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【Objective】 It is of great importance to construct a shareable high-quality crop variety standard DNA fingerprint database for effectively managing the huge number of known varieties.【Method】 Based on fluorescence capillary electrophoresis detection platforms and the plant variety DNA fingerprint database management system, a database containing 3 998 maize authorized accessions was built with 40 SSR primer pairs. Multi-laboratories and multi-detecting platforms were used to conduct the quality evaluation of the database.【Result】 Allele frequency distribution graphs of the 40 corn primers were plotted as characteristic spectrums of each primer, which played the role of the similarity of reference samples in the database construction. A decuplet fluorescent capillary electrophoresis combination was formed and a set of system default PANEL was established in the SSR analyzer. Statistics were conducted on the experimental conditions of the database construction. Of the total samples, 61% of them were subjected to two group independent trials and 33% of them were subjected to three group independent trials. Each sample had 2-5 sets of original experimental data and the corresponding fingerprint maps. The accumulated loss and variable sites of the final built standard fingerprint database accounted for only 0.2%, the data integrity reached 99.8%. The assessment results in different laboratories and different electrophoresis platforms showed that the SSR fingerprint data obtained high agreement on the same electrophoresis fluorescence detection platform, but showed a certain bias in different electrophoretic detection platforms. In order to realize the sharing of SSR fingerprint data in different laboratories, a unified fluorescent primer, analysis software and electrophoresis detection platform were needed. Overall pairwise comparisons were conducted on all the fingerprint data, the results showed that there existed a relative big overall difference among the certification varieties of corn in China. Percentage of different sites among the authorized varieties was mainly concentrated between 80% and 95% (accounted for 78.28%), the percentage of different sites with more than 50% reached 99.21%, and less than 20% of only 0.09%. The average hybrid rate of the authorized varieties reached 64% and mainly concentrated between 50% and 80% (accounted for 89%). By using the corn variety standard fingerprint matching service platform (URL: http: //www.maizedna.org/), a shared fingerprint database is realized. 【Conclusion】 A standard procedure in constructing crop variety SSR fingerprint database was formed in this study and the SSR fingerprint database was constructed with a scale of nearly 4 000 corn authorized varieties. Through joint multi-laboratory comparison tests, the accuracy of database building and the sharing property of database were ensured. A service platform website for corn variety standard fingerprint matching was established in this study, thus achieving sharing of corn authorized variety fingerprint database in national seed identification system, and providing an important reference for other crop species in building high-quality SSR fingerprint database.

【Objective】 Identification of the regulatory loci and candidate genes governing salt stress tolerance in Brassica napus at germination stage could lay the foundation for improvement of B. napus salt resistance. 【Method】 In this study, 317 representative B. napus inbred lines were genotyped under normal and salt-stressed conditions in a sand culture system. Significant SNPs associated with root length and hypocotyl length in B. napus under normal and saline stress conditions and their linkage disequilibrium (LD) were determined by genome-wide association studies (GWAS), based on the Brassica 60 K SNP array. Candidate genes were selected based on the combination analyses results of functional annotation of genes within the LD blocks and transcriptome analyses of seedling roots and leaves in B. napus under saline stress treatments. Accuracy of candidate gene selection was improved by real-time quantitative reverse transcriptase PCR (qRT-PCR). 【Result】 Hypocotyl length and root length of B. napus showed large variation among accessions at germination stage under normal and salt-stressed conditions, and frequency distribution revealed that all the target traits were quantitative traits and controlled by polygenic genes. Comparison of different models showed that MLM+P+K model was the optimal model. Based on this model, GWAS identified 45 loci significantly associated with target traits, including 40 and 5 SNPs associated with hypocotyl length and root length, and each of SNP explained 9.12%-14.46% and 7.67%-8.93% of phenotypic variation, respectively. Among the significantly associated SNPs, rs8970 on chromosome C04 was the most notable, since it was the only SNP, which could be repeatedly detected between root length and hypocotyl length, and associated with four traits simultaneously, explaining 7.67%-12.35% of observed phenotypic variation. Of the 11 important significantly associated SNPs, 6 SNPs were distributed in 10 to 442 kb of linkage disequilibrium (LD) blocks. By combining differentially expressed genes detected by transcriptome analysis with LD block identification, 447 genes were identified within the 11 important LD intervals, of which 15 were activated by salt stress. BnaSRO1, BnaPAGR2, BnaNPH3, BnaMYB124, BnaSAM-Mtase, BnaBIN2, BnaUMAMIT11, BnaEXPA7, BnaRPT3, BnaEF-hand and BnaF3H were most likely the candidate genes within their LD blocks. Results of qRT-PCR detection showed that 10 candidate genes were induced by salt stress treatment in root or hypocotyl at germination stage, except for BnaNPH3. In addition, tissue-specificity detection of candidate genes also showed that BnaUMAMIT11, BnaPAGR2 and BnaEXPA7mainly expressed in the root and hypocotyl at germination stage, and BnaRPT3, BnaBIN2 and BnaMYB124 possessed the highest expression in hypocotyl, confirmed that these genes might be involved in development of root and hypocotyl and salt resistance of B. napus at germination stage. 【Conclusion】 A total of 45 significantly associated SNPs controlling development and salt resistance in root and hypocotyl of B. napus at germination stage were identified by GWAS. By combined LD block identification, transcriptome analyses and functional annotation, 11 important candidate genes were screened within different LD blocks.

【Objective】Understanding of the genetic variations in response to drought conditions of four physiological indexes, namely stomatal conductance (Gs), original light energy transformation efficiency of PSII (Fv/Fm), leaf elongation (LE) and leaf relative water content (RWC) could help their adaption to the current breeding program.【Method】The genetic variation (s_g²), broad sense heritability (h_b²) under rainfed and irrigated conditions for four physiological indexes, namely Gs, Fv/Fm, LE and RWC were measured for 13, 18, 15 and 10 times, respectively, from two sets of field trials in 22 and 18 genotypes which were consistently conducted at two locations in Kaiyuan and Yuanjiang counties of Yunnan province in the crop growing periods of 2013 and 2014. In the trials, rainfed and irrigated treatments were set as the main plot, and genotype was used as the sub-plot. The s_g² and error variation (s_e²) for each index at each measurement was determined using software GenStat, and h_b² was calculated. Paired t tests for the differences of s_g² and h_b² between drought and irrigated treatments were processed using software SAS9.1.【Result】The mean differences between drought and irrigated treatments were all significant (P＜0.01) in 13, 18, 15 and 10 measurements of Gs Fv/Fm, LE and RWC, respectively. Under drought and irrigated treatments, the differences in Gs among the genotypes was significant in 10 and 11 out of 13 measurements with the ranges of h_b² at 0.19-0.68 and 0.19-0.82, and grand means of 0.49 and 0.53, respectively, overall significantly higher s_g² and h_b² were found under the irrigated treatment. The differences in Fv/Fm, among the genotypes were significant in 17 and 16 out of 18 measurements with the ranges of h_b² at 0.26-0.83 and 0.16-0.85, and grand means of 0.64 and 0.58, respectively, overall higher s_g² and h_b² were found under the drought treatment. The differences in LE among the genotypes were significant in 14 and 10 out of 15 measurements with the ranges of h_b² at 0.09-0.89 and 0.09-0.81, and grand means of 0.58 and 0.50, respectively, overall higher s_g² and h_b² were found under the drought treatment. The differences in RWC among the genotypes were significant in 8 and 6 out of 10 measurements with the ranges of h_b² at 0.10-0.76 and 0.16-0.77, and grand means of 0.57 and 0.47, respectively, overall higher s_g² and h_b² were found under the drought treatment. 【Conclusion】The s_g² and h_b² of Gs, Fv/Fm, LE and RWC were impacted by water stress, in general, much higher s_g² and h_b² of Gs could be obtained under irrigated conditions and that of Fv/Fm, LE and RWC under drought conditions. However, higher h_b² could be obtained under irrigated conditions for all the four physiological indexes.

 In the past 20 years, cotton production in Xinjiang has developed considerably through a series of technological strategies such as “exploration of heat potential via earliness-stimulating cultivation”, “exploration of solar radiation potential via dense and dwarf planting”, “improvement of water and fertilizer use efficiency via fertigation”, and improvement of net returns with convenient and simplified cultivation through the integration of agronomic techniques and mechanization. These strategies have considerably reduced labor input by reliance on mechanization rather than manual operations, precision seeding after plastic mulching, simplified plant pruning and synchronized harvesting achieved through rational and high plant density combined with chemical regulation, and improvements in yield and net returns through water-saving irrigation techniques and fertigation. The efficient use of key agronomic techniques and related materials and machinery ensures not only a high or super-high yield, but also a convenient and simplified management, thus resolving the contradiction between high yield and simplification in Xinjiang. The northwest inland of which Xinjiang is the main region has become the country's largest cotton-producing region with the highest average unit yield. To ensure continued high yield and efficiency of cotton production in the future, the cultivation strategy should also advance with the times. On the one hand, it should evolve from achieving high yield and benefits of cotton by exploration of heat and water potential to achieving high yield, fine quality and high net returns by exploitation of the light potential, fertigation, and integration of agronomic techniques and mechanization; on the other hand, in order to achieve simplified management of cotton, the traditional cultivation and management with “30% input to seeding and 70% to field management after seeding” should be changed to that with “70% input to seeding and 30% to field management after seeding”. To simultaneously improve cotton yield and quality, it is important to ensure a high photosynthetic efficiency population through comprehensive regulation of cotton plants. More attention should be paid to seed quality and seeding, and thus to further save costs and increase economic benefits by reducing management processes in cotton production. Studies on mechanisms for achieving simplified cultivation with high economic benefits of cotton in Xinjiang should be strengthened to lay a theoretical foundation for sustainable production.

【Objective】At different growth stages of the foxtail millet, selenium was sprayed at different concentrations to study the change rule of millet yield components, quality, protective enzyme activity and grain selenium content to determine the optimum amount of selenium and spraying period for foxtail millet, so as to provide a theoretical basis for production of selenium-rich foxtail millet. 【Method】The varieties Changnong35, Jigu20 and Jingu50 were used as test materials, and 6 selenium concentrations were designed, 0 Na₂SeO₃ (T0), 16.96 g·hm^-2 Na₂SeO₃ (T1), 33.92 g·hm^-2 Na₂SeO₃ (T2), 67.84 g·hm^-2 Na₂SeO₃ (T3), 135.68 g·hm^-2 Na₂SeO₃ (T4), 271.36 g·hm^-2 Na₂SeO₃ (T5). Study on influence of selenium levels on different stages of different millet varieties physiological and biochemical indexes, yield, quality and the content of selenium, spraying in seedling stage, heading stage and filling stage. 【Result】The different development stages of the different concentration of exogenous selenium foliar treatment millet, SPAD, POD, SOD, MDA, GSH and GSH-Px 6 physiological and biochemical indexes difference reached extremely significant level among varieties (P＜0.01). In addition to the MDA, other physiological indexes increase at first and then descend with the Se concentration increasing, reached the maximum when selenium concentrations T3. The activity of SOD, POD and GSH-Px, the content of GSH and SPAD values respectively after spraying treatment and compared with the control increased by 11.8%, 44%, 94%, 97.4% and 9% more than CK under heading spraying. Exogenous selenium can significantly improve the millet grain selenium content, and spraying at different time, different varieties increased with spraying selenium concentrations increased. Spraying time impact on grain selenium content in filling stage＞heading stage＞seedling stage, filling stage spraying influence on selenium content of different varieties Jingu50＞Changnong35＞Jigu20. Filling stage T3 treatment, Jingu50 grain selenium content reached 0.297 mg·hm^-2, which was increased by 8.6 times compared to the CK within the scope of the safety of the intake of selenium. Foliar spraying selenium can improve crude protein, lysine, and folic acid content of the foxtail millet, different spraying period different millet varieties T3 treatment of crude protein, lysine and folic acid content is the highest, compared with the control increased by 13.9%, 17.9% and 7.5%. Different concentration of selenium can improve millet production at T3 treatment achieve maximum, increase first and then decrease with selenium concentrations increased. Heading spraying T3 selenium concentration, production of Jingu50, Jigu20 and Changnong35 compared with the control respectively increased by 4.9%, 4.7% and 1.2%. 【Conclusion】The right amount of exogenous selenium on foxtail millet can play a significant role in promoting physiological characteristics, quality and production, Se-rich millet production prospects. At heading stage spraying sodium selenite at 67.84 g·hm^-2 is an optimal concentration and best period of millet foliar spraying selenium.

