Genetic Diversity in Commercial Rapeseed (Brassica napus L.) Varieties from Turkey as Revealed by RAPD

In cultivated commercial crop species, genetic diversity tends to decrease because of the extensive breeding processes. Therefore, germplasm of commercial crop species, such as Brassica napus L. should be evaluated and the genotypes, which have higher genetic diversity index, should be addressed as potential parental cross materials in breeding programs. In this study, the genetic diversity was analysed by using randomly amplified polymorphic DNA analysis (RAPD) technique in nine Turkish commercial rapeseed varieties. The RAPD primers (10-mer oligonucleotides) produced 51 scorable loci, 31 loci of which were polymorphic (60.78%) and 20 loci (39.22%) were monomorphic The RAPD bands were scored as binary matrix data and were analysed using POPGENE version 1.32. At locus level, the values of genetic diversity within population ( H s ) and total ( H T ) were 0.15 and 0.19 respectively. The genetic differentiation ( G ST ) and the gene flow ( N m ) values between the populations were 0.20 and 2.05 respectively. The mean number of alleles ( n a ), the mean number of effective alleles ( n ae ), and the mean value of genetic diversity ( H e ) were 2.00, 1.26, and 0.19 respectively. According to Pearson’s correlation, multiple regression and principal component analyses, eco-geographical conditions in combination had significant effect on genetic indices of commercial B. napus L. varieties were discussed.