Effect of parental genotypes, cross direction and temperature on the crossability of bread wheat with triticale and on the viability of f1 embryos

Summary The relevant importance of parental crossability genes, cross direction and ambient temperature in bread wheat/triticale hybridisation were evaluated. Crossability genes were found to be useful but not essential. The use of triticale as the female gave significantly fewer embryos, but these embryos were symmetrically shaped and normal. The use of bread wheat as the female gave a seed set generally above 30% and sometimes as high as 86%, but embryo necrosis resulted in rapid death in vivo or non‐regeneration in vitro. By keeping the plants at 14 °C during pollination and in vivo embryo growth, necrosis was partly eliminated, so that in one case the rate of plant production in crossing bread wheat/triticale became about as good as for the triticale/bread wheat cross direction. Crossing at 14°C could be useful when a bread wheat cytoplasm is desired by the breeder.