Study On Salt Tolerance Of Garden Greening Plant Hippophae Rhamnoides And Selection Of Salt-tolerant Hippophae Rhamnoides Varieties

Hippophae rhamnoides is one of the widely planted tree species in northern China.It has the landscape characteristics of flower,fruit and leaf viewing.It not only has the ecological function of improving the ecological environment,but also can improve the landscape of urban roads damaged by snowmelt salt.It can win a win-win situation?Dai Wei,2018?.In this paper,three salt treatment gradients were designed to simulate the stress of saline soil on Hippophae rhamnoides under artificial conditions,and the growth,photosynthesis and physiological and biochemical indexes of Hippophae rhamnoides seedlings under salt stress were measured.After experimental study,The following conclusions were drawn from the experimental study:?1?Studies on the growth of 12 species of Hippophae rhamnoides under salt stress found that the plant height,base diameter,total biomass,underground biomass and root-to-crown ratio of different species of Hippophae rhamnoides under salt stress were inhibited,and the stress increased with the increase of salt stress concentration.?2?Studies on photosynthetic characteristics of 12 species of Hippophae rhamnoides under salt stress showed that the net photosynthetic rate?Pn?,stomatal conductance?Gs?and transpiration rate?Tr?of different species of Hippophae rhamnoides decreased significantly with the deepening of salt stress and the prolongation of stress time;Yet for the intercellular CO₂concentration?Ci?,the Ci of Hippophae rhamnoides cultivars were decreased under medium and low salt stress.When the severe level was reached,the Ci of 201303,201305Hippophae rhamnoides cultivars no longer decreased but increased,but still lower than the control.?3?The physiological indexes of 12 species of Hippophae rhamnoides under salt stress showed that the free proline content?Pro?,soluble sugar content?SSC?,soluble protein content?SPC?and peroxidase activity of Hippophae rhamnoides increased significantly compared with the control under 50 mmol/L salt concentration.When the salt concentration increased to 100 mmol/L,the content of osmotic regulatory substance and peroxidase activity of most varieties changed more significantly,and the content of osmotic regulatory substance and peroxidase activity of a few varieties decreased with lower concentration,but still higher than the control.?4?The comprehensive salt tolerance of 12 species of Hippophae rhamnoides:Za you Xiong1>Zayoufemale54>Hippophae rhamnoides,China>201307>201305>201309>201310201303>201319201301>201308>201302.Through the above conclusions,the physiological mechanism of salt tolerance of Hippophae rhamnoides was preliminarily understood,and the salt tolerance ability of Hippophae rhamnoides varieties was comprehensively evaluated,which provided guidance and reference for the popularization and application of Hippophae rhamnoides varieties.At the same time,it also provided new varieties and new ideas for ecological landscape restoration,landscape greening and beautification on both sides of the road damaged by snow melting agent salt.