TRANSMISSION RATE OF CHROMOSOMES 5A, 5D, AND 5R THROUGH GAMETES OF WHEAT-RYE DI-MONOSOMICS

The role of chromosomes of wheat and rye homeological group 5 in trans mission of univalents through gametes was studied in the following whe at-rye di-monosomics Triticum aestivum L. var. Saratovskaya 29 - Secal e cereale L. var. Onokhoiskaya: (1) di-mono 5R-5D 19 '' w + 1 '' 5A 1'5D + 1'5R; (2) di-mono 5R-5A 19 '' w + 1 '' 5D + + 1'5A + 1'5R; (3) di-mono 5A-5D 19 '' w + 1 '' 5R + 1'5A + 1'5D. The results of cytologi cal and phenotypic analysis of the di-monosomics and their progenies o btained by self-pollination showed that univalent chromosomes 5A, 5D, and 5R were transferred with various frequencies through gametes of di fferent aneuploids. Thus, transmission frequencies of univalent chromo some 5A through maternal + paternal gametes in 5R-5A and 5A-5D were eq ual to 54.22% and 17.27%, respectively. Therefore, increasing the of d ose of 5R chromosome and reducing the 5D dose resulted in a 3.14-fold decrease in transmission frequency. Univalent chromosome 5R was transm itted with approximately the same rate in both di-mono 5R-5D and 5R-5A ; differences in the number of chromosomes 5A and 5D did not affect th e transmission frequency of rye chromosome 5R. It was also found that two different univalents of the di-monosomics were distinguished by th eir transmission rates, which differed by the factor 1.96 and 3.94 in di-mono 5R-5A and 5A-5D, respectively. In di-mono 5A-5D with two 5R do ses, univalent chromosome 5D was transmitted through 68.18% of gametes , whereas in 5A, only through 17.27%. The results obtained allowed us to conclude that, against the same genomic background, the transmissio n rate is specific for each univalent.