Study of the physiological and biochemical characteristics of lentils (Lens culinaris Medik) under salinity stress conditions

Salinity stress is one of the most important abiotic stresses that diminishes the yield of crops in semi-arid and arid regions. To investigate the effect of salinity stress on the physiological and biochemical characteristics of different lentil genotypes, a split plots experiment was conducted in a randomized complete block design with three replications in the salinity research farm of the Ferdowsi University of Mashhad in the 2021–2022 cropping year. The salinity levels of 2.5, 6, and 9 ds/m-1 six lentil genotypes were placed in the main plots and the secondary plots, respectively. The results showed that the carotenoids, phenols, leaf sodium contents, and biomass decreased with the increase in salinity stress level. The highest phenolic content of leaves was observed in salinity of 2.5 dS/m and MLC178 genotype, and with increasing stress intensity to 6 and 9 dS/m, the phenolic content of leaves decreased by 28 and 238%, respectively. MLC118 genotype had the highest activity of catalase enzyme under the condition of 2.5 dS/m and catalase enzyme activity decreased by 1.09 and 1.94 times with the increase of salinity stress to 6 and 9 dS/m, respectively. On the other hand, the highest biomass was observed at the level of 2.5 dS/m in the MLC117 genotype, which produced more biomass about two times compared to higher salinity levels. The MLC26 genotype had the highest proline content in leaves at a salinity stress level of 9 dS/m, when the salinity stress level decreased to 6 and 2.5 dS/m, the proline content of leaves decreased by 4% and 46%, respectively. In general, MLC117 and MLC12 genotypes were superior in most traits under salinity stress conditions.