Studies on Behavior of Chromosomes and Development of Embryosacs and Pollen Grains in Haploid Rice Plant

Abstract

1. The present paper describes the behavior of chromosomes in meiosis and the development of embryosacs and pollen grains in haploid rice plant. 2. Two haploid plants were observed; in both of them, pollen mother cells at diakinesis of first metaphase were found to have one or two bivalent chromosomes. This seems to suggest that certain chromosomes in haploid set are to some extent homologus with each other. 3. The second division was not found in a majority of pollen mother cells. This seems to be due to the failure of the first division. 4. In a larger part of cases, two or three megaspores were formed from an embryosac mother cell and they seemed to degenerate soon. No normal embryosac tetrad was found. 5. The number of microspores produced from one pollen mother cell varied from two to four. 6. The haploid plants were completly sterile due to the failure of meiosis such as mentioned above.