The toxicity of gossypol to animals apparently is due primarily to the (-)-enantiomer. Thus, converting gossypol to its (+)-enantiomer should detoxify it. Eight accessions of moco cottons (Gossypium hirsutum var. marie galante) with high (+)-gossypol were crossed with modern cultivars then (+)-gossypol contents of flower petals and seed were determined in the F₁, BC₁F₁, BC₂F₁, BC₃F₁, BC₃S₁ and BC₃S₂ generations. The results showed that elevated (+)-gossypol concentrations were due to two major genes designated G₁+ and G₂+. The gene G₂+ was dominant and expressed mostly in flower petals, whereas G₁+ was mostly recessive and expressed equally in flower petals and seed. Plants with homozygous G₁+ contained about 90% (+)-gossypol in seed. Adding G₂+ in the homozygous condition, further increased the percentage to about 95%. A homozygous stock (BC₃S₂) with 95% (+)-gossypol has been developed and will be released to produce seed for animal feeding experiments.