Molecular Characterization of Brassica Species using SSR Markers

Abstract

Genetic diversity and relationship among F8-populations of brassica species: B. napus, B. rapa and B. juncea were carried out on eight parental-lines along with their 38 introgressed populations using SSR markers to cover the diversity present in them as broadly as possible. Diversity analysis based on three neutral markers formed four distinct clusters with 1, 3, 19 and 22 genotypes, respectively. Based on these finding traits specific markers were employed which further formed six distinct clusters of selected plants with 3, 17, 2, 6, 3 and 14 genotypes. The cluster analysis identified genotypes with desirable biochemical contents i.e. plant 1 of Bnj43 had low glucosinolate, plant 3 of Bnr38 had high oleic acid content, plant 5 of Bnr38 had low linolenic acid, plant 1 of Bnr23 had low erucic acid while plant 2 of Bnr25 had high oil content and plant 2 of Bnj13 had high protein content. Moreover, the polymorphism information content (PIC) value of neutral as well as trait specific SSRs ranged from 0.5 to 0.96 and 0.45 to 0.95, respectively with an overall PIC value for all primers of 0.67. Considerable genetic diversity found among the F8-populations and their parents using SSR markers proved SSR analysis to be a useful tool. Moreover, based on the current findings, populations Bnj50F8, Bnr38F8, Bnj43F8, Bnj3F8 and Bnj25F8 are suggested to be used as source populations for transfer of desirable traits in future Brassica improvement programs.