FORMATIVE ACTIVITY UNDER THE ACTION OF IONIZING RADIATION FOR WINTER WHEAT AT THE CELL LEVEL

Abstract

The purpose of the conducted experiments was to show the cytogenetic activity of a wide range of doses of ionizing radiation in individual genotypes of common wheat at the level of the chromosomal apparatus of the cell. In the study, seeds of winter wheat varieties Podolyanka and Smuglyanka were used, irradiated with gamma rays in doses of 100, 150, 200, 250, 300 Gy. The control was seeds without treatment. Based on the data of cytological analysis, the frequencies and spectra of chromosomal aberrations after exposure to gamma rays were studied. The total number of mitoses (in the corresponding phase) found in the preparations (20 - 25 preparations for each variant), the number of cells with chromosomal abnormalities and the percentage of such cells (from the number of mitotic), the frequency of chromosomal aberrations (from the total number of cells with rearrangements). The sample was approximately 500 - 1000 cells for each study variant. Variety Smuglyanka is significantly less stable compared to the variety Podolyanka at the cytogenetic level, with the presence of significant differences in the interaction of the genotype-mutagen system for gamma rays. The number of chromosomal rearrangements increases linearly under the influence of gamma rays up to 200 - 250 Gy, where a significant drop begins with stabilization at a lower level at doses of 250 - 300 Gy. It was found that the dose of the mutagen is a significantly more significant factor of influence, but the nature of the genotype is also important. Significant variability parameters are the total frequency of chromosomal aberrations, the frequency of micronuclei and lagging chromosomes, the frequency of bridges, and the frequency of complex rearrangements. The ratio of fragments to bridges is standard for gamma rays. A higher level of variability in subsequent generations is foreseen for the variety Smuglyanka, the possibility of differences in the spectrum of changes in subsequent generations due to the action of gamma rays.