Genetical and Cytological Studies in the Breeding of Amphidiploid Types Between Triticum and Secale
V. External characters and meiosis of the F1 T. pyramidale×S. cereale
1953 Volume 18 Issue 2 Pages 122-127
Details
1953 Volume 18 Issue 2 Pages 122-127
1. In 1951, 1064 flowers on 56 spikes of Triticum pyramidale (n=14) were pollinated with the pollen of Secale cereale (n=7). Only one F1 plant was obtained. The percentage of the raised F1 individual to the number of all the pollinated flowers was found to be 0.094 percent.
2. Almost all the external characters of the F1 plant, excepting one or two, show intermediate characters between those of the parents (Table 1).
3. The number of somatic chromosomes of F1 plant was counted to be 21, and it corresponds to the sum of the gametic numbers of the parents.
4. In the heterotypic division in PMC's of the F1 plant, 04 bivalents and 2113 univalents were observed (Table 2). 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. Those 04 bivalents may probably be derived from autosyndesis between the chromosomes of AB genomes of Triticum pyramidale used as the mother plant.
5. At ana-telophase in the heterotypic division of PMCs, the chromosomes were distributed to the opposite poles in the ratios from 11:10 to 15:6, and the distribution of chromosomes of the case 11:10 appeared to be the mode.
6. At meta-anaphase in the heterotypic division in PMCs, univalent chromosomes were usually scattered in the spindle, but in some cases the longitudinal splitting of all the univalent chromosomes were observed and consequently the formation of restitution nucleus were occasionally observed.
7. The F1 plant shows fertility of low percentage and 7 grains of seed were obtained from 37 spikelets by natural selfing. These grains were sown in October of 1952, and 5 F2 plants were raised.
