Cytological Evidence on Meiotic Restitution in Pentaploid F_1 Hy-brids between Synthetic Hexaploid Wheat and Aegilops variabilis

摘要

Meiotic restitution responsible for the production of unreduced gametes is significant in both al-lopolyploid origin and plant breeding. There are lots of reports on meiotic restitution in hybrids of tetraploid Triticum turgidum wheat with alien species. Hexaploid wheat SHW-L1 was newly synthesized from the F1 plants between a T turgidum ssp. turgidum line with meiotic restitution gene(s) and Aegilops tauschii. Based on the male gametogenesis observation, the present study provided the experimental evidence on the occurring of meiotic restitution in the F1 pentaploid (2n =5x =35, ABDUS~1) hybrids of synthetic hexaploid wheat SHW-L1 with Ae. variabilis. Meiotic restitution resulted in unreduced gametes that in turn spontaneously produced ne-opolyploids with genome AABBDDUUS~1S~1. The implications of these findings for gene flow between hexaploid wheat and alien species were discussed.