Genetic diversity analysis of mustard (<i>Brassica</i> spp.) germplasm using molecular marker for selection of short duration genotypes

Abstract

Molecular characterization of 16 mustard (Brassica spp.) genotypes by using 12 RAPD markers revealed that three primers GLA-11, OPB-04 and OPD-02 showed good technical resolution and sufficient variations among different genotypes. A total of 40 RAPD bands were scored of which 38 (94.87%) polymorphic amplification products were obtained. Besides, the primer OPD-02 amplified maximum number of polymorphic bands (100.00%) while the primer GLA-11 and OPB-04 generated the least (92.31%) polymorphic bands, which were minimal in number. The present study produced 13.33 scorable bands per primer and 12.67 polymorphic bands per primer. Frequencies of maximum number of polymorphic loci were found to be high with the exception of GLA-11(0.750), OPB-04 (0.875) and OPD-02 (0.750). The estimate of Nei's genetic diversity for the entire genotypes of mustard was 0.3596 and Shannon's information index was 0.535. There was a high level of genetic variation among the mustard genotypes studied from the proportion of polymorphic loci point of view. The values of pair-wise comparison of Nei’s genetic distance between genotypes were computed from combined data for the three primers; ranged from 0.1054 to 0.9862. BINA Sarisha-3 and BINA Sarisha-4 showed the lowest genetic distance of 0.1054 where Tori-7 and NAP-0758-2 showed highest genetic distance of 0.9862. The 16 mustard genotypes were differentiated into three main clusters: BARI Sarisha-14, BARI Sarisha-9, BARI Sarisha-15, BINA Sarisha-4, BINA Sarisha-3, BARI Sarisha-8, Sampad and Tori-7 in cluster A, NAP-0763, NAP-0721-1, BARI Sarisha-4, BARI Sarisha-6, NAP-0762-2 and NAP-0848-2 in cluster B and NAP-0838 and NAP-0758-2 were grouped into cluster C by making dendrogram based on Nei’s genetic distance using unweighted pair group method of arithmetic means (UPGMA).

Keywords: Mustard, diversity analysis, RAPD marker, genetic distance, cluster analysis.

Abbreviation: UPGMA, Unweighted pair group method of arithmetic means; RFLP, restriction fragment length polymorphism; RAPDs, random amplified polymorphic DNAs; AFLP, amplified fragment length polymorphism; SSRs, simple sequence repeats; CTAB, cetyl trimethyl ammonium bromide.