EN
An attempt was made to produce interspecific hybrids among Trifolium species. In situ pollination followed by in ovulo embryo culture and culture of the excised embryos, and in vitro pollination have been applied. 21 embryos were obtained from 636 in situ pollinations. 13 embryos were green and showed normal development. It was found that these embryos were produced in the result of self-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 and died within two or three weeks of culture. Only a single embryo from 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 callus. It is supposed that albino embryos were hybrids. In vitro pollination of T. repens pistils with T. nigrescens pollen resulted in the formation of 27 hybrid embryos (6 embryos were produced in reciprocal cross) from which 11 hybrid plants were raised. Hybrid embryos not growing 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 via organogenesis.