Gene recombination for resistance to bacterial wilt and yield components in brinjal

Abstract

Brinjal (solanum melongena) is an important vegetable crop of India. It's cultivation is threatened by the bacterial wilt disease caused by Psuedomonas solanacaarum in many places. The cultivation of resistant high yielding varieties is the only effective method of controlling the disease. But the assocation of bacterial wilt resistance with poor yield has obstructed conventional breeding approaches aimed at, deriving useful' recombinations. The present study explores the possibility of developing a resistant high yielding variety by selection in the segregating generation of inter varietal crosses. The plants of the crosses between three resistant varieties, SM-6, SMI-10 and Pusa purple cluster with the susceptable variety Pusa purple long as the male parent, were selfed. The seeds were sown and seedlings raised under two environments, (i) in the field where there is chance for natural incidence of bacterial wilt. (2) in pots with sterilised soil under healthy condition, in both the experiments, mean, variance and correlation coefficients of yield and yield contributing characters were estimated. Study of f2 variability has revealed that, the characters plant height number of fruits per plant and weight of fruit are governed by polygenes. The characters, number of days to first harvest, number of days to final harvest and weight of fruits per plant were governed by major genes with late bearing and low yield dominant over early bearing and high yield respectively. Comparison of means and variances under healthy and infected condition gave an insight into the influence of selection on the expression of these characters. Natural selection for resistance eliminated the early bearers and high yielders leading to directional selection in favour of late bearers and poor yieldes.