三属間雑種の細胞遺伝学的研究
III. 2n=28 染色体をもつ TperHRF1 植物の花粉母細胞成熟分裂
1959 年 34 巻 3 号 p. 96-101
詳細
1959 年 34 巻 3 号 p. 96-101
1. In the present report, the result of cytological studies on the maturation division of PMC's of TperHRF1 plants having 2n=28 chromosomes as the number for the eu-trigeneric triple hybrid was descrived. These F1 plants were obtained in 1958.
2. At the heterotypic metaphase on meiosis of PMC's of these F1 plants 0-6 bivalents and 28-16 univalents were observed (Figs. 1-7). The frequency of the bivalents in one PMC was shown in Table 1. Almost all the bivalents consisted of two elements of equal size, but in very rare cases, heteromorphic bivalent was observed (Fig. 8). Most of the bivalents were stick-shaped loosely conjugated end to end, but some of them were ring-shaped joined closely at two ends (1077 ring-shaped in 18224 bivalents). It seems that 4 of the 6 bivalents are raised from autosyndesis of the chromosomes of AB genomes of T. persicum and the other 2 may be raised from autosyndesis of which V and R genomes of H. villosa and S. cereale respectively, considering the results of cytological researches on the intergeneric hybrids between Triticum, Secale and Haynaldia and on the haploid plant of S. cereale by Kostoff (1937), Nordenskiöld (1939) and Nakajima (1956, '57).
3. Trivalent was observed, though rarely, in addition to bivalents at the heterotypic metaphase, and tetravalent only once among 12600 PMC's.
4. In most individuals of the TperHRF1 plants used in this research, the meiosis of PMC's showed F1-type division just as in the Triticum-Secale F1 hybrids, but in two individuals (Tper HRF-1S-5, -S-17) all the 28 univalents were found to form the equatorial plate besides the F1-type division (Table 2).
5. All the 22 TperHRF1 plants investigated may be considered as, what might be called, the eu-trigeneric triple hybrid in which AB genomes of Triticum persicum, V genome of Haynaldia villosa and R genome of Secale cereale are completely included.
6. The distribution of chromosomes to opposite poles at the anatelophase in heterotypic division proceeded at random in F-type division, while in the case of the formation of equatorial plate some 28 chromosomes were distributed to each pole (Table 3).
