Evaluation of ethyl methanesulfonate-induced in vitro mutagenesis, polymorphism and genomic instability in wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) is highly rich in nutrients and is an important staple food for humankind. Mutation breeding offers a relatively quick method for crop improvement and it provides variation for selective breeding programs and functional gene studies. In vitro mutagenesis, coupled with in vitro regeneration procedure, can offer a wide variety of plant materials for mutagenesis; enable generation of large mutant populations in a relatively short period. Present experiments were conducted to investigate potential use of conventional chemical mutagenesis technique through ethyl methanesulfonate (EMS) for mature embryo culture in wheat. EMS mutagenesis was experimented with 4 treatment durations (2, 4, 6, and 8 h) and 5 treatment concentrations (0, 0.1, 0.2, 0.3, and 0.4%). Mature embryos were treated to detect optimum doses of mutagenesis and to estimate polymorphism and genomic instability. First of all, 50% reduction in number of regenerated plants as compared to the control (LD) was adopted as the optimum dose. Treated and untreated mature embryos were transferred to callus induction media. EMS mutagens at different duration and concentration had significant effects on callus formation rate (%), embryogenic callus formation rate (%), responded embryogenic callus rate (%), regeneration efficiency and number of plants parameters. Based on LD50 criterion, the optimum value was achieved at 8 h duration of 0.1% EMS concentration. Secondly, inter-primer binding site (iPBS) markers was applied to investigate insertion polymorphism and genomic instability in the regenerated plants. EMS mutagenic treatments had significant effects on different effects on polymorphism and genomic instability of regenerated plants. Present findings revealed that in vitro mutagenesis might be a useful approach for accelerating breeding strategies to create enough genetic variation in wheat populations. Besides, an integrated approach can be used to carry out mutation-assisted breeding and subsequent selection of desired mutants using molecular markers in wheat.