Effects of exogenous putrescine and calcium on ion uptake of strawberry seedling under NaCl stress

he effects of exogenous putrescine and calcium on plant biomass, leaf water content, proline content and ion uptake including Ca2+, Na+ and Cl- in strawberry (Fragaria ananassa Duch. cv. Darselect) under 150 mmol/L NaCl stress were studied. The plants for experiment were cultivated with medium in spot. NaCl and calcium nitric acid were dissolved in nutrient solution. The results showed that fresh weight and dry weight of shoot and root were increased by 14 mmol/L Ca(NO3)2 added in culture solution and 1×10-5mol/L putrescine sprayed on leaf. Although leaf water content, proline content, K+/Na+ and Ca2+/ Na+ were improved, assimilation and transport of natrium and chlorine were inhibited. Although K+ to Na+ ratio and Ca2+ to Na+ ratio were promoted by putrescine and calcium, both ratios were lower in plants treated by putrescine but without calcium. It indicated that the role of putrescine was promoted by calcium, but weakened overall or partly by calcium deficiency. It suggested that the role of exogenous putrescine controlling salinity-tolerance was related to Ca2+.