1952 Volume 65 Issue 773-774 Pages 288-294
In the present report, the result of cytological studies on the maturation division of PMC-s of TSF2 plants having 2n=42 chromosomes was described. These TSF2 plants, 24 in (total) were obtained in 1942.
At the heterotypic metaphase in PMC-s of TSF2 plants with 2n=42 chromosomes, 7-21 bivalents and 0-28 univalents were observed (Figs. 1-5). The frequency of bivalents in the PMC-s was shown in table 1.
In the case of fertile individuals the number of bivalents were found almost all to lie between 17 and 21, and of sterile individuals between 14 and 21.
Tetravalents were observed, though rarely, in addition to bivalents at the heterotypic metaphase but no trivalent was found.
Almost all the plants of the 24 individuals investigated may be considered as what might be called the eu-amphidiploid in which AB genomes of Triticum turgidum and R genome of Secale cereale are included completely.
In most cases the distribution of chromosomes to the opposite poles at the anaphase in heterotypic division was observed to be 21:21 (Table 2).
The nuclear plate showing 39II+6I chromosomes at the heterotypic metaphase of PMC-s was observed (Fig. 11). This case ought to be due to the duplication of chromosomes of AB genomes of T. turgidum and R genome of S. cereale. Further, the nuclear plate having 7II+14I chromosomes was observed. This case may be thought of as due to the deficiency of chromosomes corresponding to any two genomes (14 chromosomes) in AABB genomes of T. turgidum and RR genomes of S. cereale.
11 plants of the 24 individuals investigated were appeared to be fertile and the remaining 13 individuals sterile.
