II. 15. Dihaploids of H. murinum L., and H. secalinum Schreb. from interspecific crosses with H. bulbosum. L.
M. Gaj and M.D. Gaj, Department of Genetics, Silesian University, Katowice, Jagiellonska 28, Poland.
Crosses between H. vulgare and H. bulbosum followed by selective elimination of bulbosum chromosomes reults in haploids of vulgare (Kasha and Kao, 1970). Chromosomes elimination leads to haploid formation from other Hordeum interspecific crosses (Subrahmanyam, 1978) and from intergeneric crosses of T. aestuvum x H. bulbosum (Barcley, 1975), T. ventricosum x H. bulbosum (Fedak, 1983), Aeglops crassa x H. bulbosum (Shigenobu and Sakamoto, 1977), H. vulgare x Psathyrostachys fragilis (Linde-Laursen and von Bothmer, 1984) as well.
Plants of two tetraploid species, H. murinum and H. secalinum, were pollinated by diploid and tetraploid plants of H. bulbosum. The progenies of various crosses were obtained using the Jensen's (1975) method (Table 1).
Table 1. Progenies obtained from Hordeum interspecifie crosses.
The different frequency of the seeds set in crosses with diploid and tetraploid forms of H. bulbosm seems to be caused by the influence of a genome balance on the extent of chromosomes elimination. The seeds set in crosses with H. murinum was higher with diploid than with tetraploid bulbosum (50.3% and 33.3%, respectively). All plants were dihaploids and H. murinum phenotype. Similarly, the frequency of seeds set in crosses with H. secalinum was higher after pollination by diploid than tetraploid form of bulbosum.
Interspecifie crosses of wild Hordeum species with H. bulbosum have resulted in hybrid plants. Such plants were obtained as a result of crosses involving tetraploid H. bulbosum (Subrahmanyam 1978). In our study any hybrid plant was observed after pollination of H. murinum and H. secalinum by diploid as well as by tetraploid form of H. bulbosum.
References:
Barlcay, I.R. 1975. Nature 256:410-411.
Fedak, G. 1983. Can J. Genet. Cytol. 2:104-106.
Jensen, C.J. 1975. Barley Genetics III. PP. 316-345. Verlag Karl Thieming, Munchen.
Kasha, K.J. and K.N. Kao. 1970. Nature 225:874-876.
Linde-Laursen, I. and R, von Bothmer, 1984. Can J. Genet. Cytol. 4:434-444.
Shigenobu, T. and S. Sakamoto. 1977. Jpn. J. Genet. 52:397-401.
Subrahmanyam, N.C. 1978. BGN 8:97-99.
