Genetic variability studies in french bean (Phaseolus vulgaris L.)

Abstract

Investigations on genetic variability studies in 47 genotypes of french bean (Phaseolus vulgaris L.) were carried out at Indian Institute of Horticulture Research, Hessaraghatta, Bangalore. Wide range of variability was observed for most of the characters studied. The analysis of variance revealed significant differences among the genotypes for all the characters studied. Phenotypic coefficient of variability was found to be higher than the genotypic coefficient of variability. The estimates of phenotypic and genotypic coefficient and variability were high for green pods per plant, number of pods per plant, plant height and 100 seed weight; moderate for number of branches per plant, number of inflorescence per plant, number of seeds per pod, pod length, pod width, pod weight and low values were observed for days to first flowering, days to 50 per cent flowering and days to pod maturity. Heritability estimates in broad sense were very high for pod length, green pod weight per plant, pod length, pod width, number of pods per plant, plant height, number of branches per plant, number of inflorescence per plant, days to first flowering, days to 50 per cent flowering, days to pod maturity, 100seed weight, pod weight and number seeds per pod. The genetic advance as per cent mean was high for green pod yield, plant height, number of pods per plant, number of inflorescence per plant and 100 seed weight number of branches per plant, pod length, pod width and number of seeds per pod have showed moderate genetic advance over mean. While other characters had low genetic advance over mean values. The path coefficient analysis revealed highest positive direct effect of number of pods per plant and pod length. The indirect contribution of component characters on green pod yield was high through number of pods per plant, number of branches per plant, number of inflorescence per plant and 100 seed weight. In D2 analysis 11 clusters were formed, out of which cluster I with 17 genotypes was the biggest followed by cluster II consisting of 12 entries and cluster III and V had 5, 2 and 4 entries respectively, cluster VI and X had 2 entries and all the other remaining cluster were solitary. The intra-cluster distance was maximum for cluster III. The highest inter duster distance was recorded between cluster V and VI while the cluster VII and VIII were the least divergent. The investigation revealed that the cluster V (Arka Anoop, AFAI0, PNK 30, PNK34) and VI ((AKx220) 12-3 IPS1) possess the potential genotypes that can be chosen for hybridization programme to develop varieties with high green pod yield.