Abstract
Male sterile mutants were induced by gamma irradiation in a diploid monogerm strain with N cytoplasm. Cytoplasmic inheritance was demonstrated in the induced male sterility. A single gene which h as a linkage relation with the gene m for the monogerm character, was responsible for the pollen restoration interacting with a new cytoplasmic factor. The cytological evidence indicated that the abnormality of anther tapeturn and microspores are in accordance with those in the cytoplasmic-genetic male sterility. It is possible that the induced male sterility originated from a mutation of the cytoplasmic factor after gamma irradiation.