【Objective】Sensitivity analysis is an important link in crop model localization, and it plays an important role in AquaCrop model calibration and application.【Method】In this study, in order to identify the sensitivity parameters, the 2012-2013, 2013-2014 and 2014-2015 winter wheat experiments were conducted in National Precision Agriculture Demonstration Research Base in Beijing, China, the Extended Fourier Amplitude Sensitivity Test (EFAST) method was used to carry out sensitivity analysis of 42 crop parameters of AquaCrop model.【Result】The sensitivity parameters were: (1) For dry biomass: water and temperature stress (minimum growing degrees required for full biomass production (stbio), upper threshold of soil water depletion factor for canopy senescence (psen)), biomass and yield production (water productivity normalized (wp)), transpiration (crop coefficient when canopy is complete but prior to senescence (kcb)), canopy and phaenological development (GGD-increase in canopy cover (cgc), GDD-from sowing to emergence (eme), maximum canopy cover in fraction soil cover (mcc), GGD-decrease in canopy cover (cdc), total length of crop cycle in growing degree-days (mat), building-up of harvest index during yield formation (hilen)). stbio, kcb, wp and cgc were the four most sensitive parameters; (2) For canopy cover: canopy and phaenological development (cgc, mcc, number of plants per hectare (den), soil surface covered by an individual seedling at 90% emergence (ccs), mat and cdc), root development (maximum effective rooting depth (rtx)), water and temperature stress (psen), transpiration (kcb); (3) For yield: canopy and phaenological development (GDD-from sowing to flowering (flo), mat, cdc, hilen and GDD-from sowing to start senescence (sen)), water and temperature stress (psen), biomass and yield production (reference harvest index (hi) and wp), transpiration (kcb).【Conclusion】The results of first order and total order sensitivity analysis for AquaCrop model of winter wheat maximum dry biomass and dry biomass time-varying showed that there was a little difference in the choice of sensitivity parameters, but many differences in the ranking. The sensitivity analysis of maximum dry biomass was not comprehensive, which could not analyze the effect of crop parameters on dry biomass during the whole growth period. The results of the first order and total order sensitivity analysis for AquaCrop model of winter wheat canopy cover time-varying showed that there was a good consistency in the selection and ranking of sensitive parameters. The values of total order sensitivity indices of crop parameters were higher than first order, and the influences on canopy cover were more obvious. This study provides guidelines for AquaCrop model calibration and application in Beijing, China, as well providing guidance to simplify the AquaCrop model and improve its precision, especially when many parameters are used.

【Objective】Pbs2 is one of the important members of HOG-MAPK pathway in MAPK signaling pathway, and plays an important role in osmotic regulation of plant pathogens. Oidium heveae is an obligate parasite. In this paper, the function and effect of Pbs2 of O. heveae were studied by using Colletotrichum gloeosporioides.【Method】The homologous cloning method was used to amplify the OhPbs2 by using the genomic DNA and cDNA as template. The domain of this gene was analyzed by bioinformatics. Phylogenetic analysis of seven homologous protein sequences of other fungi and OhPbs2 was conducted, and the phylogenetic tree was constructed by the maximum parsimony method in MEGA6 to further analyze and identify this gene. Using homologous recombination and protoplast transformation, OhPbs2 was transformed into the ΔCgPbs2 of C. gloeosporioides. The transformant was screened on PDA+1.5 mol·L^-1 sorbitol. At the same time, the genome of the transformant was extracted as a template and identified with the primer pairs of OhPbs2, and the correct transformant ΔCgPbs2+OhPbs2 was selected for subsequent phenotypic determination. The growth state of ΔCgPbs2, ΔCgPbs2+OhPbs2 and wild type strains was compared under different culture conditions. And the pathogenicity of the three strains was detected by inoculating the leaves of the rubber tree.【Result】The full-length of the OhPbs2 is 1 927 bp, cDNA of the OhPbs2 is 1 860 bp, and contains an intron that encodes a 619 amino acids protein. Bioinformatics analysis showed that the protein had the same S_TKc domain as CgPbs2. The phylogenetic tree showed that the Pbs2 protein was closely related to Aspergillus fumigatus Pbs2 protein, and the similarity was 55%. And the similarity to Colletotrichum gloeosporioides was 49%, also it was close to Pbs2 protein of Neurospora crassa, Magnaporthe oryzae, Saccharomyces cerevisiae and Fusarium graminearum, the similarities were 54%, 53%, 53% and 50%, respectively. ΔCgPbs2+OhPbs2 strain could grow white colonies on PDA+1.5 mol·L^-1 sorbitol medium, but ΔCgPbs2 strain could not grow. The sequencing results showed that the OhPbs2 had been successfully transferred into the ΔCgPbs2. The color of ΔCgPbs2+OhPbs2 in the MM medium colony was white with short aerial hyphae, which is different from the wild type strain. The growth rate of ΔCgPbs2, ΔCgPbs2+OhPbs2 and wild type strains decreased gradually with increasing concentration in MM medium containing different concentrations of NaCl, sorbitol, SDS, H₂O₂ and fludioxonil. OhPbs2 not only restored the ability of the wild type strain to tolerate osmolality, especially to sorbitol, but also to the susceptibility to fludioxonil, and even to enhance potency. But OhPbs2 complementary changed the color of C. gloeosporioides and inhibited the growth of aerial hyphae. CgPbs2 might be involved in the pathogenicity of C. gloeosporioides, however OhPbs2 did not restore its pathogenicity, but weakened its pathogenic ability to a certain extent.【Conclusion】OhPbs2 may be involved in the regulation of the vegetative growth, oxidative stress, osmotic pressure and cell wall formation of the pathogen, and enhance the corresponding function of the C. gloeosporioides. OhPbs2 may be involved in the pathogenicity of the pathogen, but pathogenicity may be different from CgPbs2.

【Objective】The objectives of this study are to prepare the monoclonal antibody against ecdysone receptors protein and clarity the response of AlEcR-A under exogenous ecdysterone hormone (20E) in Apolygus lucorum.【Method】The vector containing AlEcR-A was double enzyme restricted by Nde Iand Xba I, then the cDNA identified by sequencing was constructed to pCzn1 vector and transformed into Arctic express of E. coli. The target recombinant protein has over expressed and has been purified by using Ni-NTA agarose. BALB/c mice were immunized with the purified recombinant fusion protein. The spleen cells of mouse were fused with SP2/0 cells. The specificity of hybridoma cell line was characterized by ELISA and Western blot analysis. Finally, the mRNA relative expression and protein content of AlEcR-A treated with exogenous 20E by RT-PCR and Western blot were analyzed, respectively.【Result】The recombinant plasmid pCzn1-AlEcR-A was high-efficient expression in Arctic express when induced by 37℃ and 5.0 mmol·L^-1 IPTG. The 55 kD target protein from the strain containing AlEcR-A was obtained by the Ni-NTA agarose. One hybridoma cell line, named 8H7, was obtained and characterized by ELISA and Western blot analysis, which could specifically combine with the total protein of A. lucorum and recombinant protein of AlEcR-A. By using RT-PCR and Western blot analysis, both the mRNA relative expression and protein content of AlEcR-A were remarkably increased after treating with 20E which compared with control.【Conclusion】the high specificity monoclonal antibody of AlEcR-A protein was obtained, and 20E could induce the mRNA and protein expressions of AlEcR-A.

【Objective】 The changes of soil microbial community structure and activity are the key indicators for evaluating soil fertility. It is important to study the effects of long-term different fertilizations and soil managements on soil microbial community structure for fertilization and soil management, and even on the sustainable utilization of farmland of the anthropogenic loess soil.【Method】This research was based on the long-term trial of “National Monitoring Base of Soil Fertility and Fertilizer Efficiency on Loess Soil” in Yangling, Shaanxi province. Soil samples were collected from treatments as farmland without fertilization (CK), farmland with N fertilizer (N), N and K fertilizer (NK), P and K fertilizer (PK), N and P fertilizer (NP), and NPK plus cattle manure (MNPK), fallow land (FL) and abandoned land (AB). The effects of long-term fertilization and soil management on soil microbial community structure and its relationship with basic soil physio-chemical properties were studied by PLFA and routine analysis. 【Result】Compared to CK, total PLFAs, bacteria, fungi, and actinomycetes PLFAs of MNPK, NP and AB were increased by 218.8%, 73.9% and 74.3%, 188.3%, 80.8% and 82.6%, 315.8%, 111.5% and 167.0%, 23.7%, 21.3% and 16.3%, respectively, and also the fungi/bacteria ratio (F/B) was significantly increased. Total PLFAs, bacteria, fungi of N, NK and PK were not significantly different, but PK reduced actinomycetes PLFAs significantly. Compared to farmland soil, FL and AB inhibited the growth of G⁺ and G^- significantly. Shannon-Winner richness index (H), Simpson dominance index (S), Pielou evenness index (J) and richness index (S) were all the highest in MNPK, and the lowest in FL. AB and NP could also increase Shannon-Winner richness index (H) and Pielou evenness index (J) significantly. The result of principal component analysis showed that MNPK, AB, NP and FL could significantly change soil microbial community structure. MNPK could increase the abundance value of G^- (18:1ω5c, cy19:0ω7c), (16:0, 10Me22:0 saturated fatty acid) and eukaryot (18:3ω6c, 16:3ω6c, 22:2ω6c). AB and NP could also increase the abundance values of bacteria (15:0, 18:0, 22:0, 17:0 saturated fatty acid). The result of redundancy analysis (RDA) showed that the importance of soil properties for microbial growth in the order were as organic matter＞total nitrogen＞soil moisture＞Olsen-P＞pH＞bulk density＞available-K, which are all important for microbial growth.【Conclusion】Farmland with NPK fertilizer plus manure, NP fertilizer and abandoned land could improve the diversity of soil microbial community structure, thus improving the ecological environment of soil, while long-term absolute bare fallow had a negative impact on soil health.

【Objective】The objectives of this study are to isolate, identify and analyze phylogenetics of endophytic diazotrophs from tuber and root crops, test plant growth promoting (PGP) characteristics of the isolates, and to explore population property and host distributions of endophytic diazotrophs from tuber and root crops. 【Method】 Surface sterilization and low nitrogen medium were used to isolate endophytic diazotrophs. nifH detection based on PCR amplification to confirm isolates as nitrogen-fixing bacteria. 16S rRNA was amplified with PCR, blasted in EzTaxon after sequencing, and analyzed with Clustalx-MEGA to make phylogenetic tree. PGP characteristics were evaluated by testing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, indole acetic acid (IAA) production and antagonism to Fusarium spp. 【Result】 Total 219 endophytic bacterial isolates were obtained from 14 tuber and root samples including radish, carrot, potato, ginger, beet, lotus, yam, taro, cabbage, and sweet potato. All isolates were verified as nitrogen-fixing bacteria after nifH inspection and identified as 79 species of 24 genera based on 16S rRNA. The 79 species are Acinetobacter harbinensis, Arthrobacter arilaitensis, Ar. bergerei, Ar. nicotianae, Ar. nicotinovorans, Ar. nitroguajacolicus, Bacillus amyloliquefaciens, Ba. aryabhattai, Ba. circulans, Ba. fengqiuensis, Ba. firmus, Ba. flexus, Ba. halosaccharovorans, Ba. idriensis, Ba. licheniformis, Ba. litoralis, Ba. luciferensis, Ba. marisflavi, Ba. megaterium, Ba. methylotrophicus, Ba. oceanisediminis, Ba. safensis, Ba. simplex, Ba. sonorensis, Ba. stratosphericus, Ba. subterraneus, Ba. tequilensis, Ba. thaonhiensis, Ba. thioparans, Brevibacillus brevis, Br. formosus, Br. nitrificans, Br. frigoritolerans, Chryseobacterium indoltheticum, Ch. lactis, Citrobacter youngae, Delftia lacustris, Domibacillus indicus, Enterobacter asburiae, E. ludwigii, E. mori, E. xiangfangensis, Fictibacillus barbaricus, Fi. enclensis, Fi. nanhaiensis, Fi. phosphorivorans, Flavimonas oryzihabitans, Flavobacterium oncorhynchi, Microbacterium hydrocarbonoxydans, Microbacterium phyllosphaerae, Micrococcus endophyticus, Paenibacillus barengoltzii, Pae. cineris, Pae. glycanilyticus, Pae. lautus, Pae. tundrae, Pantoea agglomerans, Pan. anthophila, Pan. dispersa, Pan. rodasii, Pseudomonas azotoformans, Ps. beteli, Ps. brassicacearum, Ps. geniculata, Ps. hunanensis, Ps. koreensis, Ps. parafulva, Ps. seleniipraecipitans, Ps. simiae, Ps. syringae, Rahnella aquatilis, Rhizobium leguminosarum, Rh. massiliae, Rh. radiobacter, Sphingobacterium canadense, Sp. faecium, Staphylococcus sciuri, Stenotrophomonas rhizophila, Variovorax paradoxus. This result showed the biodiversity of endophytic diazotrophs from tuber and root crops. Of the 219 endophytic diazotrophs, 77 strains are identified as 23 species of Bacillus, and 29 strains are identified as 10 species of Pseudomonas. This makes up 106 strains of 33 species, in percentages of 48.40% and 41.77% of the 219 endophytic diazotrophs and 79 identified species. Indicating that Bacillus and Pseudomonas are dominant populations of endophytic diazotrophs from tuber and root crops. Conducted with 79 representatives of the 219 strains, PGP test showed that 8.86% strains showed ACC deaminase activity ranging from 0.026 to 13.76 µmol α-ketobutyrate·mg^-1 protein·h^-1, 64.56% strains showed IAA production ranging from 0.34 to 28.99 µg·mL^-1, and 6.33%-13.92% strains showed antagonistic against phytopathogen Fusarium sporotrichioides ACCC37402, Fusarium xysporum MLS1 and Fusarium xysporum ACCC37438 with antifungal indexes of 41% to 63%. 【Conclusion】 Large number of endophytic diazotrophs habitat in the tuber and root of normally growing tuber and root crops. Endophytic diazotrophs from tuber and root crops phylogenetically belong 79 species of 24 genera showing wide distribution and huge biodiversity. Bacillus and Pseudomonas are dominant populations of endophytic diazotrophs from tuber and root crops. About 10%-60% endophytic diazotrophs have PGP property of producing ACC deaminase or IAA or antagonism. This might be the underlying reasons that endophytic diazotrophs are benefit to host plants.

