Growth and Physiological Attributes of Tomato (<i>Lycopersicon esculentum</i> Mill.) Genotypes as Affected by NaCl Stress

Abstract

High level of salinity adversely affects growth, productivity as well as quality of vegetable crops by reducing photosynthetic capacity, enzyme activities, and by enhanced production of reactive oxygen species (ROS). These ROS cause peroxidation of membrane lipids leading to disintegration of cell membrane with the leakage of electrolytes. All these detrimental effects ultimately contribute to the crop with reduced yield and low nutritive value. The present investigation was carried out to test salt tolerance capacity of ten genotypes of tomato on the basis of growth, physiological and biochemical characteristics. The results show that all the ten tested genotypes of tomato responded differently to 200 mM NaCl stress. Regarding growth parameters, BL-1076 gave higher values, while Queen gave the lowest values for most of the parameters (plant height, number of leaves, leaf area, shoot and root fresh weight and dry weight). Regarding physiological and biochemical parameters, BL-1076 gave higher values for the activities of carbonic anhydrase and nitrate reductase, leaf chlorophyll content, relative water content, and activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase). However, genotype Queen gave the lowest values for these parameters. On contrary, the least membrane damage (TBARS content) was registered in BL-1076, while the highest in Queen. Overall assessment of results leads to the conclusion that the genotype BL-1076 was found salt tolerant while Queen salt sensitive. The ten genotypes may be arranged on the basis of their salt tolerance capacity in decreasing order as: BL-1076 > Trust > Imperial > Tanshet star > PakmoreVF > L 26 > Plitz > Bonus F1 > Grace > Queen.