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INTERACTIVE EFFECT OF FOLIARLY APPLIED ASCORBIC ACID AND SALT STRESS ON WHEAT (TRITICUM AESTIVUM L.) AT THE SEEDLING STAGE

AMEER KHAN¹, MUHAMMAD SAJID AQEEL AHMAD¹, HABIB-UR-REHMAN ATHAR² AND MUHAMMAD ASHRAF¹

Abstract: A hypdoponic experiment was conducted to assess the role of ascorbic acid in alleviation of the adverse effects of salt stress on growth of two wheat cultivars, S-24 (salt tolerant) and MH-97 (moderately salt sensitive). Seven-day old plants were subjected to normal or saline conditions (0 and 150 mM) for four weeks. Ascorbic acid was exogenously applied as foliar spray with varying levels (0, 50, 100 mg L^-1) in hydroponics. Salt stress severely reduced growth of both wheat cultivars. Foliar spray with AsA improved the growth of non-stressed plants of both cultivars, but did not alleviate the adverse effects of salt stress on plants. However, salt-induced reduction in leaf chlorophyll ‘a’ was improved with AsA application. Salt-induced enhanced activities of all antioxidant enzymes were not substantially changed with AsA application. However, AsA application enhanced the Na⁺ accumulation in the leaves of salt stressed plants of both cultivars, but it did not change the K⁺ accumulation in the leaves and roots of the salt stressed plants of both cultivars. Furthermore, AsA applied as a foliar spray did not induce substantial changes and hence salt tolerance of both wheat cultivars. Thus, it can be concluded that though foliar spray with applied ascorbic acid protected the photosynthetic machinery from the damaging effects of salt stress, it did not improve growth of the two wheat cultivars under saline conditions.

¹Department of Botany, University of Agriculture Faisalabad, (38040), Pakistan

² Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan

Corresponding Author: Ameer Khan; ameeruaf@yahoo.com