ARS | Publication request: Grafting – a tool for managing root-knot nematodes in watermelon?

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 18, 2008
Publication Date: June 26, 2008
Citation: Thies, J.A., Ariss, J., Kousik, C.S., Hassell, R. 2008. Grafting – a tool for managing root-knot nematodes in watermelon?. Phytopathology. 98:S156.

Technical Abstract: Wild watermelon (Citrullus lanatus var. citroides) germplasm, bottlegourd (Lagenaria siceraria) cultivars, hybrid squash (Cucurbita moschata x C. maxima), and commercial wild watermelon (C. lanatus) were evaluated as rootstocks for cultivated watermelon (C. lanatus var. lanatus) in a field infested with the southern root-knot nematode (RKN, Meloidogyne incognita) in Charleston, SC. ‘Fiesta’, a diploid watermelon, was grafted on the rootstocks and transplanted to the field on 30 July 2007. On 8 Oct 2007, roots were lifted and evaluated for percentage of roots galled by RKN. Root galling of bottlegourd and hybrid squash rootstocks was severe (80 to 96% and 98%, respectively), and root galling was moderately severe (40%) for non-grafted ‘Fiesta’ watermelon. Rootstocks of wild watermelon germplasm derived from C. lanatus var. citroides had 11 to 34% galling and the commercial wild watermelon rootstock had 24% galling. Citrullus lanatus var. citroides germplasm lines and the commercial wild watermelon rootstock had significantly less (P less than 0.05) root galling than ‘Fiesta’, the squash hybrid rootstock, and bottlegourd rootstocks. Germplasm lines derived from C. lanatus var. citroides may provide useful sources of resistance for development of RKN resistant rootstocks for watermelon.