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ARS Home » Southeast Area » Charleston, South Carolina » Vegetable Research » Research » Publications at this Location » Publication #353289

Research Project: Biological, Genetic and Genomic Based Disease Management for Vegetable Crops

Location: Vegetable Research

Title: QTL mapping identifies novel source of resistance to Fusarium wilt race 1 in Citrullus amarus

Author
item Branham, Sandra
item Levi, Amnon
item Wechter, William - Pat

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2018
Publication Date: 3/1/2019
Citation: Branham, S.E., Levi, A., Wechter, W.P. 2019. QTL mapping identifies novel source of resistance to Fusarium wilt race 1 in Citrullus amarus. Plant Disease 103:984-989. https://doi.org/353289.

Interpretive Summary: Fusarium wilt race 1 is a major disease of watermelon in the United States and throughout the world. While Fusarium wilt race 1 resistance has been incorporated into several watermelon cultivars, identification of additional genetic sources of resistance is crucial if a durable and sustainable level of resistance is to be continued over the years. We conducted a genetic mapping study and identified a novel genetic source of resistance to Fon race 1 in a segregating population derived from a Fon race 1 resistant and susceptible wild species of watermelon. A molecular marker associated with resistance to Fon race 1 was identified on chromosome 9 of USVL246-FR2. This discovery provides a novel genetic source of resistance to Fusarium wilt in watermelon, and thus an additional host-resistance option for watermelon breeders to further the effort to mitigate this serious phytopathogen.

Technical Abstract: Fusarium wilt race 1, caused by the soil-borne fungus Fusarium oxysporum Schlechtend.: Fr. f. sp. niveum (E.F. Sm.) W.C. Snyder & H.N. Hans (Fon), is a major disease of watermelon in the United States and throughout the world. While Fusarium wilt race 1 resistance has been incorporated into several watermelon cultivars, identification of additional genetic sources of resistance is crucial if a durable and sustainable level of resistance is to be continued over the years. We conducted a genetic mapping study to identify quantitative trait loci (QTL) associated with resistance to Fon race 1 in a segregating F2:3 population (N=170) of C. amarus derived from the Fon race 1 resistant and susceptible parents USVL246-FR2 and USVL114, respectively. A major QTL (qFon1-9) associated with resistance to Fon race 1 was identified on chromosome 9 of USVL246-FR2. This discovery provides a novel genetic source of resistance to Fusarium wilt in watermelon, and thus an additional host-resistance option for watermelon breeders to further the effort to mitigate this serious phytopathogen.