| In order to reveal the genetic diversity of Core Collection from Hunan Rapeseed Germplasm Bank,this research used phenotypic trait analysis and SNP marker technique to explore the genetic diversity of core germplasm in the library.In this study,132 Brassica napus germplasm resources were applied for genetic diversity analysis based on phenotypic traits,and 276 accessions including 226 B.napus and 10 accessions of other Brassica species,were selected for genetic diversity analysis based on SNP markers.The major results are summarized as follows:1.A total of 47 variation types were detected from 16 quality traits of132 tested materials,and the average variation types of each quality character were 2.94.Among them,the least variation types of basal leaf type were all split leaves,and the most abundant variation types of petal color and seed coat color were 7 and 6,respectively.Each character type can be shown in the tested materials.This indicated that the phenotypic traits of the tested materials were rich in variation and high in genetic diversity.2.By calculating the coefficient of variation and Shannon diversity index of 11 quantitative traits of 132 tested materials,it was found that: The coefficient of variation of 11 quantitative traits ranged from 8.36% to76.57%,with an average coefficient of variation of 34.59%,among which pod length had the largest coefficient of variation(76.57%),with a range of variation ranging from 3.13 to 58 cm.The coefficient of variation of oil content was the lowest(8.36%),and the range of variation was33.05～50.01%.The Shannon diversity index of 11 quantitative traits ranged from 6.85 to 7.05.The results showed that the quantitative characters of 132 were rich in variation and high in polymorphism.By calculating the correlation between quantitative characters and principal components,it was found that there was correlation among all characters,and plant height was positively correlated with other characters.The first four principal component factors can represent most of the genetic information of quantitative traits of the tested materials.The 132 tested materials were classified into three groups by clustering,and the classification was mainly related to plant height and oil content.3.This research applied whole genomic SNP analysis to 276 accessions and related species of rapeseed using 60 K gene chip.The primary data were screened using Visual Basic software,then applied Powermarker for PIC calculation of each SNP loci,genetic distances among accessions and clustering analysis.The results showed that 24 593 SNP loci were screened according to the deletion rate of SNP markers and the evenness of chromosome distribution,with an average of 1 294 polymorphisms per chromosome.The average values of Nei’s genetic diversity index(H),main allelic frequencies and polymorphic information content were 0.401,0.6883 and 0.316,respectively.The genetic distance between 276 tested materials ranged from 0.000 1 to 0.477,with an average of 0.329 6.71.49% of the samples had a Kinship value of 0.All accessions could be divided into 5categories,among which the largest category containing 250 germplasm could be further divided into 9 subcategories,indicating that the taxa distribution of the accessions was consistent with the germplasm types and geographical sources.The results showed that the genetic diversities of the tested breeding parents were rich.In this paper,we analyzed the genetic diversity of the representative rapeseed germplasm resources in Hunan Province constructed by Hunan Crop Research Institute based on phenotypic traits and genetic diversity analysis of SNP markers,further clarify the rapeseed germplasm resources in hunan province is rich in genetic diversity and genetic background,studies have shown that SNP marker than morphological markers can more objectively reflect the genetic relationship of the selected material,used for breeding germplasm identification and provides a better technical way and theoretical basis. |
