ROLE OF RYE CHROMOSOMES IN THE GENETIC-CONTROL OF EQUATIONAL DIVISIONOF UNIVALENTS IN WHEAT-RYE DI-MONOSOMICS

Division and segregation of univalent chromosomes in the course of mei osis was studied in the wheat-rye dimonosomics 1R-1A, 1R-1D, 2R-2D, 2R -2W, 5R-5A, 5R-5D, 6R-6A, 6R-W, and 7R-W (Triticum aestivum L., cultiv ar Saratovskaya 29-Secale cereale L., cultivar Onokhoiskaya). The di-m onosomics showed significant differences in the frequency of equationa l division of univalents at meiotic anaphase 1. In di-monosomics with rye chromosomes 5R, 6R, 7R, the univalents mainly divided in the equat ional manner; the presence of 2R favored the reductional type of divis ion. Di-monosomics in 1R showed the equational-reductional type of div ision. On the basis of these results, it was concluded that Edu genes controlling equational division of univalents at meiotic AI, were loca ted on several nonhomologous rye chromosomes. P(Edu) genes, which defi ne the high level of the equational division of univalents, are locate d on rye chromosomes 5R, 6R, and 7R.