Spontaneous wheat-Aegilops biuncialis, Ae. geniculata and Ae. triuncialis amphiploid production, a potential way of gene transference

Some F1 hybrid plants between three species of the Aegilops genus and different hexaploid wheat Triticum aestivum cultivars show certain self-fertility, with averages of F1 hybrids bearing F2 seeds of 8.17%, 5.12% and 48.14% for Aegilops biuncialis, Aegilops geniculata and Aegilops triuncialis respectively. In the Ae. triuncialis-wheat combination with 'Astral' wheat cultivar, the fertility was higher than that found in the other combinations. All the F2 seeds studied were spontaneous amphiploids (2n=10x=70). The present study evidences the possibility of spontaneous formation of amphiploids between these three Aegilops species and hexaploid wheat and discusses their relevance for gene transference. Future risk assess-ment of transgenic wheat cultivars needs to evaluate the importance of amphiploids as a bridge for transgene introgression and for gene escape to the wild.