Abstract:Abstract: A total 5963 of germplasm collection of upland cotton accessions were sampled for constructing a core collection. The whole collection was firstly divided into 11 groups based on the main the traits and genotypes. The resultant core collection including 281 accessions was constructed with 21 traits in each subset by unweighted pair-group method with arithmetic means (UPGMA), which accounted for 4.71% of total collection. Furthermore the representativeness between core collection and total collections was assessed by the t test, F test of variance, coefficient of variation, the diversity index t test, average, range, phenotypic variance and variation coefficient, mean difference percentage, variance difference percentage, coincidence rate of range, changeable rate of coefficient of variation and principal component analysis. The results demonstrated that the selected core collection could represent the genetic diversity of initial collection.

Abstract:Cold tolerance of 419 accessions of primary rice core collection from Guangxi was evaluated at geminating and seedling stages. The results indicated that the cold tolerance at geminating and seedling stages mainly concentrated in grade-7 and 9, most of the accessions were sensitive to cold. 24 and 27 accessions were classed into the high-level tolerance (Grade 1) at germinating and seeding stage, accounting for 5.73% and 6.44% of the total accessions, respectively. There is highly positive correlation (r = 0.66) between the cold tolerance scores at two stages. There were significant differences of cold tolerance between Indica and Japonica, non-glutinous rice and glutinous rice. Cold tolerance of Japonica was significantly higher than Indica at geminating and seedling stages. Cold tolerance of glutinous rice was significantly higher than non-glutinous rice at the geminating stage, but no difference at seedling stages. The rice collected from alpine areas showed much higher cold tolerance than Guinan and Guibei rice regions, no difference with Guizhong rice regions. Correlation analysis was carried on using 34 SSR markers. Two loci, at 7th and 9th chromosome, respectively , were identified to have a correlation with cold tolerance at both geminating and seedling stages. The study will provide elite rice germplasm of cold tolerance and a basis for mapping and cloning cold tolerance in rice.

Abstract:The morphological diversity and classification of 646 common bean (Phaseolus vulgaris L.) germplasm resources were conducted in Bijie Guizhou in 2015. The results showed that the morphological diversity was high among the accessions assessed in this study. A total of 367 variations were detected with an average of 8.34 variations and 0.63 Ht per phenotypic trait.The range of variation was from 2 to 31 and the range of PIC was from 0.02 to 0.91. Three principal components totally represented 44.21% of morphological diversity.The first, second and third principal component represented 17.53%,15.35% and 11.33% of morphological diversity respectively. Based on the morphological data, 646 accessions were clustered into 4 groups. Ⅰgroup showed the erect determinate growth habit , higher diversity and bigger seed mainly from the Andes gene pool. Ⅱgroup with the indeterminate growth habit, the lowest diversity, smallest seed size, mainly from the Mesoamerican gene pool. 335 accessions were clustered in Ⅲ group with the highest diversity, most of them showed the sprawl indeterminate growth habit , plant height was distributed widely with an average 180.27cm. Ⅳgroup with the sprawl indeterminate growth habit, the least plant branches and the highest plant height and the widest pod. 35 germplasms were identified with bigger seed size, more pods per plant, higher yields, longer and wider pod etc..

Abstract:In order to efficiently use Malus baccata(L.) Borkh germplasm, this study analyzed the phenotypic diversity of 19 morphological traits such as leaf shape, fruit shape and tree performance of 239 Malus baccata (L.) Borkh germplasm which collected in northern China. The results showed that Malus baccata (L.) Borkh in Heilongjiang province and Nei Monggol Autonomous Region were rich in phenotypic diversity, with mean variation coefficient(VC) of 32.65% and Shannon’s diversity index( H') of 1.38. The CV and H' for 13 qualitative characters of Malus baccata (L.) Borkh such as tree performance and tree shape were 38.43% and 0.95, while were 26.87% and 1.80 for 6 quantitative characters such as leaf length and lead width. Further analysis showed that phenotypic diversity of Malus baccata (L.) Borkh exist differences among different regions, which was the highest in Wenchun of Heilongjiang. Cluster analysis based on 19 morphological traits showed that all of materials could be divided into 2 populations, 7 subpopulations and 12 inferior subpopulations when the euclidean distance in 2.5. It implied that there had been complex genetic basis for Malus baccata (L.) Borkh because of all of materials were dispersed and did not form a separate population.

