Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 23 5 2021 09 01 Physiological and biochemical responses of four genotypes of common bean (Phaseolus vulgaris L.) under salt stress پاسخ های فیزیولوژیکی و بیوشیمیایی چهار ژنوتیپ لوبیای معمولی (Phaseolus vulgaris L.) تحت تنش شوری 1091 1103 16589 EN Z. Azimychetabi Faculty of Agricultural Sciences and Engineering, College of Agriculture & Natural Resources, University of Tehran M. Sabokdast Faculty of Agricultural Sciences and Engineering, College of Agriculture & Natural Resources, University of Tehran Journal Article This investigation was conducted to determine the effects of salinity stress on some physiological and biochemical parameters of common bean (<em>Phaseolus vulgaris</em> L.). Three levels of NaCl (0, 100, and 200 mM) were applied to four common bean genotypes. In the subsequent steps, chlorophyll content, relative water content (RWC), electrolyte leakage index (ELI), Na⁺ and K⁺ concentrations, the K/Na ratio, malondialdehyde (MDA) content, total protein content, and proline concentration were determined and compared. Moreover, the activity of antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO), and guaiacol peroxidase (GPX) were analyzed. Content of Chl a, Chl b and carotenoid decreased by increasing the intensity of salinity stress along with the SPAD value. RWC dropped and ELI incremented by augmenting salinity together with the K/Na ratio. The results revealed that MDA and proline concentrations significantly increased under the mentioned conditions. Activities of antioxidant defense enzymes were altered notably. Total protein content mitigated under salt stress. Jules and 201 were detected as tolerant genotypes during this experiment. https://jast.modares.ac.ir/article_16589_6ccb2d9992760410aabb04bab13ca37e.pdf