male adults, and characterized as “sexual dimorphism”. Similarly, the NlMagR (IscA) also sensitively responds to magnetic field changes, but just for the female adults of N. lugens under the NZMF in contrast to the GMF. However, there is no response of NlCry1 to magnetic field changes, and this gene may not be involved in the regulation of female and male longevity for N. lugens.

【Objective】Vitellogenin receptor (VgR) is the main receptor that mediates the endocytosis of insect vitellin. The objective of this study is to clarify the function of VgR of beet armyworm (Spodoptera exigua) through RNA interference (RNAi) method, and to provide a basis for further understanding the molecular mechanism of reproductive physiology and developing effective new methods for prevention and control.【Method】The fragment of VgR was amplified from the cDNA of female adults abdomen tissues of S. exigua by PCR which included the ligand-binding domain region. The green fluorescent protein gene (GFP) fragment was amplified from the GFP plasmid stored in the laboratory by specific primers. The fragment of VgR and GFP was then inserted into the pMD-19T for sequencing. The nucleic acid sequence was analyzed by DNAMAN software. The correct plasmid confirmed by sequencing acted as the DNA template. PCR amplification was performed using primers with T7 promoter. VgR and GFP dsRNA were synthesized with T7 RiboMAX ^TM Express RNAi System synthesis kit. The abdomens of S. exigua female pupae on 2nd and 6th day were injected with 3 μL double RNA by 10 μL microsyringe (2 μg·μL ^-1). RT-qPCR was used to detect the changes of VgR expression in 0-, 24-, 48-hour-old female adults. Meanwhile, eclosion rate and eggs per female were evaluated in control groups (blank control, GFP-dsRNA injection) and treatment group (VgR-dsRNA injection). 【Result】 The VgR and GFP gene fragments obtained by amplification were 327 and 417 bp, respectively. The VgR expression level of 0-, 24-, 48-hour-old female adults in the VgR-dsRNA group decreased by 79.35%, 84.22% and 67.68% compared with the GFP-dsRNA group, respectively. Through anatomical observation of the ovary of 0-, 24-, 48-hour-old female adults, it was found that compared with the GFP-dsRNA group, the ovary development of the VgR-dsRNA group was significantly delayed. Compared with the GFP-dsRNA group, the length of the ovary tube in the VgR-dsRNA group decreased by 23.92% for the 24-hour-old female adults. The GFP-dsRNA group has more mature eggs in the ovary with larger average diameter of (0.46±0.05) mm while the number of mature eggs in the VgR-dsRNA group was small with an average diameter of (0.23±0.02) mm. There was no significant difference of eclosion rate between GFP-dsRNA group and VgR-dsRNA group. In the VgR-dsRNA group, the average number of eggs per female was 170, while in the control groups (blank group, GFP-dsRNA group), the average number of eggs per female was 451 and 420, respectively. There was a significant difference in the amount of oviposition between control groups and treatment group. 【Conclusion】 The function of VgR was studied by dsRNA injection in vitro, which could significantly reduce the expression of VgR. VgR plays an irreplaceable role in the reproduction of S. exigua, which directly affects the ovary development and spawning capacity, and can be used as a potential target for controlling S. exigua.

【Objective】The objective of this study is to clarify the slow-release synergistic effect of humic acid on low concentration (5 mg·L ^-1) of chlorothalonil, provide a new scientific idea for reducing pesticide use and prolonging pesticide efficacy, and to provide a theoretical basis for selecting new fungicide synergists. 【Method】Fusarium oxysporum was cultured in vitro solid and liquid medium including low concentrations of chlorothalonil with or without 50 mg·L ^-1 humic acid addition. The inhibition rate (IR) and spore number were determined through mycelium growth test and blood counting chamber. The heat released during the growth and metabolism process of F. oxysporum was measured by isothermal microcalorimetry technology. 【Result】The IR of humic acid-chlorothalonil combined treatment significantly increased by 10.29% (P<0.05) when IR of control was set to 0. The relative synergism was 25.33%. During liquid shake culture, there was no significant difference in spore number between the chlorothalonil treatment and humic acid-chlorothalonil combined treatment on the 3rd cultured day. On the 7th cultured day, the spore number of chlorothalonil treatment was significantly lower than that of other treatments (P<0.01). On the 14th cultured day, the spore number of humic acid-chlorothalonil combined treatment was significantly lower than other treatments (P<0.05), while there was no significant difference in spore number between chlorothalonil treatment and control. It showed that humic acid extended the inhibitory effect of low concentration chlorothalonil on the increase of spore number. The heat flow-time curve of each treatment showed that no heat release peak was detected in the humic acid-chlorothalonil combined treatment within 72 hours of monitoring, while that in the chlorothalonil treatment was found in later monitoring, and the heat flow-time curve of humic acid treatment was close to the control. P_max (peak power) of the chlorothalonil treatment was significantly lower than that of the control and humic acid treatment (P<0.05), while the T_max (peak power time) was significantly higher than that of the control and humic acid treatment (P<0.05). P_max, Q (total heat evolution), and k (microbial growth rate constant) of the humic acid-chlorothalonil combined treatment were all significantly lower than other treatments (P<0.05), which indicated that the pathogen metabolic activity of the combinated treatment was significantly lower than that in other treatments. That is, the growth and metabolism of F. oxysporum were most inhibited. There was no significant difference in P_max, T_max, Q, and k between the humic acid treatment and control, that is, the inhibition effect of humic acid treatment on pathogen was not monitored, and which could verify that the inhibition effect of combined treatment was irrelevant to humic acid itself.【Conclusion】The addition of humic acid can significantly enhance the ability of low concentration chlorothalonil to inhibit the growth of mycelia, increase of spore number and heat emission during growth and metabolism process of F. oxysporum. Using humic acid as a fungicide synergist of chlorothalonil is an effective measure to reduce the amount of chlorothalonil and extend the efficacy.

【Objective】It is of great importance to explore the wheat grain yield, soil available phosphorus (P) and grain nutrient contents under a long term P application at different rates, for the purpose of appropriate P application, wheat yield increase and improvement of nutritional quality in drylands.【Method】Field experiments were conducted to investigate the effects of different phosphorus (P) rates on wheat yield, biomass, yield components, grain nitrogen (N)-, P- and potassium (K)-contents, soil available P content, and P absorption and utilization, based on the long-term fixed field experiment which was initiated in 2004 in the Loess Plateau. Soil and plant samples were collected in the consecutive experimental years of 2014-2015, 2015-2016 and 2016-2017. 【Result】 The three-year averaged results showed that long-term application of P increased wheat yield, biomass, spike number and grains per spike by 67%, 58%, 64% and 8%, respectively, while 1000-grain weight was decreased by 7% compared with no P application. The wheat yield and biomass were quadratically correlated with the P rate, and the maximum wheat yield was 6 465 kg·hm ^-2 at P rate of 144 kg P₂O₅·hm ^-2. The P and K content of grain increased with the P rate increasing, while the N content showed an opposite trend. There was a significant positive correlation between the soil available P content and the P rate. The soil available P was 16.9 mg·kg ^-1at sowing and 20.4 mg·kg ^-1at harvest when the maximum yield was occurred. The P absorption and utilization efficiency decreased with the increased of P rate. For each 50 kg P₂O₅·hm ^-2 increment, the P requirement increased by 0.4 g·kg ^-1 for the grain yield formation, while the P harvest index and the P physiological efficiency decreased by 1.3% and 45.1 kg·kg ^-1, respectively. 【Conclusion】 By balancing the wheat grain yield and key nutrient contents, the target grain yield should be 95% of the maximum yield in drylands of the experimental area, and the corresponding P application rate should be kept at 94 kg P₂O₅·hm ^-2, the available P at 12.0 and 13.8 mg·kg ^-1 at sowing and harvest, respectively.

【Objective】Substrate cultivation is one of the effective ways to solve the adverse influences of soil texture deterioration on crop production which were cultivated in protected environment. With lacking standard of water and fertilizer management for substrate cultivation, in order to ensure the standard of irrigation and fertilizer coupling on yield, dry weight, quality, partial factor productivity of fertilizer and water use efficiency of cucumber cultivated in substrate in spring, the irrigation and fertilizer supply systems for high yield, quality, and efficient production of cucumber substrate were investigated.【Method】‘ChunyouNo.1’ cucumber was chosen as the materials, and the experiment was subjected to three irrigation water levels (W1 (75% crop evapo-transpiration, ETc), W2 (100% ETc) and W3 (125% ETc)) and three Yamazaki cucumber nutrient solution formula concentrations (F1 (75%), F2 (100%), F3 (125%)). The study analyzed the effects of different water and fertilizer coupling on cucumber yield, dry weight, quality, partial factor productivity of fertilizer and water use efficiency. The multivariate regression analysis and spatial analysis methods were used to obtain the best combination of irrigation and fertilizer for efficient cultivation of spring cucumber in plastic greenhouses. 【Result】The increase of irrigation was beneficial to the growth of cucumber yield and partial factor productivity of fertilizer (PFP). The yield (7 667.3 kg/667m ²) and PFP (205.67 kg·kg ^-1) of W3F1 treatment were the largest during the 60 days of the harvest period. Under the same fertilization conditions, PFP was increasing with the increase of irrigation volume. Under the condition of F1, the net photosynthetic rate of W3 treatment was lower than W1, but its leaf area index was larger, therefore higher assimilation amount and yield were obtained. Under the same irrigation condition, the Vitamin C and reducing sugar performance of cucumber fruit under W1 level was the best, while the soluble solids and soluble protein of cucumber fruit under W3 had the best value. Through the multivariate regression analysis and the spatial analysis methods to evaluate yield, quality and partial factor productivity of fertilizer, the results showed that the fertilization and irrigation amount obtained was about 36.0-42.2 kg/667m ² and 198.0-219.8 m ³/667m ², or 42.2-44.6 kg/667m ² and 206.3-219.8 m ³/667m ². 【Conclusion】Irrigation level and fertilization level significantly affected growth, yield, quality, WUE and PFP. The best strategy of fertilization and irrigation for the production of drip-irrigated cultivated cucumber grown in substrate bags in Spring is level which yield, nitrate content and PFP of cucumber were ±10% of optimal value.