Abstract:In order to explore the excellent germplasm resources from Yunnan tartary buckwheat germplasm resources, broaden the genetic basis of tartary buckwheat, six agronomic traits and five quality traits of 48 taytary buckwheat genotypes in Yunnan had been analyzed for genetic diversity. The results showed that the abundant genetic diversity existed among the tartary buckwheat in Yunnan, the variation coefficient of seed weight per plant in agronomic traits was 34.4% largest, and the variation coefficient of total flavonoids in quality traits was 66.7% largest. The results of the cluster analysis indicated that 48 accessions could be classified into 3 clusters including the low yield type, shorter plant height with high yield type and middle plant height with high yield type. The principal components analysis based on six agronomic traits and five quality traits, indicated the accumulation indices of respectively 84.105% and 80.332% from the top three principal components which reflecting the breeding potential of major quantitative traits. Comprehensive analysis of main traits provided scientific information for effective use of tartary buckwheat hermplasm resources in Yunnan genetie resources.

Abstract:In order to breed high-yield species, associated with 9 phenotype characters of 40 varieties(1ines) of kenaf were observed and analyzed by factor and cluster analysis methods. The results showed that, the coffident variation of 9 phenotype characters ranged from 5.13% to 25.33 %, the varieties(1ines) had significant differences and abundant genetic diversities. Cluster analysis showed that 40 varieties(1ines) of kenaf were classified into 3 groups, the Group Ⅲ have some traits of high yield. The scatter plot of the former two main factor indicated T17-2, Fuhong 951, FHhang992, H1301, ZHKX-01, Fuhangyou 1, Fuhangyou 3 were better than others. and these accessions could be used in the production and breeding.

Abstract:In Southeast Asia countries, diversified natural resources、planting practice and consumption habit gave birth to a large number of special rice resources, including the colored rice, glutinous rice and fragrant rice types. These resources were long-term planted in relatively closed area, therefore, there are highly homozygous genes and stable phenotypic characteristics. They are ideal materials for genetic and physiological research. Fifty-six special rice resources collected from Vietnam, Laos and Cambodia were used to measure their photosynthetic parameters and statistical analysis. The results showed photosynthetic rate (Pn) and photosynthetic function duration (RSP) of the test material were extremely significant level, with the average values being 27.15μmol m-2 S-1 and 35.3d respectively; By making two-dimensional drawing quadrant, screened out 14 germplasm with relatively higher Pn and RSP, accounting 25% of the total.These germplasm can be used as an intermediate material of special rice type breeding, but also provides genetic resources for the photosynthetic mechanism research and high efficiency gene mapping. In additions, the correlation between special rice photosynthesis rate and agronomic traits were discussed, It was suggested that which an intermediate type plant type, leaf color is green or dark green, flag leaf state erect or intermediate type ,photosynthetic rate were relatively high, will be a potential material of high photosynthetic breeding.

Abstract:330 accessions of common bean were employed for evaluation of drought tolerance in seedling stage. Drought stress treatments for common bean seed germination modulated using PEG6000 solution and for common bean seedlings used the method of withholding water content of soil. Eleven traits were evaluated for assessment of drought resistance, including seed germination rate, relative shoot fresh weight, relative root fresh weigh, relative water content, relative electrical conductivity and three chlorophyll fluorescence parameters. Comprehensive assessment of drought tolerance based on membership function and grey-relation analysis indicate that the materials have different responses to drought stress, accessions of F1863、F2973、F3992 and F3057 showed the strongest drought tolerance among all tested materials. Relative seed germination rate, relative shoot fresh weight, relative root fresh weigh, relative plant fresh weight, relative electrical conductivity and chlorophyll fluorescence parameters Fv/Fm has closely association with comprehensive drought tolerance indices, and the association degree are more than 0.8, thus could be used as comprehensive index for identification of drought resistance at the seedling stage．

Abstract:Camellia japonica is one of the most famous traditional flowers of China. The present paper reviews the research progress of various aspects of C. japonica, such as reproductive biology, genetic diversity, chromosome ploidy, breeding method, propagation techniques, chemical composition, ornamental value, ecological value, edible, oil-used and medicinal value. In the future, it should be emphasized to carry out breeding research with combination of molecular technique and traditional cross. In addition, mining the oil-used and medicinal value of C. japonica in depth and exploiting it reasonably will be highlighted.

