Abstract
1. In the present report, the external characteristics, fertility and the meiosis in PMC's of F1 (TperR perH F1) plants and the external characteristics, fertility and the somatic chromosomes of F2 plants raised from Triticum persicum-Secale cereale amphidiploid (TperR) and T.persicum-Haynaldia villosa amphidiploid (TperH) were described. These F1 and F2 plants were obtained in 1961 and '62 respectively.
2. Hybridization was successful in producing trigeneric F1 in crossing TperR amphidiploid with TperH amphidiploid, but it failed in crossing TperH with TperR (Table 1).
3. The number of somatic chromosomes of the trigeneric F1 hybrids were 42 in 25 individuals and 41 in 5 respectively. The number of chromosomes, 42, corresponds exactly to the sum of the gametic number of these parental plants.
4. At the heterotypic metaphase on meiosis of PMC's of F1, 12-15 bivalents were observed (Figs. 5-11, 13-18). The frequency of the bivalents in one PMC was shown in Table 3. Almost all the bivalents consisted of two elements of equal size, but in very rare case, heteromorphic bivalent was observed. Most of the bivalents were ring-shape conjugated closely, though some of them were stickshaped. The case of 14II appeared to be the mode in every F1 plant (Table 3). It is thought that 14 of the 15 bivalents may be due to autosyndesis of the chromosomes of AB genomes of Triticum persicum derived from both parents, and the remaining one riled from autosyndesis of V or R genome, considering the results of cytological research on the intergeneric hybrids between Triticum, Secale and Haynaldia and one the haploid plant of Secale by Kostoff (1937), Nordenskiöld (1939) and Nakajima (1951, '56, '57, 'S9).
5. Trivalent was observed occasionally, in addition to bivalents at the heterotypic metaphase, and tetravalents were very rare.
6. As the anomalous PMC's, the large PMC having 2 nuclei, the giant PMC having 4n chromosomes (No. 11, 2n=41) and the many smaller PMC's having lesser chromosomes such as 2II+5I (Fig. 18), 3II+16I, 4II+17I, 5II+12I and 6II+12I and many others were observed. They may be thought of as caused by the anomalous division not of PMC but of archesporial cells of these F1 plants.
7. Most of the individuals of TperRperHF1 were almost fertile, though partial, and some anthers opened and some grains were obtained in natural selfing (Table 2) and by sowing them in October 1962, 63 matured F2 plants were raised. The number of somatic chromosomes of these F2 plants was found to vary from 21 to 54 (Table 7).
8. 12 individuals of 35 F2, the external characteristics of which were observed, showed fertility while others were completely sterile (Table 9). And as the total number, 562 grains were obtained from these 12 F2 plants, and a part of them were sown in October 1963 and many F3 plants were obtained.
