Investigation of Morphological and Physiological Responses of Suaeda fruticosa to Different Concentrations of Saline Water

This studywas conducted as a completely randomized design with 3 replicates at Research Greenhouse of National Salinity Research Center, during 2017-18 growing season. Treatments were seven levels of water salinity: 3 (control), 10, 20, 30, 40, 50 and 60 dS.m-1. Throughout the experiment, plant length, fresh weight, dry weight, leaf area, chlorophyll content, soluble sugars and proline were measured. Results showed that salinity treatments significantly affected all the traits. Salinity significantly reduced plant height, such that plants in 60 dS/m were 12.37% shorter than those of 3 dS/m. Fresh weight, dry weight, leaf area, chlorophyll a, and total chlorophyll were increased by increasing stress level from 3 to 30 dS/m, but then significantly decreased by increasing salinity up to 60 dS/m. Increasing salinity from 3 to 30 dS/m increased plant dry weight by 3.7 g per plant, but increasing it to 60 dS/m reduced dry weight. Increasing salinity to 60 dS/m led to enhanced proline (52.03%) and soluble sugars (21.21%). Salinity tolerance threshold of Suaeda fruticosa was 31 dS m-1 and the slope of dry matter decrease was 0.22% per increase in each salinity unit.