【Objective】 The changes in the ascorbic acid (AsA) contents and the enzymatic activities during the anabolic process of different cultivars and growth stages of black currant fruits were studied to determine the relationship between AsA contents and anabolic enzymes during the growth and development of fruits, so as to provide a theoretical basis for comprehensively revealing the accumulation rule of AsA in black currant fruits. 【Method】 Three different cultivars of black currant fruits (Adelinia, Brodtrop and Heifeng) were studied and determined the contents of reduced AsA, oxidized ascorbic acid (DHA), reduced glutathione (GSH) and oxidized glutathione (GSSG) and anabolic enzymatic activities of young, expansion, half-veraison, veraison and maturity stages. 【Result】 There were significant diversities in fruit sizes, AsA contents and AsA metabolites of different cultivars of black currant fruits. The Adelinia had the largest weight of single fruit (1.97 g). During the growth and development process of fruits, the changes in the total ascorbic acid (T-AsA) and AsA contents of fruits were consistent among the three cultivars, and the young fruits had the highest contents. The AsA content of young Adelinia fruit was the highest (83.17 μmol?g ^-1 FW) and then sharply decreased rapidly to the maturity stage with the growth of the fruit, which decreased to 21.28 μmol?g ^-1 FW at maturity stage. The contents of GSH and T-GSH in the three cultivars increased with the development of fruits, but the different cultivars increased in different stages and degrees. The content of GSSG was quite different among different cultivars. For the mature fruits, the GSSG content of Heifeng was the lowest, which was 0.008 μmol?g ^-1 FW and only accounted for 10.2% of Adelinia. In AsA-GSH recycling regeneration metabolism, the activities of dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) showed the highest level at expansion period, and finally decreased to the lowest level at maturity stage. The DHAR and MDHAR activities of Brodtrop fruits showed slightly higher than those of Adelinia and Heifeng fruits. The activity of glutathione reductase (GR) was the highest level at young stage. The GR activity of Adelinia young fruits was the highest (0.06 μmol?min ^-1?g ^-1 FW), and then decreased with the growth of fruits. The changes in the activities of ascorbate peroxidase (APX) were similar to the changes in the activities of GR. The changes in the activities of L-galactose-1,4-lactone dehydrogenase (GalLDH), a key enzyme of L-galactose pathway, were consistent with the changes in AsA contents. The GalLDH activity of Adelinia young and mature fruits showed higher than that of Heifeng and Brodtrop young and mature fruits, respectively. According to the correlation analysis, the GalLDH activity showed a highly significant positive correlationship with T-AsA, AsA, DHA, DHAR and MDHAR. The correlation coefficient was above 0.91. The higher GalLDH activity was found in the fruits, the higher AsA contents of fruits also was found. There was a highly significant positive correlationship between DHAR and MDHAR, T-AsA and AsA. The APX had a high correlation with T-GSH and GSH. 【Conclusion】 The AsA content of black currant young fruits was the highest and there were significant differences among the three cultivars. The GalLDH, MDHAR and DHAR might be the key enzymes for AsA anabolism in black currant fruits. The accumulation of AsA content of black currant fruits resulted from the activity of GalLDH, which indicated that the anabolic pathway played a more important role and were found to be a dominant position. The related enzymes of AsA-GSH recycling regeneration pathway also contributed to the AsA anabolism. The accumulation of high AsA content in black currant fruits resulted from the combined effects of anabolic and recycling pathways.

【Objective】 The study was carried out to identify characteristic organic acids and disclosing their dynamic changing law of Chaenomeles speciosa fruit from Qijiang, Chongqing during its fruit developing period, so as to provide the basic data for the C. speciosa fruit organic acids metabolic research. 【Method】 By methanol extracting, methyl derivating and GC-MS detecting, the organic acids composition and their content of 8 developing period C. speciosa cv. Daluo fruit samples of Qijiang was measured. The 2012 chromatographic similarity analysis software of Chinese Pharmacopoeia Commission was used to match their common constituent peaks. The dynamic law of the total organic acids, strong-sour and weak-sour organic acids were showed in SigmaPlots10.0 software and the PCA and HCA of all the samples was processed separately by Simca-P 11.5 and SPSS 20.0 softwares. 【Result】 The total 41 common characteristic constituents, including 10 short-chain carboxylic acids, 21 long-chain fatty acids, 5 aromatic-organic acids, 3 monobasic-phenol acids and 2 amino-acids, were successfully matched among 8 TICs of different period fruit samples C. speciosa cv. Daluo from Qijiang. The baseline of all the TICs were smooth and stable, the organic acid derivatives peaks' distribution were well-distributed, and the separating-degree of samples’ peaks was high. All target components were well separated. The total organic acids content of Qijiang C. speciosa cv. Daluo fruit from 90 ^th day after its full-bloom stage to 160 ^th days showed the changing on reversed ‘Z’ that including the sharply decreasing, slowly increasing and then decreasing again. The total organic acids content was significant positive correlated with the strong sour (r=0.970) and the weak sour taste organic acids (r=0.998). At the same time, the strong sour taste organic acids were significant positive correlated with short-chain carboxylic acids (r=0.999) and positive correlated with monobasic phenol acids (r=0.747). The weak sour taste organic acids were significant positive correlated with long chain fatty acids (r=0.999). The malic acid, laevulic acid and citric acid, whose relative content sum was more than 90%, were the key ingredients of strong sour organic acids. The malic acid content had experienced a reverse ‘Z’ trend that decreased firstly (90 ^thd-120 ^thd), increased slightly (120 ^thd-130 ^thd) and decreased finally (130 ^thd-160 ^thd). The citric acid had a similar process, but the levulic acid had an obviously reverse process of changing with malic acid. Actually the levulic acid showed the increasing progress gradually. The correlation analysis showed that the strong sour taste organic acids had significant positive correlation with malate and citrate, but weakly negative correlation with levulic acid, isocitric acid, and salicylic acid. The analyzing result showed that most of the weak sour organic acids including 9-octadecenoic acid, 9,12-octadecadienoic acid, hexadecanoic acid and 10-hydroxy-hexadecanoic acid experienced the similar accumulating progress which was rapidly decreasing firstly, then slowly increased and decreased in the final stage. However, nonadecanoic acid showed an opposite process that was gradually increasing. Correlation analysis showed that the total weak sour organic acids were positively related to most of them such as 9-Octadecenoic acid and 9, 12-Octadecadienoic acid but negative to nonadecanoic acid. The PCA result by Simca-p 11.5 disclosed that PC1 and PC2 separately distributed 40.00% and 23.20% of the total variance contribution rate. The main component score of each sample showed that: S1 and S2 clustered together which decided by α-Ketoglutaric acid, malic acid, quinic acid, shikimic acid, hexadecanoic acid and linoleic acid. The S3, S4 and S5 got into one branch that mainly because of oleinic acid and 10-hydroxy-Hexadecanoic acid. The S6 was closer to S7 largely because of malonic acid, levulic acid, isocitric acid, salicyluric acid. The S8 formed a unit alone that mostly decided by succinic acid, nonadecanoic acid, tetracosanoic acid. This result was very similar to the other one that clustered by Ward's method with Squared Euclidean Distance in SPSS. 【Conclusion】 C. speciosa cv. Daluo in Qijiang,Chongqing is a typical malate-accumulating fruit. During its developing period of C. speciosa fruit, the accumulating pattern of organic acids changed from Malate-Citrate accumulating type on 90 ^th days to Levulinic acid-Malic acid - Citric acid accumulating type on 160 ^th days after its flower-blooming. The change of acid accumulation pattern played a key role in the determination of acidity and flavor quality of C. speciosa fruit in Chongqing.

【Objective】The aim of the paper was to establish suitability evaluation model for apple chips-processing from different cultivars and to achieve the quality prediction of apple chips based on raw material indicators.【Method】34 fresh apple samples of 21 apple varieties from 7 major growing regions were selected as research objects. Factor analysis (FA) and analytic hierarchy process (AHP) were used to establish comprehensive quality evaluation model for chips, and Error Back Propagation (BP) artificial neural network was used to establish chips-processing suitability evaluation model for apple fruits. (1) Chips were prepared by instant controlled pressure drop (DIC, French for détente instantannée controlee, also known as explosion puffing) and 17 indicators were measured. The core indexes of chips were selected by FA and correlation analysis. The weights of the core indexes were determined by AHP, and then the comprehensive quality evaluation scores of chips were calculated. (2) 22 indicators of 34 fruit samples with different cultivars and regions were measured. Then the characteristic indicators of apple fruits related to chip qualities were screened out by correlation analysis between data groups of apple fruit indicators and chip core indexes. Learning model with input of fruit characteristic indicators and output of chip comprehensive evaluation scores was established by database of 29 apple samples. 5 apple samples were chosen as test samples to verify the prediction accuracy of the learning model. Modified leaning models from different sample groups were compared by prediction accuracy, which could be the evidence to evaluate rationality and stability for application of BP neural network in the present research.【Result】The results showed that L* value, brittleness, puffing degree, titratable acid, soluble sugar and crude protein of apple chip were determined as the core indexes which the weights were 0.3724, 0.2665, 0.1583, 0.0890, 0.0569 and 0.0569, respectively. The comprehensive quality scores of chips from 34 apple samples ranged from 0.2069 to 0.7933, indicating significant variation. The top 3 apple samples with high scores were Liaoning Huahong, Liaoning Huajin and Shandong Yanfu 6, and the final ranking for Shanxi Qinguan. Correlation analysis was performed between core indexes of chips and quality indicators of apple raw materials to achieve characteristic indicators of apple fruits, including the fruit shape index, a* value (pulp), pH value, titratable acid content, Vc content, proportion of core, protein content, b* value (pulp), density, soluble solids content, crude fiber content and total sugar content. Therefore, learning models were established with input layer of the characteristic indicators value of fruit and output layer of the comprehensive quality score of apple chip, which could predict the comprehensive quality of apple chips from indicators of raw materials. Moreover, the model showed high prediction accuracy. The relative errors between the predicted and actual values of the three learning models groups did not exceed 10%, and the coefficients of determination R ² of linear fitting were higher than 0.95.【Conclusion】Suitability evaluation of apple fruit for chips-processing could be evaluated by fruit shape index, a* value (pulp), pH value, titratable acid content, Vc content, proportion of core, protein content, b* value (pulp), density, soluble solids content, crude fiber content and total sugar content. The established model could be used to quantitatively predict apple fruit suitability for chips-processing based on the indicators of raw fruits.

【Objective】The objective of this paper was to investigate the effects of long non-coding RNA LncRNA-133a on the proliferation and differentiation of bovine skeletal muscle satellite cells. 【Method】 This study used qRT-PCR to detect the expression level of LncRNA-133a in the skeletal muscle tissues of 3, 6 and 9 months old fetal cattle and 24 months old adult bovine skeletal muscle, and obtained the tissue temporal expression profile of LncRNA-133a. The in vitro induced myoblast differentiation model of bovine skeletal muscle satellite cells was constructed to simulate the growth and development of bovine skeletal muscle. The qRT-PCR was used to detect the cells temporal expression profiles of LncRNA-133a and myocyte differentiation markers MyoG and MHC. The bovine skeletal muscle satellite cells were transfected with LncRNA-133a overexpression vector (pCDNA3.1-EGFP- LncRNA-133a) or LncRNA-133a inhibitor (si-LncRNA 133a), and the transfection efficiency and the mRNA expression levels of LncRNA-133a, MyoD, MyoG and MHC were detected by qRT-PCR in each transfection treatment group, then the protein expression level of MHC gene was detected by western blotting. In addition, the cell proliferation of the bovine skeletal muscle satellite cells and the extent of myotube fusion at the differentiation stage were detected by EdU cell proliferation assay and immunofluorescence protein staining, respectively. 【Result】 Tissue expression profiling revealed that LncRNA-133a had the highest expression in the muscle tissue of 3 months old fetal bovine, followed by the 6-month-old fetal bovine muscle tissue, and the lowest expression in the 9-month-old fetus and adult bovine muscle tissue, which demonstrated that the time expression showed a downward trend. Cell-time expression profiles of LncRNA-133a, MyoG, and MHC were analyzed by a successfully constructed bovine skeletal muscle satellite cell differentiation model in vitro, and the results showed that the expression levels of myogenic differentiation markers MyoG and MHC gradually increased during the differentiation of bovine skeletal muscle satellite cells (D0-D3). The expression of LncRNA- 133a increased in the differentiation stage, and the expression level reached the highest at 48 h of differentiation (D2). The bovine skeletal muscle satellite cell model of overexpressing LncRNA-133a or inhibiting LncRNA-133a was constructed successfully, and in the proliferative phase (D0): the number of EdU positive cells in the overexpressed LncRNA-133a-treated group was significantly increased (P<0.01), and the number of EdU positive cells in the LncRNA-133a inhibition treatment group was significantly decreased (P<0.01), compared with the control group. At 48 h of differentiation (D2): compared with the control group, the results of LncRNA-133a overexpression treatment showed that mRNA expression levels of myocyte differentiation markers MyoD, MyoG and MHC were significantly increased (P<0.05). Western blotting showed that the expression of MHC protein was also significantly increased (P<0.01), and the immunofluorescence protein staining of MHC protein showed that the volume of fusion myotubes was larger. On the contrary, in the LncRNA-133a inhibition treatment group, the mRNA expression levels of MyoD, MyoG and MHC were decreased, and MyoG was significantly decreased (P<0.05). Meanwhile, the expression of MHC protein was significantly decreased (P<0.01), and the volume fraction of MHC protein fusion myotubes was also decreased. 【Conclusion】Thus, this study confirmed that LncRNA-133a promoted the proliferation and differentiation of bovine skeletal muscle satellite cells, which laid a foundation for further research on the regulatory network mechanism of LncRNA-133a regulating the proliferation and differentiation of bovine skeletal muscle satellite cells.

