Effect of salinity stress on plant fresh weight and nutrient composition of some Canola (Brassica napus L.) cultivars
Soil salinity is a major limitation to crop production in many areas of the world. A pot experiment was carried out with rapeseed cultivars in order to investigate the effects of salinity stress on plant development and nutrient composition. For the salinity studies, 150 mM NaCl concentration was applied to12 rapseed cultivars (Marinca, Kosa, Spok, Semu DNK207 NA, Tower, Liraspa, Star, Tobin, Helios, Semu 209/81, Regent and Lirawell) under the greenhouse conditions. All the cultivars were harvested after 45 days from planting. Green plants parts were weighted. Harvested rapeseed plants were separated into root, shoot and leaf parts for nutrient (K+, Na+, K+/Na+, Ca2+ and Cl-) analysis. As shown in this study, salinity stress affected negatively all the canola cultivars investigated. Generally, salinity reduced the green parts’ weight. K+, Ca2+ and K+/Na+ contents in plants decreased by salt stress, but Na+ and Cl- content in the roots, shoots and leaves of all the cultivars significantly increased. In the salt treatment, the K+ and Ca2+ concentrations were the highest in the leaf samples as compared to root and shoot samples. Furthermore, the highest concentration of Na+ and Cl- was observed in the leaf and shoot. Under salinity, Regent and Lirawell cultivars retained the highest K+ and Ca2+ content in leaves, with respect to the K+ content. The effect of NaCl treatment on the canola cultivars’ growth was not considerable.
Key words: Canola cultivars, green plant parts, nutrient content, salt stress.