Abstract:Flavonoids, as one of the important functional components in loquat flower, play a significant role in anti-inflammation and relieving cough. In this study, the flower flavonoid contents were analyzed in 55 accessions of loquat germplasm from National Fruit Fuzhou Loquat Gene-pool. The result showed that, the flavonoid contents among the germplasm were significantly different, ranged from 0.44 % to 2.28 %. The highest content (Zhuonan No.1) was 5.18 times higher than the lowest one (Xiangzhong No.25). The average flavonoid level of loquat germplasm from Fujian province was significant difference with that from Zhejiang province (P＜0.01), as well as Guizhou province and Guangxi Zhuang autonomous region (P＜0.05). One loquat germplasm of ultra-high flavonoid content was screened out in this study, which is a promising material for further research. Meanwhile, the classification index for loquat flower flavonoid content level was establishedin, which provides a basis for further exploitation of loquat flower.

Abstract:ERF transcription factors are widespread in plants, which are widely involved in plant response to biotic and abiotic stress. In this research, a gene GmERF8 encoding a new ERF protein was isolated using RT-PCR from soybean. GmERF8 consisted of an ORF (open reading frame) with a length of 627 bp , and encoded a 23.43 kDa protein with 208 amino acids. Bioinformatics analysis indicated that GmERF8 contained a typical AP2/ERF binding domain, two putative nuclear localization signal sequences and a conserved repression-associated EAR motif. The amino acid sequences of GmERF8 and NtERF3 shared high homology through phylogenetic analysis. Real-time fluorescence quantitative PCR results revealed that GmERF8 expressed highly in roots and leaves. The expression of GmERF8 decreased under ABA, salt and cold treatments. Whereas it decreased firstly and thereafter increased under ethylene and drought treatments. Transcription regulation experiments demonstrated that GmERF8 downregulated the transcriptional level of the reporter gene. As the result, GmERF8 may founctions as a transcriptional repressor in soybean to response to environmental stress.

Abstract:The deployment of broad-spectrum resistance genes is the most effective and economic approach for controlling rice blast. The landrace Xianluozhan from South China displayed a broad-spectrum resistance against rice blast fungus. The resistant spectrum of the near isogenic line NIL-XLZ, derived from the Xianluozhan with the blast susceptible cultivar Lijiangxintuanheigu as a recurrent parent, is higher than that of the near isogenic lines of Pi2 and Piz and similar to that of Pi9 and Pi50. To identify the rice blast resistance gene(s) of Xianluozhan，we constructed an F2 population derived from Guanghui 290 (as a female parent) and Xianluozhan (as a male parent) for genetic analysis. The blast isolate GD08-T19 which had a broad virulence to rice cultivars from South China was used to inoculate the F1 and 1760 F2 individuals derived from the cross between Guanghui 290 and Xianluozhan. The genetic assay indicated that Xianluozhan carried a dominant blast resistance gene, since all of the F1 plants showed resistant and the segregation of resistant and susceptible progenies tend to fit a 3R:1S ratio in the F2 population. Based on the bulked segregant analysis (BSA) and recessive class analysis (RCA) with 44 microsatellite markers distributed around the loci of Pi2、Pi1 and Pita , the resistance gene hand been mapped in a 247 kb region of Pi2/Pi9/Pi50 family on chromosome 6 . The results of resistance spectrum analysis, gene specific markers detection and gene sequence comparison showed that Xianluozhan carried a broad spectrum blast resistance gene Pi50. This study provides useful information for the application of Xianluozhan in rice breeding.

