Mutagenic Variations in Four Successive Generations of Cotton Varieties from Gamma Ray Treated Seeds

Seeds of cotton varieties Ganja-160, Ganja-182, and Ganja-183 were γ-irradiated with the isotope Co-60 at doses of 5, 10, 50, 100, 200, 300, and 400 Gy (at a dose rate of 0.342 rad/sec). Irradiated seeds, along with non-irradiated seeds (controls), were sown at the experimental base of the Center for Agricultural Sciences under open-field conditions in four replicates. The aim was to obtain mutant cotton lines with high quality and improved technological parameters, as well as resistance to various diseases and extreme environmental factors, and to use them as starting material for breeding. The nature of phenotypic changes occurring in four successive generations obtained by radiation mutagenesis was studied, and the economically valuable characteristics of mutant forms and fiber quality parameters were determined. Based on changes across four successive generations of plants, it was possible to identify mutant forms with 46 economically important traits, such as productivity, high fiber yield, and long, strong fiber, for breeding purposes. The results also showed that these plants not only exhibited high productivity but also had improved fiber parameters, such as fiber length and strength. The mutant cotton lines also exhibited improved technological parameters, such as fiber linear density, breaking strength, and staple length. The results demonstrated that γ- irradiation of seeds not only resulted in numerous phenotypic changes, high genetic diversity, and a wide spectrum of mutations in subsequent generations of these plants, but also enabled the development of mutant forms with several economically important traits. Based on these results, it can be concluded that radiation mutagenesis is an effective method for creating mutant plant libraries.