【Objective】In this study, the growing male Yanshan cashmere goats were used as experimental animals, and the objective was to explore the proper energy level, protein level and energy-to-nitrogen ration according to effects of diets with different energy-to-nitrogen rations on growth performance and nutrients apparent digestibility in goat by feeding trial and digestion-metabolism trial.【Method】Eighty-one six-month-old growing male goats (24.96±2.95) kg were divided into 9 groups according to a 3×3 (energy × protein) completely random experiment design and offered 9 pellet total mixed ration (nine lambs per diet), in which metabolic energy (ME) were formulated at 9, 10 and 11 MJ/kg·DM, and digestible crude protein (DCP) were 8.5%, 9.5%, and 10.5%, respectively. There was a 10-day adaption period before the 50-day experimental period, and then 4 goats in each group were selected for digestion and metabolism test when the average body weight reached 30 kg. The total collection of feces and urine was conducted for 3 days after a 4-day adaptation, and residual feed, feces and urine were collected continuously.【Result】The results showed that: 1) The dry matter intake (DMI) and ratio of feed to gain (F/G) were decreased significantly (P<0.05) with the increase of dietary ME levels, while no extremely effect on ADG (P>0.05). ADG and DMI increased first and decreased afterwards with the increase of dietary DCP levels, and ADG and DMI in medium DCP groups were extremely higher than low and high DCP groups (P<0.05). The interactions of dietary ME×DCP had a remarkable effect on DMI (P<0.05). ADG of Group Ⅴ was highest (222 g·d ^-1), ADG of Group Ⅴ was significant higher than Group Ⅰ, Group Ⅳ and Group Ⅵ (P<0.05), and higher than the other 5 groups with no significant difference (P>0.05). 2) The fecal energy decreased significantly (P<0.05) with the increase of dietary ME levels, while digestible energy and gross energy (GE) apparent digestibility increased significantly (P<0.05). The dietary DCP levels and the interactions of dietary ME×DCP had no significant effect on energy digestion and metabolism. 3) The nitrogen (N) intake, fecal N decreased significantly (P<0.05) with the increase of dietary ME levels while digestible N had the trend to decrease, and N apparent digestibility in high ME groups were extremely higher than low and medium ME groups (P<0.05). N intake, urinary N, digestible N and N apparent digestibility increased significantly (P<0.05) with the increase of dietary DCP levels. The interactions of ME×DCP had a significant effect on N digestibility (P<0.05). 4) The apparent digestibility of dry matter (DM), organic matter (OM), ether extract (EE) and calcium (Ca) increased significantly (P<0.05) with the increase of dietary ME levels (P<0.05), while Ca digestibility in low DCP groups were extremely lower than medium and high DCP groups.【Conclusion】The trial results showed the most suitable diet (ME:10 MJ?kg ^-1, DCP:9.5%) with the highest ADG (222 g·d ^-1) and lower F/G.

【Objective】MicroRNA (miRNA) is a kind of key gene expression regulator, which can affect the interactions between host and pathogen. Ascosphaera apis is a lethal fungal pathogen that specifically infects honeybee larvae. The objective of this study is to analyze the differentially expressed miRNAs (DEmiRNAs) and their target genes in the Apis mellifera ligustica larval gut during the early infection stage of A. apis, reveal DEmiRNA’ roles in the stress responses of host at the miRNA omics level, and to screen the key miRNAs related to host response by constructing regulation networks of significant DEmiRNAs. 【Method】Normal and A. apis-infected 4-day-old larval gut of A. m. ligustica (AmCK and AmT) were deep-sequenced using small RNA-seq (sRNA-seq) technology, followed by quality-control of raw data and then mapping of the filtered data with the reference genome of Apis mellifera. The mapped tags were compared to the miRBase database to identify the expression of known miRNAs. The expression of miRNAs in each sample was normalized by TPM (tags per million) algorithm and significant DEmiRNAs were gained according to the standard |log₂ fold change|≥1 and P≤0.05. Target genes of significant DEmiRNAs were predicted utilizing TargetFinder, and then annotated to the GO and KEGG databases. Cytoscape was used to visualize the regulation networks between significant DEmiRNAs and target mRNAs. Finally, Stem-loop RT-PCR and qPCR were conducted to verify the reliability of the sequencing data.【Result】sRNA-seq of AmCK and AmT produced 13 553 302 and 10 777 534 raw reads, and after strict filtration, 13 186 921 and 10 480 913 clean reads were obtained, respectively. The Pearson correlation coefficients among different biological replicates in each sample were above 0.9822 and 0.9508. There were 10 significant DEmiRNAs including 4 up-regulated miRNAs and 6 down-regulated miRNAs, and the overall expression level of DEmiRNAs in AmT was lower than that in AmCK. In total, 10 significant DEmiRNAs could link 3 788 target genes. The 1 240 target genes of up-regulated miRNAs could be annotated to 39 GO terms, and the mostly enriched terms were binding, cellular processes, metabolic processes, and response to stimulus. The 749 target genes of down-regulated miRNAs could be annotated to 34 GO terms, and the mostly enriched terms were cellular processes, binding, metabolic processes, and response to stimulus. The result of KEGG database annotation suggested that the target genes of up- and down-regulated miRNAs were respectively annotated in 95 and 66 pathways, the most abundant pathways were Wnt signaling pathway, Hippo signaling pathway, phototransduction and endocytosis, phosphatidylinositol signaling system, as well as purine metabolism. For up- and down-regulated miRNAs, there were 31 and 52 target genes could be annotated to endocytosis, 15 and 7 target genes could be annotated to ubiquitin-mediated proteolysis, 11 and 5 target genes could be annotated to Jak-STAT signaling pathway, 1 and 3 target genes could be annotated to the MAPK signaling pathway, respectively. Complex regulation networks existed between significant DEmiRNAs and their target mRNAs, among them 7 significant DEmiRNAs targeted 96 mRNAs associated with Wnt signaling pathway, and 8 significant DEmiRNAs targeted 55 mRNAs involved in endocytosis. Finally, the results of Stem-loop RT-PCR and qPCR verified the reliability of the sequencing data.【Conclusion】A. m. ligustica larval gut’s DEmiRNAs and their target genes during the early infection stage of A. apis were predicted and analyzed. DEmiRNA-mRNA regulation networks in the host were constructed and investigated. The results provide the expression profile and differential expression information of host miRNAs, and reveal that these DEmiRNAs likely participate in the stress responses of host via regulating biological processes such as cellular activity, metabolism, and immune defense. miR-4331-y, miR-4968-y, miR-8440-y, novel-m0023-5p and novel-m0025-3p jointly regulate Wnt signaling pathway and endocytosis of host and can be used as potential molecular targets for chalkbrood control.

【Objective】The objective of this study is to analyze the gene sequence and structural characteristics of integrin β2 in silkworm (Bombyx mori), and its expression profile in hemocytes following the larval exposure to different bacterial pathogens, investigate the binding and agglutination properties of the recombinant integrin β2 protein to various pathogen-associated molecular patterns (PAMPs) and bacteria, which will lay a foundation for further exploring the protein function of integrin β2 in B. mori. 【Method】Bioinformatics tools were used to determine the sequence and structural characteristics of integrin β2, and real-time fluorescent quantitative PCR (RT-qPCR) assay was executed to evaluate expression profile in hemocytes after microbial (Escherichia coli and Staphylococcus aureus) challenge. The cDNA fragment of integrin β2 was amplified using PCR, and the fragment containing the extracellular domain was inserted into a prokaryotic expression vector (pET22b). The insertion was confirmed in the recombinant plasmid and transformed into E. coli Rosetta (DE3), and then induced by IPTG to produce recombinant protein. The recombinant protein was purified using Ni-NTA affinity chromatography and analyzed by SDS-PAGE and Western blot. ELISA and Western blot were executed to determine the binding abilities of the recombinant protein to PAMPs (LPS and PGN) and different bacteria. Moreover, the agglutination ability and bacterial clearance assay were performed to understand the specific biological roles of integrin β2 in immunity.【Result】B. mori integrin β2 contains typical integrin β subunits, which comprises a long extracellular domain, a single transmembrane region and a short cytoplasmic tail. Further, it has several conserved motifs such as the MIDAS, EGF domain, Cys-repeat sequences and NPxY motifs. The RT-qPCR analysis showed that the integrin β2 expression varied significantly in hemocytes after infection with bacteria. High purity recombinant protein was obtained by prokaryotic expression and protein purification. The results of SDS-PAGE and Western blot showed that the purified recombinant protein was of high purity and could be used in subsequent tests. ELISA assay indicated that the purified recombinant integrin β2 protein had a strong binding ability to PAMPs (LPS and PGN). The results of bacterial binding test showed that the recombinant protein could bind many bacteria, but the binding ability with Gram-positive bacteria was higher than that with Gram-negative bacteria. The agglutination assay showed that the recombinant protein had strong agglutination effects on S. aureus in the presence of ca ²⁺. Further, bacterial clearance assay suggested that the recombinant protein could effectively promote the cleaning of exogenous invading bacteria from B. mori. 【Conclusion】The integrin β2 has a typical structure of the β integrin family, and it can recognize PAMPs (LPS and PGN) and enhance the aggregation of invading microbial pathogens by directly binding to them. Taken together, integrin β2 may play an important biological role in the bacterial immune response of B. mori.

