Differential response of ion and osmolyte accumulation to salinity stress in salt-tolerant and salt-sensitive seedlings of safflower (Carthamus tinctorius L.)

摘要

The response of four salt-tolerant and four salt-sensitive safflower genotypes to 0, 50, 100, 150 and 200 mM NaCl treatments was evaluated using leaf dry weight, free proline, total carbohydrates, and concentration of Na~+, K~+ and Ca~(2+) in the leafand root. The results of analysis of variance showed significant effects of genotype, salinity and genotype x salinity interaction for all the traits. The inverse relationships between dry weight and Na~+concentration as well as their positive correlations with K~+/Na~+ and Ca~(2+)/ Na~+ ratios were obtained by linear regression analysis in 200 Mm NaCl treatment. Leaf K~+/ Na~+ and Ca~(2+)/Na~+ ratios have been able to distinguish salt tolerant from salt sensitive genotypes, where the higher ratios were observed in salt tolerant genotypes particularly at the 200 Mm NaCl treatment level. It may, therefore, be concluded that maintenance and acquisition of both K~+ and Ca~(2+) are important determinants of salinity tolerance in safflower.