Dc. Angra et al., Embryo culture of backcrosses between hybrids of Triticum aestivum Thell. and Agropyron elongatum Host. & Beauv., PESQ AGROP, 34(2), 1999, pp. 209-215
Resistance to fungal diseases of wheat has been transferred from perennial
species of tribe Triticeae, but the hybrid so formed presents immature embr
yos. Although rescue and in vitro culture of these embryos has been widely
utilized, its efficiency is still very low. This work aimed to obtain backc
rossing progenies in hybrid Fl (2n=56), derived from crossing between wheat
(Triticum aestivum) (2n=42) and Agropyron elongatum (2n=70), through in vi
tro culture of immature embryos. Starting from the perennial material of Fl
generation, several backcrosses were made using wheat as the recurrent par
ent. Polinization efficiency was 6.0% in BC1 and 12.4% in BC2. All plants f
rom the BC1 were obtained by in vitro embryo culture. The culture medium us
ed was potato regeneration plus vitamins. From 22 seeds collected 18 embryo
s 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 d
eformed 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, all
owing viable backcrosses progenies from intergeneric hybrids.