Chromosomal rearrangements caused by gamma-irradiation in winter wheat cells

Abstract

In this article we report the results of our investigation into several cytogenetic parameters of variability in mutation induction of modern winter wheat varieties and some connections between the means of cytogenetic indices and different doses of gamma-rays. Analysis of chromosomal aberrations following the action of any kind of mutagen by the anaphases method is one of the most widely investigated and most precise methods which can be used to determine the fact of mutagenic action on plants and identify the nature of the mutagen. We combined in our investigation the sensitivity of genotype to mutagen using cytological analysis of mutagen treated wheat populations with the corresponding different varieties by breeding methods to reveal its connections and differences, specific sensitivity to mutagens action on the cell level. Dry seeds of 8 varieties of winter wheat were subjected to 100, 150, 200, 250 Gy gamma irradiation, which are trivial for winter wheat mutation breeding. We investigated rates and spectra of chromosomal aberrations in the cells of winter wheat primary roots tips. The coefficients of correlations amid the rate of chromosomal aberrations and the dose of gamma-rays were on the level 0.8-0.9. The fragments/bridges ratio is a clear and sufficient index for determining the nature of the mutagen agent. We distinguished the following types of chromosomal rearrangements: chromatid and chromosome bridges, single and double fragments, micronuclei, and delayed chromosomes. The ratio of chromosomal aberrations changes with the change in mutagen; note that bridgetypes are characteristic of irradiation. Radiomutants are more resistant to gamma rays. This is apparent in the lower rate of chromosomal aberrations. Varieties obtained by chemical mutagenesis (varieties Sonechko, Kalinova) are more sensitive to gamma-irradiation than others. We propose these varieties as objects for a mutation breeding programme and radiation of mutants for planting in areas subject to the action of gamma-rays.

Rates and spectra of chromosome aberrations in winter wheat cells after dimethylsulfate action

“…Number of any type of chromosomal changes was leaped with concentration ascended (correlation coefficients 0.87 was significantly higher than for other chemical mutagens, comparable with gamma-rays). In this case, like as for nitrosoalkylureas (Nazarenko, 2016) and DAB , more fragments and double-fragments were caused by DMS action (fragmentsbridges ratio more than 1), except some variants with difference concentration of DMS, which depends on genotype (variety) (sometimes equally or slightly less than 1, as for example at any concentrations for variety Voloshkova)) (Nazarenko, 2016;Nazarenko, Izhboldin, 2017;. But in the most cases we will be able to use this parameter for identify difference between gamma-rays action and chemical mutagenesis in case of unknown mutagen factor.…”

“…Influence of DMS is compared with gamma-rays (in spite of other chemical mutagens) and, not only by aberration rates, but by parameters of spectra of chromosomal aberrations is very similar to gamma-irradiated. We can range mutagens in next sequence by its genetic activity (from lowest to peak) DAB ) → NEU → NMU (Nazarenko, 2016) → gamma-rays (Nazarenko, Izhboldin, 2017) → DMS. From Table 1 we cannot identify in any way varieties or group of varieties more or less sensitive to DMS action.…”

“…DMS as a mutagen factor is traditionally related to the same family of mutagens (supremutagens), which used in our previous investigations (Nazarenko, 2016;Nazarenko, Izhboldin, 2017; due to mechanism of action on DNA-level, but with a little distinguishes (Eiges, 2013). Mutagen effects on cell and whole plant level (named as mutagen depression) are the key factors which limited either winter wheat productivity for agricultural purpose at first generation (due to some modern investigations at next generations too (Mangi et al, 2016) or quantity of materials obtained for next stapes of mutation breeding programs after mutagen action for identification and selection of mutants.…”

“…This article is a forth part of our investigation of recurrent mutagen treatment of winter wheat varieties. In previous parts we developed effects of genotype-mutagen interaction after gamma-ray irradiation and nitrosomethilurea (NMU), nitrosoethilurea (NEU), 1,4-bisdiazoatsetilbutan (DAB) (Nazarenko, 2016;Nazarenko, Izhboldin, 2017;. In spite of previous mutagens DMS didn't use in breeding of varieties, which we used for investigation.…”

Detection of cytogenetic and genotoxic effects of gamma radiation on M1 generation of three varieties of Triticum aestivum L.

“…Spontaneous chromosome aberration rates are about 0.6% in plant cells which are first-tier assay systems for the detection of possible genetic damage by environmental chemicals (Grant, 1978;Rakhmatullina & Sanamyan, 2007;Nikolova et al, 2015). Numerous cytogenetic studies have reported that mutagenic disorders on plant cell metabolism result from possible structural or numerical abnormalities on chromosomes (Gadano et al, 2002;Swierenga et al, 1991;Bolwell & Wojtaszek, 1997;Nazarenko & Izhboldin, 2017). One of the most important effect of seeds treated to higher gamma ray dose through inhibition of cell division in the meristematic cells is impaired mitosis (Nurmansyah et al, 2018).…”