1. In the present research, the germination of F
3 seed, and the number of somatic chromosomes, external characteristics and fertility of F
3 plants of
Triticum-Secale triple hybrid raised between F
1 T. turgidum×S. cereale and
T. vulgare were studied.
2. 736 grains of F
3 seed were obtained from 21 fertile individuals among 40 F
2 plants, and 674 grains of them were sown in separate pots in October 1938 and 1939, and 177 F
3 individuals were obtained (Table 1). The fertility of the F
3 varies with the each parent, and the percentage of the F
3 seed has been shown to vary from 2.50 to 65.37. As a whole, the percentage of the number of F
3 seed obtained from the F
2 plants having 2n=29-31 or 45 chromosomes showed a rather high percentage in germination.
3. As seen in Table 2, the number of somatic chromosomes of the 177 F
3 hybrids varies from 28 to 49. These individuals may be divided into three groups. The F
3 individuals raised from F
2 having 2n=29-33 chromosomes have 2n=28-32, and these seem to make a group, and most of them have 28-29 chromosomes (71.43% in this group). The number of chromosomes of other F
3 individuals raised from F
2 having 2n=43-47 chromosomes varies from 2n=40 to 49, and they make another group. The rest of the F
3 raised from F
2 having 2n=37-39 have 2n=32-43, making a group lying between the above two groups.
4. The external characteristics were observed with 153 individuals of the 177 F
3 plants. The length of culms and awns, spikelet number on a spike and spikelet density of F
3 individuals having smaller number of chromosomes (2n=28-32) surpass the other F
3 plants having the larger number of chromosomes, while, on the length of spikes, the former individuals were inferior to the latter.
5. 126 individuals among the 153 triple F
3 plants were somehow fertile. And the fertility per spikelet has shown to vary from 4.2 to 128.0% according to individuals (Table 3). Generally speaking, the percentage of seed fertility per spikelet has been higher in F
3 plants having smaller number of chromosomes (28-29). and as the somatic chromosomes increase above these numbers the fertility falls gradually but again rises.
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