Selecting Parental Lines among Cultivated and Wild S pecies of Okra for Hybridization Aiming at YVMV Disease Resis tance

Abstract

Yellow Vein Mosaic Virus (YVMV) disease of okra is the single major production constraint and causes yield loss to the tune of 50- 90% in India. Hence continuous search for new sources of resistance and development of be tter varieties/hybrids with durable level of resistance should receive attention of bre eder. An attempt was made to screen twenty-six advanced lines/varieties of okra in one of the hot spots of YVMV disease in eastern India to identify suitable parents for resi stant breeding program. The study revealed high magnitude of genetic variability and high degree of transmission of majority of the growth, earliness, and yield compon ent traits under consideration. Based on the degree of divergence, the genotypes were gro uped into four clusters. Hybridization between genotypes belonging to Cluster II and Cluster III c ould combine early maturity, higher yield, and having high tolerance against YVM V disease. Dendrogram among the genotypes also revealed high diversity along with s trong inter cluster relationships. Based on averages and principal component analysis, six g enotypes viz ., BCO-1, A. caillei , A. manihot , 11/RES-6, VNR Green and 12/RES-2 appeared very pr omising candidates for future use in resistant breeding programs. Keywords: Genetic diversity, PCA analysis, Resistant breeding , Tolerance against YVMV.