Growth performance and physiological response in the halophyte Lycium barbarum grown at salt-affected soil

As a traditional Chinese medicinal plant, Lycium barbarum is of high economic value and has attracted many considerable interests in recent years. The plant is a perennial halophyte grown under extreme conditions, especially under highly saline soil. A pot experiment was carried out to quantify the responses of L. barbarum plants to soil salinity applied at 100 and 200 mM NaCl. The results demonstrate that 100 mM NaCl soil improves the growth of L. barbarum seedlings. Because the 100 mM NaCl soil enhanced plant height and dry matter by 20% and 30% compared with the nonsalinised soil, it is considered suitable, and the 200 mM NaCl soil showed negative effects, too extreme for the growth of L. barbarum. The leaf cations and betaine content increased significantly under salt stress. The leaf chlorophyll, gas exchange, photochemical efficiency, leaf area and soluble sugar contents showed a significant decrease under 200 mM NaCl stress compared with the nonsalinised and the 100 mM NaCl-affected soil. The results do not provide a basic mechanism for the observed growth stimulation; however, they suggest that L. barbarum may be an economic species for cultivation in moderately saline areas such as northwest China.