Reaction of Winter Barley Specimens to Seed Treatment With Chemical Mutagens
In nature, a huge variety of traits is created in the systems of living organisms due to the occurrence of mutations. The use of ionizing radiation, ultraviolet rays, and many chemical compounds makes it possible to significantly increase the frequency of gene mutations, the genotypic and phenotypic variability of traits, and to achieve a sharp increase in the efficiency of artificial selection and the intensity of the selection process. The genotypic flexibility of the population and selection ensure adaptation to long-term changes in environmental factors. In the present work, the specificity of the mutagenic effect of some chemical mutagens on the winter barley variety Ardak on the variability of population and individual traits was studied for the first time. Our goal was to study the effect of carbolite and N-nitrosomethylurea in different concentrations on the agrobiological characteristics of winter barley. The scientific novelty of the conducted research lies in the study of the effect of carbolite and N-nmm in different concentrations on the agrobiological characteristics of winter barley, as well as on the content of total nitrogen and proteins in barley grains at previously unused or little studied doses. The object of the study was the seeds of barley variety Ardak. Carbolite compounds, N-nitrosomethyl urea were used as mutagenic factors. Carbolite was used at a concentration of 2n, the seeds were treated with carbolite solution for 6, 12, 18 and 24 hours. In the present studies, N-nitrosomethyl urea was used at concentrations of 0.012% and 0.025%. Barley seeds were treated with aqueous solutions of the mutagen for three hours, and then washed in running water at a temperature of 22 °C for 30 minutes. Control seeds were soaked in water. After treatment, the seeds were dried on filter paper and sown in the soil after 10 days. Each option contains 250 seeds. Seed germination was counted after two weeks. Subsequently, the linear parameters of plants were measured every 10 days. After harvesting, the plants were analyzed for morphological changes and the total percentage of changed plants was calculated. In addition, the sign was studied - the weight of 1000 grains. Seeds of the first generation for the next year were sown in the soil according to the treatment options (250 pieces). Second generation plants were analyzed in the same way as M<sub>1</sub> plants. Next, a biochemical analysis of the seeds was carried out to determine the total amount of nitrogen and protein according to the treatment options. The Kjeldahl micro-method was used to determine total nitrogen. As a result of the research, it was found that carbolite at a concentration of 2n in 6- and 18-hour exposures stimulates the content of total nitrogen and protein in the first generation in grains of barley variety Ardak. It has an overwhelming effect on the biochemical processes of barley seeds in the second generation. At the same time, carbolite inhibits the development of barley and causes the appearance of a large number of speltoid and sterile plants. But at the same time, it should be emphasized that a large number of speltoids and sterile plants in the variants treated with carbolite decreases in the second generation. N-nmm at concentrations of 0.012% and 0.025% contribute to an increase in the content of total nitrogen and protein in barley grains. The increased content of nitrogen and protein in the treated N-nmm variant is preserved in the second generation. It should be noted that N-nmm at a concentration of 0.012% is more effective for this variety than at a concentration of 0.025%. Also, N-nmm inhibits the development of barley and causes a large number of morphological changes. In a comparative study of the effect of mutagens N-nmm and carbolite on the content of the total amount of nitrogen and protein, it was found that N-nmm contributes to an increase in the amount of nitrogen and protein, while carbolite decreases.