Effect of drought and salinity stresses on morphological and physiological characteristics of canola

Environmental stresses such as salinity and drought are the most important factors affecting yield reduction and crops productivity. In order to investigate the effects of drought and salinity stresses on morphological and physiological characteristics of canola, an experimental campaign was conducted as a split plot based on a randomized complete block design with three replications at greenhouse of Agriculture Research Center and Natural Resources of East Azarbaijan in 2014. Main plots were including drought stress at four levels (0, -4, -8 and -12 bar polyethylene glycol solution) and subplots including salinity stress at four levels of sodium chloride (0, 75, 150 and 225 mM). The results analysis of variance indicated that the interaction of drought and salinity stresses was significant on leaf area and relative water content of leaf. The most leaf area (383.03 cm(-2)) was obtained at non-stress treatments. The results showed that drought stress conditions led to significant reduction in relative water content in leaf. The highest proline (0.08 mu m/g fresh weight) and soluble sugars (0.12 mg/g fresh weight) contents were observed at treatments of -12 bar polyethylene glycol. Also, the least proline (0.04 mu m/g fresh weight) and soluble sugar (0.06 mg/g fresh weight) contents were achieved at treatments of drought non-stress.