【Objective】 Utilization of parental species is helpful to broaden and improve genetic basis of Brassica napus. A strategy of using hexaploid derived from hybrid between B. napus and B. oleracea as bridge was evaluated to improve B. napus by crossing with B. rapa. 【Method】 Hexaploid derived from interspecific hybrid between B. napus (Zhongshuang 9) and B. oleracea (C01, high resistant to Sclerotinia sclerotiorum) was developed to cross with B. rapa by evaluating its fertility, meiotic chromosome segregation and resistance to S. sclerotiorum. Hybrids between hexaploid and 110 B. rapa were developed to evaluate crossability, seed setting percentage and resistance to S. sclerotiorum. 【Result】Hexaploid had higher resistance to S. sclerotiorum than Zhongshuang 9. Its pollen fertility was 90.6%-92.7%, seed setting was 3-7 seeds/pod. The 68.80% pollen mother cells at anaphase I was 28﹕28. The hybrids between 110 B. rapa and hexaploid could be obtained when hexaploid was used as either female or male parent, with an average seed setting rate of (4.25±3.91) seeds/pod (hexaploid used as female parent: 4.27 seeds/pod, male: 3.95 seeds/pod on average, P=0.69). Embryos 15 d after pollination grew well when crossing hexaploid with B. rapa. Although crossability among genotypes of B. rapa with hexaploid was different, no significant difference was detected in crossability among ecotypes of B. rapa (semi-winter: (4.35±3.77) seeds/pod, spring: (4.34±4.51) seeds/pod, winter: (4.01±3.43) seeds/pod，P=0.44). Hybrids owned kinds of morphology at the seedling stage, but were similar with B. napus. Seed setting rate of hybrids was (7.72± 4.45) seeds/pod on an average, without significant difference among hybrids derived from spring, winter and semi-winter ecotypes of B. rapa (seed setting rate of hybrids derived from winter: (8.07±3.43) seeds/pod, semi-winter: (7.88±4.64) seeds/pod, spring: (6.41±3.00) seeds/pod, P=0.95). Compared with Zhongshuang 9, 6 hybrids had higher resistance to S. sclerotiorum via two years identification (P＜0.05). 【Conclusion】It was concluded that it is an efficient way to improve B. napus by transferring elite traits from parental species via hexaploid strategy.

【Objective】In order to clone gene and provide technical supports for molecular assisted breeding for Fusarium oxysporum race 1 resistance in watermelon, combined QTL mapping and re-sequencing of parental lines, tightly linked InDel (insertion/deletion) markers were developed and finally the major QTL was fine mapped.【Method】Firstly, genome-wide QTL scanning for Fusarium oxysporum race 1 resistance in an F₂ segregating population derived from a cross between the cultivated resistance female parent ‘ZXG01478’ and the cultivated susceptible male parent ‘14CB11’ was performed using the composite interval mapping program of the WinQTL cartographer 2.5 software. Secondly, InDel markers were developed based on the InDel information on the QTL region by re-sequencing of parental lines. Finally, fine-mapping, genetic map and QTL analysis were re-performed using developed InDel markers. Moreover, a total of 130 watermelon germplasms with different Fusarium oxysporum race 1 resistances were used to perform validation analysis.【Result】In the F₂ population, the frequency distribution of susceptible plant rate deviated from normality and appeared to have a discontinuous bimodal pattern. Moreover, the ratio of resistance to susceptible to Fusarium oxysporum race 1 corresponded to the expected 3﹕1 segregation for a single-locus inheritance (c²=0.52，P=0.47). Preliminary QTL mapping only identified one QTL (fon1) for Fusarium oxysporum race 1 resistance on LG1, which showed peak LOD of 26.05 and could explain 80.18% of the phenotype variation. The confidence intervals of fon1 was 193 333- 2 775 577 bp on chromosome 1 (physical map). A total of 19 InDels with length more than 20 bp were detected on QTL region by re-sequence analysis. Of these, 12 showed polymorphism between two parents. Six primer pairs were selected to genotype in the F₂ population. Using four recombinant lines in F₂ population, preliminary fine-mapping narrowed the QTL region to upstream of InDel2_fon1. QTL re-analysis showed that one of the new developed markers (InDel1_fon1) located on the peak QTL region, which showed peak LOD of 31.65 and could explain 91.46% of the phenotype variation. The genotype of InDel1_fon1 and 7716_fon were consistent with each other for all of the 130 watermelon germplasms, and there was a relative high coincidence rate (70.8%) of genotype and phenotype. Target QTL region was narrowed to physical distance of 246 kb using new developed InDel markers and flanking SNP markers. 【Conclusion】 Major QTL (fon1) confirmed the existence of Fusarium oxysporum race 1 resistance gene Fon-1 and was finely-mapped to a relative small region. One of the new developed markers, InDel1_fon1, was tightly linked to gene Fon-1, which could better applied in molecular assisted breeding for resistance to Fusarium wilt in cultivated watermelon.

【Objective】 Through laboratory simulation of dynamic temperature and humidity conditions, the volatile compositions of rice were studied to find out some characteristic volatiles closely related to the rice quality. The objective of this paper is to provide reference for the construction of dynamic storage and transportation of rice. 【Method】 According to the actual transportation conditions of rice, rice was stored by simulating dynamic temperature and humidity of storage and transportation. Rice samples with 5 moisture contents (14%, 16%, 18%, 20% and 22%) were stored and transported for two months, respectively, at low temperature, middle temperature and high temperature (respectively fluctuates around 10℃, 20℃, and 30℃, humidity fluctuates around 80%). All rice samples were tested by SPME-GC/MS and electronic nose (e-nose) in this study. Principal component analysis (PCA) was used to analyze the data. 【Result】 Under different temperature conditions, the radar graphs of different moisture contents and time of rice all were different. The response values of the same moisture content rice had obvious differences under the different temperature conditions at 15 day. With the time, the differences of 14%-18% moisture contents rice samples reduced. Principal component analysis of e-nose could significantly distinguish all rice samples during storage. There were 275, 262 and 215 kinds of volatile compositions of rice samples including alkanes, olefin or alkyne, aromatic compounds, glycol ether, aldehydes, ketones, acid esters, and heterocyclic were detected, respectively, under low, medium and high temperature conditions, but only 46 kinds of which were detected in the original samples. Alkanes showed a bigger difference under low temperature conditions, and followed by medium temperature, high temperature. Olefin or alkyne, aromatic compounds, glycol ether and heterocyclic showed greater difference with temperature rising, and aldehydes, ketones, acid esters showed the largest difference under medium temperature conditions. With the time, characteristic alkane transformed from straight-chain into cycloalkane under low temperature or moisture content conditions. Haracteristic olefin or alkyne were mainly oxygen-containing or ring-shaped material at the late stage of storage. The 2,6-Di-tert-butyl-4-methylphenol, octyl phenol, and cinnamonitrile were aromatic compounds of fresh rice. With the deterioration of rice quality, methoxy or naphthalene ring materials were main characteristic aromatic compounds in rice. The 2-methyl-1-hexadecanol, benzyl alcohol, decanal, and piperitone were main characteristic glycol ether, aldehydes or ketones and had special fruity or irritating smell. Methyl-2-aminobenzoate, methyl salicylate, dihydroactinidiolide were main characteristic acid esters and had a sweet taste at early stage or under low temperature conditions, and myristic acid, decanoic acid were found at later stage and were tasteless or offensive. Furan, quinolone were characteristic heterocyclic substances with special flavor.【Conclusion】 E-nose could quickly and effectively distinguish rice samples under different moisture contents and temperatures conditions. The types and content of volatile compositions are affected by moisture content and temperature conditions of rice. Low moisture contents of rice (14%-16%) and short-term storage (30 days) are conducive to control the change of volatile compositions, and high moisture contents (20%-22%) could speed up the change of volatile compositions in rice.

【Objective】Using Electronic Nose (E-nose), Electronic tongue (E-tongue) and Fuzzy Mathematics Sensory Evaluation to pick out a bacon smoked by a certain brand and concentration of smoking liquid which resembles the traditional wood chips smoking bacon in flavor, and study the feasibility and accuracy of optimizing the bacon smoking procedure with E-nose and E-tongue. 【Method】Bacons made with three brands and three concentrations of smoking liquid and traditional wood chips smoking were analyzed by E-nose and E-tongue and verified with fuzzy mathematics sensory evaluation.【Result】After analyzing the E-nose Principle Component Analysis (PCA) chart, the accumulating contribution of Principle Components (PC) 1 and 2 is 99.760%, much larger than 85%, which means PC1 and PC2 have contained enough information to reflect the whole sample information. The distribution areas of sample 4 (3‰ Minghua MH-SO152) and sample 1 (woodchips smoked) are obviously separated, which suggests that the odor of the two samples are clearly different. However, the distribution areas of sample 5 (1‰ Minghua SY-SO968), sample 7 (3‰ Minghua SY-SO968), sample 9 (2‰ Jinniushan Ⅱ), and sample 10 (3‰ Jinniushan Ⅱ) are close to that of sample 1, which means their smell is close to sample 1 as well. The distribution areas of sample 6 (2‰ Minghua SY-SO968) and sample 1 overlap partially, which means the smell of sample 6 (2‰ Minghua SY-SO968) and sample 1 (wood chips smoked) are basically the same, thus the bacon added with 2‰ Guangzhou Minghua SY-SO968 smoking liquid smells basically the same as the traditional one. By analyzing the E-tongue Principle Component Analysis (PCA) chart, the accumulating contribution of Principle Components 1 and 2 is 88.903%, larger than 85%, enough to reflect the general sample information. The distribution areas of sample 2 (1‰ Minghua MH-SO152), sample 3 (2‰ Minghua MH-SO152) and sample 4 (3‰ Minghua MH-SO152) are far away from sample 1, which shows that their taste can be effectively distinguished from woodchips smoked sample 1. And the distribution areas of sample 8 (1‰ JinniushanⅡ), sample 9 (2‰ Jinniushan Ⅱ) and sample 10 (3‰ Jinniushan Ⅱ) locate near sample 1, thus they taste relatively like sample 1. The distribution areas of samples 5 (1‰ Minghua SY-SO968), 6, and 7 (3‰ Minghua SY-SO968) are closest to sample 1, which means they taste closest to sample 1, thus the bacons added with Guangzhou Minghua SY-SO968 smoking liquid taste closest to the traditional one. In Fuzzy Mathematic Sensory Evaluation and flavor description, the comprehensive scores of samples 1, 6, 7 and 10 (3‰ Jinniushan Ⅱ) are close and higher than sample 8, and described as heavy smoking flavor and good taste. The Fuzzy Mathematic Sensory Evaluation score of sample 6 is closest to sample 1, and the difference is merely 0.05, which verifies the E-nose and E-tongue results.【Conclusion】After analyzing the E-nose and E-tongue Principle Component Analysis charts, the bacon added with 2‰ Guangzhou Minghua SY-SO968 smoking liquid smells basically the same as the traditional one, and tastes closest as well, which means it can be used to replace the traditional smoking technique. Fussy mathematics sensory evaluation scores verified the fact and proved E-nose and E-tongue can be used to optimize bacon smoking procedure efficiently, thus provides a reference method to optimize meat production technique from flavor perspective. 

