Male sterility conditioned by cytoplasm was first reported in wheat by KIHARA (1951, Cytologia 16: 177) who transferred the chromosome complement of common wheat (2n=42) into the cytoplasm of Aegilops caudata (2n=14) by successive backcrossing. FUKASAWA (1953, Cytologia 18: 167) similarly transferred cytoplasmic male sterility from Aegilops ovata (2n=28) into emmer and durum wheats (2n=28) and later (1958, W.I.S. 7: 21) observed that a variety of the wild emmer, Kotschyanum (2n=28), when used as the pollen parent, restored fertility of the male sterile lines. This source of male sterility was later transferred to some commercial common wheat varieties by workers in Kansas State University, U.S.A. However, the common wheat varieties used thus far as pollinators of these male-sterile types have produced only male-sterile hybrids.

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