【Objective】 Plant height has an great effect on lodging resistant, productivity and mechanical operation in rapeseed. Identification and research of dwarf and semi-dwarf germplasm in rapeseed will facilitate genetic improvement of plant height. At present, excellent dwarf germplasm in rapeseed is seriously deficient. In this study, we obtained a semi-dwarf natural mutant in B. napus and it was evaluated by phenotypic identification, genetic analysis and morphological and physiological analysis correlated to plant hormone. This work provide a theoretical basis for dwarf breeding and will contribute to further gene mapping and cloning.【Method】 A semi-dwarf mutant discovered from rapeseed line 141492 after six generations of self-crossing was used to produce DH population by isolated microspores culture, from which we choose one named dw-1 with the average plant height of 95 cm (83-105 cm) to identify its performance on agronomic traits, economic traits and disease resistance. Joint segregation analysis of six generations derived from a cross between dw-1 and wild type was carried out to reveal the inheritance of plant height based on major gene plus polygene mixed model. Morphology analysis of light and dark treatment (16 hL/8 hD, 24 hD) and exogenous gibberellins sensibility test of hypocotyls and stems were performed to classify the mutant. 【Result】 Compared with wild type, 1000-seed weight did not change while disease index of sclerotinia stem rot, number of secondary braches and number of siliques per plant increased significantly or extremely significantly in dw-1. Length of main inflorescence, number of primary branches, plant height, branch height, height of gravity center, number of siliques on main inflorescence, seeds per silique and yield per plant decreased significantly or extremely significantly and growth duration was shortened remarkably. Genetic analysis indicated that dw-1 was controlled by a pair of major gene with additive-dominant effects plus polygene with additive-dominant-epistasis effects (D-0 model). Additive effect and degree of dominance of major gene were -47.5 and 0.2, respectively. The heritability of major gene in B₁, B₂, F₂ population were 76.0%, 84.0% and 85.0%, respectively, and those of polygene were 4.1%, 5.6% and 6.7%, respectively. Morphogenesis of dw-1 was normal and the length of hypocotyl of dw-1 was decreased significantly compared with the wild type regardless of light or dark condition (P < 0.01). Exogenous gibberellic acid 3 (GA₃) with lower concentration had no obvious effect on elongation of hypocotyls and stems in dw-1 while they could be partially rescued in higher concentration but not to the wild type phenotype. 【Conclusion】 Mutant dw-1 with good comprehensive performance was mainly controlled by one pair of additive-dominant major gene dominated by additive effect. Selection of plant height can be carried out in earlier generation of conventional hybridization breeding. dw-1 was unrelated to brassinosteroid (BR) pathway and showed a reduced response to GA₃.

【Objective】 Sesame SiSAD (△9 stearoyl acyl-carrier-protein desaturase) gene was cloned and the expression of it was detected. It was transformed into Arabidopsis to investigate its role in the oleic acid synthesis. This study aims to provide molecular basis for the genetic improvement of sesame oleic acid content. 【Method】Total RNA was extracted from leaf of the variety Zhongzhi13 and then was reverse transcripted into cDNA. Using the primers that designed according to the reference genome, the coding region sequence of SiSAD was obtained by RT-PCR. The sequence was further compared with the reference genome. The conserved motifs of SiSAD protein were identified by InterPro and the homologous proteins of SiSAD were recognized by BLAST. A phylogenetic tree of SiSAD from sesame, Olea europaea var. sylvestris, Ipomoea nil, Ricinus communis, Lactuca sativa, Vitis vinifera, Citrus sinensis and Arabidopsis thaliana was constructed by neighbor-joining method to reveal the relationship of SiSAD protein in these species. Expression profiles of SiSAD in roots, stems, leaves, buds and seeds at two varieties Zhongzhi33 and Zhongfengzhi No.1 were investigated. The SiSAD gene was linked to a 35S vector and transformed into Arabidopsis by the Agrobacterium tumefaciens-mediated floral dip method. Based on the qRT-PCR detection, successful transformed Arabidopsis individuals were selected from the progenies. The stearic acid and oleic acid content in the seeds of transgenic T₃ Arabidopsis seeds and Col-0 were detected and function of SiSAD was concluded. 【Result】 Total coding region sequence of SiSAD was cloned and the sequence was the same as the reference genome. It consisted of 1 152 nucleotides encoding a protein of 383 amino acids with a calculated molecular mass of 43 kD and a predicted pI of 6.18. We found that SiSAD gene contained one conserved function domain, which had been identified as a signature motif within the fatty acid desaturase family members. The similarity of SiSAD proteins from different species was quite high, indicating that SiSAD in different plant might had conserved function. The phylogenetic tree composed of SAD proteins showed that SiSAD, InSAD and OeSAD had been grouped together, suggested a close relationship of SiSAD protein among sesame, O. europaea var. sylvestris and Ipomoea nil. In contrast, SiSAD had a far relationship to AtSAD, CsSAD and RcSAD. qRT-PCR results showed that SiSAD is organ-specific expressed and had a highest expression level in seeds. We successfully constructed the overexpression vector of SiSAD and introduced the vector into Arabidopsis by Agrobacterium-mediated transformation. qRT-PCR was used to test the transcription of SiSAD in transgenic Arabidopsis plants. Compared with the Arabidopsis wild type Col-0, stearic acid content of 3 transgenic lines with overexpressed SiSAD gene was decreased by 3.0%, 4.8% and 6.1%, respectively. Which oleic acid content in these lines was increased by 2.8%, 4.3% and 7.8% (4.97% in average). 【Conclusion】 In this study, the total coding region sequence of SiSAD was cloned and function of SiSAD was characterized. SiSAD might plays important roles in improving oleic acid content, which could be used in the genetic improvement of oleic acid content in sesame seeds.

【Objective】This article was to study the spatial-temporal distribution and interaction between agronomic traits of winter wheat and precipitation of growth period, and to provide a theoretical basis for variety improvement of winter wheat in Huang-Huai dryland under climate change.【Method】The data of agronomic traits and precipitation of the national regional trials of Huang-Huai dryland from 2010 to 2017 were used to analyze the spatial-temporal distribution and interaction by geographic methods and statistical methods.【Result】In terms of spatial distribution, the actual yield per unit area and 1000-kernel weight of winter wheat showed an increasing trend from west barren dryland to east fertile dryland. The plant height showed higher in the west barren dryland and lower in the middle and east fertile dryland. The total precipitation of different growth stages in the north of central and eastern Huang-Huai dryland was generally low, the south of central and eastern Huang-Huai dryland relatively high. In terms of time change, the total precipitation of germination to maturity period in the central and western dryland of Henan, Shanxi and Shaanxi showed a significant increasing trend. The total precipitation of germination to heading period was significantly positively correlated with actual yield, plant height, and number of effective ears. The results of path analysis showed that the plant height and the number of effective ears determined 53.2% of the actual yield variation in Huang-Huai fertile dryland, and the plant height and 1000-kernel weight determined 67% of the actual yield variation in Huang-Huai barren dryland. 【Conclusion】 It was suggested that winter wheat breeding in Huang-Huai fertile dryland should increase plant height appropriately, improve the ability of efficient use of limited precipitation before flowering and increase ear development. Huang-Huai barren dryland breeding should stabilize plant height and improve the efficiency of transporting dry matter after flowering and harvest index.

【Objective】The purpose of this paper was to improve the extraction accuracy of soil salinity information based on remote sensing and understand accurately the degree and distribution of soil salinization. 【Method】Firstly, the severe and concentrated saline soil area of Huanghekou town, Kenli district, was selected as the experimental area, and the unmanned aerial vehicle (UAV) equipped with Sequoia multispectral camera was adopted to acquire the near earth remote sensing image from April 26th to 28th, 2018, then the image preprocessing, including image splicing, radiation correction, orthorectification and geometric correction, was performed. Secondly, the sensitive bands of soil salinity were screened by correlation analysis and grey correlation analysis, respectively, and the spectral parameters were constructed and screened. Thirdly, the soil salinity quantitative analysis models were built by multivariate linear regression (MLR), support vector machine (SVM) and partial least square (PLS) method, then the models’ accuracy was evaluated and the best one was selected. Finally, the best model was applied to the inversion and analysis of soil salinity distribution in the experimental area, and the inversion accuracy was compared with the interpolation result by inverse distance weighting (IDW) method. 【Result】The results showed that the accuracy and significance of the estimation model based on gray correlation analysis were improved by compared with the correlation analysis; Compared the three modeling methods, the prediction ability of the SVM was the best, followed by the PLS, the MLR models’ precision was the lowest, with the calibration R ² and RMSE of 0.820 and 3.626, the validation R ², RMSE and RPD of 0.773, 4.960 and 2.200, and the SVM model of soil salinity based on screened variables by grey correlation analysis was selected the best one; Based on the best model, the soil salinity content in this region was between 0.323 and 21.210 g·kg ^-1 with the average of 6.871 g·kg ^-1 and the severe salinity accounted for 58.094%, which was consistent with the result of the field investigation; The 80% of the error between the inversion result and the interpolation result by the IDW method was controlled within 20% of the sample salt content average, which showed that the two kind of result were similar. 【Conclusion】It could be concluded that the accurate extraction of severe soil salinity information could be achieved on the UAV multi-spectra.

【Objective】The protein encoded by NS3 is a suppressor of RNA silencing of Rice stripe virus (RSV). In previous study, it was found that NS3 expression enhanced the resistance of Nicotiana benthamiana to RSV using transgenic technology. In order to reveal the detailed function of NS3 in host plants, the resistance of NS3-transgenic N. benthamiana to other tobacco diseases will be analyzed in this study.【Method】Wild-type and NS3-transgenic N. benthamiana were used to study the infection of Potato virus X (PVX), Ralstonia solanacearum, and Phytophthora parasitica var. nicotianae. PVX infectious clone was inoculated by agro-infiltration, viral symptoms were observed. The total RNA of infected leaves was extracted, and viral relative accumulation was detected by RT-qPCR. The method of filling root was used to inoculate R. solanacearum and P. parasitica var. nicotianae, respectively, disease symptoms were observed, and the incidence and disease index were analyzed.【Result】The main symptoms of PVX in N. benthamiana leaves were mosaic and chlorosis, and the NS3-transgenic N. benthamiana plants had the same PVX symptoms as those of wild-type plants. At 10 days past inoculation (dpi), the results of RT-qPCR showed that NS3 expression inhibited the accumulation of PVX in N. benthamiana, the relative accumulation of PVX in NS3-6 line and NS3-9 line was 68.17% and 81.01% of that of wild-type N. benthamiana, respectively. After the infection of R. solanacearum, the symptoms both in wild-type and NS3-transgenic N. benthamiana plants were wilting and damping-off. In the early stage of disease, the expression of NS3 was beneficial to the infection of R. solanacearum to a certain extent, which showed that it was more sensitivity to bacterial wilt. At 14 dpi, the incidence and disease index of bacterial wilt of wild-type N. benthamiana were 100.00% and 78.67, while the incidence of NS3-6, NS3-9 line was 95.00%, 98.33%, and the disease index was 70.00, 73.00, respectively. After 14 dpi, the incidence and disease index increased gradually, while the disease index of NS3-transgenic lines was lower than that of wild-type plants. The black-brown necrotic patches at the base of stem were observed both in wild-type and transgenic plants after P. parasitica var. nicotianae infection, and the expression of NS3 did not affect the symptoms of N. benthamiana. At the early stage of P. parasitica var. nicotianae infection, the incidence of black shank disease in NS3-6 was higher than that of wild-type N. benthamiana, however, during the whole process of black shank disease, the disease index of NS3-transgenic lines was lower than that of wild-type N. benthamiana. At 12 dpi, the incidence and disease index of black shank disease in wild-type N. benthamiana were 96.67% and 77.50, while the incidence of NS3-6, NS3-9 line was 90.00%, 86.67%, and the disease index was 64.17, 62.08, respectively.【Conclusion】The observation of pathogen infection process showed that the expression of NS3 affected the infection and severity of tobacco diseases on N. benthamiana to a certain extent, and the effects on different pathogens were also different.

