GENETIC DIVERSITY, CORRELATION AND PATH CO-EFFICIENT ANALYSIS IN COUNTRY BEAN (Dolichos lablab L.)

Abstract

fwenty six genotypes of Country bean (Do/ichos labia/i L.) were studied at the experimental farm of Sher-e-Bangla Agricultural University. Dhaka, during October 2009 to March 2009. The objectives of the study were to measure the variability among the genotypes for yield and yield contributing characters, estimate genetic parameters, association among the characters and their contribution to yield. There was a great deal of significant variation for all the characters among the genotypes. High genotypic co-efficient of variation (CCV) was observed for pod width, inflorescence length, pod per inflorescence whereas low genotypic co-efficient of variation (('CV) was observed for seed Nvidth, seed length, days to first flowering. In all cases, phenotypic variances were higher than the genotypic variance. Heritability with low genetic advance in percent of mean was observed in seed width which indicated that non-additive gene effects were involved for the expression of this character and selection for such trait might not be rewarding. High heritability with high genetic advance in percent of mean was observed for pod width, inflorescence length indicated that this trait was under additive gene control and selection for genetic improvement for this trait would be effective. Correlation studies revealed that the highest significant association of yield per plant was observed with pod length, pod weight, pods per plant, inflorescence per plant. Path co-efficient analysis revealed the maximum direct contribution towards yield per plant was with pod weight followed by pods per plant, pod width and number of flower per inflorescence. The highest intra-cluster distance was found in cluster IV and lowest in cluster 1. Among five clusters, the highest inter-cluster distance was observed between cluster I and cluster TI and the lowest between cluster Ill and cluster IV. Considering all the characters the 67 (1313-8832). G (1113-7985), G3(1313-8034) and G15 (BD-8816) were selected for thture breeding programme.