Examination of genetic diversity in common bean (Phaseolus vulgaris L.) using random amplified polymorphic DNA (RAPD) markers
To study the pattern of genetic diversity in 45 genotypes of common bean, 19 RAPD primers were used. Of 253 bands produced, 236 bands (94.22%) were polymorphic in which maximum number (20 polymorphic bands) were observed in the profiles of the primer OPB-07. Highest PIC value (0.79) was observed for the primers OPG-14 and OPE-1, whereas lowest PIC value (0.34) was recorded for the primer OPA-11 with an average PIC value of 0.54. Similarly, highest effective multiplex ratio value (0.11) was scored for the primers OPA-04 and OPG-6 and the lowest value (0.05) was recorded for the primer OPB-07. Primer OPG-14 and OPE-1 exhibited the highest marker index value (0.078) and the lowest value (0.024) was recorded for OPA-11. Pair-wise genetic similarity coefficients of genotypes varied from 0.56 to 0.92 with an average of 0.70 amongst 45 genotypes. The maximum similarity coefficient (0.92) was noticed between G-9 and G-8. Cluster analysis separated 45 genotypes into seven major clusters which were further grouped into various sub-clusters. Among these seven clusters, the maximum number of genotypes (12) were recorded in cluster I, while cluster VII formed a mono-genotypic cluster.
Key words: Genetic diversity, polymorphism, cluster analysis, random amplified polymorphic DNA markers (RAPD), common bean.