Ralstonia pseudosolanacearum Infecting Pumpkin (Cucurbita Maxima) and its Pathogenicity on Cucurbitaceae Family

Ralstonia solanacearum species complex (RSSC) is a devastating phytopathogen with wide host range in many economically important crops all over the world. Bacterial wilt on a pumpkin (Cucurbita maxima) caused by Ralstonia pseudosolanacearum was observed in Chiang Rai, Thailand. The symptoms that appeared were wilting, drooping of half leaves, and oozing from crosscut stems of these diseased plants. The R. pseudosolanacearum-specific 280 bp amplicon, and sequevar 17 confirmed by sequencing the hrpB gene. The hrpB gene have been shown to be key determinants for pathogenicity in the phytopathogenic bacterial wilt. The susceptibility of different Cucurbitaceae species to bacterial wilt were tested. Members of the Cucurbita, Cucumis, Citrullus, Momordica, and Lagenaria genera were susceptible to bacterial wilt, with disease incidence ranging from 30% to 100%. The susceptibility of different Cucurbitaceae species to bacterial wilt, which can provide valuable information for the plant breeding programs to the improvement of pathogen-targeted.