Abstract
1. In the present report, the result of a cytogenetical research on the F2 plant (TsphRF2) raised from T. sphaerococcum×S. cereale was described.
2. The external characters of TsphRF2 plant, length of spike, density of spikelets and number of flowers in a spikelet resembled closely to the F1, while length of culms and of awns, and number of spikelets per spike resembled closely to T. sphaerococcum than those of the F1 (Fig. 1, and Table 1).
3. The TsphRF2 plant has somatic chromosomes the number of which is less than the number of amphidiploid by 15 chromosomes.
4. At the heterotypic metaphase in meiosis of PMC'S of the TsphRF2, 10_??_17 bivalents or 7_??_21 univalents were observed (Figs. 3-9). The frequency of bivalents and univalents in PMC'S was shown in Table 2.
5. Both male and female gametes of the TsphRF2 plant were completely sterile.
6. It seems to me that the majority of chromosomes of the F2 are due to T. sphaerococcum, considering from the external characters of the F2.