【Objective】 The objective of this study is to explore the optimum light wavelength, light intensity and related factors, such as sex, daily rhythm, starvation time, temperature and relative humidity of Thrips tabaci through behavioral responses study under the different conditions of laboratory, greenhouse and field, and to provide a theoretical support for improving the control techniques and products of T. tabaci, such as color sticky cards and light traps. 【Method】 Firstly, the behavioral responses of T. tabaci to 10 different wavelengths of monochromatic light were conducted by using monochromator testing device with high resolution, wide spectrum measurement range and high stability under laboratory condition. Monochromatic light with high response rate was screened and the initial light intensity was attenuated by neutral density filter to explore the effect of light intensity on the behavioral responses of T. tabaci. Secondly, the effects of sex, daily rhythm, starvation time, temperature and relative humidity on phototaxis of T. tabaci were also examined by using the rate of phototaxis as statistical index. Based on laboratory experiments, using the relationship between Dan Bruton’s virtual wavelength and RGB values, the blue and yellow sticky cards of the corresponding wavelengths were printed and the plates were glued. The tendency of T. tabaci to the self-made sticky cards of different wavelengths and sticky cards produced by different manufacturers was evaluated in the greenhouse and in the open field.【Result】The results of laboratory experiment showed that phototaxis behavioral response rate was the highest on blue light at 450 nm, and the rate of photaxis was as high as 75.34%, followed by the yellow light at 562 nm and the blue-purple light at 430 nm, the rate of photaxis was 73.61% and 64.03%, respectively. Under the stimulation of 430, 450 and 562 nm monochromatic light, the phototaxis rate of female T. tabaci was higher than that of male. The light intensity attenuation test of the three monochromatic light showed that the tendency of T. tabaci increased with light intensity. At 8: 30-10: 00 am, the T. tabaci was most sensitive to monochromatic light at 430, 450, and 562 nm. After 4 hours of starvation, the phototaxis rate of T. tabaci was the strongest, and then decreased with the prolongation of starvation time. The phototaxis rate of T. tabaci to three monochromatic light was significantly higher than that of the control at 25-30℃. At 15℃, T. tabaci was not sensitive to monochromatic light stimulation. Under the relative humidity of 45%-60%, the phototaxis rate of T. tabaci was significantly stronger than that of the control at 430, 450 and 562 nm. However, there was no significant difference with the control under the relative humidity of 30% and 90%. The trapping effect on T. tabaci was evaluated by using different wavelength sticky cards and different manufacturers in the greenhouse and field, and the results showed that the blue self-made sticky cards and the No.2 sticky cards with reflection wavelength of 440-470 nm had the best effect. The results of this test were in agreement with the optimum wavelength of laboratory screening. 【Conclusion】 Sex, daily rhythm, starvation, temperature and relative humidity all have certain influence on phototaxis of T. tabaci. Comprehensive analysis on laboratory, greenhouse and field revealed that T. tabaci has obvious tendency to monochromatic light and sticky cards at 450 nm. The blue trap sticky card of about 450 nm can be used to monitor and control T. tabaci.

【Objective】 By studying the effects of nitrogen releasing and nitrogen absorbing by maize under the application of different ratios with coated urea and ordinary urea, this paper aimed to screen the optimal ratio, which was beneficial to the outputs of spring maize in the northeast China and nitrogen utilization efficiency, and to provide the basis for the generalizing of controlled release nitrogen fertilizer on maize.【Method】Field experiments were set in Shenyang and Haicheng of Liaoning province in 2017, and crop strains were Dongdan6531 and Tieyan358, respectively. The experiment fertilizers were ordinary and coated urea. The treatments in both set points included blank control (CK0), ordinary urea nitrogen control (CK) and decreased urea N control treatments (CK1), decreased coated urea N control (T0)compared with (CK)treatments; three different ratios urea between ordinary and coated were arranged in Shenyang (T1, T2 and T3) and two in Haicheng (T1 and T2). The ratios of T1, T2 and T3 were 8:2, 6:4 and 4:6, respectively; the ordinary urea control rate was 244 kg·hm ^-2 and decreased coated urea N control was 220 kg·hm ^-2 in Shenyang and that were 217 kg·hm ^-2 and 195 kg·hm ^-2 in Haicheng, respectively. Soil and plant samples were collected according to the maize growing season, respectively. Determination of the content of soil inorganic nitrogen and different plant parts nutrient, and the biological yield of different treatments were also measured.【Result】The treatments of coated urea plus the ordinary increased the maize yield significantly (P<0.05), and with the ratio increasing, the yield first rise and then drop. The yield of T2 was the highest (10 250 kg·hm ^-2), and CK1 was the lowest (9 307 kg·hm ^-2). The yields of equal N inputting treatments were in the order as T2>T3>T1>T0>CK1, and the grain yield increased 3.89%-25.76% compare to CK1, but there was no significant difference between T2 and CK. The soil inorganic N content was increased at the early maize growth stage applying with either type urea, and the soil N content was rich at the late maize growth stage applying with coated urea. Under the same N input treatments, the N use efficiency (NUE) and agronomic efficiency of N fertilizer (AEN) applied first rise and then drop with the ratio increasing, and T2 was the highest, CK1 was the lowest, the results in different place was the same.【Conclusion】Coated urea plus ordinary urea performed better than other treatments on yield, AEN and NUE, and T2 (i.e. 6:4 of the coated and ordinary urea) was the best. According to the characteristics of coated urea and ordinary urea, we fitted a curve for those results, and made it to know that 62% coated urea plus 38% ordinary urea input could get the best NUE and maize yield in South Central Liaoning, which could increase soil N content at the late of crop growth stage by using coated urea and ordinary urea to their advantages fully, gaining yield and economic benefits.

【Objective】 The study was carried out to investigate factors affecting the decomposition and nutrient release of wheat and maize residue under indoor and field conditions, so as to provide a theoretical basis for the rational return of crop residue and its suitable nutrient management practices. 【Method】 We conducted indoor incubation experiment with nylon bag and field experiment to study residue decomposition characteristics of wheat and maize under various nitrogen (N) fertilizer dosages (0, CK; 180 kg N·hm ^-1, N180; 360 kg N·hm ^-2, N360). In indoor environment, we focused on the effects of N dosage and soil types (Shajiang black soil: ST, Fluvo-aquic soil: FT), while in field condition, we emphasized on the effects of N dosages and burying depth (surface and 20 cm depth treatment) of the residue. 【Result】 Laboratory studies found that both residue types and soil types significantly affected residue decay constant, C, N, and P release. With the increasing of N application rate, the decay constant of wheat residue increased in both soil types, while the maize residue decreased. The N releases of maize and wheat residue decreased (the wheat residue increased in FT soil). The decay constant of wheat residue of the FT soil and the release of C, N, and P were significantly higher than those of the ST soil, while the soil types had little effect on the decomposition of maize residue. Under the lab incubation condition (180d), the average C releases of wheat residue were 370 g·kg ^-1, N was 4 g·kg ^-1, and P was 3.6 g·kg ^-1; maize residue C release was 560 g·kg ^-1, N was 11 g·kg ^-1, and P was 3.3 g·kg ^-1. Under field condition, the depth of residue returning significantly affected the decay constants of wheat and maize residue and the release of C, N and P. The decay constant and nutrient releases of residues treated with 20 cm were significantly higher than that of surface treatment. For surface treatment, the decay constant and C release of wheat residue declined gradually with the increase of N fertilizer application rate, but the maize residue increased. For 20 cm treatment, the decay constant of wheat residue and the release of C, N, and P increased with the amount of N fertilizer, while maize residue showed a decreasing trend. Under field condition, surface wheat residue biomass could decompose 40% after a maize growing season (June - October 2015), releasing 150 g C·kg ^-1, 2 g N·kg ^-1and 3.5 g P·kg ^-1; burying underground to 20 cm could decompose 80%, releasing 360 g C·kg ^-1, 4 g N·kg ^-1, and 3.8 g P·kg ^-1. Maize residues biomass could only decompose 40% after a wheat growth season (October 2015-June 2016) when the residues being returned to the surface, releasing 210 g C·kg ^-1, 5 g N·kg ^-1, and 2 g P·kg ^-1, but the 20 cm treatment could decompose 60%, releasing 360 g C·kg ^-1, 6 g N·kg ^-1, and 2.5 g P·kg ^-1. Principal component analysis showed that the decay constant of wheat residue under indoor conditions was significantly positively correlated with soil inorganic N, urease and straw N content, and negatively correlated with soil sucrase and straw C/N ratio, while maize residue decay constant was negatively correlated with soil inorganic N. Under field conditions, the decay constant of wheat residue was negatively correlated with soil urease, soil invertase, residue C content, N content and residue C/N ratio, while maize residue decay constant was negatively correlated with soil inorganic N content, soil urease, invertase and residue C/N ratio, and positively correlated with residue N and P content.【Conclusion】Both indoor and field experiment showed that the decay constants and nutrient release characteristics of wheat and maize residue were different. The application of N fertilizer promoted the decomposition of wheat residue but had little effect on the decomposition of maize residue. The soil types (ST and FT) significantly affected the decomposition of wheat residue, but the effects on maize residue decomposition were small. Returning crop residue to the soil could significantly promote the decomposition of wheat and maize residue and its nutrient release. In production, the crop residue should be returned to the soil, and appropriate N dosage should be adopted to soil types and residue types to promote the decomposition of straw.

【Objective】The objectives of the study were to explore the coupling effects of water and fertilizer on tomato plant nutrient absorption, photosynthetic parameters and their relationships, so as to provide a theoretical basis for water and fertilizer management of greenhouse tomato in Northwest China.【Method】The experiment was conducted in a solar greenhouse, and water volumes based on moisture evaporation were set as 1.00E (W1), 0.75E (W2) and 0.50E (W3). Fertilizer treatments of N-P₂O₅-K₂O (F) included 320-160-320 kg?hm ^-2 (high fertilizer, F1), 240-120-240 kg?hm ^-2 (middle fertilizer, F2) and 160-80-160 kg?hm ^-2 (low fertilizer, F3), Besides, the local irrigation and fertilization was set as control (CK).【Result】The results showed that irrigation and fertilization had a significant effect on leaf area index (LAI) and chlorophyll content, as well as LAI and chlorophyll content increased with the increasing of irrigation and fertilization. LAI reached the maximum value at the ripening stage, while chlorophyll content firstly increased then decreased with plant growth, and reached the maximum value at the fruit expansion stage. The contents of N, P and K in leaves showed the N>K>P trend, and the content was 22.83-47.20, 4.45-7.08 and 22.00-34.92 g?kg ^-1, respectively. The increasing of irrigation and fertilization was beneficial to the increase of leaf nutrient content, plant nutrient accumulation and nutrient transfer to fruit, which reached the maximum value under W1F1 treatment except for the content of N at 51d and P at 89d in leaves and P accumulation in plant. Irrigation and fertilization had a significant effect on net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr). Pn, Gs and Tr increased with the increasing of irrigation amount and fertilizer amount. Among different fertilizer and water treatments, W1F1 treatment had the highest Pn, while CK had the highest Tr except for 90d. Pn reduced significantly under water stress during tomato ripening period. The Pn, Gs and Tr value did not enhance significantly when the irrigation continued to increase at W1 level. The contents of N, P and K in leaves were positively correlated with chlorophyll content and Pn at different growth stages. In addition, plant and fruit nutrient accumulation amount of tomato showed a significant positive correlation with net photosynthetic and yield. 【Conclusion】In conclusion, the W1F1 treatment (irrigation amount of 1.0E and fertilizer of N-P₂O₅-K₂O 320-160-320 kg?hm ^-2) was considered as the optimal fertilizer and water treatment through the comprehensive consideration of leaf area index, chlorophyll content, photosynthetic parameters, plant nutrient accumulation and yield of tomato.

