There exist only GG genotype in lean-type Large White and Landrace pigs. Duroc and native breeds (ningxiang and daweizhi) have three genotypes (AA AG GG), allele A frequencies of three breeds is 0.3979,0.7272,0.7295 respectively.

• 在杜洛克猪和地方品种(大围子猪和宁乡猪)中，存在AA基因型、AG基因型和GG基因型，等位基因A的频率分别为0.；3979、0