Vegetos

Abstract

The present investigation was aimed to estimate the extent of genetic variability and to characterize 76 genotypes of pumpkin for yield and its attributing traits through principal component and cluster analysis. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications of each genotype during spring-summer season of the year 2014. The analysis of variance indicated significant variations among the genotypes for all the traits studied. The phenotypic and genotypic coefficients of variability were found high for plant weight (37.64 and 33.94%), mature fruit weight (37.28 and 36.39%) and fruit yield per hectare (33.31 and 31.31%), respectively. Further, high heritability estimates coupled with high genetic gain were observed for mature fruit weight, plant weight and fruit yield per hectare, which indicated that these traits are under additive gene effects and are more reliable for effective selection. The results of principal component analysis (PCA) indicated that first three components having Eigen values greater than one explained 65.65 per cent of total variations. Further, loading of different traits based on first two principal components indicates that days to opening of first male and female flower, node number of first male and female flower and days to immature fruit at marketable maturity stage are the main components of divergence between 76 genotypes of pumpkin. Hence, main emphasis should be given on these traits for yield improvement in pumpkin. Dendrogram constructed using single linkage Euclidean distance based on 10 morphological traits divided the 76 genotypes of pumpkin into seven distinct groups. The genotype DPU-42 was found most distinct from rest of the genotypes, while DPU-18 and DPU-27 were most similar among themselves. On the basis of observed clustering pattern in different genotypes, diverse parents belonging to different clusters can be selected for exploitation of heterosis breeding in pumpkin.