Effect of salinity stress on some physiological traits of spring rapeseed genotypes at seedling stage
By: Nima Dolatabadi, Mahmoud Toorchi, Mostafa Valizadeh, Ali Bandehagh
Key Words: Brassica napus L., growth parameters, physiological traits, K+/Na+, salt stress.
J. Bio. Env. Sci. 9(6), 135-142, December 2016.
To study the effects of salinity on rapeseed (Brassica napus L.) and clear the role of K+ and Na+ in salt stress tolerance, an experiment was carried out in three salinity levels (0, 150 and 300 mM) and 16 genotypes with three replications under hydroponic culture system in greenhouse of university of Tabriz. Growth and physiological traits were measured 28 days after imposing NaCl stress at the end of seedling stage (42 days old).Salinity stress was affected all of the traits significantly. All of the traits were decreased by salt stress except electrolyte leakage and Na+ content of shoot and root. Significant differences were observed among genotypes in all of the studied traits, which indicate valuable genetic variability between the genotypes. Safi7 and Option500 genotypes with the highest and lowest performance in growth and physiological traits were identified as tolerant and susceptible genotypes, respectively. Safi7 genotype has the lowest Na+ content of shoot and highest shoot K+/Na+ ratio while genotype Option500 has the highest Na+ content of shoot and the lowest shoot K+/Na+ ratio. Due to the amount of K+ in shoots and roots weren’t significantly changed in genotypes; it seems rapeseed genotypes cope with salt stress by removing undesirable Na+ ions, not through adsorption of K+ ions.