Cytogenetic activity of a mutagenic factor with high damaging capacity in winter wheat

Abstract

The analysis of cytological abnormalities is an important method for identifying the potential of a chemical as a mutagen for future heritable genetic changes, the level of genotype-mutagen interaction and site-specific activity for the nature and/or different concentrations of the mutagen. The research aims to determine the limits of the variability of genotypes of different origins, especially those with wide ecological and genetic variability, and to show the interaction between the variety and the mutagen. Winter wheat grains of several varieties (Balaton, Borovytsia, Zelenyi Hai, Zoloto Ukrainy, Kalancha, Niva Odeska, Polianka, Pochayna) were treated with dimethyl sulphate at concentrations of 0.0125%, 0.025%, 0.05%, and exposure was 24 hours. The cytogenetic activity was studied by the frequency and spectrum of chromosomal rearrangements in the corresponding phases of cell division, depending on the variety and concentration of the mutagen as the main factors affecting these parameters, as well as the main features of the spectrum, such as the overall rate of chromosomal rearrangements, the number of fragments and double fragments, bridges, micronuclei, and lagging chromosomes. The studied concentrations of the supermutagen were found to have a significant effect on all analysed parameters and can be classified as optimal and high concentration levels in terms of the effect on cytological activity and mitotic problems for the factor, despite previous studies. The variety factor has a much greater impact on the nature and frequency of certain types of aberrations than an increase in the mutagen concentration, it was characterised by a much greater site-specific effect than other chemical agents, and various variants in mutagenic effects were identified according to the subject’s genotype. It was generalised that the features that reproduced the effect of the mutagen, according to the discriminant analysis, were the total frequency, the frequency of fragments and double fragments, and bridges. In practical use in the genetic improvement of plants and for obtaining valuable traits, the optimal concentrations are 0.0125%, and 0.025%, which is planned to be further confirmed on a wider range of genotypes and by mutation studies for the next (second or third) generations