1Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore-641003
2Division of Field Crop Improvement and Protection, ICAR - Central Island Agricultural Research Institute, Port Blair-744101
3Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi-110012
4Department of Vegetable Crops, Tamil Nadu Agricultural University, Coimbatore-641003
5Department of Nematology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore-641003
*E-mail: srinatrakamutha@yahoo.co.in
Online published on 8 May, 2019.
Eight isolates of Ralstonia solanacearum collected from tomato and brinjal crops in the bacterial wilt affected areas of Tamil Nadu were characterized for their morphological, biochemical and pathogenicity traits. All isolates produced typical whitish fluidal colonies with pinkish center on CPG agar and did not produce green fluorescence on KB medium. Upon pathogenicity test, all the isolates infected tomato seedlings and days to wilting ranged from 4.3 to 7.3 days. Genetic identity of eight isolates was confirmed as R. solanacearum through pathogen specific PCR amplification. In vitro sensitivity assay revealed that R. solanacearum isolates could not grow on bleaching powder and NaCl amended media at above 1% concentrations. Agar diffusion test for the selection of potential antagonists revealed that 12 out of 50 rhizosphere bacilli were effective against virulent R. solanacearum isolate under in vitro conditions. The results are expected to be useful for devising effective disease management strategies against this pathogen in Tamil Nadu state.
Antagonistic rhizosphere bacilli, Ralstonia solanacearum, bacterial wilt, Tamil Nadu
