Genetic Variability, Heritability and Interrelationships in Pole-Type French Bean (Phaseolus vulgaris L.)

Abstract

French bean (Phaseolus vulgaris L.), especially pole-type, is one of the most widely cultivated and popular vegetables in Mizoram due to its wide adaptability, round the year availability and better tender pod quality (slender, fleshy, soft with fewer parchment strings). However, there is little information on genetic variability, heritability and interrelationships of economic traits in pole-type French bean. Therefore, sixty-five genotypes (Indian and exotic collections) were evaluated. A significant genotypic mean square for the traits studied indicated sufficient variation among genotypes. Ten genotypes showed better pod yield potential (>13.5 t/ha) which were collected from Mizoram (IC593590, IC593591, IC593594, MZFB-48, IC595238, MZFB-32, IC593593, MZFB-29, MZFB-51 and MZFB-47). Vine length, inter-nodal length, number of nodules/plant, nodule fresh weight, tender pod fresh weight, 100 seeds weight and pod yield showed additive gene action, i.e., high heritability (>80 %) and high genetic advance (>40 %) which could be improved by selection and hybridization. While non-additive genes were responsible for days to 50 % maturity (earliness) that could be exploited through heterosis breeding. However, both additive and non-additive genes are accountable for pod length, number of seeds/pod and number of pods/plant and could be improved through reciprocal recurrent selection. Pod weight and number of pods/plant could be reliable tools for selection indices to identify the productive genotypes and to realize maximum genetic gain. Viewing the genetic potential, it is convincing to include genotypes from Mizoram regions in the genetic enhancement as well as varietal improvement of French bean for tender pod yield.