Comparative analysis of phenotypic and molecular diversity in selected pendal and non-pendal genotypes of field bean [Lablab purpurem (L.) Sweet]

Abstract

Twelve field bean (Lablab purpureus) genotypes - nine local collections, one check variety of filed bean and one lima bean local type - were selected for the study. The data on 23 quantitative traits revealed significant differences among selected genotypes for many traits. The cluster analysis of genotypes using 23 phenotypic traits revealed 3 clusters. Lima bean formed a separate cluster distinct from field bean genotypes. The pendal and non-pendal (both determinate and semi determinate) types formed two separate clusters within field bean genotypes. The RAPD analysis of 12 genotypes with 20 random decamer primers produced 200 fragments of which 178 were polymorphic. The diversity observed at molecular level was low. The dissimilarity coefficient ranged from 3.23 percent to 11.66 percent among field bean genotypes. Limabean genotype formed a distinct cluster with dissimilarity coefficient ranging from 65.65 to 67.7%. A comparison was made between genetic diversity at phenotypic and molecular level. The genotypes exhibited limited diversity at molecular level and higher diversity at phenotypic level. There was no concurrence between phenotypic and molecular diversity and clustering among the genotypes. Therefore, the degree of genetic diversity appeared to be overestimated if based solely on phenotypic variation in field bean.