Research Information System
Cururbitaceae 2010, United States Of America, 1 - 04 October 2010, vol.1, no.1, pp.259-262
Watermelons are attacked and severely damaged by Verticillium dahliae. One of the most effective means for controlling soil-borne diseases is the production of cops by grafting onto resistant rootstocks. In the first experiments, 16 isolates of V. dahliae belonging to vegetative compatibility groups (VCGs) 1A, 2A, 2B and 4B showed no or very little pathogenicity on the landraces of C. maxima, C. moschata and L. siceraria. In the second experiments, five commercial rootstock cultivars [‘Macis’ ‘Argentaria’ (Lagenaria siceraria hybrids) ‘Ferro’, ‘Kazako’ and ‘Kublai’ (Cucurbita maxima x C. moschata)] and seven landraces of bottle gourd collected from the Mediterrenean region of Turkey were used as rootstocks. Crimson Tide watermelon cultivar was used as a scion. A virulent V. dahliae isolate from watermelon was inoculated to the grafted plants and ungrafted control plants (watermelon plants and gourd rootstocks). Verticillium wilt symptoms were observed 15-20 days after inoculation on both ungrafted watermelon plants and grafted plants with varying disease severity values. However, no visual symptom was observed on ungrafted gourd rootstocks. Re-isolations were done from all plants in the pathogenicity tests. The recovery frequencies of V. dahliae from grafted and ungrafted watermelon plants and rootstocks were recorded. The results suggested that all disease evaluations should be carried out on grafted watermelon plants in order to study V. dahliae reistance of rootstocks.