Morpho-physiological Responses of Strawberry (Fragariaxananassa) to Exogenous Salicylic Acid Application under Drought Stress

Salicylic acid has been found to play an important role in the regulation of plant growth and development in response to environmental stresses. In the present study, the effect of salicylic acid (SA) (0 and 0.1 mM) on growth parameters and some physiological characteristics of two strawberry cultivars ("Kurdistan" and "Queen Elisa") was investigated under drought stress treatments (-0.1 and -1 MPa). Experimental design was factorial based on completely randomized design with three replications. Results showed that drought stress decreased leaf area, leaf dry matter, shoot dry matter, total dry matter, relative water content, stomatal conductance, yield, and fruit weight. Salicylic acid application increased total leaf area and leaf and shoot dry matter in both cultivars. Leaf number, root dry matter, total dry matter, yield and fruit weight were increased by SA application in "Kurdistan" under drought stress. "Kurdistan" cultivar had higher RWC than "Queen Elisa" and SA application increased RWC, proline and soluble carbohydrate in "Kurdistan" compared to "Queen Elisa" under drought stress conditions. RWC, proline and soluble carbohydrate of "Queen Elisa" did not change with SA spray. Total soluble protein was not affected in "Kurdistan" under drought stress, while "Queen Elisa" showed a reduction in total protein. SA application increased catalase and peroxidase activity in both cultivars under drought stress. In conclusion, "Kurdistan" was less susceptible to drought stress than "Queen Elisa" because "Kurdistan" showed less reduction in leaf number and area, crown, and total dry matter compared to "Queen Elisa". SA application altered some physiological responses of both cultivars under drought stress. The effect of SA was more pronounced in "Kurdistan" than "Queen Elisa".