Genetic Male Sterility in Barley. I. Nonallelic Genes1

Sixteen of the 19 genetic male sterile mutants in barley, Hordeum vulgate L., which have been given permanent numbers are shown to be nonallelic. Three mutants remain to be stndied. All 19 genes behave as single recessives, and except for mslS, ms9, and mslT, show completely sterile heads on all tillers. Msl5 has highly sterile early tillers and semisterile late tillers at Bozeman; ms9 sets 10% selfed seed at Bozeman and 24% at Tucson when male sterile heads are bagged; and msl7 set 1% selfed seed at Bozeman and 3% selfed seed at Tucson. Anther development in the homozygous male steriles ranges from almost normal size in ms6 and msl6 to rudimencary in ms3 and resT. No female sterility has been observed in these male sterile mutants.