A.N(msms)B.S(MSms)C.S(msms)D.N(MSMS)
A.S1S1×S1S2B.S1S1×S1S1C.S1S2×S3S4D.S1S2×S1S3
A.雄性不育系B.自交不親和系C.遲配系D.雌性系