【Objective】The objectives of this study were to investigate the developmental changes of the PPARγ and C/EBPα mRNA expression level in different tissues，months and breeds, and its effect on intramuscular fat accumulation in pig. 【Method】Jiangkou Luobo Pig, Congjiang Xiang Pig and Large White Pig were slaughtered at 3, 4, 5, 6, and 7 months to collect samples from heart, liver, spleen, lung, kidney, small intestine, longissimus dorsi, and subcutaneous adipose for the purpose of determing the IMF content in Longissimus dorsi and extracting total RNA in order to investigate the developmental changes of the PPARγ and C/EBPα expression by real - time PCR.【Result】By real-time PCR, PPARγ and C/EBPα had the mRNA expression in all tissues of Large White Pig at 3, 4, 5, 6, and 7 months, but highly in liver, small intestine, longissimus dorsi, subcutaneous adipose, lowly in heart, spleen, lung, and kidney. The expression levels of PPARγ in the small intestine, longissimus dorsi, and subcutaneous adipose at 3, 4 months were extremely different with that at 6, and 7 months (P＜0.01). The expression levels of C/EBPα in the liver, lung, small intestine, and subcutaneous adipose at 3 month was extremly different with that at 6, and 7 months (P＜0.01); The mRNA expression of PPARγ and C/EBPα were lower in heart, spleen, lung, kidney, and longissimus dorsi of Jiangkou Luobo Pig, higher in subcutaneous adipose with issue-specificity. The expression amount increased with the age, and the increase of subcutaneous fat was the most. The expression levels of PPARγ in the small intestine, longissimus dorsi, and subcutaneous adipose at 3, and 4 months also were extremely different with that at 6, and 7 months (P＜0.01). The expression levels of C/EBPα in the small intestine, subcutaneous adipose at 3 month were extremely different with that at 5, 6, and 7 months (P＜0.01). The mRNA expression of PPARγ and C/EBPα in the Subcutaneous adipose of Congjiang Xiang Pig was the highest. The expression of PPAR was not significantly increased with the age. The expression of C/EBPα was significantly increased with the age. The expression levels of PPARγ and C/EBPα in the small intestine, longissimus dorsi, and subcutaneous adipose at 3, 4 months were different with that at 6, and7 months (P＜0.05). With growing, the mRNA expression levels of PPARγ and C/EBPα were basically the same in the model, and showed an increasing trend, then maintained the higher expression levels in 6, and 7 months. The mRNA expression levels of PPARγ and C/EBPα were gradually increased with the increase of the age and maintained a relatively stable level at the late growth stage. The expression of PPARγ and C/EBPα was the highest in Subcutaneous adipose, the higher in Liver, Lung, Small intestine, and the lowest in heart, spleen, and kidney. The PPARγ and C/EBPα mRNA expression in different tissues of Jiangkou Luobo Pig, Congjiang Xiang Pig were higher than that of Large White Pig. The correlation of gene expression and IMF content showed that the PPARγ and C/EBPα expression level were positively related to IMF content. 【Conclusion】It was inferred that PPARγ and C/EBPα gene may be related to regulatory mechanism of lipid metabolism and fat deposition.

【Objective】 The objective of this paper is to study the genetic diversity of Sanjiang cattle group and discuss its genetic variation at the genome level.【Method】Fifty individual genomic DNA were extracted and mixed with isocratic and equal volumes, then the DNA pool of the mixed samples were constructed. Genomic DNA was interrupted randomly by using CovarisS2 and the DNA fragments of 500 bp were recovered by electrophoresis, and  DNA library was constructed at last. Finally, the sequencing data were obtained through the Illumina HiSeq 2000. The short reads were mapped to bovine reference genome (UMD 3.1) to detect the genomic mutations of Sanjiang cattle using BWA software. The analysis of the re-sequencing data was implemented using SAMtools, Picard-tools, GATK, Reseqtools, the SNPs and indels were annotated based on the Ensembl, DAVID and dbSNP database. 【Result】A total of 77.8 Gb of sequence data were generated by whole-genome sequencing analysis, 99.31% of the reference genome sequence was covered with an mapping depth of 25.32-fold, 778 403 444 reads and 77 840 344 400 bases were obtained, of which 673 670 505 reads and 67 341 451 555 bases covered 86.55% and 86.51% of bovine reference genomes (UMD 3.1) respectively, paired-end reads mapping were 635 242 898 (81.61%), paired-end bases mapping were 63 512 636 924 (81.59%). A total of 20 477 130 SNPs and 1 355 308 small indels were identified, of which 2 147 988 SNPs (2.4%) and 90 180 (6.7%) indels were found to be new. Of the total number of SNPs, 989 686 (4.83%) homozygous SNPs and 19 487 444 (95.17%) heterozygous SNPs were discovered, homozygous/heterozygous SNPs was 1﹕19.7. Transitions were 14 800 438, transversions were 6 680 058, transition/transversion (TS/TV) was 2.215. SNPs of splice site mutations were 727, the number of SNPs which the start codon converts into no stop codon were 117, SNPs of premature stop codon were 530, the number of SNPs which stop codon converts into no stop codon were 88. A total of 57 621 non-synonymous SNPs and 83 797 synonymous SNPs were detected, the ratio was 0.69. Non-synonymous SNPs were detected in 9,017 genes, 567 genes were assigned as trait-associated genes, which included meat quality, disease resistance, milk production, growth rate, fecundity with the number of 471, 77, 21, 10, and 8 respectively, the function of some genes were overlap. In detection of indels, 693 180 (51.15%) were deletions and 662 148 (48.85%) were insertions, 161 198 (11.89%) were homozygous and 1 194 110 (88.11%) were heterozygous. Most variations were located in intergenic regions and introns. Heterozygosity (H), nucleotide diversity (Pi) and theta W of Sanjiang cattle genome-wide were 7.6 × 10^-3, 0.0039, 0.0040, respectively, which indicated that Sanjiang cattle have an abundant genetic diversity. The Tajima'D of Sanjiang cattle population was-0.06 832, which speculated that the population exists an unbalanced selection.【Conclusion】Results of this research will provide valuable genomic data for further investigations of the genetic mechanisms underlying traits of interest and protection of Sanjiang cattle breeds genetic diversity.

【Objective】Bombyx mori nucleopolyhedrovirus (BmNPV) can lead the B. mori nucleopolyhedrosis, which caused a huge loss in the sericulture industry. The objective of this study is to map the controlling genes and understand the genetic basis underlying the BmNPV resistance to serve the theory support for resistant variety breeding. 【Method】Backcross population BC₁F (using for linkage analysis) and BC₁M (using for mapping analysis) were derived from crosses between the highly resistant B. mori strain 99R and the sensitive strain Dazao-N. Concentration gradient of virus was used to treat the parents, and the number of infected individuals was recorded. Then by using SPSS17.0, the LD₅₀ for each parent was calculated. Based on appraisal of resistance performance of two parents, the virus adding concentration for BC₁ population was determined and then the virus was fed to larva quantitatively at the start of 4th instar one by one. The infected individuals in the BC₁F were chosen as linkage analysis materials. By using the screened polymorphism markers covering all B. mori autosomes, linkage analysis was conducted and then the genotype data were analyzed by T test to get the linkage significance level of each polymorphism marker to show whether it linked with resistance. Thereafter, polymorphism markers will be enriched on the chromosomes which include the resistance linked polymorphism markers to map resistance locus on them. 【Result】Median lethal dose (LD₅₀) of 99R and Dazao-N is 2.92×10⁶ and 9.78×10⁵ polyhedral bodies, respectively, and the dose 2.0×10⁶ was chosen as the infection dosage of BC₁ backcross population, which is slightly higher than the average of two parents’ LD₅₀. Two independent linkage analyses were conducted successively in the autumn of 2014 and spring of 2015, which got a discrepant result that the linkage analysis result could not be repeated in the following confirmation; i.e., one marker, S2205, on Chr 22 was identified to link with resistance in the 1st experiment, while no linked marker was identified in the following one. Comparison with the previous reports on the linkage and mapping analysis of BmNPV resistance, it was found that the nonrepeatability was ubiquitous in the related researches in B. mori. Previously, a molecular marker (AY380833) was found to highly link with the resistant trait in NB and 871C, which are both the highly resistance strains to BmNPV. However, the linkage relationship was not detected in the linkage analysis population of 99R and 871C here.【Conclusion】the genetic complexity of resistance by molecular linkage analysis was further proved, including the variation among different resistant strains, as well the plausible multiple resistant loci in one single strain. At the same time, it was proposed that the BmNPV resistance may be a complex trait, as a prerequisite to be one type of qualitative-quantitative traits, the quantitative trait characteristic of BmNPV resistance is very obvious.

【Objective】Experiments were carried out in 2014 and 2015 to study the yield related traits in rice under salt and alkaline stress in order to explore the QTL of major genes of salt and alkaline tolerance, and analyze the interaction effects between QTL and environment, thus revealing the genetic mechanism of panicle number per plant, seed setting rate, thousand grain weight and panicle weight per plant in rice under salt and alkaline stress. The results of the present study will provide a scientific basis for the rice genetic mechanism of salt and alkaline tolerance and molecular marker assisted breeding. 【Method】The recombinant inbred line (RIL) population derived from a cross between Dongnong 425 (DN425) with high yielding ability and quality as the female parent and Changbai 10 (CB10) with salt and alkaline tolerance as the male parent. A genetic linkage map was constructed with 120 SSR markers. The panicle number per plant, seed setting rate, thousand grain weight and panicle weight per plant in rice were measured under 6ds·m^-1 NaCl solution of salt stress, Na₂CO₃ solution (pH = 9.0) of alkaline stress and the normal water irrigation as control conditions during the whole growing period in 2014 and 2015. The additive quantitative trait loci (QTL) analysis was conducted by using the complete interval mapping method (ICIM)，the additive and epistatic QTL×environment interaction effects was analyzed by using the mixed composite interval mapping method (MCIM). 【Result】Compared with the salt stress, the alkaline tolerant traits of rice decreased significantly, and were more sensitive to the alkaline stress, the alkaline stress was more restrictive to the high-yield and stable-yield in 2014 and 2015. Under the condition of alkaline stress for two years, no significant correlation was found between the traits of salt stress. There may be genetic differences in rice under salt stress and alkaline stress. By using ICIM, a total of 61 additive QTLs for salt and alkali tolerance-related traits were detected, which were distributed on chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 10, 11 and 12. By using MCIM, a total of 17 the additive QTL×environment interaction effects QTLs for salt and alkali tolerance-related traits were detected, which were distributed on chromosome 1, 3, 5, 7, 8, 9, 11 and 12. By using ICIM, qPN1-1 which was repeatedly detected under both natural and salt stress conditions for two years, qPN11-2 which was repeatedly detected only under alkaline stress conditions for two years, qPN3-3 which was repeatedly detected under both salt and alkaline stress conditions for two years, qRPN1-1 which was repeatedly detected under both natural and salt stress conditions for two years, qGW7 which was repeatedly detected only under natural conditions for two years and qPW11 which was repeatedly detected under salt, alkaline stress and natural conditions for two years, all of them were detected by MCIM. A new salt and alkali tolerance QTL qPW11, can explain 7.94%—20.13% of phenotypic variance. By using MCIM, a total of 13 epistatic QTL×environment interaction effects QTLs for salt and alkali tolerance-related traits were detected. Two pairs of epistatic QTLs which are related to panicle number per plant were detected have significant environmental interaction effects. Two pairs of epistatic QTLs which are related to panicle number per plant under ratio of stress and natural were detected have significant environmental interaction effects. Two pairs of epistatic QTLs which are related to seed setting rate were detected have significant environmental interaction effects, two pairs of epistatic QTLs which are related to seed setting rate under the ratio of stress and natural conditions were detected have significant environmental interaction effects. One pairs of epistatic QTLs which are related to thousand grain weight were detected have significant environmental interaction effects. One pairs of epistatic QTLs which are related to thousand grain weight under the ratio of stress and natural conditions were detected have significant environmental interaction effects. Three pairs of epistatic QTLs which are related to panicle weight per plant were detected have significant environmental interaction effects.【Conclusion】Both the salt stress and the alkaline stress could affect the yield - related traits in rice, but they are two kinds of stresses with different properties. Alkaline stress damage is more severe, and yield reduction is more significantly.

 【Objective】 The progenies of Sesamum indicum and wild species were obtained by interspecific hybridization in order to improve charcoal rot disease (Macrophomina phaseolina) resistance of sesame cultivars. 【Method】 No.3 wild sesame (S. indicatum) (P₃), Zhongzhi 14 (P₁) and autotetraploid of Zhongzhi 14 (P₂) were used as reciprocal cross parents, the F₁ plants of interspecific hybrids were obtained using the immature embryo culture technique. First, the authenticity of F₁ progenies were confirmed by using phenotypic, cytological and SSR marker methods in order to screen out the true hybrids . Then the three parents of the interspecific hybrids (No.3 wild sesame, Zhongzhi 14 and autotetraploid of Zhongzhi 14 )and hybrids of F₁ lines resistance to Macrophomina phaseolina was identified by artificial inoculations. 【Result】The seedling ratios of immature embryos between reciprocal combinations existed significant difference. The 773 immature embryos were inoculated of which 155 embryos developed into seedlings and the average seedling rate was 20.05%. The seedling ratios of combinations (P₃×P₁ 32.75%, P₃×P₂ 21.11%) were higher than those of reciprocal combinations (P₁×P₃ 8.84%, P₂×P₃ 13.41%). This indicates that the genotype of the parent affects the seedling rate of distant hybridization to a large extent. The number of chromosomes in the F₁ plants of (P₃ × P₁, P₁ × P₃) was 42 and in the F₁ plants of (P₃ × P₂, P₂ × P₃) was 55. The majority of the pollen grains of the F₁ hybrids were regular but no inclusions, all of which were highly sterile. HS142 primer with a better polymorphism could be clearly amplified two specific types in Zhongzhi14 (about 460 bp and 500 bp) and the one in No.3 wild sesame(about 380 bp) .Then, it could be used to identify twelve hybrid progenies and their parents. There are ten of F₁ progenies with three male and female-specific markers of the parents, the other two plants only appeared in the female parent or male parent type which was the fake hybrids. The infected lesion length of progenies from interspecific hybridization P₃×P₁, P₃×P₂, using No.3 wild sesame with high charcoal rot resistance as female parent, was 9.35 cm and 6.65 cm, respectively, while 9.90 cm and 8.90 cm from reciprocal combinations. The resistance to Macrophomina phaseolina of progenies from all combinations was higher than their cultivated parents (P₁ 14.30 cm and P₂ 11.46 cm), but weaker than wild relative (P₃ 4.80 cm). 【Conclusion】 New germplasms with high charcoal rot resistance can be created through interspecific hybridization combined with immature embryo culture, which provides important materials for genetic improvement of sesame with charcoal rot resistance.

