Salinity Induced Differential Growth, Ionic and Anti-Oxidative Response of Two Bell Pepper (Capsicum annuum) Genotypes

Salinity poses a serious threat to vegetable crop production in terms of crop quality and yield reduction globally. This pot experiment was performed to evaluate the effect of different salinity levels (0, 25, 50, 75, 100 and 125 mA4 of NaCl) on seedling growth, antioxidant activity and ionic concentration of different ions in two bell pepper genotypes viz., California Wonder (salt tolerant) and Green Beauty (salt sensitive). With increasing salinity levels from 0 to 125 mA4 bell pepper shoot fresh and dry weight, root dry weight, shoot and root lengths, leaf potassium (K+) and root sodium (Na+) contents decreased linearly in both genotypes. However, this decrease was more pronounced in genotype Green Beauty at 125 mA4 salinity level compared to California Wonder. In contrast, peroxidase, catalase, leaf proline, leaf Na+ and root K+ contents increased significantly with increasing salinity stress levels (0 to 125 mM) in both genotypes. Since magnitude of this increase was much higher in genotype California Wonder at 125 mA4 salinity level when compared to Green Beauty. Moreover, shoot fresh and dry weights, root dry weight and shoot and root lengths were positively correlated with leaf and root K+ contents and had negative correlation with leaf and root Na+ ions, respectively. Therefore, by maintaining better seedling growth with higher accumulation of catalase, peroxidase and proline contents as well as K+ and Na ion ratios at all salinity levels California Wonder better tolerated the salinity stress as compared to Green Beauty. (C) 2020 Friends Science Publishers