Abstract: The regenerated plants had high frequencies of changes in chromosome number and the pairing variation. The chromosome number was more or less variably decreased in different pollen mother cells. Most of regenerated plants were mixoploids. Some had higher frequency of homolgous chromosome pairing because double doses of rye genome had inhibited the effect of Ph gene. But, there was obvious different of chromosome pairing among regenerted plants. The difference was related to numerical chromosome change. Meiosis in a regenerant was analysed with Giemsa-C banding technigue. Partial rye chromosomes did not pair homologously or only very loosely paired. There was moderate level of wheat-wheat homologous partial pairing, however, wheat-rye chromosome pairing also occurred.

Key words: Octoploid triticale × rye hybrid, Regenerated plants, Chromosome pairing