Effect of soil salinity on growth, metal distribution and photosynthetic performance of two Lycium species

Abstract

The effect of salinity on gas exchange and fluorescence characteristics in Lycium barbarum and Lycium chinense grown on nonsaline and saline soils was investigated. The distribution of Na+ between three types of substrates and different organs showed acropetal concentration gradient for Na+ accumulation only in L. barbarum grown on peat-moss-perlite and saline soil. Selective uptake of K+ over Na+ in the L. barbarum leaves was established. All plants grown on saline soil showed a slight inhibition of PSII activity as revealed by the quantum yield of the primary photochemical reaction. Intersystem electron transport, reduction of the end electron acceptors, and the performance index of photosynthesis declined to a greater extent in L. barbarum than that in L. chinense. The higher tolerance of L. chinense to salt stress was accompanied with the higher overall photosynthetic performance.

Keywords

• additional key words: chlorophyll fluorescence; metal contents; net photosynthesis; salinity.