【Objective】 Tea caffeine synthase 1 (TCS1), a key enzyme in the caffeine biosynthesis pathway, shows a wide range of allelic variation within Camellia sect. Thea germplasm. Discovery of the specific alleles of TCS1 as the genetic basis of natural variation in caffeine levels will increase the understanding of the mechanism of caffeine synthesis and accumulation, and provide new genetic resources for improving caffeine content in tea plant. 【Method】 An unique PCR primer set, namely TCS1P InDel F/R, was used to detect TCS1 alleles in 673 accessions of tea germplasm. The primer set (TCS1cDNAF/R) was used to clone the full-length cDNA sequence of novel allele, whose function was subsequently validated by bioinformatics quantitative real-time PCR (qRT-PCR) and prokaryotic expression analysis. 【Result】 The novel rare allele, TCS1g, was identified in the several germplasm of C. taliensis. The TCS1g sequence was obtained by using the accession ‘LL17’, which contained both TCS1a and TCS1g. The CDS of TCS1g was 1098 bp, encoding 365 amino acids with a calculated molecular weight of 40.9 kD and a theoretical isoelectric point 5.1. The sequence similarities between TCS1g and TCS1a, TCS1b, TCS1c, TCS1d, TCS1e, TCS1f ranged from 94.1% to 99.2%. The TCS1g showed a high level (>96%) of amino acid sequence identity with the alleles (TCS1b and TCS1c) which had only theobromine synthase (TS) activity, while it was slightly lower for other alleles (TCS1a, TCS1d, TCS1e and TCS1f ) having both TS and caffeine synthase (CS) activity. The amino acid residue in position 221, located at the active center motif of TCS1, was histidine (His) in the TCS1g, as well as TCS1b and TCS1c, however it was arginine (Arg) for the others. The mutation (His to Arg) would change the isoelectric point and hydrophilicity from 5.05 to 5.06, and from -0.119 to -0.123, respectively. Meanwhile, the 5' upstream regulatory region of TCS1g, TCS1b and TCS1c was 15 bp longer than that of TCS1a, TCS1d, TCS1e and TCS1f. The results of prokaryotic expression analysis indicated that TCS1g had only TS activity (44.3 pkat/mg), and qRT-PCR analysis showed the TCS1g was expressed in the ‘LL17’. The contents of caffeine and theobromine in the ‘LL17’ were 40.3 mg·g ^-1and 5.4 mg·g ^-1, respectively. 【Conclusion】 A novel rare allele of TCS1 (TCS1g) was cloned, and the expression was detected in the ‘LL17’. TCS1g had TS activity, but no CS activity, which might be caused by the change of amino acid residue in position 221.

【Objective】The aim of this study was to establish the classification criteria of different maturities to determine the optimal harvest time of Actinidia arguta fruits. Furthermore, the fruit qualities of 70%, 80% and 90% maturity levels were investigated, in order to provide theoretical guidance for the storage characteristic studies of Actinidia arguta fruits.【Method】Different indicators, including hardness, seed color transformation index, the contents of soluble solids, titratable acid, starchand tannin, were studied and analyzed by correlational and hierarchy analysis. Consequently, the comprehensive scoring model was established for the classification criteria with different fruit maturities. Then the physico-chemical changes of fruits at different harvesting stages were determined.【Result】During blossom period, the comprehensive scores of fruits were ≤0.3209 (at 76 and 78 d), 0.3209-0.4562 (at 80 and 82 d), 0.4562-0.6440 (at 84 and 92 d), ≥0.6440 (at 94 and 96 d), the maturity levels were 70%, 80%, 90% and 100%, respectively. Compared with 70% maturity fruits, the decay index of the 80% maturity fruits was significantly lower and the hardness was significantly higher. The contents of tannin and soluble solids of 80% and 90% maturity fruits were similar, and the other indicators could reach optimum ripeness during storage, but the latter had shorter storage life. The70% maturity fruits, which soluble solid content was the lowest, which couldn’t undergo after-ripening process during storage.【Conclusion】The comprehensive scores of Actinidia arguta fruit were ≥0.6440, 0.4562-0.6440, 0.3209-0.4562, ≤0.3209, and the corresponding maturities were 100%, 90%, 80% and 70%, respectively. Fruits of 80% maturity level were more suitable for long-term storage, staggered season and long-distance selling. Fruits of 90% maturity level were preferred to sale and process locally.

【Objective】 This study was aimed to investigate the methane (CH₄) emission and develop CH₄ prediction models of growing sheep. 【Method】 The average daily weight gain of the treatment of NFC/NDF = 0.78, 1.03 and 2.17 was used as the reference for the restricting level of feed for the other three treatments, respectively, and the digestibility of nutrients and methane production of meat sheep were measured on this basis. Furthermore, the regression relationships were established between CH₄ production and dietary nutrient content, nutrient intake, digestible nutrients intake, and apparent digestibility of nutrients. 【Result】When the sheep grew from 25 to 35 kg BW, the most accurate single-variable and multivariate regression model were shown below: CH₄（L/d）= -26.58 × NFC/NDF + 92.70（R ² = 0.772, P <0.001）; CH₄ (L/d) = 2.71 × NDFD - 2.45 × DMD - 0.97 × CPD + 124.46 (R ² = 0.846, P = 0.001). When the sheep grew from 48 to 55 kg BW, the most accurate single-variable and multivariate regression model were shown below: CH₄ (L/d) = -57.00 × GE (MJ·kg ^-1) + 1076.01 (R ² = 0.581, P = 0.002); CH₄/BW ^0.75(L·kg ^-1) = - 0.01 × NDFI (g·d ^-1) - 0.13 × CPI (g·d ^-1) + 0.02 × DMI (g·d ^-1) + 0.84 (R ² = 0.652, P = 0.019). The most accurate single-variable and multivariate regression model in the overall growing period of sheep were shown below: CH₄(L/d)= -26.94 × NFC/NDF + 90.71（R ²= 0.655, P <0.001）; CH₄/BW ^0.75(L·kg ^-1) = 0.005 × DNDFI (g·d ^-1) + 0.011 × DDMI (g·d ^-1) - 0.097 × DCPI (g·d ^-1) - 4.78 (R ² = 0.722, P <0.001). 【Conclusion】 The regression relationships were established for the respective growth periods (25-35 kg and 48-55 kg BW) and the overall growth period (25-55 kg BW). The studies showed that the optimal methane prediction factors for meat sheep at different weight were various, and methane production was greatly affected by dietary NFC/NDF, which could be used as a theoretical basis for the evaluation of methane production under the breeding model in China and a reference for the diets of meat sheep.

【Objective】In this study, polymorphisms and linkage relationship of ovine ADIPOQ (adiponectin) gene were investigated and their effects on some growth and carcass traits were estimated, so as to enrich the molecular genetic data for sheep. 【Method】Mutations in Exon-1 and Exon-2 of ADIPOQ gene were detected by PCR-SSCP in 8 commodity sheep populations, and the relationship between mutations in growth and carcass traits in New Zealand (NZ) Romney lambs was investigated using General Linear Models (GLMs). 【Result】In total, thirteen SNPs were detected in Exon-1 and Exon-2 regions of ovine ADIPOQ gene, and the nucleotide substitution c.46T/C in Exon-2 resulted in amino acid change (p.Tyr16His). Allele A₁ and B₁ were the dominant allele in Exon-1, Allele A₂ and D₂ were the dominant allele in Exon-2, and there were difference of allele frequencies between these two regions. The majority population was moderately polymorphic in all regions (PIC<0.5), except Texel, Perendale and Dorset Down was low polymorphic in Exon-2 region (PIC<0.25), and there was a high linkage relationship of these mutation and tend to shared genetic linkages (D’=0.952, r ²=0.365). The association analysis showed that the mutations in Exon-1 region of ovine ADIPOQ gene had different effects on growth traits of male and female lambs. In male lambs, individuals with possessing allele A₁ had lower tailing weight, weaning weight and pre-weaning growth rate than those no-possessing (P<0.05), but no associations were detected in female lambs (P>0.05). In female lambs, individuals with possessing allele B₁ had higher tailing weight than those no-possessing (P<0.05), however, no associations were detected in male lambs (P>0.05). And individuals with possessing B₁B₁ had higher tailing weight and weaning weight in male lambs. The carcass traits association analysis results showed that individuals with possessing allele A₁ had lower hot-carcass weight, loin yield, leg yield and total yield than those no-possessing (P<0.05), and individuals with possessing allele B₁ had higher leg yield, proportion of led yield and lower proportion shoulder yield than those no-possessing (P<0.05), individuals with possessing B₁B₁ had higher hot carcass weight, loin yield, leg yield and total yield (P<0.05). 【Conclusion】Exon-1 and Exon-2 of ovine ADIPOQ gene had abundant polymorphisms, and SNP c.46T/C was non-synonymous. The mutations of Exon-1 of ovine ADIPOQ gene might affect some growth traits and carcass traits, and selecting sheep with allele B₁ and genotype B₁B₁, or eliminating ones with allele A₁ and A₁A₁ could improve some growth traits and carcass traits of Romney sheep.

【Objective】The aims of the present study were to investigate molecular function of SMAD1 gene in the bovine myoblast cell differentiation and to explore its role in the growth and development of Qinchuan cattle for beef production.【Method】SMAD1 gene was silenced and overexpressed through RNA interference and adenovirus recombinant over expression vector containing SMAD1. The negative control siRNA-NC and RNA interference specific targeted SMAD1 gene (siSMAD1) were designed and synthesized against the bovine SMAD1 mRNA sequence (CDS), which was obtained by RT-PCR using cDNA of Qinchuan cattle myoblast as template, and then, which was inserted into a shuttle vector pDC316-mCMV-EGFP to construct the over expression of adenovirus shuttle vector pDC316-mCMV-EGFP-bSMAD1. Adenovirus genome plasmid and adenovirus shuttle vectors were cotransfected into HEK293 cell line to pack and obtain recombinant adenovirus. Adenovirus containing target gene was named as AD-bSMAD1, while pDC316-EGFP was used as a reference vector and was considered as control group "AD-NC". Their titers were tested by using LaSRT method. Bovine myoblast were transfected with siSMAD1 and AD-bSMAD1, the mRNA level of SMAD1 gene and myogenesis-related genes, such as MyoD, Myf5 and MyoG, were detected by real-time quantitative PCR, and the impact on myotube formation was observed. 【Result】 The mRNA level of SMAD1 gene transfected with siRNA was reduced 75.4% (induced differentiation for 1 day, P<0.01), 66.7% (induced differentiation for 3 days, P<0.01), 60.0% (induced differentiation for 6 days, P<0.01), 54.7% (induced differentiation for 9 days, P<0.01), respectively, compared with the siRNA-NC. The optimum titer of AD-bSMAD1 infectious was found at 1×10 ¹⁰pfu/mL. The expression levels of SMAD1 were rapidly increased 2.10 (induced differentiation for 1 day), 3.19 (induced differentiation for 3 days), 105.3 (induced differentiation for 6 days, P<0.01) and 144 (induced differentiation for 9 days, P<0.01) times of the control group after infected by AD-bSMAD1, respectively. In addition, both myotube formation and qRT-PCR results proved that SMAD1 gene promoted myoblasts differentiation and myotube formation, as well as the mRNA expression level of MyoD, Myf5, and MyoG. 【Conclusion】 We could conclude from the present study that SMAD1 gene performed its function in the myoblast differentiation and myotube formation. Based upon these findings, SMAD1 gene could be used as potential marker for the breed improvement of Qinchuan cattle through marker assisted selection for beef production.

