Response of Brassica napus L grains to the interactive effect of salinity and salicylic acid

Soil salinity is a serious environmental problem that has negative effect on plant growth, production and photosynthesis. Fresh and dry plant weights decreases with salinity treatments. The very important role of salicylic acid (SA) in response to different stress and modification and decline damages due to stresses has established in different studies. In this research, effect of grain soaking presowing in (0, 1, 1.5, 2 and 5 mM) of salicylic acid (SA) and NaCl (0, 4, 8 and 12 dsm-1) on canola (Brassica napus L) was studied. Increasing of NaCl level reduced the germination percentage(GP), Average velocity of germination (AVG) and growth parameters of 15-day old seedlings in compared to control plants. pretreated of SA in content 1mM significantly increased the germination percentage, and in contents more than of 1mM reduced the germination percentage in seeds under salinity stress. SA in content 1mM increased RWC, root and shoot of fresh weight in the stressed seedlings. Increasing of NaCl level increased Electrolyte leakage and MDA content in the stress seedling. electrolyte leakage and MDA content were markedly reduced under salt stress with SA 1mM than without. It was concluded that SA could be used as a potential growth regulator to improve salt tolerance in canola. Our observations indicate that, although SA is not essential for germination under normal growth conditions, it plays a promotive role in seed germination under high salinity by reducing oxidative damage.