Genetic diversity and distinctiveness revealed by SSR markers among rapeseed (Brassica napus L.) genotypes from Australia, China and India
Rapeseed (Brassica napus L.) is one of the most imporant sources of vegetable oil. Its limited geographic range of origin and intensive selection in breeding programs have led to relatively limited genetic diversity in current breeding material. Consequently, many characters of commercial value show little genetic diversity in this important crop. We characterised the genetic diversity of 72 B. napus genotypes from Australia, China and India using 55 SSR markers that span the B.napus genome.The SSR markers amplified 365 alleles at 127 polymorphic loci and provided unique genetic fingerprints for 72 rapeseed genotypes, and genotypes from 5 other Brassica species. Hierarchical clustering and two-dimensional multidimensional scaling were used to identify three main groups: a group with all Indian genotypes, a group with 22 Chinese genotypes (China-1), and a mixed group. The mixed group could be divided into three subgroups: one with all Australian genotypes, one with Chinese genotypes (China-2), and one with genotypes from Europe and Canada. The subgroups from Australia, Europe/Canada and China-2 were more closely related to each other than they were with the Indian and China-1 groups. This suggested a relatively broader genetic diversity among the rapeseeds in China than among those in Europe, Canada and Australia. The Indian B. napus genotypes were rather distant to the other B.napus genotypes tested in this study, and India might be a good resource for describe alleles that are unique to a particular endemic species, were most richly represented in the Indian rapeseed population (average 4.00 private alleles per genotype). The Chinese population had moderate richness (1.03), whereas both the Australian population (0.50) and the European and Canadian population (0.40) showed low private allelic richness. Private allelic richness supported the results obtained from hierarchical cluster analysis and suggested that the richness of private SSR alleles could be considered as a measure of genetic distinctiveness. Therefore they might be used as an important indicator when choosing parents in rapeseed breeding.
rapeseed Brassica napus genetic diversity genetic distance genetic distinctiveness private allele SSR
Sheng Chen Matthew N.Nelson Kioumars Ghamkhar Wallace A.Cowling
School of Plant Biology,Faculty of Natural and Agricultural Sciences, The University of Western Aust Centre for Legumes in Mediterranean Agriculture,Faculty of Natural and Agricultural Sciences, The Un
国际会议
第十二届国际油菜大会( The 12th International Rapeseed Congress)
武汉
英文
720-724
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）