Evaluation of genetic polymorphism and drought and salinity tolerance of Amaranthus cruentus L. mutants

Abstract

Background. Drought and salinization are serious environmental problems in agriculture. Therefore, it is important to grow cultivated plants resistant to abiotic environmental factors in the fields. Due to its high nutritional value and adaptation to diverse environmental conditions, amaranth is considered a promising crop for cultivation, including in arid zones. In connection with modern climate change, the urgency of breeding more stressresistant amaranth varieties is increasing.The purpose of the study is to assess the genetic diversity and stress resistance of mutant forms of red amaranth Amaranthus cruentus L. obtained using sodium azide. Materials and methods. Using microsatellite markers at three SSR loci, the molecular genetic polymorphism of seven mutant forms of amaranth generation M3 was evaluated. According to SSR markers GB-AM-132 and GB-AM-137, mutant plants did not differ from each other and from the wild type. Using the SSR marker GBAM-099, three alleles with three combinations of them were identified among the analyzed mutant plants. Results. According to the results of morphophysiological analysis under conditions of abiotic stress, one of the mutant lines during drought had the best indicator of the relative water content, was characterized by the highest results in terms of stem height and biomass, and in these mutants an increase in the activity of ascorbate peroxidases and glutathione-S-transferases was recorded, compared with wild type. The results obtained indicate a high drought resistance of this mutant line. Another mutant line showed high salt tolerance. Thus, under saline conditions, these mutants were characterized by an increased stem height, an increase in the total antioxidant capacity, as well as an increase in the activities of ascorbate peroxidases and glutathione-S-transferases compared to the wild type. Conclusions. Thus, as a result of our study, mutant forms of amaranth were identified that are resistant to lack of water and excessive salt content in the soil. These forms of amaranth can be used as a material for breeding of stress-resistant varieties.

Keywords

• amaranth
• sodium azide
• microsatellite markers
• ssr analysis
• antioxidant system
• drought resistance
• salt resistance