Abstract: Th e rootstock potential of 21 bottle gourds (Lagenaria siceraria) collected from the Mediterranean region (Turkey) was investigated for watermelon with regard to plant growth, yield, and fruit quality. Th e Crimson Tide watermelon cultivar was used as a scion and 2 commercial rootstocks (L. siceraria) were also used for comparison. In greenhouse conditions, the survival rate of graft ed plants and the eff ect of rootstocks on plant growth were determined. Th e graft ed plants were planted under low tunnels in early spring and the eff ects of the rootstocks on early yield, total yield, and fruit quality were evaluated. Th e survival rates of the graft ed plants varied from 83% to 100%. Survival rates of those with commercial rootstocks and local rootstocks were similar. Plants graft ed onto 20-02, 31-09, 31-43, 35-01, and 46-03 were more vigorous than ungraft ed control plants. Compared to the control plants, graft ed plants had 37% to 80% higher plant dry weight. All of the graft ed plants except CT/Macis produced a higher yield than the control plants. Th e plants graft ed onto 6 of the local rootstocks had signifi cantly greater total yields than those graft ed onto the commercial rootstocks. Among the local bottle gourd landraces tested, the 01-16, 07-45, 20-06, 31-09, 31-15, and 46-03 were found to be promising genotypes with regard to total yield. Early yield was not signifi cantly aff ected by rootstock. Th e quality parameters of the fruits harvested from the graft ed and control plants were found to be similar except for a limited number of graft combinations. It was concluded that germplasm from Turkish bottle gourds has a high rootstock potential for watermelon with regard to the investigated parameters.