The Physiological Response Of Different Salt-Tolerance Medicago Sativa L. Colonized By Arbuscular Mycorrhiza Fungi To Salt Stress

In order to discuss the effects of inoculated arbuscular mycorrhizal fungi (AMFs) under salt stress on physiological actions of alfalfa with different salt tolerance, the changes of inoculated three different kinds of AMFs(Gm,Ge and Gi) under salt stress on three different salt tolerance alfalfas on photosynthetic and Physiological and Biochemical Characteristics were analyzed. Salt stress test environment for greenhouse conditions 0 mM,50 mM and 100 mM,150 mM and 200 mM NaCl five single salt gradient, the effects of different salt resistance alfalfa growth under different salt stress with different arbuscular mycorrhizal fungi were analyzed.The results showed that under the non-salt stress, infection rate in (Zhongmu NO.1、Queen and Golden Queen)inoculated Gi were 81.13%,80.15%、75.05%, respectively higher than those that inoculated Gm with 78.17%、77.30%、74.19% and that inoculated Ge with 61.22%、61.19%、58.11%.This declared inoculated Gi on alfalfa infection rate higher. Infection rate between Gi and Gm had no significant difference, and that of Gi and Gm was significantly higher than Ge(P<0.05). The Physiological indexes and photosynthetic parameters of plant under salt stress inoculated Gi and Gm had obvious differences, and this stated host plant had less dependent on the Gi. The experimental results showed that AMF and better salt resistance of plant ware easy to form symbionts, but worse salt resistance of plant to form symbionts under salt stress was significantly suppressed.Under the condition of salt stress, AMF inoculation significantly improved the antioxidant enzyme activity of alfalfa, and the content of proline, soluble sugar, malondialdehyde, and soluble protein were increased, and enhanced with the increase of salt concentration. Salt stress inhibited plant photosynthesis at the same time, the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) were decreased, and the intercellular CO2 concentration (Ci) were raised. And different to the influence of different salt resistance of the plant. The promoting effect of salt tolerance of single AMF inoculation of better salt resistance Zhongmu NO.1 salt resistance is significantly higher than moderate salt tolerance of Queen and sensitive salt of Golden Queen. The experimental results showed that the Gm role in promoting greater than Ge and Gi, Gi promote greater than Ge, and significant difference.