Effects of salt stress on chlorophyll content and net photosynthetic rate of woody saltbush

To provide an excellent plant resource for vegetation restoration in saline land region, Atriplex tridentate, Atriplex gardneri and Atriplex canescen were taken as study objects and Hippophae rhamnoides and Ulmus pumila as a control group, the effects of the varying saline soil on chlorophyll content, net photosynthetic rate and the growth of three woody saltbushes were analyzed under different concentration stress of NaCl and Na2SO4. The results showed that: 1) the effect of different salt stress treatments on chlorophyll content in Atriplex tridentate, Atriplex gardneri and Atriplex canescens was less than that in Hippophae rhamnoides and Ulmus pumila; 2) the net photosynthetic ratio of three woody saltbushes was less than the control group as well. Under the high salt concentration stress treatment, three woody saltbushes in treatment group showed high stress resistance ability with higher net photosynthetic rate and normal metabolism; 3) the height and basal diameter of three woody saltbushes in treatment group was less than the control group. The change of plant height and basal diameter of 5 species on salinity gradient was similar to the change on plant photosynthetic rate under salt-stressed; 4) The slat-resistant ability of 5 species was assessed by the membership function method. The salt-resistant ability of NaCl was ranked as Atriplex gardneri＞Atriplex tridentate＞Atriplex canescens＞Hippophae rhamnoides＞Ulmus pumila, and the salt-resistant ability of Na2SO4 as Atriplex canescens＞Atriplex tridentate＞Atriplex gardneri＞Hippophae rhamnoides＞Ulmus pumila. Three woody saltbushes had high salt-resistant ability in photosynthetic and growth and were suitable to be planted in saline region. This paper provides theoretical basis for the use of saline land in arid area in the north of China.