Determination of Salinity and Drought Tolerance in Different Cynodon dactylon Genotypes

In this study, the effects of salinity (0, 100, 200, 300, 400, and 500 mM NaCl) and drought stress on the germination and seedling development of five Cynodon dactylon genotypes (A, B, C, D, and Gobi), collected from different regions of Iğdır Province, Türkiye, were investigated. Analysis of variance showed that both stresses significantly affected the germination percentage, seedling growth, and physiological parameters. Increasing NaCl concentrations drastically reduced normal germination and biomass accumulation, completely inhibiting germination at 400-500 mM levels. Similarly, severe drought stress (75–95% water deficit) substantially decreased plant height, branch number, and biomass, whereas moderate stress (50%) resulted in limited reductions, indicating partial tolerance. Among the genotypes, Gobi showed the highest tolerance to both Stressors, providing greater germination, chlorophyll content, and biomass under adverse conditions. Genotype D also exhibited remarkable drought tolerance, attributed to its robust root system development. In contrast, Genotype A showed the lowest tolerance, with minimal germination and growth under stress conditions. These findings reveal significant genotype-by-environment interactions and confirm Gobi's superior adaptive capacity to salinity and drought stress, suggesting its potential use in breeding programs and for the restoration of marginal lands.