Assessment of genetic diversity of some <i>Brassica napus</i> L. cultivars revealed by molecular markers and phenotypic evaluation

Abstract

The genetic diversity of 50 oilseed rape cultivars was studied using phenotypic evaluation and molecular markers. For the phenotypic evaluation, seven morphological traits were analysed. Euclidian distances among mean values of the obtained data, after the morphological evaluation of genotypes, were used to form a matrix for the construction of a dendrogram. For the molecular studies, RAPD and SSR markers were employed. In the RAPD analysis, 20 decamer primers were used, which gave 301 fragments, where 215 were polymorphic. The SSR analysis used 55 primers, which gave 123 polymorphic fragments. In order to determine the genetic diversity between the oilseed rape cultivars, both RAPD and SSR data were used. With this data, genetic similarity (GS) was estimated, which led to generate two similarity matrices. These two matrices were correlated using the Mantel test and the final matrice was used to design an UPGMA dendrogram using cluster analysis. Among the studied cultivars, significant genetic variability was obtained both at the morphological and molecular level. The obtained dendrogram for the morphological traits and for the RAPD and SSR results were compared. In both the cases, the genotypes were grouped after the geographical origin.