Abstract:Cucumis sativus L.var. xishuangbannanesis is characteristic varieties resource with orange flesh in our country. The beta carotene content has obvious difference between different germplasm. Phytoene synthase (PSY) is the first speed limit enzyme in the pathway of carotene biosynthetic. Full length cDNA and DNA sequences of Psy1 were cloned respectively according to Cucumis sativus L.var.xishuangbannanesis. Corresponding DNA sequence was 2797bp, containing 5 introns and 6 extrons. cDNA sequence was 1385bp, encoding 421 amino acids. The deduced amino acid sequence contains two sequences with high conservation which were characteristic sequences in PSY family. The protein was unstable, having no obvious hydrophobic domain, and the membrane structure was not predicted. The deduced protein PSY1 showed the highest homology with melon, watermelon and bitter gourd based on phylogenetic tree. Four SNPs and one InDel of 13bp were found in Cucumis sativus L.var.xishuangbannanesis by sequence alignment with deep sequencing material "9930" and "GY14". The SNP1 occurred in 27bp of the upstream of the initiation codon, other mutations were located in the introns. SNP1 had the highest specificity based on the sequence analysis of 115 resequencing material. Its mutation rate was 100% in 19 Cucumis sativus L. var. xishuangbannanesis, and 5.3% in 96 cultivated cucumbers. The relative expression of Psy1 in 7 different developmental stages of fruit was studied by real-time fluorescence quantitative PCR. The results showed that the expression level of Psy1 gene increased and then decreased in different cucumber fruit development period, and the amount was significantly different in Cucumis sativus L.var.xishuangbannanesis. In the conversion period (50d after pollination), it reached the maximum value which was more than 8 times of the initial stage of fruit development and more than 4 times of the same stage in common cucumber. The expression amount of common cucumber changed mildly in general. In addition, the amount of expression of the inner peel of Cucumis sativus L.var.xishuangbannanesis was significantly higher than that in the middle peel, and the maximum difference was 5 times. The difference between the inner and middle peel of common cucumber was small relatively. Psy1 may affect the accumulation of beta carotene in Cucumis sativus L.var.xishuangbannanesis.

Abstract:Three pathogenic samples of Plasmodiophora brassicae from Changyang in Hubei Province, Taibai in Shanxi Province, and Xinye in Henan Province were used for inoculation to evaluate the clubroot disease resistance of 22 cabbage materials, respectively. The homologous genes of CRa and Crr1a in Brassica oleracea genome were analyzed by sequence homology analysis and then were amplified, sequenced and alignment for analysis. The results showed that 22 cabbage materials showed different resistance spectrum to three P. brassicae samples, indicating that three pathogenic samples were different physiological races. Screened resistant materials BDH3, Chou hybride Tekila, SW-110, CGL-8, Syngenta varieties, SW-109 could be used as clubroot-resistant breeding materials and mining new resistance gene in the future. Three genes (Bo7g107710, Bo7g107730 and Bo7g107740) on chromosome 7 of B. oleracea genome were identified as homologues of CRa, and the DNA sequence of Bo7g107730 gene showed relatively high variation in resistant material SW-110, which may be related to clubroot resistant. In addition, only one gene Bo3g164040 homologue to Crr1a were identified on chromosome 3 of B. oleracea genome, and we speculated that this gene was not resistant to clubroot disease because of this gene showed high sequence identity between resistant and susceptible material.

Abstract:Abstract :【Objective】The purpose of this experiment is to study the genetic diversity of Xinjiang wolfberry germplasm resources at molecular level by SCoT, and established their DNA fingerprints, which will provide some guidance for the Germplasm identification, Breeding of new varieties and Variety improvement.【Methods】The molecular marker technique of SCoT,PopGen32 software and NTSYS-pc2.10e statistical software were used to study the genetic diversity of 26 type and 4 wild varieties in Xinjiang , and the DNA fingerprinting was also established.【Results】A total of 256 bands were produced by 9 SCoT primers, and polymorphic bands were 217 which accounted for 84. 90% in the total amplified fragments.The polymorphism information content(PIC) values of these markers varied from 76.75% to 91.31%，The average value of effective number of alleles,Nei's genetic diversity and Shannon information index were 1.4303,0.2583 and 0.3948. respectively,The genetic similarity coefficient of 30 wolfberry samples ranged from 0.5938 to 0.8398. Based on SCoT molecular markers and the unweighted pari group method with arithmetic average (UPGMA) and Principal coordinate analysis，All samples could be divided into two groups and 4 subgroups accordingly at the GS of 0.65 and 0.72，In addition, the DNA fingerprints of 30 wolfberry samples was constructed by using the 5 SCoT primers，【Conclusion】the genetic diversity of Xinjiang wolfberry germplasm resources was relatively abundant, The results indicated that SCoT marker is suitable for the analysis of genetic diversity and construction of DNA fingerprinting of Xinjiang wolfberry germplasm resources. Moreover, It provides a wealth of genetic basis for Xinjiang Wolfberry Germplasm Resources identification and breeding of new varieties.

