A Cytological Study on the Intergeneric F<sub>1</sub> Hybrid between <i>Triticum sphaerococcum and Secale cereale</i>

Abstract

1. In the present investigation, cytological studies on the F1 plants, raised from Triticum sphaerococcum and Secale sereale, was carried out.2. 160 flowers on 10 spikes of T. sphaerococcum (n=21) were pollinated with the pollen of S. cereale (n=7), and 46 grains were obtained. From these grains 5 F1 plants were raised. The percentage of the raised indivi-duals to the number of all the pollinated flowers was 3.13 per cent.3. The external characters of F1 plants seem to have resemblance to the parents, although much more closely to the mother plant (T. sphaerococcum) than the intermediate of the parents (Photo. 1 and Table 1).4. The number of somatic chromosomes of F1 plants counted to be 28 (Fig. 1) and it corresponds to the sum of the reduced chromosome numbers of the parents.5. At first maturation division in PMCs of the F1 plants, 04 bivalents and 2820 univalents were observed (Figs. 28). The frequency of bivalents in PMCs was shown in Table 2, and the case of zero in the number of bivalents appeared to be the mode. These bivalents seem to be derived from synthesis between A and B or among A, B and D genomes of T. sphaerococcum which is the mother plant. As there seems to be no homology between A, B, D genomes of T. sphaerococcum and R genome of S. cereale, synthesis will not occur between their chromosomes.6. At ana-telophase in heterotypic division of PMCs, the chromosomes were distributed to the opposite poles from 14:14 to 27: 1.7. The anther of these F1 plants was not opened and pollen grains showed almost sterile, but on rare occasions, some anthers were opened and consequently a few seed (5 grains) were obtained in natural selfing. From these 5 grains one F2 plant was raised.