Impact of ecogenetic factors on cytogenetic variability of winter wheat

The study focused on the mutagenic potentials of ethylmethanesulfonate (EMS) and sodium azide (SA), their abilities to induce chromosomal aberrations, interactions with various winter wheat genotypes, and the nature of genotype-mutagenic interactions. Additionally, their feasibility for future applications was examined, particularly regarding their predictive value at the cellular level in determining mutation-inducing capacity at the plant level. The cytogenetic effects of ethylmethanesulfonate (EMS) and sodium azide (SA) were tested on two winter wheat varieties, Vezha and Ihrysta. The seeds were treated with EMS at concentrations of 0.025%, 0.05%, and 0.1%, and SA at 0.01%, 0.025%, 0.05% and 0.1%. The cytogenetic activity was assessed through pollen sterility and the frequency and spectrum of chromosomal abnormalities in mid-phase cell mitosis. The results provided significant insights into the genotype-mutagenic interactions in these wheat varieties. The study found that the winter wheat variety Ihrysta exhibited a higher genotype-mutagenic specificity, making it a strong candidate for inducing genetic variability and producing mutant forms. The most effective mutagenic response was observed following the use of EMS and SA concentrations ranging 0.025% to 0.05%, optimizing mutation induction while minimizing the adverse effects. The study identified the variety Vezha as particularly responsive and promising for breeding programs targeting mutagenic variability. Mode­rate concentrations of EMS and SA were found to be the most effective, striking a balance between inducing beneficial genetic changes and minimizing adverse effects. The key indicators of genetic susceptibility to mutagens included pollen fertility, the overall frequency of chromosomal aberrations, and the number of induced fragments, while rare chromosomal rearrangements had limited analytical value. The induction patterns of EMS and SA were consistent with other chemical supermutagens, although the responses varied depending on the plant's genetic background. The findings will be integrated with further studies on hereditary changes in biochemical and physiological traits, providing a basis for refining mutagenic strategies and optimizing breeding programs.