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

Abstract

Salicylic acid has been found to play an important role in the regulation of plant growth and development in response to environmental stress es. In the present study, the effect of salicylic acid (SA) (0 and 0.1 mM) on growth parame ters and some physiological characteristics of two strawberry cultivars ("Kurdi stan" and "Queen Elisa") was investigated under drought stress treatments (-0.1 and -1 MPa). Experimental design was factorial based on completely randomized design wit h three replications. Results showed that drought stress decreased leaf area, leaf dry m atter, shoot dry matter, total dry matter, relative water content, stomatal conductanc e, 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, yie ld 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 Elis a" 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 pro tein. 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 an d area, crown, and total dry matter compared to “Queen Elisa”. SA application altered s ome physiological responses of both cultivars under drought stress. The effect of SA wa s more pronounced in "Kurdistan” than "Queen Elisa". Keywords: Antioxidant enzymes, Dry matter, Proline, Soluble c arbohydrate, Yield.