There are four types in chicken combs:pea comb,rose comb,single comb and walnut comb. The comb morphology of chickens is determined by the rose comb gene(R)and the pea comb gene(P),but they are on different chromosomes.
家鸡冠型主要有单冠、豆冠、玫瑰冠、胡桃冠等4种类型,它们由2对基因控制,即玫瑰冠基因R和豆冠基因P,这2个基因位于不同的染色体上。
参考来源 - 家鸡冠型与生产性能及冠型基因遗传规律的研究进展