Agrology (Dec 2022)
Cytogenetic effects of low-damaging chemical supermutagen action on winter wheat samples
Abstract
By using specifics of initial material for activation of the mutagenic process, the variability of the resulting material can be increased significantly. This is especially important for mutagens with low damaging effect, but with a high affinity for certain structural DNA peculiarities at the same time. We studied the cytogenetic activity of mutagens according to several parameters of chromosomal abnormalities during mutagenic depression in the first generation subject to water solution of DAB (1,4-bisdiazoacetylbutane) in 0.1%, 0.2%, 0.3% concentrations. Eight varieties of winter wheat were used as objects for maximal characterization of possible genetic variability and its influence on the cytogenetic activity. The varieties were obtained from both national and international breeding institutions. It was found that this mutagen agent induced cytogenetic activity at a significantly lower level than other substances generally accepted for the practice of genetic improvement using this method. The total number of chromosomal aberrations was 10 times lower, but significantly higher than in the case of using epimutagens. The absence of significant effects consisting in cell elimination as a result of disorders in the chromosomal apparatus indicates moderate concentrations. We determined that in the case of increasing concentrations, the model parameters can be the total rate of rearrangements, presence of fragments, presence of cells with two or more aberrations. For the variety factor, only the presence of micronuclei and lagging chromosomes was significant. This feature is not sufficient for effective classification of the group of genotypes, i.e., the variability of the group as a whole is too low. However, there are two varieties significantly differing from the other six by this parameter. This gives hope for a significant increase in mutational activity at the plant level due to optimization of the genotype-mutagenic interaction in the case of DAB. Also, despite the low damaging effect, this mutagen can be promising for induction of certain types of changes, as indicated by presence of a fairly significant number of rare changes. The initial material showed a fairly high stability, which practically excludes the occurrence of spontaneous changes in the future. It is planned to screen the obtained forms to detect changes in the phenotype, primarily in the architecture of the plant, identifying the inheritance of the identified traits in the next generations in order to identify change in the mutation. Also, we plan to analyse the obtained forms for valuable properties in terms of grain quality.
