Determination of salt stress tolerance levels of different bean genotypes

In this study, which was carried out to determine the salt tolerance levels of different bean genotypes, 20 different bean genotypes were used as materials. Seeds of the genotypes were planted in 12 L pots containing peat: perlite mixture in a ratio of 2:1. Stress treatments were started 36 days after seed planting. For this purpose, starting from a dose of 50 mM NaCl, the salt concentration was gradually increased and a final concentration of 150 mM NaCl was reached. Plants exposed to salt stress for sixteen days were harvested and measurements and analyzes were carried out. Plants were examined in terms of morphological and physiological parameters. In terms of scale evaluation, GT 1 and GT-16 genotypes showed the closest development to control plants with a scale value of "1,33", while GT-8, GT-14, GT-18 and GT-19 genptypes showed the most development against salt stress with a scale value of "5". In other words, the genotypes that suffered the most were determined to be affected. Salt stress (150 mM NaCl) caused a decrease at varying rates in terms of shoot fresh and dry weights, stem length and diameter, leaf area, leaf relative water content (RWC) and SPAD value. Accordingly, the genotypes with lower losses compared to control plants are GT-6, GT-7, GT-11 and GT 16, it was observed that the genotypes with the highest losses were GT-8, GT-14, GT-18, GT-19 and GT-20. Membrane damage index (MDI) increased by 42%, Na and Cl ion contents increased by 724% and 845% on average compared to control plants. Among the genotypes that act selectively in terms of toxic ion content and accumulate less Na and Cl ions, GT-6, GT-7, GT11 and GT-16 ranked first, GT-2, GT-4, GT-8 and GT-9. Were the genotypes containing the most Na and Cl ions. K (48,16% decrease) and Ca (43,53% decrease) ion contents decreased with the application of 150 mM NaCl. This ii decrease was at a lower rate in GT-6, GT-7, GT-11 and GT-16. Losses in K and Ca ion content increased significantly in GT-8, GT-14, GT-19 and GT-20 bean genotypes. In line with all these results, in the study carried out at the early development stage, bean genotypes GT-6, GT-7, GT-11 and GT-16 were found to be tolerant, Genotypes GT-8, GT-14, GT-18 and GT-19 were determined to be sensitive.