Genetic studies on diversity and variability in dolichos bean (Lablab purpureus L.)

The field experiment was carried out by using twenty-six field bean genotypes to study the genetic divergence and genetic variability parameters. The characters studied were days to 50 per cent fowering, days to maturity, plant height, the number of branches per plant, the number of pods per plant, grain yield per plant and green pod yield per plant. On the basis of mean performance, the genotypes, PYR 15–01, Nagavalli local 1 and Nallur local were found to be superior for yield and yield contributing traits. The genotype HA 3 was an early maturing type but possess an optimal green pod yield of 327 g/plant. Twenty-six genotypes were grouped into six clusters and based on the genetic distance, maximum divergence was observed between cluster II (HA4, CO1, CO2, Arka vijay, Arka Swagath & Arka Amogh) and cluster V (Udhuru local & Bannekuppe local), hence parents can be selected from these clusters to exploit better heterosis for hybridization. Maximum intra cluster distance was observed for cluster III (13.88). Among the six clusters, cluster VI (Arka Joy) contributed to wider divergence and promote direct selection of genotypes falling in the respective cluster for plant height, the number of branches per plant, the number of pods per plant and grain yield per plant. The major contribution for divergence was occupied by the characters viz., days to 50 per cent fowering (46.77%), days to maturity (29.85%) and a moderate level of divergence was contributed by the number of pods per plant (12.62%). Therefore, these characters were taken into consideration for selection. With respect to variability studies, all the seven characters viz., days to 50 per cent fowering, days to maturity, plant height, number of branches per plant, number of pod per plant, grain yield per plant and green pod yield per plant recorded high value of PCV, GCV, heritability and genetic advance indicated the involvement of additive genes for the control of these characters and favours selection.