【Objective】The objective of this study is to identify whether the flowering repressor TFL1 interacts with the two GRFs family members GRF4 and GRF7, and to provide a basis for illustrating the mechanism of TFL1 repressing flowering.【Method】The TFL1, GRF4 and GRF7 genes were cloned by specific primers using the Arabidopsis cDNA as the templates. These three genes were linked into pCR8 vector to get the entry vectors. The correct entry vectors TFL1-pCR8, GRF4-pCR8 and GRF7-pCR8 were obtained by colony PCR screening and sequencing. The yeast two hybrid assay vectors, including TFL1-BD, GRF4-AD and GRF7-AD, were obtained by LR reaction between these three entry vectors and the destination vectors pGADT7 or pGBKT7. The yeast competent cells which were co-transformed with TFL1-BD plus GRF4-AD or GRF7-AD vectors were incubated on –Leu/-Trp growth medium under 30℃ for 2-3 days until the yeast colonies show up. The yeast colonies in proper size were chosen and transferred to both –Leu/-Trp and -Leu/-Trp/-His/-Ade growth medium. The interaction between TFL1 and GRFs was determined through observing the growth conditions of those yeast colonies on -Leu/-Trp/-His/-Ade growth medium. The BiFC assay vectors, including TFL1-nYFP, TFL1-cYFP, GRFs-nYFP and GRFs-cYFP, were also obtained by LR reaction between these three entry vectors and the destination vectors px-nYFP or px-cYFP, and were transformed into Agrobacterium competent cells. The tobaccos, which were co-transformed by the Agrobacterium harboring TFL1-nYFP or TFL1-cYFP vector and the Agrobacterium harboring GRFs-nYFP or GRFs-cYFP vector, were grown for more 48 hours before observing YFP fluorescence signals under confocal microscopy. The interaction between TFL1 and GRFs was determined if the fluorescence signals in tobacco cells were observed under confocal microscopy.【Result】The three genes, including 534 bp TFL1, 888 bp GRF4 and 798 bp GRF7, were cloned successfully. The entry vectors (TFL1-pCR8, GRF4-pCR8 and GRF7-pCR8), yeast two hybrid assay vectors (TFL1-BD, GRF4-AD and GRF7-AD), and BiFC assay vectors (TFL1-nYFP, TFL1-cYFP, GRFs-nYFP and GRFs-cYFP) of the three genes were obtained successfully. Compared with the negative controls, the yeast colonies which were co-transformed with TFL1-BD plus GRFs-AD vectors grew well in both -Leu/-Trp and -Leu/-Trp/-His/-Ade media in yeast two hybrid assay. Compared with the negative controls, the obvious nuclear YFP fluorescence signals were observed in the tobacco cells which were co-transformed with the Agrobacterium harboring TFL1-cYFP vector or GRFs-nYFP vector. Meanwhile, the obvious nuclear YFP fluorescence signals were also observed in the tobacco cells which were co-transformed with the Agrobacterium harboring TFL1-nYFP vector or GRFs-cYFP vector.【Conclusion】The flowering repressor TFL1 directly interacts with the two GRFs family members GRF4 and GRF7 in Arabidopsis.

【Objective】Freeze injury in wheat often happens and affects wheat yield formation during the wintering stage. There was less study on the remedial measures to recover wheat yield after low temperature stress at wintering stage. Hence, effects of remedial fertilizer after low temperature stress on yield recovery in wheat at tillering stage and its mechanism were studied, which will provide a basis for anti-cultivation technology in wheat. 【Method】The spring wheat cultivar Yangmai16 was treated at -2℃/-6℃(day/night, 2012) and -2℃/-8℃ (day/night, 2013) for 24, 48 and 72 h, respectively, using artificial temperature-controlled phytotron system. Then the different remedial urea (N 46%) amounts of 75, 150 kg·hm^-2 (2012) and 75, 120, 180 kg·hm^-2 (2013) were all used at a time after low temperature stress. The degree and freezing injury proportion of wheat plant under low temperature stress and the changes of soluble sucrose, proline and endogenous hormone contents in the second leaves from the top on the 10th, 20th and 30th day after applying remedial fertilizer were investigated. Plant height and yield at maturity were also recorded. 【Result】The index of freezing injury increased from 0.2 to 0.5 under longer stress at tillering stage. The contents of soluble sugar, proline, abscisic acid (ABA) and zeatin riboside (ZR) in leaves of the treatment increased under longer stress. These parameters in the treatment without fertilizer amendment were higher than those in the treatment with fertilizer amendment on the 10th day after applying remedial fertilizer. The parameters reduced more rapidly with more applying fertilizer under the same duration time. The content of gibberellines (GA₃) decreased gradually with longer stress at tillering stage. The contents of soluble sugar and proline, and the contents of ABA and ZR of these treatments using fertilizer after cold stress gradually declined on the 20th day after applying remedial fertilizer. While the change of GA₃ contents was opposite to ABA and ZR contents. All these parameters reached the levels of the controlled plants in natural environment on the 30th day after applying remedial fertilizer. Wheat yield, the first and second basal internode length and plant height all lowered with longer cold stress. With increased fertilizer applying amount under the same treatment duration, the length of wheat plants were better restored and the loss of grain yield was lessened.【Conclusion】Cold injury wheat will recover growth after using the right urea amount scientifically in time depending on the cold index at tillering stage. Osmotic adjustment substance contents declining and hormone contents becoming balance, new tillers emergency and the basal internode length becoming longer were the main reason for increasing grain yield at tillering stage after applying the urea. At tillering stage, considering recovery effect and nitrogen partial factor productivity, 75 kg·hm^-2 urea would be recommended for nitrogen amendment when wheat plants were damaged slightly and the cold index was about 0.2. When the cold index was about 0.36, 120 kg·hm^-2 urea would be suggested. When the cold index was about 0.50, 180 kg·hm^-2 urea was recommended for recovering wheat growth after severe cold damage.

【Objective】 This paper analyzed the advantages and disadvantages of current crop yield estimation methods and proposed a novel hybrid yield estimation model which combines statistical yield estimation and yield estimation methods. 【Method】The model consists of three parts, trend yield estimate (Yt), remote sensing correction yield (Ys) and random error. The trend yield estimation was firstly calculated by using the polynomial regression method based on a long time series data of historical yield and then corrected by ARIMA model, which was set up by using the bias between the trend yield estimates and the historical yields. After that, a multiple linear regression model was set up to further reduce the estimation errors by using the bias between the trend yield estimates (Yt) and the reference yields as dependent variable and NDVI in critical growth period of crop as independent variables. In order to verify the feasibility and accuracy of the new hybrid estimation model, this paper estimated the yield of winter wheat in Beijing in 2015 based on three HJ Imagery obtained in winter wheat growing season, winter wheat yield of 30 sampling fields in 2015, and a nearly 30 years time series data of winter wheat yield (1985-2014) of Beijing. The estimation results from the hybrid yield estimation model was then compared with the true yield (2015 statistic winter wheat yield).【Result】The accuracy of winter wheat yield by using novel hybrid yield estimation model was 98.7% at city level and above 90% at country level. Except Fangshan(90.3%), the relative accuracy of yield estimation at the other countries was above 95%. The accuracy of winter wheat yield by using traditional trend yield model in Beijing was 94.75%, but the accuracy by using traditional trend yield model at country level was low, especially was lower 80% in Fangshan. ARIMA model was used for improving the accuracy of the traditional trend yield model. The accuracy of winter wheat yield improved in average by introducing the ARIMA model. For the remote sensing correction model established in this paper, using three remote sensing images for improving the accuracy was better, and this method improved the accuracy of winter wheat yield by 3.55%, especially the accuracy had a significant ascension in Fangshan and Pinggu.【Conclusion】The accuracy of winter wheat yield by using the novel hybrid estimation model is good at city level and county level. The model considers the change of time and spatial and can be used in crop yield estimation.

【Objective】The objectives of this study are to obtain the sequences of ITS, EF-1α and β-tubulin gene regions from plant pathogen, Fusarium spp., compare the suitable gene sequences for species identification, and to analyze the population distribution and genetic variation of Fusarium spp. in Shanxi province by using the suitable gene sequences. 【Method】 A total of 625 Fusarium strains were collected from 28 counties and 11 cities in Shanxi Province from 2013 to 2015. The ITS, EF-1α and β-tubulin gene fragments of the morphology of clear strains from 625 strains were sequenced and analyzed. The sequences were assembled and edited using Sequencher software, then blasted in Genbank in NCBI and FUSARIUM-ID databases. The sequences from the clearly documented and reference species were downloaded. All the sequences were aligned and edited manually using ClustalX and GelDoc. The inter- and intra-specific variations of Fusarium spp. were analyzed with MEGA, Excel, DNAstar and TaxonGap. All the three gene sequences consisting of ITS, EF-1α and β-tubulin were selected for the taxonomy of the Fusarium species and then the best optimal fragment genes were used in the analysis of the population distributions of Fusarium spp. in Shanxi Province. 【Result】EF-1α was the best gene fragment for identifying Fusarium species among the three candidate gene fragments. Intra-specific pairwise distances was 24 times higher than that of the inter-specific pairwise distances. The intra-specific variation was smaller than those of the inter-specific variation by 73% of the tested species. The accuracy rate for identification was the highest, reached 87%. The phylogenetic relationships derived from the EF-1α sequences showed that different strains in 22 of 27 Fusarium species were monophyly, clustering in a same clade with high supporting values. Among the 27 species of Fusarium, F. oxysporum was the dominant species with 22.1% frequency and covered the largest geographical distribution in the 23 counties or regions in Shanxi province. Followed by F. solani with 13.8% in 14 counties or regions. The results of population distribution of Fusarium in different geographical regions in Shanxi province showed that F. oxysporum was the dominant species in Yuncheng, Linfen, Xinzhou, Changzhi, Lüliang, Jinzhong and Taiyuan city; F. lateritium was the dominant species in Shuozhou, F. solani in Datong, F. verticillioides in Jincheng and F. incarnatum in Yangquan. Among the different regions in Shanxi province, the most abundant Fusarium species was in Jinzhong and Xinzhou, followed by Linfen, and the least distribution was in Shuozhou. The results of the population distribution of Fusarium from different hosts showed that the 15 Fusarium species extracted from Lycopersicon esculentum, 13 species from Solanum tuberosum and 12 from Glycine max. In these hosts, F. oxysporum was the dominant species in Lycopersicon esculentum, Cucumis sativus, Citrullus lanatus, Solanum tuberosum, Solanum melongena, Cucurbita pepo and Brassica oleracea. F. verticillioides was the dominant species in Glycine max and Zea mays. F. avenaceum and F. graminearum were the dominant species in Triticum aestivum. 【Conclusion】There are abundant genetic variation between inter- and intra-specific of Fusarium. Of the three gene regions, EF-1α is the most suitable region for Fusarium species identification. Fusarium morphological taxonomy results are not fully agreed with the molecular phylogenetic results using EF-1α sequences. F. oxysporum is the dominant Fusarium species in Shanxi province. There are obvious genetic variations of Fusarium populations in different districts and hosts. The research results will provide a theoretic and scientific basis for Fusarium taxonomy, DNA barcode screening, quarantine and integrated control.

