Abstract
Brassica napus L. (AACC, 2n = 38) is one of the most economically important crop species worldwide. Evaluating the genetic diversity of this crop species is essential for establishing efficient conservation and breeding practices. This study aimed to assess the genetic diversity, genetic structure and relationships of 26 Brassica napus accessions of different origins using SDS-PAGE of total seed proteins and microsatellite (SSR) markers. The percentage of protein polymorphism observed among accessions was 61%. SDS-PAGE results also revealed that the total amount of variation accounted for the first three principal components was 73%. Cluster analysis based on the protein data divided the 26 accessions into 4 groups. The 11 SSR primer pairs used revealed 14 loci of a total of 50 alleles. The observed heterozygosity (0.47) was higher than the expected one (0.298). Polymorphic information content (PIC) varied from 0.141 to 0.743, with an average of 0.59 per SSR primer pair. SSR results also showed that 58.8% of the total variation was found among accessions, and 41.2% of the SSR variation resided within accessions. Cluster analysis based on SSR data revealed that the two winter oilseed rape cultivars CGN06870 and CGN17374 were grouped with the spring oilseed accessions. The spring oilseed rape cultivar CGN11019 was grouped with the winter oilseed accessions. The genetically diverse spring and winter oilseed genotypes identified could be useful resources for oilseed rape breeding. The useful results of this study could be used for enhancing and broadening the genetic base of Brassica napus gene pool.

Key words: Brassica napus, genetic diversity, phylogenetic relationships, SDS-PAGE, SSR.