Breeding for resistance to distortion mosaic virus in bittergourd (momordica charantia L.)

Abstract

The investigation on "Breeding for resistance to distortion mosaic virus in bittergourd (Momordica charantia L.)" was conducted at Department of Plant Breeding and Genetics, College of Horticulture, Kerala Agricultural University, Trichur, during 2000 to 2002. This study aims to identify the source(s) of resistance against bittergourd distortion mosaic virus (BDMV) and scope of incorporating these genes to high yielding varieties. This project also envisages the extent of genetic diversity, character association, combining ability, heterosis and gene action of quantitative traits in bittergourd. Out of 86 genotypes screened against BDMV, mne genotypes from Northern and Central parts of Kerala were identified as resistant viz., IC 68296, IC 68335, IC 68263B, IC 68275, IC 68250A, IC 85620, IC 68285, IC 68312 and IC 68272. Clustering pattern of genotypes did not follow geographical origin, but they were grouped based on BDMV reaction. The parent IC 68275 was identified as the best general combiner for BDMV resistance and fruit yield per plant. The other resistant parents viz., IC 68335 and IC 68263B were resulted in low fruit yield per plant can be used to diversify the source of resistance in hybridisation programme. Hybrids le 68250A x Preethi and VKV 134 x IC 68342B can be exploited commercially for high fruit yield in seasons of less incidence of distortion mosaic. The resistant hybrids IC 68263B x IC 68275 and IC 68275 x IC 68342B having moderately high yield can be utilized commercially during seasons or areas of high incidence of distortion mosaic. The resistant genes for this disease are freely transferable to high yielding varieties. Selection based on number of fruits, fruit weight and resistance to BDMV can be used for improving fruit yield. BDMV resistance is controlled by polygenes and their expressions are highly influenced by environment. The higher incidence of distortion mosaic was noticed during summer. Scope of exploitation of heterosis with resistance to distortion mosaic is suggested for further studies for confirmation and utilization.