【Objective】Microsporidia are eukaryotic intracellular obligate parasites that infect almost all organisms, including human. As a special infection organ, the polar tube is mainly composed of polar tube proteins. The polar tube protein plays an important role in microsporidia invasion host and maintaining the structure of polar tube. The objective of this study is to clone and express Nosema bombycis polar tube protein 2 (NbPTP2), analyze its localization characteristics in mature spores, and to lay a foundation for further study the function of polar tube proteins.【Method】NbPTP2 was amplified from N. bombycis genome. The amino acid composition, theoretical molecular weight and predicted isoelectric point of NbPTP2 were analyzed by Expasy online software. SignalP 4.1 and TMHMM Server V. 2.0 were used to predict the signal peptide and transmembrane domain of NbPTP2. The phosphorylation site of NbPTP2 was analyzed by NetPhos 3.1 Server. The phylogenetic tree of NbPTP2 from different microsporidia species was constructed by MEGA 7.0. NbPTP2 was amplified from N. bombycis genome, then ligated with prokaryotic expression vector pET32a (+). The correctly sequenced recombinant plasmid was transformed into Escherichia coli Rosetta, and protein expression was heterologous induced by IPTG. The polyclonal antibody of NbPTP2 was prepared by immunizing New Zealand rabbits with the fusion protein by affinity chromatography purification. The expression of NbPTP2 in mature spores was detected by Western blot. Indirect immunofluorescence assay (IFA) was used to analyze the localization characteristics of NbPTP2 in mature spores of microsporidia. 【Result】 The NbPTP2 with a length of 834 bp was successfully cloned. The protein encodes 278 amino acid residues with a theoretical molecular weight of 30.9 kD, and isoelectric point of 9.39. Moreover, it was predicted to have a N-terminal signal peptide and potential phosphoric acid sites, but no transmembrane domain. The phylogenetic tree analysis result showed that NbPTP2 from N. bombycis was closely related to NaPTP2 from N. apis and NcPTP2 from N. ceranae. Western blot result showed that NbPTP2 was expressed in mature spores of N. bombycis and its molecular weight was about 39 kD. The localization analysis result of IFA indicated that NbPTP2 could locate on the whole polar tube of N. bombycis, and it was confirmed that NbPTP2 was a polar tube protein. 【Conclusion】 The relationship between NbPTP2 and polar tube protein 2 from other microsporidia was clarified. NbPTP2 was expressed in N. bombycis and could be localized on the whole polar tube after germination. These results can provide a basis for polar tube structure analysis and polar tube protein function research.

【Objective】 Chlorophyll content was positively correlated with crop yield, improving crop yield by increasing chlorophyll content has become an important breeding goal in maize. Thus, elucidating the genetic basis of chlorophyll content using genome-wide association study (GWAS) can provide theoretical support for ideotype-based maize breeding with high photosynthetic efficiency. 【Method】 The association mapping panel (AMP) used in this study was consisted of 538 maize inbred lines, chlorophyll content of maize three leaves (above the uppermost ear leaf, uppermost ear leaf and below the uppermost ear leaf ) of the AMP was investigated at 5 days after pollination at five locations, then a GWAS with three models (Q, K, Q+K) were carried out using 558 629 single nucleotide polymorphisms (SNPs). The combination of optimal GWAS model with expression quantitative trait loci (eQTL) analysis, natural variation of chlorophyll content was further explored. 【Result】 All traits measured at the five locations exhibited an approximately normal distribution and positive correlations between paired traits were also observed. Analysis of variance indicated that significant variations were observed across environment, genotype and the genotype × environment interaction. In addition, the heritability of chlorophyll content was 0.66, 0.66, and 0.67 for above the uppermost ear leaf, uppermost ear leaf and below the uppermost ear leaf, respectively. When test with the optimal GWAS model, K model has the greatest success in reducing false positive (type I errors) than other two models. Based on the result of K model, a total of 18 loci involving in 29 significantly SNP-traits associations were detected (P≤3.99×10 ^-6), and 76 candidate genes were found, including 42 genes that have functional annotation that involved in energy metabolism, biosynthetic regulation and material transportation and metabolic pathways. Of which, 85.5% (65/76) of the candidate genes have eQTLs and 11.8% (9/76) of the candidate genes were significantly associated with the corresponding phenotype (P＜0.05), indicating that these nine genes may affect phenotypic variation by regulating their expression. Moreover, two loci were found to be co-localized in two environments or leaves, the gene GRMZM2G074759 within the co-localized locus, encodes an acyl-activating enzyme, highly similar to AAE3. It can increase the lysine content and improve maize quality by increasing the content of α-ketoglutarate (ALA) and oxaloacetate, in addition, ALA could promote chlorophyll biosynthesis and improve crop yield, this gene was considered as the most likely candidate gene. 【Conclusion】 The results indicated that K model having the best result in reducing the false positive. Based on the K model, a total of 18 loci associated with chlorophyll content and several candidate genes may be involved in chlorophyll synthesis pathway were identified.

【Objective】 Verticillium wilt is an important disease in cotton production, and it seriously affects the yield and quality of cotton. Genome sequences of Gossypium hirsutum provide valuable information resources for searching for resistance genes. In this study, an uncharacterized gene, designed as CRVW (cotton resistance to Verticillium wilt), was cloned and identified for disease resistance. The results will lay a foundation for upgrading cotton genomic information, further studying the resistance mechanism and molecular breeding. 【Method】 The open reading frame (ORF) of CRVW was cloned from upland cotton cultivar ND601 using the primers, which were designed according to the reference genome sequence. The online software ProtParam was used to predict protein properties, including amino acid composition, molecular weight, the theoretic isoelectric point, instability index and grand average of hydropathicity. PSIPRED v3.3 was used to predict the protein secondary structure. The prediction of protein subcellular localization and cis-acting elements in the promoter was performed using ProtComp v. 9.0 and PlantCARE, respectively. To elucidate the subcellular localization of the CRVW protein, the CRVW-GFP fusion construct was transformed into onion epidermal cells by particle bombardment. qRT-PCR was performed using normal cotton tissues and tissues that were treated with exogenous application of salicylic acid (SA) and Verticillium dahliae stress. The function of CRVW involving in cotton resistance to V. dahliae was further verified by the technology of virus-induced gene silencing (VIGS). To preliminarily analyze the disease resistance pathway mediated by CRVW, the expression of some marker genes related to plant disease resistance was assayed in CRVW-silenced plants.【Result】 A 780 bp ORF of CRVW was successfully cloned from G. hirsutum ND601. CRVW encodes a putative protein of 259 amino acids with a molecular mass of 30.2 kD and an isoelectric point of 9.59. The protein secondary structure of CRVW contains 69.50% random coil, 17.76% α-helical, 11.20% extension and 1.54% β-sheet. By bioinformatics prediction and fluorescence observation, we found that CRVW was mainly located in the cell membrane and cytoplasm. CRVW was expressed in the roots, stems and leaves of cotton, but the highest expression occurred in the roots. The upstream sequence of CRVW ORF (CRVW-P) contains cis-acting elements in response to four kinds of hormones, including ethylene, SA, auxin and abscisic acid. Additionally, CRVW-P includes a few other elements relating to injury, defense, stress, disease, drought and low temperature. The expression of CRVW was significantly upregulated in the leaves sprayed with SA. After inoculated with V. dahliae, CRVW was dramatically upregulated both in resistant cultivar ND601 and susceptible cultivar CCRI8, but the upregulated expression in susceptible cultivar lagged behind in the resistant cultivar. After 20 days inoculated with V. dahliae, CRVW-silenced cotton seedlings showed more clearly chlorosis, wilting and defoliating comparing to CK. Further statistical analysis showed that CRVW-silenced cotton seedlings had higher disease index than the CK, suggesting that the silence of CRVW significantly reduced the resistance of cotton seedling to V. dahliae. Endogenous SA content in CRVW-silenced cotton seedlings was significantly lower than in CK. The expression of marker genes related to SA accumulation and signal regulation, including ICS1 (isochorismate synthase 1), EDS1 (enhanced disease susceptibility 1), PAD4 (phytoalexin deficient 4), NPR1 (nonexpresser of PR gene 1) and PR1 (pathogenesis- related protein 1), were significantly down-regulated after silencing CRVW.【Conclusion】 CRVW is located in the cytoplasm and the cell membrane, mainly expressed in cotton roots, and involved in the process of cotton resistance to Verticillium wilt, perhaps through SA-mediated defense pathway.

【Objective】 The aims of this study were to provide scientific basis for the selection of tillage method of soil moisture accumulation and yield increase in different precipitation types of winter wheat in the arid region of China. 【Method】 Long-term no-tillage and subsoiling rotational tillage experiments were carried out in the Loess Plateau dryland, Shaanxi province from 2007 to 2018. Three tillage treatments, including no-tillage/no-tillage/subsoiling(NNS), no-tillage/subsoiling(NS) and continuous no-tillage (N), were set up to compare and analyze the effects of different precipitation patterns and tillage treatments on soil water storage, ET, WUE, yield and economic profits of winter wheat during its summer-fallow and growth period. 【Result】 Different precipitation patterns had significant impact on soil water storage, ET, WUE, yield and economic profits during the fallow and growth period of winter wheat. Compared with dry and normal year, the soil water storage of 0-200 cm soil layer in fallow period (23.9% and 31.9%) and growth period (6.5% and 16.6%) of winter wheat could be increased in humid precipitation pattern, and the water consumption in elongation and grain-filling period of winter wheat with rapid water consumption increased by more than 1 and 3 times, respectively; Whilst, the WUE increased by 21.1% and 16.3%, yield increased by 70.0% and 25.8%, and economic profits increased by more than 2 and 1/2 times, respectively. The soil water storage of 0-200 cm in fallow period was better treated by dry, humid and normal year under no-tillage/subsoiling (NS) (106.1mm), continuous no-tillage (N) (192.0 mm) and continuous no-tillage (N) (91.5 mm), respectively. The soil water accumulation of 0-100 cm in the growth period fluctuates greatly under the influence of precipitation and the growth of winter wheat. However, the soil water storage in 120-200 cm soil depth showed a stable change trend of “first increase, then decrease”, and the water storage effect of no-tillage and subsoiling rotational system was better. No-tillage/no-tillage/subsoiling (NNS) treatment had significant advantages in prompting yield and increasing the WUE in dry and humid year. In normal year, the yield and economic profits of continuous no-tillage (N) treatment were the highest, 4 297 kg·hm ^-2 and 4 773 yuan/hm ², respectively. Under the influence of subsoiling and its frequency, the production cost of no-tillage/no- tillage/subsoiling (NNS) and no-tillage/subsoiling (NS) average increased by 172 and 227 yuan/hm ², respectively, but the level of production input was not the key factor affecting economic profits. Compared with no-tillage/subsoiling (NS) treatment, no-tillage/no-tillage/subsoiling (NNS) treatment could save production input with less subsoiling frequency and increase grain yield at the same time to maximize economic benefits. It had the advantages of reducing consumption and saving water, improving WUE and saving cost of winter wheat and increasing economic profit and maintains a positive production effect in most experimental years, also had more universal application. 【Conclusion】 Based on the comprehensive analysis of sustainable agricultural production and the development goals of green, low consumption and high water efficiency, no-tillage/no-tillage/subsoiling (NNS) rotational tillage was recommended as the most suitable tillage method for the winter wheat continuous cropping field in the Loess Plateau.

