Abstract
In order to elucidate the relationship among diploid species in the O. officinalis complex, 25 F1 hybrids between O. officinalis and its related species of strains (Intermediate, Ceylonese officinalis and O. eichingeri) were studied cytologically.
Pollen was almost completely sterile in these hybrids, but occasionally some fertile pollens were produced. At diakinesis and MI of PMCs in all the F1 hybrids, 12 compactly paired bivalents were observed in most cases. On the other hand, crosses between O. officinalis and diploid O. punctata were unsuccessful, though more than two thousand spikelets were cross-pollinated.
Based on these results, the authors postulated that the genome of Intermediate, O. eichingeri and the Ceylonese officinalis is homologous with that of O. officinalis and that there may be distinct reproductive barriers between diploid O. punctata and its related species or strains.
