Cytogenetic analysis of the effects of a new epimutagenic agent on chromosomal stability in winter wheat (Triticum aestivum)

This study evaluated the epimutagenic potential of Nonidet P-40 (NP-40) in winter wheat (Triticum aestivum L.) by assessing its capacity to induce chromosomal aberrations, elucidating genotype–mutagen interactions, and determining its predictive value at the cellular level for inducing heritable epigenetic mutations. Four winter wheat varieties (Farell, NE 12443, Ronin, and Seilor) were exposed to NP-40 concentrations of 0.01%, 0.05%, 0.1%, and 0.5%. The cytogenetic analyses included assessments of pollen sterility and the frequency and spectrum of chromosomal aberrations in root-tip meristematic cells during mitosis. The results demonstrated significant genotype-specific responses to NP-40 treatment, with varieties Farell and, to a lesser extent, Ronin identified as particularly sensitive. These varieties exhibited a pronounced susceptibility, highlighting their suitability for targeted induction of genetic variability and subsequent mutant selection. Of the tested NP-40 concentrations, 0.5% NP-40 was observed to be the most effective, inducing substantial chromosomal aberrations while maintaining acceptable plant viability, thereby optimizing mutation induction and minimizing adverse cytotoxic effects. Conversely, moderate NP-40 concentrations (0.01–0.1%) were less effective, yielding a suboptimal balance between induced genetic variability and viability. Key cytogenetic indicators of genotype-specific sensitivity included pollen fertility, the total frequency of chromosomal rearrangements, and the number of chromosomal bridges. By contrast, parameters such as fragment abundance and the occurrence of rare aberrations were analytically less informative. Notably, the NP-40-induced chromosomal aberration patterns differed markedly from those typically observed with classical chemical supermutagens, with responses significantly influenced by genetic background. These findings offer valuable insights into the epimutagenic properties of NP-40, emphasizing the critical role of genotype selection and concentration optimization in effective mutation breeding strategies. Future research will integrate these cytogenetic observations with analyses of hereditary variability in biochemical and physiological traits, enhancing epimutagenic methodologies and improving breeding programs aimed at winter wheat cultivar advancement.