Studies on genetic divergence in bitter gourd (Momordica charantia L.)

Abstract

The experiment was conducted during the spring-summer season, 2017 in Eastern Uttar Pradesh, to evaluate the nature and magnitude of genetic divergence among the thirty genotypes of bitter gourd were carried out by using Mahalanobis D2 statistics. Thirty genotypes were grouped into 6 different non-overlapping clusters. Cluster III had the highest number of genotypes (8) followed by cluster II (7), cluster V (6), cluster IV (5) and cluster I, VI (2) whereas cluster I and VI had only two genotypes. The highest intra-cluster distance was observed for cluster VI recorded for (123.61) followed by cluster V (91.85), cluster I (69.08) and cluster II (62.75), cluster IV (47.92). The maximum inter-cluster distance observed between cluster III to cluster VI (231.577), which suggested that members of these two clusters are genetically very diverse to each other. The inter-cluster values between cluster II to cluster VI (222.683), cluster II to cluster V (220.722), cluster V to cluster VI (205.629), cluster I to cluster VI (187.421), cluster III to cluster V (148.762), cluster II to cluster IV (134.414) and cluster I to cluster V (133.185) were very high. The minimum inter-cluster distance was recorded in cluster I to IV (91.813) and cluster IV to V (104.356). Highest inter-cluster distances recorded indicated between two cluster pairs greater genetic divergence between the genotypes of those clusters, whereas, lower inter-cluster values between the clusters suggested that the genotypes of the clusters were not much genetically diverse from each other. The intra-cluster means for twelve characters in bitter gourd. Among 12 characters studied, average fruit weight (g) contributed maximum (27.82%) towards genetic divergence followed by fruit yield/plant (18.39%) and fruit length (12.64%) in bitter gourd. Ranking of genotypes based on intra-cluster mean performance for these characters which are major contributors of genetic diversity revealed its usefulness in selecting parents for heterosis breeding.