THE USE OF TISSUE-CULTURE METHODS IN INTERSPECIFIC HYBRIDIZATION WITHIN THE GENUS TRIFOLIUM L

An attempt was made to produce interspecific hybrids among Trifolium s pecies. In situ pollination followed by in ovulo embryo culture and cu lture of the excised embryos, and in vitro pollination have been appli ed. 21 embryos were obtained from 636 in situ pollinations. 13 embryos were green and showed normal development. It was found that these emb ryos were produced in the result of sell-fertilization, The remaining 8 embryos were albino or chlorotic. The albino embryos originated from the combinations: T. hybridum x T.montanum (1 embryo); T. repens x T. resupinatum (6 embryos) and T. resupinatum x T. montanum (1 embryo). All the albino embryos produced were cultured on EG medium. The growth and development of embryos were abnormal. Most of them did not grow a nd died within two or three weeks of culture. Only a single embryo fro m the cross T. hybridum x T. montanum survived and after transferring to MS medium supplemented with 0.5 mg/l NAA and 2 mg/l 2iP produced ca llus. It is supposed that albino embryos were hybrids. In vitro pollin ation of T. repens pistils with T. nigrescens pollen resulted in the f ormation of 27 hybrid embryos (6 embryos were produced in reciprocal c ross) from which 11 hybrid plants were raised. Hybrid embryos not grow ing were passaged to the MS medium supplemented with 0.5 mg/l NAA and 2 mg/l 2iP to induce callus. Plants were regenerated from the calli vi a organogenesis.