抄録
Twenty-five hybrids between forms possessing the A genome (O. sativa, O. sativa f. spontanea, O. breviligulata, O. glaberrima, O. perennis and O. formosana) and those with the BC genomes (O. minuta and O. punctata) were used as materials.
From 778 flowers pollinated, 233 seeds (almost all of them were imperfect) of various degrees of development were produced. One hundred grains chosen at random from 20 cross-combinations were sown on the culture medium in test tube. Sixteen true F1 plants were studied cytologically.
At pachytene stage, 12 bivalents and 12 univalents were observed. At diakinesis and metaphase I, the number of bivalents ranged from 3 to 12 or from 1 to 11, respectively.
From the previous results of pachytene analysis in the F1 hybrid of the cross, O. sativa×O. officinalis (Shastry et al. 1960, 1961; Katayama 1965), and of pachytene analysis and of bivalent formation at diakinesis and at metaphase I in the F1 hybrids, O. sativa ×O. minuta and O. sativa×O. punctata, the author could conclude that the C genome of O. minuta and O. punctata is partially homologous to the A genome of O. sativa.
