|SMITH, CODY - University Of Florida|
|FREEMAN, JOSH - University Of Florida|
|Wechter, William - Pat|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/20/2017
Publication Date: N/A
Technical Abstract: Fusarium wilt (caused by the fungus Fusarium oxysporum f.sp. niveum) has been a consistent problem in the production of cucurbit species like watermelon. One method for combating this pathogen in the field is to graft a susceptible, high yielding scion on to a Fusarium wilt resistant rootstock. A concerning issue with rootstocks resistant to Fusarium wilt is that they have not been tested for their susceptibility to plant pathogenic nematodes, more specifically the southern root-knot nematode (Meloidogyne incognita) and the reniform nematode (Rotylenchulus reniformis). Preliminary findings have demonstrated that many of these Fusarium resistant rootstocks are highly susceptible to root-knot nematode and other plant parasitic nematodes. Research was conducted during the spring and fall of 2015 as well as the spring and fall of 2016 to evaluate the resistance to root-knot nematode in rootstocks with known resistance to Fusarium wilt. Seven rootstocks were evaluated in the spring and six in the fall of 2015. Ten rootstocks were evaluated in the spring of 2016 and twelve in the fall of 2016. A highly susceptible interspecific hybrid (Cucurbita maxima x C. moschata) rootstock ‘Carnivor’ was included as a positive control in both years and seasons. In 2016, RGI was evaluated at 30, 60 and 90 DAP in addition to root and soil samples at 90 days after planting (DAP). Results from 2015 correlated with 2016 and demonstrated that several Citrullus lanatus var. citroides rootstocks (‘Bulldog’, USVL 246, USVL 252, USVL 360) being developed by USDA-ARS Vegetable Lab and ‘SP-6’ a pollinizer from Syngenta exhibited significantly greater resistance plant parasitic nematodes when compared to the susceptible control. When compared to the control, these rootstocks also had less M. incognita and R. reniformis per gram of root. These findings indicate that rootstocks may soon be available to manage both Fusarium wilt of and root-knot nematode in grafted cucurbit production system.