| F1 hybrids between four species of Secale
and Agropyron intermedium A. ZENNYOZI Biological Laboratory, Faculty of Technology, Gumma University, Kiryu, Japan Four species of Secale, i. e. cereale, africanum, montanum and kuprijanovii were crossed with A. intermedium, and the following results were obtained. S. cereale x A. intermedium: In 1958, 429 florets of S. cereale were pollinated with the pollen of A. intermedium, and obtained three F1 hybrids. The F1 plants grew slowly and were weak. As F1 hybrids of all the three plants were lacking alike the anther in all the florets, it was not possible to carry out any observation of PMC's. S. africanum x A. intermedium: The hybridization was made out in 1960. 582 florets of S. africanum were crossed with A. intermedium, obtaining 118 grains. 25 of those grains were sown and six F1 hybrids were obtained. External features of the F1 plants were intermediate of both parents, but in several characteristics they resembled the Agropyron. Individual variations in some characteristics were also observed. At IM, various kinds of chromosome conjugation from 6II + 16I to 1III + 9II + 7I were observed. 0 - 3 trivalents and 0-1 tetravalent were also found frequently. It was in 1III + 6II + 13I that the conjugation pattern was most frequently observed. The average of the chromosome conjugation was 0.03IV + 0.84III + 6.48II + 12.40I. Most of the bivalents observed were of open type and 1 - 5 bivalents of ringshaped type were also observed (average being 1.99 per cell). Further, a heteromorphic bivalent was found in only one of 100 PMC's observed. S. montanum x A. intermedium: The hybridization was carried out in 1960, pollinating 206 florets of S. montanum by A. intermedium pollen and 63 grains were obtained. And 14 F1 hybrids were produced by sowing 30 of those grains. The results regarding external characteristics of the F1 plants were such as that of S. africanum x A. intermedium F1 plants mentioned a bove, i. e. being approximately intermediate of the parents, showing their individual differences among the F1 plants. Further, as S. cereale x A. intermedium F1 plants this F1 hybrids were very weak, and there were some individuals that stopped the growth before the earing stage. Althongh eared in some plants, there were those F1 plants that were lacking the anther in the florets. |
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