Submitted to: Methyl Bromide Alternatives and Emissions Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 8, 2006
Publication Date: November 15, 2006
Citation: Thies, J.A., Levi, A. 2006. Resistance of Watermelon Germplasm to Root-Knot Nematodes. Methyl Bromide Alternatives and Emissions Research Conference Proceedings. pp. 20-1, 20-2. Technical Abstract: Root-knot nematodes (Meloidogyne spp.) seriously impact yields of watermelon throughout the southern U.S. Pre-plant fumigation of soil with methyl bromide is the primary method for controlling these pests in watermelon. Although host resistance would be one of the most economical and environmentally friendly alternatives to methyl bromide for managing root-knot nematodes, no root-knot nematode resistant watermelon cultivars are available. We evaluated all Plant Introductions (PI) of Citrullus colocynthis (21 PI) and Citrullus lanatus var. citroides (88 PI), and approximately 10% of Citrullus lanatus var. lanatus entries (155 PI) from the U.S. PI watermelon collection for resistance to M. arenaria race 1 in greenhouse tests. Twenty C. lanatus var. citroides were moderately resistant to M. arenaria race 1. In further tests, we evaluated the PI that were most resistant to M. arenaria race 1 for their reactions to M. incognita race 3 and M. arenaria race 2. Twenty-three C. lanatus var. citroides accessions exhibited low to moderate resistance to M. incognita race 3 and M. arenaria race 2. We observed significant genetic variability within C. lanatus var. citroides for reaction to M. incognita and M. arenaria races 1 and 2. These C. lanatus var. citroides accessions may be useful sources of resistance for developing root-knot nematode resistant watermelon cultivars.