Characterization of Brassica napus germplasm based on molecular markers

Evaluation of genetic relationships is of prime importance in any breeding studies. The present study was carried out to estimate the genetic diversity of Brassica napus germplasm using randomly amplified polymorphic DNA (RAPD) primers. A total of 16 B. napus genotypes were evaluated using ten RAPD primers. Bivariate data matrix was generated and genetic distances were calculated using unweighted pair group of arithmetic mean (UPGMA) procedure, which amplified 2.31, 2.70, 1.14, 2.46, 1.82, 2.24, 1.78, 3.06, 2.25 and 2.46 alleles per genotype, respectively. All the genotypes showed various levels of genetic polymorphism for the loci detected by using RAPD primers. A total of 217 alleles (bands) were amplified in 16 genotypes using 10 primers giving the average of 13.56 alleles per primer. Among the ten primers used in the present study, primer GLA-09 yielded an average minimum number of bands (1.14), while primer GLD-08 yielded maximum (3.06) number of alleles per genotype on average. Level of genetic polymorphism (estimated as percent genetic distance) observed during the study varied, but on average, and it was in the range of 19 to 93%. Maximum genetic distances were observed among PR-102 and Dunkled, closely followed by PS-1 and PR-111. These findings were further strengthened by dendrogram analyses. Genetically distinct lines pointed out in the present study (PR-102 and Dunkled) could be used in future breeding programs for developing better quality canola inbred lines/varieties.   Key words: Genetic diversity, randomly amplified polymorphic DNA (RAPD),Brassica napus, rapeseed.