Haploid regeneration from tetraploid wheat using maize pollen

Crosses were made between 21 tetraploid wheat genotypes (6 parents, 15 F1 hybrids) and a single F1 hybrid of maize that was used as the male parent. Plants were grown under controlled greenhouse conditions (daylength, 16 h; temperature, 25 degrees C days and 15 degrees C nights). To enhance embryo survival, 2,4-D (10 mg/L) was applied to spikes 24 h after pollination with maize. Embryos were recovered from the tetraploid wheat genotypes at a rate of 2.34-14.14/100 developed ovaries. Sixty-nine haploid plants were obtained from 3 parents and 12 F1, hybrids. Fifty-six of these were successfully doubled. General combining ability was significant for the two traits studied, indicating that additive genetic control is important for the number of developed ovaries and haploid embryo production in tetraploid wheat x maize crosses. In this report, we demonstrate the potential of using maize pollen to produce haploid plants from tetraploid wheat genotypes.