| At IM, the chromosome conjugation patterns from 6II + 16I
to 10II + 8I were found. In addition to the bivalents
0 - 4 trivalents and 0 - 1 tetravalent were observed. The modal configuration
was found to be 1III + 6II + 13I, and the
average being 0.04IV + 0.81III + 6.52II
+ 12.37I. Most of the bivalents were open type, though often
1- 6 closed ones were observed ( average being 3.03 per cell ). The case
having a heteromorphic bivalent was observed twice out of 100 PMC's. S. kuprijanovii x A. intermedium: In 1960, 550 florets of S. kuprijanovii were crossed with A. intermedium pollen and obtaining 96 grains. 25 out of them were sown and six F1 hybrids were obtained. In their external features the same cases were observed as that of the two hybrids mentioned above. At IM, the patterns of the chromosome conjugation were observed from 5II + 18I to 9II + 10I. Simultaneously, 0-4 trivalents and 0-1 tetravalent were observed. The conjugation pattern of 1III + 6II + 13I was found to be the mode such as the above two hybrids and the average being 0.06IV + 0.82III + 6.35II + 12.60I. The ring-shaped bivalents were observed 1-5, average being 2.46 per cell. In one out of 100 PMC's was found a heteromorphic bivalent. In the F1 hybrids between three species of Secale and A. intermedium of the cytological studies of PMC's, most of the conjugated chromosomes may have been occurred due to the autosyndesis on the basis of homologies of the chromosomes among three genomes of A. intermedium. However, as a larger bivalent than the other ones was found in every F1 hybrid, it may be assumed to be the autosyndesis of the chromosomes of Secale. Further, according to the observations of the heteromorphic pair in these F1 hybrids, a bivalent is considered to indicate the occurrence of the allosyndesis between the chromosome of the Secale and that of the A. intermedium. No pollen - and seed - fertility showed completely in the all F1 hybrids. The three F1 hybrids, except for S. cereale x A. intermedium F1, were perennial. |
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