A Recessive Gene for Male Sterility in Hexaploid Wheat 1

A recessive gene for male sterility in wheat ( Triticum nestivum L. em Thell.) was transferred to ‘Chancellor’ from a heterogeneous stock commonly known as Pugsley Male‐sterile Wheat. Complete male sterility occurred at a relatively low frequency in the original stock. After the initial cross and four backcrosses to Chancellor, accompanied by rigid selection for single gene segregation for male sterility, some populations were obtained which segregated according to a ratio of three fertile plants to one malesterile plant. Intermediate types (partial sterility) did not occur in the most advanced and highly selected populations when grown in the greenhouse. Transmission of the recessive allele for male sterility by the male gamete occurred at the same frequency as by the Ieniale gamete. Number of gametes tested, however, was small. Female fertility was normal. Pollen produced by fertile plants was normal ‐ whether those plants were homozygous for the dominant allele or heterozygous. Pollen produced by male‐sterile plants was smaller than normal, irregular in shape, and did not stain in iodine solution. Fertile plants with the dominant allele ( homozygous or heterozygous ) did not restore fertility to Triticum titmpheevi ‐derived cytoplasmic male‐sterility.