Bacterial Wilt Caused by Ralstonia solanacearum: A Potential Threat to Brinjal Cultivated in Sikkim, India

Bacterial wilt caused by Rolstonia solanacearum is one of the devastating soil-borne disease that leads to death of numerous crops worldwide. In this study bacterial wilt of brinjal (Solanum melongena L.) those are cultivated in Sikkim, India was identified based on the wilting symptoms of plants and ooze test. Pathogen was isolated following incubated stem segments of the wilted plants on the Casmino acid, Peptone, Glucose Agar (CPGA) medium. Morphological, biochemical and microscopic observations confirmed the isolates as R. solanacearum, race 1, biovar -3, and phylotypes I (Asiaticum). Molecular identification by using the R. solanacearum species-specific (RSSS) primers (759R and 760F) consisting small subunit region of rRNA gene with 282 bp amplicon confirmed the pathogen as R. solanacearum. The 16S rRNA sequence data was subjected to BLASTn in the NCBI database showed 98% similarity to R. solanacearum with accession number OM044161, and OM666560. To the best of our knowledge this is the first report of the occurrence of R. solanacearum pathogen causing bacterial wilt in brinjal cultivated in organic Sikkim.