【Objective】The objective of this study is to obtain a cDNA sequence of endocuticle structural glycoprotein LmAbd-5based on Locusta migratoria transcriptome, clarify its molecular characteristics and biological function, reveal its role in the formation of cuticle in L. migratoria, and provide a new molecular target for pest control. 【Method】The full length cDNAof LmAbd-5 was searched from transcriptome database of L. migratoria using bioinformatics method. The cDNA was cloned and sequenced. The signal peptide and function domain of deduced amino acid were analyzed by SignalP and SMART, respectively. Phylogenetic tree was constructed using the sequences of amino acid from different insect species by the MEGA 7.0 software with the neighbor-joining (NJ) method. Reverse transcription quantitative PCR (RT-qPCR) was applied to reveal the expression patterns of LmAbd-5 in different tissues on day 2 of 5th instar nymph and different developmental stages of integument. The effects of LmAbd-5 on locust growth development and the structure of cuticle were investigated by using RNA interference (RNAi) and transmission electron microscopy (TEM). 【Result】The full length cDNA of LmAbd-5 was got from transcriptome database, which had 520 bp including ORF 303 bp. The gene structure analysis showed that LmAbd-5 has three exons. The deduced protein contains a signal peptide and one chitin binding domain 4 (ChtBD4) through the BLAST analysis, Abd-5 was highly conserved among insect species, and the sequence identity is as high as 81% between LmAbd-5 and SgAbd-5. Abd-5 belongs to the RR-1 class of CPR family by WebLogo analysis. The result of phylogenetic tree showed that LmAbd-5 has a close genetic relationship with SgAbd-5. RT-qPCR results showed that LmAbd-5 was predominately expressed in the tissues originated from ectoderm, such as the foregut, hindgut, trachea and integument, and lower expressed or not detected in the gastric caecum, midgut, Malpighian tube, fat body and wing pads. The expression at different stages showed that LmAbd-5 mainly expressed at early of 5th instar (0-72 h after ecdysis from 4th instar nymph), and up to the peak at 72 h after molting, then markedly decreased at 96-168 h. The expression pattern is related with the formation of endocuticle. Compared with dsGFP injected control, the nymphs with the injection of dsLmAbd-5 could normally molt, and no visible abnormal phenotypes was found although the expression of LmAbd-5 was decreased significantly after dsLmAbd-5 injection. However, compared to the control group, the lamellar structure from adult cuticle with injection of dsLmAbd-5 was loose, and lamellar became thicker, finally led to the endocuticle thickening. 【Conclusion】LmAbd-5 was obtained from locust transcriptome database, which contains a signal peptide and ChtBD4, belonging to the RR-1 class of CPR family. LmAbd-5 mainly expressed in the tissues derived from ectoderm and in integument at early of 5th instar. Although there was no visible phenotypes after silencing LmAbd-5, but it was found that the lamellar structure of endocuticle is loose and endocuticle becomes thicken from ultrastructure by TEM, suggesting it may be participated in the formation of endocuticle in L. migratoria.

【Objective】A large number of studies have indicated that application of biochar in cropland has significant effects on crop yield due to its unique physical and chemical properties. It is of important significance to quantify the effects of management practices and biochar quality on crop yield by statistical analysis of large sample numbers.【Method】By collecting global relevant published literatures, 97 relative independent studies with 819 paired datasets on biochar’s effects of crop growth were selected. A meta-analysis was undertaken to quantify the effect of biochar characteristics (e.g., raw material, pyrolysis temperature, C/N, pH etc.) and artificial application management practices (e.g., application amount and duration), soil properties (soil texture and pH) on the crop yield improvement.【Result】Results showed that biochar could improve crop yield significantly by 15.0% in average compared with the control. As for crop types, the effect of biochar on crop yield was significantly different: The yield increase of cash crops (25.3%) was significantly higher than that of grain crops (10.0%). The characteristics of biochar had a significant impact on crop yield. Biochar produced with pyrolysis temperature lower than 600℃, pH over 7, and C/N value between 20-300, obtained significant increase in crop yield ranging from 9.2% to 26.6%. Moreover, the improved percentage of crop yield decreased with increase in pyrolysis temperature and biochar C/N. As for different soil textures and acidities, the order of yield-improving effect was clay soil > sandy soil > loamy soil. The yield-improving effect of biochar application for acid soil (29.2%) was 7.9 and 2.5 times of that for neutral and alkaline soil. Under the condition of management practices, biochar application increased crop yield significantly (by 18.0%) at rates less than 10.0 t·hm^-2. However, there was no significant effect on crop yield when the application rate was more than 80.0 t·hm^-2. The response ratio of biochar application on crop yield decreased with increase in the application duration. Six months to two years after biochar application increased crop yield by about 13.4%-17.5%, whereas after more than 2 years, the response ratio reduced to 9.6%.【Conclusion】The effect of biochar on crop yield varied according to variation in biochar quality and application rate and duration. Choosing biochar in specific quality for application can not only achieve sustainable improvement in crop production, but also minimalize the cost and improve economic efficiency according to crop types and soil texture. This result would provide an option for the development of sustainable agricultural management practices.

【Objective】This study was conducted to evaluate the accuracy of the AquaCrop model in the simulation of winter wheat growth, soil moisture, yield, and water use efficiency under plastic mulching, which can provide a theoretical basis and scientific method for the calibration of the AquaCrop model under plastic mulching.【Method】The experiment was conducted at Yangling, Shaanxi, from 2013 to 2016 including the flat planting under plastic mulching (PM) and a control treatment without mulching (CK). The AquaCrop model was calibrated using the experiment data in 2014-2015 and was validated using the data in 2013-2014 and 2015-2016. 【Result】The determination coefficient (R²) of the simulated and the measured canopy cover was between 0.86 and 0.99. The root mean square error (RMSE) of the simulated and the measured canopy cover was between 2.1% and 8.1%, indicating AquaCrop model a good simulation for canopy cover. The R² of the simulated and the measured biomass was greater than 0.95. Meanwhile, the RMSE of the simulated and the measured biomass was between 0.814 and 1.933 t·hm^-2. The R² of the simulated and the measured soil water content in CK was greater than 0.85, and the R² of the simulated and the measured soil water content in PM was greater than 0.75. The RMSE of the simulated and the measured soil water content in both CK and PM was between 9.2 and 17.6 mm. The normalized root mean square error (NRMSE) of the simulated and the measured soil water content in both CK and PM was lower than 5.5. Moreover, the RE of the simulated and the measured yield in both CK and PM was from -4.4% to 9.0%. The simulated and the measured yield in PM increased 40.5% and 40.3% compared to that in CK, respectively, and there was a significant difference between CK and PM. The RE of the simulated and the measured water use efficiency in both CK and PM was from -10.4% to -1.5%. The simulated and the measured water use efficiency in PM increased by 54.1% and 47.5% compared to that in CK, respectively, and there was also a significant difference between CK and PM. The results showed that the simulated and measured values had the similar trend in wheat canopy coverage, biomass, yield, and water use efficiency. Those indicated a good performance of the AquaCrop model in modeling plastic mulching treatment. 【Conclusion】 The AquaCrop model can be used to model the winter wheat growing development and productivity under plastic mulching. This study provides a scientific method to calibrate the AquaCrop model and a good data support for the application and development of the AquaCrop model.

【Objective】 To understand the molecular mechanism of Cd tolerance in cucumber, a NAC transcription factor CsNAC019 was obtained by using bioinformatics analysis. CsNAC019 was cloned and its expression was analyzed under Cd stress. The results of the present study will provide an experimental foundation for breeding of cucumber cultivars with high capacity for Cd tolerance.【Method】The full length sequence of CsNAC019 was cloned by PCR. Sequence comparison and conserved domain were analyzed by NCBI and DNAMAN. Amino acid composition, stability coefficient, and hydrophilic coefficient were analyzed by online software Expasy and TMHMM. The promoter region was analyzed by online software PlantCARE. Phylogenic tree was constructed by MEGA 6.0 according to the NJ method. The real-time PCR (qRT-PCR) was used to analyze the expression pattern of CsNAC019 under Cd treatments. The variance and significance were analyzed by DPS 7.05.【Result】CsNAC019 contained a typical conserved NAC domain. BLAST analysis revealed that CsNAC019 had 60% homology with NAC019 in the amino acid sequence, and the five relatively conserved regions of its amino acid sequences, A, B, C, D and E, were highly consistent between them from the N-terminal to the C-terminal. The full-length CDS of CsNAC019 was 960 bp, which encoded 319 amino acids with a molecular weight of 35.66 kD. The theoretical isoelectric point is 8.72, the instability coefficient is 68.18, and the average hydrophilic coefficient is -0.483. Besides the eukaryotic promoter TATA and CAAT natural elements, promoter analysis showed that the promoter sequence of CsNAC019 also had cis elements in response to stress, such as G-box, ABRE, W-box, P-box, TCA-element, TC-richrepeats, and HSE, etc. Phylogenetic analysis showed that CsNAC019 had 64%-96% homology with NAC transcription factors of other 15 plants (melon, peach, apple, citrus, grape and soybean, etc). CsNAC019 had the highest homology, 96%, with the NAC sequence of melon. qRT-PCR analysis revealed that the expression of CsNAC019 was significantly increased (8.2 folds) compared with the control under Cd tolerance condition.【Conclusion】CsNAC019 is a Cd tolerance induced gene. It was speculated that CsNAC019 may regulate the cucumber to response to Cd tolerance by regulating the expression of downstream genes.

【Objective】The experiment was conducted to study the effects of preharvest acetylsalicylic acid (ASA) sprayed for four times during fruit development on ripening and softening of muskmelon fruit (Cucumis melo cv. Agate) at harvest and during storage, and to explore softing mechanism caused by ASA treatments.【Method】The muskmelon, cultivar ‘Agate’, was used as material. The plants were sprayed with ASA at 1mmol·L^-1 for four times at young fruit period (2 weeks after flowering), enlarging period (3 wk after flowering), netting period (4 wk after flowering) and mature period (preharvest 48 h). The changes of physiological and biochemical parameters were determined on respiratory rate and ethylene production, firmness, cell wall component and cell wall-degrading enzymes activity of fruit at harvest and during storage (7℃, RH 55%-60%).【Result】Preharvest spray of ASA significantly decreased respiratory rate and ethylene production of muskmelon fruit at harvest, and delayed climecteric peak and ethylene peak for 1wk during storage. ASA treatments increased the firmness of fruit, the contents of propectin, cellulose, hemicellulose and hydroxyproline-rich glycoproteins (HRGPs) in fruit at harvest, retarded the conversion of propectin to water soluble pectins (WSP), maintained a higher level of cellulose, hemicellulose and HRGPs, kept firmness of fruit during storage. Preharvest spray of ASA noticeably decreased the activity of cell wall degrading enzymes in fruit at harvest and during storage, mainly inhibited the activity of pectin methylesterase (PME), polygalacturonase (PG), cellulase (Cx) and β-gluosidase (β-Glu). The correlation analysis indicated that there was a significant positive correlation between ethylene production and PG activity, respiratory rate and PG activity. And a very significant positive correlation between ethylene production and β-Glu activity, respiratory rate and β-Glu activity in treated fruit. There was a highly significant positive correlation between firmness and PME activity, propectin and hemicellulose content in treated fruit. Moreover, a significant positive correlation was found between firmness and Cx activity, and WSP content in treated fruit, and a significant negative correlation was also observed between firmness and ethylene production, and respiratory rate in treated fruit.【Conclusion】Preharvest ASA treatments promoted the synthesis of cell wall components during fruit development, significantly inhibited the respiratory rate and ethylene production, reduced the activity of cell wall degrading enzyme, such as PME, PG, Cx and β-Glu, prevented the release of cell wall components and maintained higher fruit firmness at harvest and during storage.

【Objective】On the basis of dynamic trend of separating and purifying of fermented apple pomace polysaccharides, the authors further investigated the structural properties , and in hoping of further elucidating the separating, purifying, bioactivity and processing properties of fermented apple pomace polysaccharides.【Method】Apple pomace polysaccharides (AP), wine fermented apple pomace polysaccharides (WFP) and vinegar fermented apple pomace polysaccharides (VFP) were used as experimental materials. On the basis of analysis of polysaccharides content, the authors used DEAE-52 cellulose column, NaCl as eluent, to separate polysaccharides according to the polarity difference among polysaccharides components. Through collecting effluent liquid using fraction collector and then the polysaccharides content was determined using with phenol sulfuric acid method, and the elution curve was depicted. Meanwhile, the obtained polysaccharides components with DEAE-52 cellulose column were further separated using Sephadex G-200 gel column, distilled water as eluent. After obtaining the separated polysaccharides components, the structural properties were thoroughly analyzed by using X-ray powder diffraction to observe the crystallographic structure, Thermogravimetric Analyzer was used to analyze thermogravimetric characteristics, Laser particle size analyzer to analyze granularity, and Congo red was used to explore triple helix structure of polysaccharides. Finally, Desktop Scanning Electron Microscope was also used to observe and analyze micro-structure of apple pomace polysaccharides.【Result】The content of original apple pomace polysaccharides was approximately 70%. Because the polysaccharides didn’t include protein and nucleic acid, so the extraction efficiency was excellent. NAP0.1 and NAP0.2 were obtained after AP were purified firstly through DEAE-52 cellulose column and 0.1, 0.2 mol·L^-1 NaCl were respectively used as eluents and then through Sephadex G-200 gel column and distilled water as eluent. Meanwhile, NWFP0, NWFP0.1 and NWFP0.2 were obtained after WFP was purified with DEAE-52 cellulose column and subsequently Sephadex G-200 gel column. After VFP was separated, NVFP0, NVFP0.1 and NVFP0.2 were obtained, too. All the separated constituents included over 92% polysaccharides, suggesting separation effect was satisfactory. Three polysaccharides, AP, WFP and VFP, were non-crystalline material between before and after separation. Concentration temperature of polysaccharides was strictly limited below 65℃, and the processing temperature was below 150℃. Before separation, AP, WFP and VFP all had triple helix structure. After separation, triple helix structure still existed in NWFP0, NVFP0, and NVFP0.1, while NAP0.1 and NAP0.2 had no triple helix structure. Compared with the original apple pomace polysaccharides, the separated apple pomace polysaccharides had better stability and smaller particle size, because lower dispersion coefficient of particle size was observed. Besides, flake structure in polysaccharides was less, and cross-linking effect attenuated after separation, which is beneficial for development of polysaccharides bioactivity.【Conclusion】Fermented apple pomace included over 70% polysaccharides, and polysaccharides content was up to 92% after crude polysaccharides was separated and purified. Besides, according to XRD, TG, LPSA and Congo red as well as DSEM analysis, it was concluded that the changes of solubility, viscosity and physical characteristics facilitated separated apple pomace polysaccharides developing bioactivity and processing characteristics.

