Effects of salt stress on physiological indexes of Caragana leucophloea and Caragana aurantiaca seedlings

This study was to evaluate the physiological changes of Caragana leucophloea and C.aurantiaca seedlings under salt stress. One year old of C. leucophloea and C.aurantiaca seedlings were treated with 0.2%, 0.4%, 0.6%, 0.8% and 1.0% NaCl solution for 7 and 15 days, respectively. Leaf relative conductivity, contents of MDA and proline (Pro) of the seedlings were measured. The results showed that with increased NaCl concentration and longer of stress time, the leaf relative conductivity of C. leucophloea gradually decreased whereas the leaf relative conductivity of C. aurantiaca gradually increased. The MDA content of C. leucophloea decreased at first and then increased; MDA of C. aurantiaca gradually increased when NaCl concentration increased or salt stress was prolonged. When C. leucophloea and C. aurantiaca. plants were subjected to salt stress, the Pro content in leaves went up in order to maintaining the osmosis balance. Ultimately through overall assessment, it was concluded that salttolerance of C. leucophloea was higher compared wit C. aurantiaca.