A Second Source of Cytoplasmic Male Sterility in Maize Induced by the Nuclear Gene Iojap

A new source of cytoplasmic male sterility (cms) was found in a plant derived from the F2 progeny of fertile, normal cytoplasm plants of the inbred W 182BN pollinated with a genetic stock carrying the recessive nuclear gene, iojap. This male sterile line was maintained by pollinating with W 182BN, which maintains all known sources of cms. Progeny from the new male sterile were found to exhibit stable male sterility under field conditions in two environments. Fertility restoration reactions, restriction endonuclease digest patterns, and sensitivity to Helminthosporium maydis race T toxin indicated that the new cytoplasm fits into the cms T group. Data comparing fertility restoration reactions and mtDNA restriction endonuclease digest patterns of this new source with an iojap-derived cms S source are presented.