Studies On Core Ssr Primers For Brassica Napus

Rapeseed is one of the most important oilseed crops not only in China, also in the world. Now the proportion of hybrid cultivar planting areas is about 70% in China, and about 40% around the world. It is difficult to separate the varieties by phenotype because of the increasing large numbers of varieties.In crops; SSR marks were popular in analyzing purity identification, genetic diversity, protecting variety and so on. In this research, firstly, Screening of Brassica napus core SSR primers; the purity of the varieties was identified by core SSR primers.The main results are as follows:1. To select the SSR core primers, we collected 85 varieties of Brassica napus totally, which originated from different regions and periods in China mainly and parts of introduction species.2. From 746 primers, 20 primers were screened as the core primers; 20 primers were screened as the alternative primers and 40 primers nearly distributed across all of the linkage groups.3. The PIC of core primers ranged from 0.527 to 0.787 and the average of the PIC was 0.663. The average of Shannon-Weaver index was 1.382and the average of Simpson diversity index was 0.711.4. The results showed the observed 103 polymorphic markers are suficient to separate all 89 varieties from one another at the maximumgenetic similar coeficient of 0.89 in the core primers; from the cluster analysis of 40 primers, varieties bred by the same institute have the highest level of genetic similarity.5. The results of purity identification for two varieties indicate that the results of molecular markers and field identification were highly consistent, and the core primers were considerably accurate.