آسکوربیک اسید و تاثیرات آن در کاهش صدمه ناشی از تنش شوری در گیاه آفتابگردان

In order to investigate the germination and seedling growth reaction of sunflower to salinity stress and ascorbic acid priming, this experiment was done in factorial arrangement based on completely randomized design with three replications. In this experiment the first factor was ascorbic acid priming with 3 levels included 0, 1 and 2 mM and second factor was salinity stress with 3 levels included 0, 100 and 200 mM of NaCl. Some seedling characteristics including number of germinated seeds, hypocotyl length, radicle length, hypocotyl dry weight, radicle dry weight, relative water content and ion leakage were measured. The effect of different salinity levels on sunflower germination was significant so that number of seed germinated decreased with increasing in saline concentration. The reaction of sunflower seeds to ascorbic acid priming was difference from salinity so that with increasing in ascorbic acid concentration the number of seed germinated was better than control. Also the effect of this matter on other indicators measured was significant statistically.
Results showed that seed primed with ascorbic acid under salinity stress could be alleviated the stress effect that concentration of 2 mM ascorbic acid was found as the best concentration in order to apply pretreatment before planting.