Abstract: Subgynoecious watermelon (Citru llus lanatus) line BG1 and normal sexual line ZY10 were crossed in this study. Female flower p roportion within 30 nodes for each plant was counted. Six populations ( P₁ , P₂ , F₁ , F₂ , BC₁ P₁ and BC₁ P₂ ) derived from this crosswere used to investigate the inheritance of subgynoecious by using the mixed major gene and poly-gene inheritance models. The results indicated that subgynoecious in this combination was controlled by two major genes with additive-dominance-epitasis gene effects
(B-1 model). While the major genes showed recessive expression, the additive effects of the 1 st and 2nd major genes were 33.46 and 5.17, respectively and their dominance effects were - 20.56 and - 11.20, respectively. Heritabilities of major genes in the BC₁ P₁ , BC₁ P₂ and F₂ populations were estimated as93.75% , 60.91% and 94.32%, respectively.

Key words: watermelon, subgynoecious, genetic analysis