【Objective】 Foxtail millet (Setariaitalica (L.) P. Beauv.) is rich in nutrition, has a short growth period, and is resistant to drought and barren. Planting foxtail millet plays an important role in optimizing the agricultural planting structure and promoting farmers’ income in arid and semi-arid areas. It was of great significance for the sustainable development of foxtail millet production to analyze the spatiotemporal characteristics and regional advantages of foxtail millet production in China. 【Method】 Based on the provincial and county production statistics of foxtail millet from 1985 to 2015, the spatial and temporal variation rules of foxtail millet production in China were analyzed by using the yield contribution rate, center of gravity migration, comparative advantage index and other indicators.【Result】 In the last thirty years, the sown area of foxtail millet in China decreased from 3.318×10 ⁶hm ² to 7.88×10 ⁵ hm ² and then recovered to 8.39×10 ⁵hm ². The yield increased from 1 801.2 kg·hm ^-2 to 2 342.9 kg·hm ^-2. The area contribution rate of total production change was 80.3%, the yield contribution rate was 18.4%, and the yield contribution rate gradually increased. The center of foxtail millet production in China varied little in recent 30 years. The advantageous production areas were stable in the midwest part of northeast China, the north-central part of the North China Plain and the southeastern part of the middle-low plateau area in the north, which were concentrated in the counties bordering Inner Mongolia and the three provinces in northeast China, most of Hebei, northwest Henan, central Shandong, most of Shanxi, northern Shaanxi, eastern Gansu and central Ningxia. In the last thirty years, the yield increased in the North China Plain, the northeast plain and some counties in the northwest area, but the sown area decreased significantly, which made these regions show efficiency advantage and scale disadvantage. After 2000, the sown area of Jilin Tongyu, Inner Mongolia Aohan banner and some counties in Shanxi province in the middle and low plateau area in the north were recovered. The counties with scale advantage and efficiency disadvantage were concentrated in Shaanxi and parts of north-central Shanxi in Loess Plateau area.【Conclusion】 In the past 30 years, the sown area of millet decreased first and then increased, the concentration of foxtail millet production in China had been increasing, the advantageous production areas tended to be stable, and the yield had been gradually increased. The summer foxtail millet replaced by summer corn in North China Plain was difficult to recover, and the foxtail millet production in the midwest regions of northeast China, the northern agro-pastoral interleaving areas and the areas along Taihang mountain had the potential to recover. The progress of foxtail millet breeding, cultivation technology and production processing machinery were very important for improving the quality and efficiency of foxtail millet production and realizing industrialization development.

【Objective】 The objective of this study is to clarify the composition and toxigenic chemotype of Fusarium species causing maize ear rot in Guangxi, and to provide important guidance and theoretical basis for comprehensive control of maize ear rot and reasonable distribution of varieties and resistance breeding.【Method】 The diseased ear samples were collected from main maize producing areas in Guangxi between 2016 and 2018, a total of 138 isolates from 21 counties (districts) were obtained by tissue separation and single-spore purification. Fusarium species were identified and determined according to morphological characteristics and molecular methods. The phylogenetic tree was constructed based on TEF-1α gene sequences, and specific primers were used to detect toxigenic chemotype.【Result】 A total of 10 Fusarium species were identified and confirmed among 138 isolates, including F. verticillioides, F. proliferatum, F. kyushuense, F. meridionale, F. sacchari, F. fujikuroi, F. asiaticum, F. concentricum, F. incarnatum and F. graminearum, with the isolation frequencies of 50.72%, 12.32%, 10.87%, 8.70%, 6.52%, 3.62%, 3.62%, 1.45%, 1.45% and 0.72%, respectively. F. graminearum species complex (FGSC) contained three independent species, i.e. F. meridionale, F. asiaticum and F. graminearum. F. verticillioides was the predominant pathogen, FGSC, F. proliferatum and F. kyushuense were the secondary predominant pathogens. F. sacchari and F. concentricum were the first reported to be the pathogen of maize ear rot in China. The key gene FUM1 responsible for the biosynthesis of fumonisins was detected among 67 F. verticillioides, 13 F. proliferatum, 5 F. sacchari and 3 F. fujikuroi strains, respectively, which indicated the potential ability of producing fumonisins. FUM1 was not detected in the F. concentricum strains. Four toxigenic chemotypes including NIV, 15-ADON, NIV+15-ADON and DON+15-ADON were detected among FGSC, F. kyushuense and F. incarnatum strains. Strains containing NIV chemotype included 8 F. kyushuense, 2 F. asiaticum, 2 F. meridionale, and 1 F. incarnatum. Strains containing 15-ADON chemotype included 2 F. meridionale. The NIV+15-ADON chemotype was detected among 8 F. meridionale, 2 F. kyushuense, 1 F. asiaticum and 1 F. incarnatum strains. Only 1 F. graminearum strain carried DON+15-ADON chemotype. The 3-ADON chemotype was not detected among these strains.【Conclusion】 F. verticillioides is the predominant pathogen of maize ear rot in Guangxi. FGSC, F. proliferatum and F. kyushuense are the secondary predominant species. FUM1 was detected among F. verticillioides, F. proliferatum, F. sacchari and F. fujikuroi. The main toxigenic chemtype of FGSC in Guangxi is NIV+15-ADON, while NIV is the main toxigenic chemotype of F. incarnatum and some F. kyushuense. The population composition of Fusarium species causing maize ear rot in Guangxi is different from equivalent study of temperate zone in China, which may be due to the fact that Fusarium species adapt to the high temperature and humidity growth environment in tropical and subtropical Guangxi and thus leads to the differences of toxigenic chemotypes.

【Objective】 The objective of this study is to clarify the antagonistic effect of Bacillus velezensis strain E69 isolated from rice endophytic bacteria against various fungal plant pathogens in vitro, especially the control efficacy of B. velezensis E69 on rice blast, and to reduce the use of chemical pesticides.【Method】 B. velezensis E69 and B. subtilis (most commonly used microorganisms in biological control of rice blast) E66 strains were isolated from endophytic bacteria of rice leaf tissue. The antagonistic effect of strains E69 and E66 and their fermented liquid, sterile supernatant against Magnaporthe oryzae was tested by confrontation culture method. Also, the antagonistic effect of strains E69 and E66 against other 11 pathogenic fungi, such as Rhizoctonia solani, Fusarium spp., Botrytis cinerea, Colletotrichum gloeospoioides, Phytophthora parasitica var. nicotianae, Alternaria alternate, F. oxysporum, et al., was determined. The preventive efficacy of E69 and E66 was tested for the control of rice leaf blast under greenhouse condition. The field experiments were conducted to evaluate the preventive efficacy of E69 and E66 against rice leaf blast and neck blast. The inhibitory effect of E69 and E66 against conidial germination and appressorial formation of M. oryzae was assessed in laboratory. The colonization of GFP-marked strain E69 in rice stem was observed by laser scanning confocal microscope.【Result】 Strains E69 and E66 significantly suppressed the mycelia growth rate of M. oryzae P131, the preventive efficacy against rice blast under greenhouse condition was 83.24% and 76.57%, respectively. The preventive efficacy of E69, E66 against rice leaf blast and neck blast in field was 85.97%, 79.76% and 69.67%, 68.82%, respectively. The preventive effect of E69 on leaf blast was significantly higher than that of 75% tricyclozole wettable powder, but there was no significant difference between the preventive efficacy of strain E69 and 75% tricyclazole powder against rice neck blast. E69 and E66 had significant antagonistic effects against 11 plant pathogens, such as R. solani, Fusarium spp., B. cinerea, C. gloeospoioides, P. parasitica var. nicotianae, A. alternate, F. oxysporum, et al. The antagonistic effect of E69 was higher than that of E66. E69 and E66 could strongly inhibit the conidial germination and appressorial formation of M. oryzae P131, the inhibitory effect of E69 fermented liquid was 95.28% and 94.16%, respectively, and the inhibitory effect of E69 sterile supernatant was 85.36% and 84.31%, respectively. The inhibitory effect of E66 fermented liquid was 89.15% and 87.38%, respectively, and the inhibitory effect of E66 sterile supernatant were 79.65% and 72.45%, respectively. The GFP-marked strain E69 showed good colonization ability in rice stem, and could be stably colonized in rice stem epidermis, parenchyma and vascular bundles. 【Conclusion】 B. velezensis strain E69 is a potential biocontrol strain with obvious preventive effects, which has the application potential of preventing rice blast, sheath blight and other fungal diseases.

【Objective】 A meta study was conducted to investigate the comprehensive effect of fertilization on rice yield in Chinese paddy soils during the past 30 years, and to provide a theoretical basis for the scientific correct application of fertilizers in rice cultivation areas. 【Method】 Based on the long-term paddy soil monitoring sites from Ministry of Agriculture and Rural Affairs, we conducted meta-analysis to investigate the rice yield response to no fertilization versus fertilization in different agro-climatic regions. 【Result】 Rice yield in the past 10 years (2008-2017) was significantly higher than the corresponding rice yield in 1988-1997 and 1998-2007, regardless of fertilization. The increase of rice yield with fertilization in southwest of China was by 98.5%, which was significantly higher than that of in north of China (70.3%). Fertilization increased rice yield by 99.1%, 84.2% and 78.1% during 1988-1997, 1998-2007 and 2008-2017, respectively. For the cropping system, the increase of rice yield under triple cropping system (92.0%) was significantly higher than that under single cropping system (76.2%) and double cropping system (81.9%). Fertilization increased rice yield by 85.9% under double rice cropping system, by 75.9% under single cropping system, and by 79.5% under other cropping system. Compared with no fertilizer, chemical plus organic fertilizer application increased rice yield by 88.3%, which was higher than that of single chemical fertilizer application (76.6%). Fertilization significantly increased rice yield in clay soil by 92.0%, compared with no fertilization, which significantly higher than that in sandy soil (58.0%) and loam soil (77.5%). With the increase of soil organic matter and available phosphorus, the increasing trend of fertilization on rice yield was decreased compared with no fertilization. Under higher soil pH (＞7.5) and lower soil total nitrogen (＜1.5 g·kg ^-1) and slow available potassium (＜150 mg·kg ^-1), the rice yield increasing was more than that of corresponding the rest of level. Random forest analysis showed that the region, soil total nitrogen and cropping system had greater impact on the response ratio (RR) of rice yield. In addition, the agronomic efficiency of fertilizer was positively correlated with rice yield RR. 【Conclusion】 Although the trend of increasing rice yield by fertilization was decreasing at present, but combined appropriate chemical plus organic fertilizer, especially in southwest of China, were important measures to improve and maintain high rice yield. Base on the cropping system, combining soil texture, soil nitrogen and potassium content should be the main basis for fertilizer input in different rice cultivation areas.