Department of Agronomy, Taiwan Provincial Chung-Hsing University, Taichung, Taiwan, Republic of China
Two colchicine-induced autotetraploids of O. officinalis (CCCC) were used as the pollen parents in crosses with related species. The F1 hybrids with O. minuta (BBCC) and O. grandiglumis (CCDD) were successfully produced and the meiosis in pollen mother cells was studied. BCCC plants formed nine tri-valents (maximum number) and a few quadrivalents. This suggests that there is a certain degree of homology between the B and C genomes. In a CCCD plant, however, chromosomes were mostly present as univalents and 12 bivalents were found at maximum pairing. It is inferred that the D genome has a suppressing effect on chromosome pairing in the C genome.