Abstract:Applied with the SRAP molecular labeling method and 15 selected primer combinations, this paper analyzes 23 cultivars of Castanea henryi and 17 populations resources of wild Castanea henryi in 5 provinces (Hunan, Zhejiang, Sichuan, Guizhou and Fujian), aming to provide a basis for genetic background analysis and germplasm innovation of Castanea henryi. A total of 221 sites were amplified in 17 wild Castanea henryi populations, with the average number and ratio of polymorphic loci being 155.06 and 70.16%. The number of total genetic diversity index (Ht), intra-population genetic diversity index (Hs), Nei’s genetic diversity index and Shannon’s information index are respectively 0.3636, 0.2466, 0.2460 and 0.3677, indicating relatively high genetic diversity and variability of wild Castanea henryi populations. Among them, the polymorphic rate of Hengshan (HS) population is the highest, which accounts for 85.07%; the polymorphic rate of population in Jishou Brook Village counts secondarily 83.26%. This evidence suggests that populations in Hengshan and Jishou (JS) have the richest genetic diversity in Hunan province. UPGMA cluster analysis shows that Xijiang population in Liuyang and Hengshan(HS) population bear the closest genetic similarity and relationship, while the contrary is the case of Liping population in Guizhou (GZ) and Yuetianzhen population in Yueyang. The polymorphic rate of 23 varieties of Castanea henryi is 89.14% and the genetic similarity coefficient is between 0.66 and 0.85. At coefficient 0.66, Dajianzui alone are clustered into one category, which reflects there is a big difference in genetic basis between Dajianzui and others; at coefficient 0.85, Huali2 and Tiezhui are clustered into one category, implying they share the closest relationship with minimum genetic diversity. In addition, during the research, we have built a SRAP digital fingerprint for the 23 varieties of Castanea henryi by using 4 primer combinations, namely Em1-Me2, Em2-Me1, Em2-Me2 and Em2-Me3. Thus providing references for rapid identification of Castanea henryi varieties.

Abstract:The Trinity program was used to assemble the transcriptome sequences of eggplant. In total，45 404 Unigenes were obtained with the length of 4 791 066 bp. We detected 8 316 SSR loci from these Unigenes by using MISA software. The density of the SSR were 5.63 kb with the frequency of 18.32%. The single nucleotide SSR is the most abundant （5 372） type which count for 64. 60% the total loci and followed by the tri-nucleotide （1 628） for 19.58%. The tri-nucleotide repeat motifs of AAG/CTT was the predominant repeat types that accounting for 31.6% of the tri-nucleotide repeat motifs. The dinucleotide repeat motifs of AG/CT is the predominant repeat format in this types of repeat and accounting for 42.3%. A total of 858 pairs of SSR primers are designed by using primer3 online program and 100 pairs of SSR markers are randomly selected and verified by using 17 eggplant germplasms. Among them，84 pairs of primers are able to amplify PCR products， of which 47 pairs of primers produced polymorphic bands. The PIC values range was between 0.10 to 0.64，the average value was 0.32. The 17 eggplant germplasms could be divided into three phylogenetic groups by analysis with UPGMA method. The results indicated that the SSR markers based on the transcriptome sequencing in eggplant will provide more reliable markers for map structure，analysis of genetic polymorphism for eggplant.

