Characterization and genetic divergence analysis in pointed gourd (Trichosanthes dioica Roxb.) clones. (222)
Keywords:Pointed gourd, Genetic divergence, Morpho-reproductive traits, Multivariate analysis, Cluster pattern
AbstractThe characterization and genetic divergence of 68 female clones of pointed gourd (Trichosanthes dioica Roxb.) were studied by using morphological and reproductive traits. The clones fell under four basic groups according to fruit shape and size. Significance of group means for 17 characters was tested. Clones bearing small fruits of different size (Group 1) was most diverse from the clones having near cylindrical fruits (Group 4) and markedly divergent from the clones with spindle-shaped fruits (Group 2) and oval-shaped fruits (Group 3). However, divergence of Groups 2 and 3 and Groups 3 and 4 were not distinct, and Groups 2 and 4 could not be distinguished. The data on 19 characters were subjected to multivariate analysis to obtain D2 values between the clones. Based on genetic distance, the clones were grouped in 16 clusters. In most of the cases, fruit shape and size did not influence clustering pattern, however, in some cases clones having the same fruit shape and size clustered together. Medium and consistent inter-cluster distance indicated closer genetic relationship among the clones. Indian distribution of this cucurbitaceous vegetable crop primarily in eastern and north-eastern states and asexual propagation of the heterozygous clones may be the cause of such genetic closeness of the clones. However, fruit characters and yield per plant contributed significantly towards clonal diversity.