Further discovery of alien cytoplasms inducing haploids and twins in common wheat.

In addition to the already known Aegilops caudata cytoplasm, the cytoplasms of five Aegilops species, all belonging to the section Polyeides, were found to induce haploids (11-56%) and twins (0.5-15%) in a common wheat, Salmon, at high frequencies. The great majority of the twin pairs were of the diplo-haplo type. The origin of both the haploids and twins was ascribed to the induction of parthenogenesis in Salmon by the alien cytoplasm. Pollen parents produced some differences in haploid frequency. The distribution of the parthenogenesis-inducing cytoplasms in the genus Aegilops is discussed in relation to the phylogeny of the donor species.