Abstract:Random amplified polymorphic DNA(RAPD) was employed to detect a molecular marker linked to Fusarium wilt resistant gene in the wild watermelon ( Citrullus lanatus (Thunb.) Mansfeld var. citroides ) germplasm P1296341. The resistance to race 1 Fusarium wilt of PI296341 was controlled by one dominant gene. A RAPD marker OPPO1/700 was proved to be linked to the resistant gene. The genetic distance is 3.0 cM (centimorgan). This work has provided a solid basis for molecular marker-assisted selection (MAS) for disease resistance, and made location and cloning of disease resistant genes possible.