Megasporogenesis in Oryza sativa L. and Rhynchoryza subulata (Nees) Baill. indicating some taxonomic significance

The megasporogenesis and structure of the embryo sac in Oryza sativa L. and Rhynchoryza subulata (Nees)Baill. (syn. Oryza subulata Nees.) were studied. The embryo sac is of the 8 nucleate Polygonum type in both species. The main differences between the two species were in the ratio of length to width of the egg cells and in the distances between egg cells, polar cells and antipodals. R. subulata had a smaller, wider egg cell and greater distance between the mega structures. The importance of these differences in classification and for fertility are discussed.