Abstract:Mutants are valuable for expanding the genetic diversity of wheat resources, cloning of genes for economically important traits. In this paper, 11 traits of the Chinese wheat landrace Huangfangzhu (HFZ) and its 11 EMS-induced mutants (F2～F12，Mu4), and the Chinese wheat landrace Haiyanzhong (HYZ) and its 12 EMS-induced mutants (Y2～Y13，Mu4) were investigated, and these traits include type 2 resistance to FHB after single floret inoculation method at anthesis, number of tillers per plant, plant height, flag leaf length, flag leaf width and chlorophyll content (SPAD value) at filling stage, and 1000-grain weight, grain length, grain width, number of spikelets per spike and number of grains per spike after harvest. At least one of 11 traits showed significant differences between the mutants and the wildtypes. Both the wildtypes confer a moderate to high level of resistance to FHB. HFZ-derived mutants F6, F9 and F12 as well as HYZ-derived mutants Y6, Y7 and Y9 showed moderate to high susceptibility to FHB, thus were the ideal lines for understanding type 2 resistance to FHB. HYZ-deirved mutants had lower values than the wildtype in plant height, 1000-grain weight, number of grains per spike and grain width. Dynamic clustering analysis classified the wildtypes and their mutants into 3 distinct groups in both the two populations, which allowed for understanding the potential genetic relationships among the lines. Those mutants such as F2, F7, Y2, Y3, Y4, Y8, Y10 and Y12, which had remarkedly improved agronomic traits but kept similar resistance to FHB to the wild types, could be useful in wheat genetics and breeding.

Abstract:Abstract: It is a general trend to grow cotton in saline alkali arid area in order to solve the contradiction between grain and cotton. Therefore, it is of great significance to carry out the identification and screening of resistant germplasm .Salt tolerance of 179 glandless cotton germplasm resources was identified by using germination box and quartz sand in the incubation room. The results showed that no high salt resistant variety was found. However, 4 resistant, 54 tolerant and 121 sensitive varieties were discriminated, accounting for 2.2%, 30.2% and 67.6% in the glandless cottons, respectively. The better salt resistant and tolerant materials are Yuwu424, Hengwu87-306, Zhongwu1651, Zhongwu3385, Duomao101, Zhongwu374-G, Zhongwu1038 and Zhongwu642. The relative survival rate of seedlings of these materials was above 70%under salt stress. For the sources of the cottons, salt tolerance of domestic materials was better than that of foreign materials. Salt tolerance of materials from Hebei, Shandong and Henan provinces was better than that of materials from other provinces. In this study, we selected good glandless cotton materials with good salt resistance, which provided excellent germplasm resources for the breeding of glandless cotton.

Abstract:Clubroot is爋ne爋f爐he爉ajor diseases爋f燾ruciferae爒egetable燾rops,燼nd燾auses爂reat爀conomic爈oss.?Broccoli爄s an important燾ruciferae爒egetable,爓hich爃as燼 good anti-cancer effects. In recent years, the occurrence of clubroot is growing in the main producing areas of broccoli, such as Zhejiang, Yunnan province. Cultivating resistant varieties based on identification and screening clubroot-resistance accessions is the most cost-effective method of preventing the disease. To爀xplore燼vailable爎esistant germplasm aganinst NO.4 race, the mainstream Plasmodiophora brassicaerace race in china, 525燽roccoli燼ccessions and their relatives were artificial爄noculated using irrigating injured root method. The爎esults爏uggested爐hat?燼ccessions?爄nbred爈ines) were middle resistant (MR),燼ccounting爁or?.12%?189 accessions爓ere susceptible牋(S), accounting爁or?2.38%;252燼ccessions爓ere爃ighly susceptible (HS),燼ccounting爁or?6.50%;no accessions were highly爎esistant?HR)爋r爎esistant?R)燼mong 446 broccoli accessions (including 393 inbred爈ines,?3爃ybrids). Among 85 relatives?including? cabbage accessions,?2 cauliflower,7 Chinese燾abbage?? turnip, 12 chinese kale,? kohlrabi,8 flowering chinese cabbage,2 oilseed rape,2 wild accessions,1 Barbarea vulgaris),爐here were 1 immune(I) accession 1爃ighly 爎esistance?HR)燼ccession,?爎esistant?R)燼ccessions,?爉iddle爎esistance?MR)accessions,?9 susceptible?S)燼ccessions and 37爃ighly susceptible?HS)燼ccessions.營n short,there were more resistant type lines(HR,R,and MR) in relatives than that in broccoli lines. These materials would provide clubroot-resistance source for breeding in燘rassica爋leraece.