【Objective】This experiment was conducted to quantify the effect of environmental factors on milk yield of first lactation Holsteins in Ningxia, and to estimate genetic parameters of test day milk yield using test-day model, to provide a theoretical foundation for genetic parameter and breeding value estimation of milk components and somatic cells, and provide basic parameters for optimal breeding scheme which is suited to the Holstein population in Ningxia.【Method】A total of 550 078 test-day milk yield records from Holstein in Ningxia were collected, and the standards of calving month between 22-36 mo, the milk days between 5-305 d, and test day milk yield between 5.9-53.3kg were used to edit data, and finally a total of 127478 test-day milk yield records from 14320 Holstein heifers distributed in 24 herds between 2009 and 2013 in Ningxia were used in lactation curve mimicking and genetic analysis. Pedigree information of three generations were collected (father, mother, grandfather and grandmother from both father side and mother side) to form the pedigree file consisting 24 272 individuals. Microsoft Excel 2013 was used to manage the data to derive average milk production for each test-day, and NLIN procedure of SAS 9.1 was used to fit the Wood model and used to mimic the lactation curve to derive the population characters of milk yield. A random regression test-day animal model was employed and DMU 5.2 software was used for parameter estimation. The model included general fixed effect and fixed regression, random regression. In the present study, herd-test-day was the fixed effects, and a fixed regression were fitted for calving year and calving month combination effects, direct additive genetic, permanent environment were the random effects. Regression curves were modeled using Legendre polynomials of order 4. Based on climate characteristics in Ningxia, four calving seasons were categorized, spring (Mar. 11th to May 20th), summer (May 21^st to Aug. 25^th), autumn (Aug. 26^th to Oct. 15^th) and winter (Oct.16^th to Mar. 10^th).【Result】 The results showed that the average of test-day milk yield in Ningxia was 29.66 kg, milk yield reached its peak at about 90 days and peak yield was 31.84 kg. Through fitting lactation curves to first lactation cows in different seasons, calving years, and farms, the effect of these factors on lactation curves were quantified. Furthermore, lactation curves should be fitted as sub-models in the model for genetic evaluation. The heritabilities of 5-305 day milk yield were from 0.08 to 0.29, and the overall heritability of daily milk yield was 0.16. 【Conclusion】The study mimicked lactation curves for first lactation Holstein cows in Ningxia using WOOD model, the proper model was defined for this population. Results of estimated heritability for daily milk yield was lower than the results in the literatures using similar models. To evaluate the performance of test-day model, the hypothesis for residual variance (e) and integrity of pedigree needs to pay attention. These estimates derived from current study will provide reference for evaluating milk components and somatic cell counts using random regression model, and further establishing breeding value estimation system for performance of Holstein in Ningxia.

【Objective】Using the lentivirus-mediated overexpression technique, the aims of this study were at determining the effects of K26 and KAP26.1 gene overexpression on keratin-associated protein genes KAP6.2, KAP7.1, KAP8.2, and KAP11.1, and bone morphogenetic protein genes BMP4 and BMPR1B, and exploring the mechanism by which these genes influence hair fineness in mice, to achieve the goal of improving the quality of animal hair, to realize artificial regulation (such as lentivirus-mediated technology) of overexpression of some genes, and to lay a theoretical foundation for investigating the artificial regulation of mammalian hair fineness.【Method】In October, the experiment was conducted in Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery. The Kunming species mice aged five weeks were obtained from Experimental Animal Center of Dalian Medical University. The mice gene sequences of K26 (Gene ID: NM_001033397) and KAP26.1 (Gene ID: NM_027105. 2) were retrieved from Genbank, and the primers were designed according to the sequences of target genes. The healthy 293T cells were transfected with the plasmid to establish the vectors of mice K26 and KAP26.1 gene lentivirus overexpression, respectively, which were transfected into mice skin fibroblasts. Transfection efficiency was observed by quantitative fluorescence microscopy. After determining the success of lentivirus overexpression, the total RNA was extracted from the transfected cells, and after reverse transcription, the obtained cDNA was measured with the Eppendorf Realplex florescent quantitative PCR to detect the influence of K26 and KAP26.1 genes overexpression on KAP6.2, KAP7.1, KAP8.2, KAP11.1, BMP-4 and BMPR-IB gene expression 【Result】Proved by RT-PCR detection, mice lentivirus vectors pLenti6.3-K26-IRES-EGFP and pLenti6.3-K26.1-IRES-EGFP were established successfully. Compared by fluorescent field, the highest transfection rate of 293T cell transfected lentivirus vectors was reached after 72hr. Confirmed by PCR detection, packaged K26 and KAP26.1 lentivirus vectors transfected into mice fibroblast successfully after 72hr.Through RT-PCR detection and analyzed by SPSS 19 software, expression levels showed significant difference among the target genes, positive control group (empty plasmid, BLACK) and negative control group (mice skin fibroblasts, NC), indicating that after K26 overexpression, the expression level of KAP26.1 was up-regulated, and vice versa. This finding suggested synergy between K26 and KAP26.1. After K26 and KAP26.1 overexpression, the expression levels of KAP6.2, KAP7.1, KAP8.2, and KAP11.1 were down-regulated. After K26 overexpression, BMP4 gene expression increased, while BMPR1B gene expression decreased. After KAP26.1 overexpression, expression levels ofBMP4 and BMPR1B both were up-regulated.【Conclusion】K26 and KAP26.1 genes had a synergistic effect on the inner root sheath of the hair follicle by influencing the downstream protein synthesis signal of mTOR pathway. The high expression of K26 and KAP26.1 genes could inhibit the expression of KAP6.2, KAP7.1, KAP8.2, and KAP11.1 genes and thereby regulated hair fineness. Both K26 and KAP26.1 overexpression could up-regulate the expression level of BMP-4 gene which is the activator of BMP signaling pathway and could activate the BMP signaling pathway and then affected the growth of hair follicle cycle. K26 gene overexpression could down-regulate BMPR-IB gene expression, while KAP26.1 gene overexpression up-regulate BMPR-IB gene expression. BMPR-IB gene is the receptor I of the BMP signal. When BMPR-IB receptors decreased, the BMP downstream signal transduction will be inhibited, and then restarted hair growth cycle. When BMPR-IB receptors increased, the downstream signaling molecules transcription will be promoted, and then affected hair follicle growth cycle. Both K26 and KAP26.1 overexpression could activate BMP signaling pathway, and the expressions of KAP6.2, KAP7.1, KAP8.2, KAP11.1,BMP-4 and BMPR-IB genes were in turn regulated by the mTOR and BMP signaling pathways. But the opposite regulation effects of K26 and KAP26.1 genes on BMPR-IB gene still need to be further explored.

【Objective】Bumblebee Bombus lantschouensis is one of the most important pollinators for wild plants and crops in North China. Odorant receptors (Ors) gene family from the genome of B. lantschouensis was identified and characterized. Result of this study will help to explore the function of this gene family in foraging, mating and other social behaviors in bumblebee.【Method】Genomic DNA of thorax of B. lantschouensis was extracted and sequenced by the high-output of next generation sequencing. The original sequence of the sequencing was quality controlled and assembled to the genomic sequence. The contigs and scaffolds were used to build local sequence database. Gene sequences of Bombus terresters and Apis mellifera ligustica were used to query the local database. The characteristics and gene structure of Ors were analyzed by EMBOSS1.5 and GSDS2.0 software, respectively. Conservative motif analysis of amino acid sequences was performed using MEME 4.11.2. The phylogenetic analysis of Ors of B. lantschouensis, B. terresters and A. mellifera was studied by ClustaW 2.1, TrimAl 1.2 and PhyML3.0.【Result】One hundred and sixty-five Ors were identified from the genome of B. lantschouensis, including an Orco, 5 pseudogenes and 159 Ors. Gene structure analysis showed that the number of exons of these Ors are varies from 4 to 9. The least number of exons found in Or 47-57 was 4 and the largest number of exons found in Or 128-161 was 9. According to gene structure, Or was classified into 10 groups. Similarity in exon lengths and numbers was identified in the sequence of each group. The numbers of subgroup members were about 10, except in Or 1-38, Or 69-85 and Or 128-164 (which has 38, 17 and 37 members, respectively). The members of each subgroup are arranged in tandem on chromosomes and Or 1-38 have a longer first exon. Conserved motif analysis revealed that 9 motifs are present in Ors conserved domains (7tm_6 domain) except for motif 5 in all 10 motifs. While Or 1-38 and Or 39-46 have all predicted motifs and motifs 2, 3, 4, and 9 are widely present in sequences, which may be the key functional regions of the family. Phylogenetic analysis showed the 5 subfamilies of Ors family. Whereas the subfamily II contains 2 groups (BlOr 97-100 and BlOr 69-85) and subfamily V contains 4 groups (BlOr 1-46, 47-57, 86-95 and 101-107). BlOr 150-155 and AmOr 122-139 were clustered into two branches, and similar phenomena were also found in BlOr 47-57 and AmOr 63-65. It indicates that Ors has species-specific loss or expansion in evolution of Apis and Bombus. Or 115 is located at the base of the tree, suggesting that the sequence may be closer to the ancestor sequence of the odor receptor family.【Conclusion】Numbers, gene structure and phylogenetic relationships of Ors from the genome of B. lantschouensis were clarified in current study. Conserved motif analysis indicated that motif has been missed during the evolution of Ors family among bees. These results would provide an important information for exploring the gene evolution and function of Ors in future.

【Objective】 The Omega -3 fatty acid desaturase (ω-3 FAD) is a key enzyme in the fatty acid biosynthesis pathway of plant. Through analysis of omega-3 fatty acid desaturase gene structure and its expression in different tissues from Paeonia ostii, this study will lay a foundation for the research of regulating effects of FAD3 gene on fatty acid biosynthesis and provide a theoretical basis for the formation in the process of regulation. 【Method】 The FAD gene from Paeonia ostii (FAD3) was cloned using RT-PCR and RACE-PCR strategies. Nucleotide sequence was analyzed using Vector NTI Advance 11 software. Homology was analyzed using BLAST. A phylogenetic tree was constructed using neighbor-joining of MEGA 7.0. The secondary structure and three-dimensional model of FAD3 were predicted using ExPASy and Phyre2, respectively. Expression profiles of FAD3 at different developmental stages and in different tissues of the P. ostii were assayed using real-time quantitative PCR. 【Result】 The FAD gene in P. ostii was cloned and named as FAD3 (GenBank accession number: KX906966). The full length of FAD3 cDNA is 1 723 bp, contains a 1 308 bp open reading frame (ORF) encoding a putative protein of 435 amino acids with a molecular mass of 49.9 kD and an isoelectric point (pI) of 7.42. The 3′-untranslated region of 287 bp and 5′-untranslated region of 99 bp were obtained from the FAD3 gene of P. ostii. N end without signal peptide, fat coefficient is 83.08, instability index 35.67, the grand average of hydrophobicity value of -0.222. By FAD3 protein secondary structure prediction, FAD3 mainly in the alpha helix and random coil, followed by less extended strand, beta turn content; multiple sequence alignment results showed that it contains two conserved domains of FAD3 gene. Phylogenetic tree analysis showed that the P. ostii has the closest evolutionary relationship with P. lactiflora. Subcellular localization analysis of TMHMM and Target P indicated that it might be targeted to the endoplasmic reticulum with three transmembrane regions. FAD3 gene was expressed in the root, stem, leaf, petal, pistil, stamen and seed of P. ostii by the tissue-specificity expression. The expressive content of FAD3 gene in different tissues of P. ostii was different: The highest was leaf, the next was pistil, and the lowest level was in stamen; In different periods of seeds, the highest expression was seeds of 10d, the next was 20d, in 60d expression was the lowest. 【Conclusion】 The full length cDNA sequence of FAD3 gene was successfully cloned from P. ostii, It shows a variety of expression patterns in different tissues, which laid a foundation for the further study on the function and expression regulation mechanism of FAD3 gene in the process of unsaturated fatty acid biosynthesis.

