Abstract
One hybrid embryo of intersectional origin between Oryza australiensis Domin (W008, 2n=24) and O. ridleyi Hook. (W0001, 2n=48) was successfully obtained. The Fl hybrid had the expected chromosome number of 36 in the somatic cells. The average of meiotic chromosome pairing was 0.24II+34.27I. Meiotic irregularities, such as bridge, laggards and unequal separation of univalents were observed at almost all PMCs. This analysis leads to the conclusion that the two genomes of O. ridleyi differ from the EE genome of O. australiensis.