​Estimation of Genetic Variability and Genetic Divergence in Dolichos Bean [Lablab purpureus (L.) Sweet.] Genotypes

Background: Dolichos bean is an important leguminous vegetable having a wide range of variation in different quantitative characters. Assessing genetic diversity among dolichos bean accessions can ensure development of suitable high-yielding and adapted varieties with suitable maturity period. Methods: Fifteen genotypes were evaluated for different characters in Dolichos bean at two locations of Dr. Rajendra Prasad Central Agricultural University viz. Vegetable Research Farm, Pusa and Krishi Vigyan Kendra, Birauli, Samastipur, Bihar during the year 2018-19 and pooled data was analyzed. The genotypes were evaluated for genetic variability and genetic divergence for 14 characters. For the assessment of genetic diversity among the fifteen genotypes of dolichos bean, Mahalanobis (D2) statistic (Mahalanobis, 1936) was used, following the procedure given by Rao, 1952. Grouping of genotypes into clusters was done using Tocher’s method as described by Rao, 1952. Result: Phenotypic Coefficient of Variation (PCV) was slightly higher than Genotypic Coefficient of Variation (GCV) for all the characters indicated that the characters were less influenced by environment. The characters having high heritability and high genetic advance include harvesting duration, number of pods per plant, pod length, pod diameter, individual pod weight, weight of seeds per pod, 100 fresh green seed weight, pod yield and percent incidence of yellow mosaic virus. Therefore, selection for above characters is highly effective. Genetic diversity analysis evaluated that all genotypes could be placed into 6 clusters. Genotypes grouped in Cluster III and I have highest mean value for all characters as well as highest inter-cluster distance.