Pathogenic Variability of Ralstonia solanacearum Causing Bacterial Wilt of Brinjal in Red and Lateritic Agro-climatic Zone of West Bengal
Abstract
Brinjal (Solanum melongena L.) is one of the most economically important solanaceous vegetables in India. The crop is suffering severely from bacterial wilt disease caused by Ralstonia solanacearum (Smith) Yabuuchi et al. that considerably limits its cultivation and production. Symptoms of the disease in brinjal appeared usually at flowering and fruiting stage of the crop growth. Drooping of the top most leaves followed by total or partial wilting was common. Infected plants showed vascular browning. Variability of the pathogen was recorded in respect to their aggressiveness and pathogenicity. Presence of more aggressive isolates in Bahadurpur (BAHRS5) and Halsidanga (HALRS6) and moderately aggressive isolates in Mukundapur (MUKRS2) and Gorabari (GORRS3) may be due to higher cropping intensity of solanaceous vegetables. Stem incision appeared superior to the stem injection method for pathogenicity test through cross inoculation studies. No host specificity was observed among the isolates of the pathogen from brinjal, tomato and Amaranthus spinosus revealed race 1 while host specificity was recorded in case of the pathogen isolated from Costus speciosus revealed race 4.
Bacterial wilt of brinjal is a threatening disease causing havoc loss of the crop.
Symptoms usually appeared at flowering and fruiting stages of the crop growth.
Isolates of the pathogen showed variability in respect to aggressiveness and pathogenicity.
The pathogen isolated from diverse sources and climatic situations did not show any variation in respect to physico-biochemical traits.
Isolate of the pathogen from Costus speciosus showed host specificity.
Keywords
Aggressiveness study, bacterial wilt, brinjal, cross inoculation, host specificity, pathogenicity, Ralstonia solanacearum, variability
