CYTOGENETIC VARIABILITY UNDER THE ACTION OF THE EPIMUTAGEN TRITON-305X

Abstract

Epimutagens are an important tool in the genetic improvement of plants due to their ability to significantly increase the frequency of beneficial hereditary changes. Purpose. To reveal the specificity of the action on the parameters of cytogenetic variability according to the frequencies and spectra of chromosomal aberrations in winter wheat cells depending on the concentration and variety. Methods: Seeds of 4 varieties of winter wheat Perspektyva Odeska, Sonata Poltavska, Shpalivka and MIP Lada were treated with an aqueous solution of ТХ-305 (Triton-305X) at concentrations of 0.01%, 0.05%, 0.1% and 0.5%. The analysis of chromosomal aberrations at the late stage of metaphase and early anaphase was carried out by the method of light microscopy. Results. The influence of the variety was significant only on the induction of aberrations by the type of cities, but increasing the concentration of Triton-305X had a significant and reliable effect on the overall frequency of chromosomal rearrangements and other types (micronuclei, lagging chromosomes). According to the index of the total frequency of aberrations, the variety MIP Lada was significantly different, which turned out to be more vulnerable. The pairwise comparison showed for all types of chromosomal rearrangements showed that the difference was not always reliable during the transition between individual concentrations, mostly there were no differences between the first-second and third-fourth variants. Factor analysis showed that the significant increase in the concentration of TX-305 was for the total frequency and number of rare changes, while the genotype affected only the number of bridges. The results of the analysis are not typical for the cytogenetic activity of chemical mutagens (among the model features, only the frequency and the number of bridges are present as indicators of the force of action). According to the analysis of the centroid distances, it is inappropriate to use the concentrations of TX-305 0.01 and 0.05% and TX-305 0 at the same time. 1 and 0.5%, respectively. Variants TX-305 0.01% and TX-305 0.1% should be removed. Findings. TX-305 as an epimutagen model induced the number of bridges when the cytogenetic activity was studied. Quite often, there is no difference when acting between TX-305 0.01 and 0.05%, TX-305 0.1 and 0.5%, respectively. The variety MIP Lada showed a higher genetic affinity to the action of Х-305 due to a higher vulnerability to the effects of the action due to an increase in cytogenetic variability, especially according to the indicators of the total frequency of rearrangements and the number of bridges.