Resistance to fungal diseases of wheat has been transferred from perennial species of tribe Triticeae, but the hybrid so formed presents immature embryos. Although rescue and in vitro culture of these embryos has been widely utilized, its efficiency is still very low. This work aimed to obtain backcrossing progenies in hybrid F1 (2n=56), derived from crossing between wheat (Triticum aestivum) (2n=42) and Agropyron elongatum (2n=70), through in vitro culture of immature embryos. Starting from the perennial material of F1 generation, several backcrosses were made using wheat as the recurrent parent. Polinization efficiency was 6.0% in BC1 and 12.4% in BC2. All plants from the BC1 were obtained by in vitro embryo culture. The culture medium used was potato regeneration plus vitamins. From 22 seeds collected 18 embryos were cultured in vitro and gave rise to 12 plants. Fifty percent of those embryos were normal. The remaining 27.8% showed reduced size, 16.7% were deformed and 5.5% had slow growing. The efficacy of immature embryo culture was 66.6%. This result indicates that rescue and culture medium techniques used were efficient for cultivation and regeneration of hybrid embryos, allowing viable backcrosses progenies from intergeneric hybrids.
wheat; breeding; wide crosses; resistance to fungal disease
