Ascorbic Acid and It′S Effects on Alleviation of Salt Stress in Sunflower

Salinity, a severe environmental factor, has limited the growth and productivity of crops. Many compounds have been applied to minimize the harmful effects of salt stress on plant growth. A laboratory experiment was carried out to assess the effects of seed priming with ascorbic acid (ASA) on germination characteristics of sunflower (Helianthus annuus L.). The seeds were treated with different concentrations of ASA (0, 1 and 2 mM) before germination, then the primed seeds were germinated under salinity stress conditions using different concentrations of NaCl (0, 100 and 200 mM). Some germination characteristics including germination percentage, germination rate, seed stamina index, hypocotyl dry weight, radicle dry weight, relative water content and ion leakage were measured after imposing salinity stress for 8 days. Salinity stress caused a significant reduction in germination and seedling growth of sunflower. Seeds primed with various concentrations of ascorbic acid proved to be effective in salinity tolerance at the germination stage of sunflower. In general, priming with 2 mM ascorbic acid was more effective than the other concentrations.