ELEMENTS OF THE GENETIC CONTROL OF THE MORPHOLOGICAL DIFFERENCES BETWEEN FAGOPYRUM ESCULENTUM MOENCH AND F. HOMOTROPICUM OHNISHI, AND SOME RESULTS OF THE USE OF INTERSPECIFIC HYBRIDIZATION IN BREEDING OF COMMON BUCKWHEAT

The genetic control of differences between Fagopyrum esculentum and F. homotropicum has been studied on a number of features that are significant for breeding (1000 seed weight, number of vegetative nodes on main stem, winged/non-winged seeds). A wild species carries dominant minus-alleles at loci controlling the variation in weight of 1000 seeds. Interspecies difference in the number of vegetative nodes on stem was inherited additively. The gene, the dominant allele of which determines the winged seeds, is linked to the locus D (DET) which mutation determines the determinate growth habit. New approaches have been tested to accelerate selection in population of interspecific hybrids. Indeterminant hybrids were sown in the field with a high seeding rate (3 million seeds per hectare) and were harvested in time which is optimal for medium-ripening buckwheat varieties. Any selection was not carried out to maximally preserve the genetic diversity of the hybrids. The manipulations during three generations allowed to significantly increase the share of the earlier (4-5 vegetative nodes) morphotypes. Determinant interspecific hybrids were drilled in the field in a mixture with seeds of the indeterminant variety Molva. Strong competition with taller indeterminant plants in conditions of dense cenosis ensured the culling of the least competitive genotypes; the presence of a morphological marker (determinate type of growth) made it possible to remove indeterminant hybrids with the Molva variety from the population. The next stage was the sowing of the progenies and selecting plants with pin flowers (which progenies are only from cross-pollination) in order to avoid inbreeding depression and for recombination of favorable alleles. Three cycles of such selection allowed not only to significantly reduce both the potential of branching of plants and the duration of their vegetation, but also to increase the height of plants and the number of inflorescences on shoots up to the level of variety Dikul