Abstract:Abstract: Utilizing the high performance liquid chromatography method to measure the γ- aminobutyric acid content of seed in the 108 rice germplasm resources, and analysed correlation between γ- aminobutyric acid content of seed and grain traits of different germplasm resources, and test the determination of γ- aminobutyric acid content in rice parents、hybrids F1、F2 grains come from a hybrid combination of Gaoliangdao-1/Ningnongheijing with great different content of γ- aminobutyric acid, and analysed the correlation between the content of seed and relative embryo weight、grain traits and coefficient of variation, and estimated the broad heritability for each trait. The results showed that: the variation range was 2.39 mg/100g～12.03 mg/100g of the γ- aminobutyric acid content in 108 germplasm resources, the average content was 6.30?.99 mg/100g, the variation coefficient was 31.59%; the γ- aminobutyric acid content of seed had an extremely significant negative correlativity with grain thickness、1000-grain weight, and had an negative correlativity with grain length、grain width, but the correlation coefficient was not significant; the content in hybrids F1 grains by Gaoliangdao-1 and Ningnongheijing was 8.39?.11 mg/100g; testing a normal distribution of the γ- aminobutyric acid content frequiency in F2 plant grains, the results showed that the γ- aminobutyric acid content in hybrids F2 plant grains tend to skewed normal distribution and appear obvious transgressive phenomenon, and showed that the γ- aminobutyric acid content in rice grains was quantitative trait with controlled by multiple genes; the γ- aminobutyric acid content in hybrids F1 grains had an extremely significant positive correlativity with relative embryo weight, and had an extremely significant negative correlativity with grain thickness、1000-grain weight, and had an significant negative correlativity with grain length,; and analysed the broad heritability of the γ- aminobutyric acid content、grain length、grain width、grain thickness、aspect ratio、1000-grain weight and relative embryo weight, the results showed that the γ- aminobutyric acid content、grain thickness and 1000- grain weight of F2 plant grain had relatively high broad heritability, respectively were 98.12%, 91.99%, 96.37%, and these traits can be selected at an early time in rice breeding.

Abstract:Morphological identification and PCR confirmed that the Plasmodiophora brassicae is the pathogen caused cabbage clubroot. Using European ECD identification system, the?pathogen?was?further?identified?as a?physiological?strain coded as ECD17/31/13.?Field?trial?of?88?cabbage?germplasm?artificially?inoculated?by?ECD17/31/13?was?conducted?in village Huoshaoping(HShP),?Hubei?Province,?to?assess?their?resistance?nature?to?the?clubroot. After?evaluation,? their resistant phenotypes?were?leveled?as?high?resistance?(HR),?resistance?(R),?tolerance?(T) and susceptible(S).?The?results?showed?that:? among?the?88?cabbage?germplasm?engaged,?one?was?HR,?seven?R?and?seventeen?T?in?seedling?stage,?and?four?HR,?four?R,?15?T? in?plant?stage.?Germplasm?CR21?was?the?HR?material?which?performed?the?best?in?both?stages?stably.?Materials?CR55?and?CR54?were?found?as?the?most?susceptible.?The?disease?index?of?CR55?and?CR54?were?76.19?and?75.97?in?seedling?stage,?and?74.10 ?and?81.54?in?plant?stage?respectively,?when?the?incidence?rates?of?CR55?and?CR54?were?100%?both.?The?taxonomic?and?virulence?evaluation?on?the?pathogen?of?clubroot?disease,?and?screening?resistant?germplasm?in?cabbage?would?bring?clue?to?further?understand?the?phytopathological?mechanism?underlying?and?material?for?plant?breeding.