Comprhensive Evalution Of Saline-alkali Resistance And Research Of Physiological Adaption Mechanism Of Alfalfa

The alfalfa was disposed by using different concentrations of mixed saline-alkali stress of NaCl:NaHCO3:Na2SO4:Na2CO3=1:9:9:1, and was evaluated about saline-alkali resistance ability, so to analyze adaptive physiological mechanism of alfalfa under saline-alkali stress, The results show that:1. Different alfalfa varieties had big differences of saline-alkali resistance in seed imbibition period and seedlings, clustering analysis indicates that:23alfalfa varieties were divided into4types, XinmuNO.l, WL414, Sardi5, Derby and WL343HQ were tolerant saline-alkali varieties of alfalfa,WL323HQ, Queen and Algonquin were sensitive saline-alkali varieties of alfalfa. Fuzzy Mathematics membership function showed: resistance to saline-alkali order of23alfalfa varieties were XinmuNO.1>WL414>Sardi5>Derby>WL343HQ>Concept>WL232HQ>Ieon>Sitel>Adre nalin>WL903>Lobo>Eureka>Sandity>ZhongmuNo.1>WL525HQ>WL323ML> Aohan> Baoding>WL323HQ>Queen>Algonquin.2. Using4alfalfa varieties of different saline-alkali resistance ability as material were disposed by different concentrations of mixed saline-alkali stress in seeding, so to analyze antioxidant properties and osmotic regulation characteristics of alfalfa, The results show that:with the increasing concentration of saline-alkali mix, the MDA content of tolerant saline-alkali varieties of alfalfa were increased firstly and then decreased, the MDA content of sensitive saline-alkali varieties of alfalfa were consistently increase. The SOD activity of4alfalfa varieties were increased firstly and then decreased, The POD activity of tolerant saline-alkali varieties of alfalfa were consistently increase, the POD activity of sensitive species of alfalfa were increased firstly and then decreased, antioxidase activity of tolerant saline-alkali varieties of alfalfa were higher than sensitive saline-alkali varieties of alfalfa. The Pro. and soluble sugar content had obvious increase trend under high concentration saline-alkali stress, the decreasing range about tolerant saline-alkali varieties of alfalfa greater than sensitive saline-alkali varieties of alfalfa, the soluble protein and organic acid had small change trend.3. Using4alfalfa varieties of different saline-alkali resistance ability as material were disposed by different concentrations of mixed saline-alkali stress on farm, Photosynthetic coefficient were measured, the results showed that:the chlT of4alfalfa varieties were increased firstly and then decreased, Ci, Cond showed a steady decline, the Pn and Tr of tolerant saline-alkali species was first increased after decreasing trend, sensitive saline-alkali varieties decreasing trend were consistently decreasing, the depressed range about the chlT-、Cond、Ci and Tr of tolerant saline-alkali varieties of alfalfa were less than sensitive saline-alkali varieties of alfalfa under saline-alkali stress.4. Using4alfalfa varieties of different saline-alkali resistance ability as material were disposed by different concentrations of mixed saline-alkali stress in seeding, so to analyze absorption characteristics of ion of alfalfa, the results show that:with the increase of saline-alkali concentration, the Na+content showed increasing trend, and the Na+content in roots were greater than the Na+content in stem and leaf, the K+content in stem and leaf of alfalfa were increased firstly and then decreased, the K+content in roots were decreasing trend, with the increasing concentration of saline-alkali mix, the S(K,Na) of4alfalfa varieties were increased firstly and then decreased, the S(K,Na) of4alfalfa varieties reach maximum under80mmol/L concentration. With the increasing concentration of saline-alkali mix, the Fe2+and Zn2+content in roots and stem-leaf, Ca2+and Mg2+in roots of alfalfa and Ca2+，Mg2+content in stem-leaf of sensitive saline-alkali varieties of alfalfa were consistently decreasing, the Ca2+,Mg2+content in stem-leaf in of tolerant saline-alkali varieties of alfalfa were increased firstly and then decreased. the Mn2+content in roots were consistently decreasing, the the Mn2+content in stem and leaf of different alfalfa varieties had different changing, the Ca2+, Mg2+, Fe2+and Zn2+content of tolerant saline-alkali varieties of alfalfa were higher than sensitive saline-alkali varieties of alfalfa.