XVI International Botanical Congess
The expression of hybrid lethality is stipulated by the existence of different genetic systems, the interaction of which brings to a distinct expression of every type. During the evolution, the elucidation of origin of every kind of dominant lethal mutation is connected with the occurrence of genoms in the line of polyploids which can be of great importance in evolutionary resettlement of wheat from the center of occurrence of cultural plants and in elucidation of regularity of phylogenesis. If genom negative mutations occured in different periods of evolutionary development of wheat, or within the genom there were partial mutations. It is possible that this is a result of the heterogenity of genoms participating in the formation of species. The presence of all members of a complementary system in one species brings an intraspecific expression of hybrid lethality. According to the maintenance of lethal geniuses the richest is T.aestivum. The next is T. macha.