PROBLEMS OF SPECIES AND GENOME IN BREEDIN G

The modern concept of the species as a complex biological system is ba sed on the work of N.I. Vavilov, who was the first to emphasize the po tential of a species for breeding. Realization of his ideas became pos sible only in the era of modern biology, with the advent of the latest biological methods of genetic and phylogenetic analysis of plants. Am ong these methods are molecular marking of genetic systems and biologi cal structures with highly informative molecules of proteins and nucle ic acids. These techniques are used to identify species, varieties, an d biotypes; detect hidden variation in populations; analyze the genome , and estimate interspecies genomic relationships in allopolyploid pla nt complexes. Genomic and genetic studies of principal species of cult ivated plants and their wild relatives have shown that the nuclear gen ome may be regarded as a genetic system of species category. The role of genetic variation in evolution and breeding; the genetic structure of species and its use for breeding; and the importance of cultivar, s pecies, and superspecies gene pool levels for determination of genetic ally and morphogenetically complex plant traits are discussed.