Embryological peculiarities of interspecific hybridization in <Emphasis Type="Italic">Pinus sibirica</Emphasis>

Cytoembryological research of the ovules in experiments with interspecific hybridization of Pinus sibirica (pollination be the pollen of P. koraiensis, P. armandii, P. parviflora, P. strobus, P. hokkaidensis, P. wallichiana, P. monticola, and P. сembra) revealed that the development of megagametophytes occurred in them by the usual scenario and resulted in the formation of mature archegonia. Pollen successfully germinated on the nucellus of ovules. However, disturbances were observed in the process of male gametophyte development, and pollen tubes on the nucellus were not visible by the period of archegonia maturation. Fertilization was usually absent. The development of embryonic channel is determined by egg cell maturity. The only exception was the variant of the controlled pollination of Pinus sibirica × P. сembra, in which the embryo has been formed.