Genetic variability and yield components of yard long bean (Vigna unguiculata var. sesquipedalis L.)

Abstract

Yard long bean (Vigna unguiculata var. sesquipedalis L.) is one of the important leguminous vegetables in Bangladesh. However, yield of this vegetable is much lower in Bangladesh compared to other yard long beangrowing countries. Therefore, it is crucial to improve the yield of this vegetable. In the present study, genetic variability, heritability, character association and genetic diversity were evaluated on randomized complete block design with three replications among seven-yard-long bean genotypes. The genotypes were significantly variable for the studied characters. High genotypic and phenotypic coefficient of variation was observed in number of pods per plant and pod yield per plant. Accordingly, high heritability together with high genetic advance in percent of mean was observed in number of pod per plant, pod diameter and hundred seed weight. The correlation studies revealed that pod yield per plant showed significant positive correlation with number of seed per pod, number of pods per plant while significantly negative correlation with days to marketable harvest at both genotypic and phenotypic level. Path analysis revealed days to first flowering, days to maturity, number of pods per plant, pod weight and number of seeds per pod had direct positive effect on pod yield per plant. The studied genotypes were clustered into 3 groups with highest of inter-cluster distance between cluster I and III while lowest between cluster II and III. The genotypes of cluster I exhibited higher mean performance while lower in cluster III for important traits including pod yield per plant.