【Objective】The objective of this study is to understand the effect of hyperosmotic stress on the growth and development, melanin content in mycelium cells, determine the probable osmolytes in the mycelium cells and to clarify the variation rule of these substances under different hyperosmotic stress conditions in Setosphaeria turcica. 【Method】The effects of hyperosmotic stress on colony growth rate, mycelium morphological characteristics and melanin content in S. turcica mycelium cell were analyzed under different hyperosmotic stress media, in which 0.4, 0.8, and 1.2 mol·L^-1 NaCl were added in PDA medium. High performance liquid chromatography (HPLC) technology was employed to detect the content of polyhydroxy-alcohol including glycerol, erythrol, glucose, mannitol, trehalose and analyzed the change profiles of these substances as time increased. 【Result】Compared to the strain cultured on PDA medium, the strain cultured under hyperosmotic stress treatments appeared with decreased in colony growth rate, shortened septum and swollen cells. Melanin content in mycelium cells cultured under hyperosmotic stress treatments in all time points showed a significant difference compared to the control group, in which melanin content in the samples treated before 12 h were lower than that in control, but there were no obvious differences between the samples treated. Moreover, there were different effects under different times (24, 48 h) and different concentration treatments. Compared to the control group, melanin content in the samples treated with 1.2 mol·L^-1 NaCl was significantly increased, melanin content treated with 0.8 mol·L^-1 NaCl was significantly decreased, melanin content in samples treated with 0.4 mol·L^-1 NaCl was significantly decreased in 24 h, but the content in the samples after 48 h treatment was almost the same with the control. Mannitol contents in mycelium cell under different hyperosmotic stress treatments were increased with the increase in time, especially the mannitol content significantly increased after 36 h treatment. There was a similar change tendency in glycerol and mannitol contents in mycelium cells under different treatments. Glycerol content increased most obviously compared with the control group and the content was significantly increased after 24 h treatment. Trehalose content in mycelium cells showed an increasing tendency as time increased, and the tendency increased with the increase of stress intensity, however, trehalose content after 36 h treatment was significantly lower than that in control group, while no significant difference was found in the changes of erythrol and glucose contents. No mannitol, trehalose and glycerol were detected in culture filtrate, while glucose content had no significant change no matter the fact that the mycelium was cultured in PDA medium or under hyperosmotic stress treatments.【Conclusion】 The colony growth rate was inhibited, mycelium cell was swollen, and septum was shortened under hyperosmotic stress. There was a significant inhibition on mannitol content before 12 h treatment. Mannitol and glycerol were main osmolytes in mycelium cells. Trehalose was also involved in hyperosmotic stress reaction in S. turcica. 

【Objective】Carotenoid Cleavage Dioxygenase 1 gene of Tagetes erecta L. ‘Scarletade’(TeCCD1) was cloned for bioinformatics and gene expression analysis, which can help clarifying its biological functions in carotenoid degradation pathway and providing a theoretical foundation to further clarify the mechanism of African marigold flower color formation.【Method】According to the transcriptome of African marigold flower bud, the full-length cDNA of TeCCD1 had been obtained, and gene expression profile of ray florets at developmental stages of closed bud, semi-open bud, open flower and fully open flower was studied by Real-time PCR.【Result】The full-length sequence of CCD1 cDNA obtained from African marigold is 1 746 bp (GenBank accession number: KX557488), with a coding region length of 1 626 bp, putatively encoding 541 amino acids. Protein analysis indicated that TeCCD1 is an unstable protein and has no signal peptide, which belongs to the RPE65 superfamily (GenBank accession number is PF03055) having the same conserved domain of CCD family, and it is mainly located in the cytoplasm. CCD1 nucleic acid sequence of African marigold is 89% homologous to that of Pyrethrum. Amino acid sequence analysis suggested that CCD1 of African marigold is 93% homologous to that of Pyrethrum, and 75%-83% homologous to that of 19 different species, indicating that TeCCD1 is highly conserved gene. Phylogenetic analysis showed that the evolution of TeCCD1 is basically in accordance with the evolution law of plant taxonomy and has obvious characteristics of species, which has a closest relationship with that of the species in Compositae. The results of Real-time PCR demonstrated that expression of TeCCD1 increased along with the development of ray floretsand reached the maximum value at S4 stage.【Conclusion】CCD1 homolog was cloned in Tagetes erecta L. ‘Scarletade’ identified to be a typical member of the CCD family, which is a highly conserved gene located in the cytoplasm. The color fading of ray florets during the late development phase is possibly caused by the increase of expression of TeCCD1, which contributes to a decrease in carotenoid content.

Maize is the first major crop in China and in the world, it plays an important role in ensuring China’s food security. At present, in the face of the rapid development of economic society and a series of problems such as population growth and land reduction, resources shortage and ecological environment deterioration, maize cultivation science is facing new historic opportunities and challenges. In this crucial historical juncture, it is of great significance to review the scientific research and technical progress of maize cultivation in China and to explore the future development direction. Analysis shows that, the aim of maize cultivation research has been transformed from yield production to collaborative development of high yield, high quality, high efficiency, eco-friendly, security and other goals after 60 years of efforts. The research contents were gradually widened and further deepened with remarkable Chinese characteristics. Since entering into the 21th century, the research of maize cultivation has entered a golden development stage. In this stage, a series of breakthroughs in maize cultivation theory, key technology innovation and application have been achieved, which have taken a positive role in ensuring China’s food security. According to the demand of maize production for science and technology in the future and the development trend of modern science and technology, this article indicated that, in the future, high quality, high efficiency, eco-friendly, security will still be the main objectives of maize cultivation. In this article, the key directions and tasks of maize cultivation research in the next 20 years were put forward: (1) Continue to explore the potential of maize yield in different ecological areas and technologies that can realize these potentials, and make every effort to raise the level of yield per unit; (2) Transform the mode of production and take the improving efficiency of resource utilization and labor productivity as goals, reduce the production costs, improve product quality and the market competitiveness of maize; to develop silage and fresh maize so as to promote the diversified development of maize production; (3) In order to respond to the global climate change, carry out the theoretical and technological researches on yield stability and anti-disaster to realize the sustainable production of maize; (4) Based on modern information technology to carry out the researches of intelligent cultivation technology to achieve maize precise production and management; (5) Strengthen the basic researches of maize cultivation and tamp the researches on maize science and technology and the basement of maize production.

【Objective】Enhancing the maize plant population has undergone a constant evolution over the years, with the purpose of increasing the crop yield. However, the rational density range was determined by environmental condition, varieties and management. The objective of this work was to reveal the approach of enhancing maize yield in the future by analyzing the change trend of planting density and its influencing factors in major producing regions. 【Method】 The research data have been obtained over the Project of Sending Agricultural Technology into Farmers’ Homes and National Maize Industrial Technology System from 2005 to 2016, including 23 provinces, more than 267 counties. From this investigation, 117 960 farmer production investigation data samples were obtained from the Northern China spring maize planting region (NM), the Northwest China maize planting region (NWM), the Huang-Huai-Hai Plain summer maize planting region (HPM), the Southwest China maize planting region(SM) and the Southern China sweet-waxy maize planting region (SWM). The number of harvested plants surveyed in nationwide investigation was used to analyze the planting density of maize main producing region and different ecological regions. The sample data were verified and complemented by averaging the values of 5 neighboring points. According to the regional environmental condition and planting patterns, the main maize producing regions have divided into 25 typical ecological regions. Boxplot analysis and Tukey’s honestly significant difference (HSD) test method were used to compare the planting density difference and its significance in different regions. Evolutionary trends of county-scale planting density in different ecological regions were subjected to the fitting linear model to analyze inter-annual trend of planting density and its significance.【Result】The results showed that there were significant differences of planting densities in different regions. At present (2014-2016), the planting density of the main producing region respectively were 6.77×10⁴, 6.19×10⁴, 5.91×10⁴, 5.13×10⁴ and 4.80×10⁴ plants/hm² in NWM, HPM, NM, SWM and SM. The planting density in NWM was significantly higher (P＜0.01) than other regions. Furthermore, planting density in SWM and SM was significantly lower (P＜0.01) than that in NWM, HPM and NM. From 2005 to 2016, the inter-annual variability of planting density showed a significant increase in NM. In NWM and SM, the planting density kept it steady between 2009 and 2016. The planting density in HPM increased obviously from 2005 to 2009 and remained stable after 2009. Planting density in SWM showed a significant decreasing trend.【Conclusion】Dense planting cultivation is commonly acknowledged by both the government and the academic researchers. However, the planting density evolution in the main production regions and different ecological regions is not uniform. Regional environmental condition is the key factor for determining the planting density, and reasonable cultivation techniques and appropriate density-resistant varieties are effective approaches to overcome environmental constraints and increase planting density. Consequently, further analysis of the promotion and restriction increase planting density factors, including environmental condition, varieties and management, will provide a theoretical foundation for establishing regional dense planting management mode.

【Objective】 The population light interception (PLI) has a great impact on growth, development, and grain production of maize (Zea mays L.) in interaction with canopy structure of maize population. It costs amounts of time and labor to measure the morphology index in the evaluation of maize canopy structure. And it is impossible to integrate solar radiation into the evaluation of canopy structure. Therefore, it is quite necessary to develop a simple but feasible model that combine canopy structure and solar radiation to improve the evaluation of maize canopy structure, and thus to guide farmers in crop management.【Method】Based on the canopy structure model and light distribution model, a simple and reliable light interception model of maize canopy was developed. In order to evaluate the prediction accuracy of this model, two field trials were conducted at Wuqiao Experimental Station of China Agricultural University in 2009-2011. Trial 1 was set up as a split-plot design with varieties (ZD 958 and DY 405) and plant densities (45 000, 60 000, and 75 000 plant/hm²) as main factors, and nitrogen management (No nitrogen; 180 kg·hm^-2 N applied at sowing﹕13-leaf stage﹕silking stage=1﹕4﹕1; 270 kg·hm^-2 N applied at sowing﹕13-leaf stage﹕silking stage =4﹕4﹕1) as second factor. Trial 2 was in a randomized complete block design, including one variety (ZD 958), one plant density (82 000 plant/hm²), and six sowing dates (April 20, May 5 and 20, June 4 and 18, and July 3, 2009). 【Result】The simulated PLI rates were significantly correlated with measured PLI rates at silking stage and mid kernel-filling stage, with r values of 0.91 and 0.85, respectively. During the entire kernel-filling stage, the PLI values first increased and then decreased, and the reduction became more obvious on 50 days after silking. Moreover, the PLI values remained at the highest level when plant density was greater than 60 000 plant/hm². Additionally, population structure under sowing date of June 4 achieved the highest PLI, demonstrating its great potential of structure-function for the yield improvement. PLI and yield were positively correlated, while their correlation coefficient declined over time during grain-filling period, indicating that the dry matter allocation might play more important roles on yield during the late grain-filling period. The decline of correlation coefficient also depended on variety; variety with erecter leaves could remain a higher coefficient value over time. 【Conclusion】The potential to further improve maize yield through increasing plant density  (＞75 000 plant/hm²) is limited at experimental site. Some strategies should be concerned, such as (1) applying varieties with erect leaves and long-lasting canopy structure persistence during late grain-filling period, and (2) adjusting sowing date according to climate situation to increase population photosynthesis at early grain-filling period.

【Objective】The purpose of this study was to investigate the regulating effect of cultivation measures and their interactions on grain yield and density resistance of spring maize hybrids, and its contribution to increase of grain yield.【Method】Maize cultivar “Zhongdan 909” was used as experimental materials in 2013 and 2014, which exhibited high yield in the high plant population. From 45 000 plants/hm² to 10 5000 plants/hm², five plant population treatments were designed. Subsoiling (S), wide-narrow planting (W) and chemical regulator (C) as cultivation measures, and composed different cultivation modes by split-split-plot design. Path analysis, factor regression and ANOVA analysis of different cultivation modes based on the yield, and using stepwise regression to analyze the efficiency of resource utilization factors under different cultivation modes, combined with the meteorological data. 【Result】The chemical regulator (C) had a significantly positive effect on yield in the integrated measures mode (contribution rate, 27%-41%), which the effect rests with the plant density increasing by 11 700 plants/hm² under only chemical regulator treatment; wide-narrow planting (W) showed obvious different effects among the treatments. However, the effect of subsoiling (S) on yield displayed priority to indirect effect (contribution rate, 24%-37%), nevertheless, subsoiling plus wide-narrow planting compared with tradition mode (RU) could increase yield by 11.28%. The yield improvement of multiple measures interaction was much higher than those of double measures interaction and a single measure. Compared with traditional mode, multiple measures, double measures and a single measure increased yield by 31.27%, 15.57% and 7.96%, respectively, in a normal year (2013); and increase yield by 15.02%, 11.32% and 5.65%, respectively, in a drought year (2014). The yield increasing was mainly due to the increased population density, and coordinated regulation among radiation use efficiency (RUE), growth degree days use efficiency (GUE) and nitrogen partial factor productivity, then achieved the high yield and high efficiency under integrated measures. 【Conclusion】The yield improvement of multiple measure interaction mode (SWC) was the highest, compared to the traditional mode, the multiple measures could increase plant density by 62 700 plants/hm² and obtain yield improvement by 11.91%, which the improvement was mainly attributed to the optimized population density under multiple measures interaction and regulating effect from integrated measures on resources utilization efficiency of intensive spring maize.