Genetic divergence of parental lines and their F1 progeny in bottle gourd [Lagenaria siceraria (Mol.) Standl.]

Abstract

The experiment was conducted in Randomized Complete Block Design with three replications. In present investigation 54 genotypes (10 lines + 4 testers + 40 F1’s) of bottle gourd were grouped into 8 distinct non over lapping clusters. This indicated presence of considerable diversity in the genotypes. The clusters contained genotypes of hetero genous origin. The genotypes of same geographic region were also found to be grouped together in the same clusters. Thus, there was no consistent relationship between genetic divergence and geographical distribution. Cluster I had maximum number of genotypes (23) followed by clusters VI (12), cluster III (10) and cluster VIII (5) while, rest of the four clusters contains mono genotypes. The intra cluster D2 values ranged from 0.00 (cluster II, IV, V and VII) to 1088.31 (cluster VIII) while, the inter cluster diversity ranged from 142.37 (cluster IV and cluster IV) to 2849.61 (cluster IV and cluster VIII). The inter cluster distances between cluster IV to cluster VII (2849.61) and cluster V to cluster VIII (2838.87) were also very high. The higher inter cluster distance indicated greater genetic divergences between the genotypes of those clusters, while lower inter cluster values between the clusters suggested that the genotype of the cluster were not much genetically diverse from each other. Cluster III showed the maximum means values for vine length at last picking stage, number of primary branches per plant, fruit circumference, fruit weight, reducing sugar total sugars whereas, Cluster V showed high mean values for days to first fruit harvest, fruit circumference, fruit weight, fruit yield per plant. The results suggested that crosses between selected lines/F1’s from widely separated clusters are most likely to give desirable recombinants/hybrids.