Abstract
Cytogenetical study on the artificial autotriploid of Oryza glaberrima was carried out.
The reciprocal crosses between the autotetraploid and the diploid were made to produce the autotriploid. Four (0.05%) autotriploids were obtained only by pollinating the autotetraploid with the pollens of the diploid.
As compared with the diploid, the autotriploid increased in stomata length, pollen diameter and length of unhulled and hulled seeds; decreased in number of panicles, pollen stainability, seed fertility and width, thickness and weight of hulled seed. The differences between them were conspicuous in stomata length, pollen diameter, seed fertility and seed weight. The autotriploid had awned spikelets, which was a single character different qualitatively from the diploid. The autotriploid was easily recognized by its seed sterility, but did not show semigigas characteristics so much expected in appearance.
In pollen mother cells of the autotriploid, 5 to 12III were observed at the stage of diakinesis to metaphase I, and 12III most frequently. The mean chromosome configuration was 9.20III+2.68II+3.05I.
