Salinity Induced Changes in Biomass Partitioning and Physiological and Biochemical Traits in Syzygium cumini

Abstract

Soil salinity reduces crop yields and ultimately reduces crop productivity in salt-affected areas, posing a global threat to global agriculture. The current study focused on the salt stress tolerance mechanism in seedlings of Syzygium cumini and its effect on biomass production and plant physiology. A pot experiment was conducted and the seedlings were taken from the forest nursery and placed into the earthen pots. These seedlings were exposed to six salt treatments such as T₁ (control), T₂ (4 dSm^-1), T₃ (8 dSm^-1), T₄ (12 dSm^-1), T₅ (16 dSm^-1) and T₆ (20 dSm^-1) for 6 months. There were four replicates per treatment and a total of 24 plants were examined. The results showed that there was significant difference in growth and physiology of Syzygium cumini under different level of salt stress. The fresh and dry weights of shoots and roots were greatly reduced due to the increase in salt concentrations. The reduction in the amount of chlorophyll contents in the leaves was correlated with these changes. The maximum Chl a, Chl b and total Chl contents were 0.7033 mg g^-1 FW, 0.9096 mg g^-1 FW, 1.5007 mg g^-1 FW in T₁ (control) while the minimum Chl a, Chl b and total Chl contents were 0.2993 mg g^-1 FW, 0.5132 mg g^-1 FW, 0.8737 mg g^-1 FW in T₆ (20 dSm^-1) respectively. However, in the case of SOD, POD and CAT the maximum activity 3.51 U mg^-1 protein, 11.98 U mg^-1 protein, 5.693 U mg^-1 protein was recorded in T₆ (Control) while the minimum activity 0.7876 U mg^-1 protein, 37.61 U mg^-1 protein, 1.692 U mg^-1 protein was recorded in T₁ (control). Overall the results showed that the Syzygium cumini showed stunted growth with the increase of salt stress. The obtained findings will be helpful for future soil reclamation projects.