Abstract
The frequencies of haploids in nucleus-substitution lines of T. vulgare var. erythrospermum and Taylor's Triticale having the cytoplasm of Aegilops caudata, were investigated and compared with those found in the ordinary strains.
The haploid frequency of the former was 1.7%, while it amounted to 53% in the latter. No haploids were found in the respective controls. The differences are significant in both cases.
This result indicates that an alien cytoplasm will increase the tendency of a species to develop parthenogenetically haploid embryos. The difference between T. vulgare var. erythrospermum and Taylor's Triticale indicates that different genotypes respond differently to the same alien cytoplasm.
The use of an alien cytoplasm provides a new means for artificial production of haploids.
