Study And Appraisal Of Salt Tolerance Drought Resistance Capacity Of Different Alfalfa Cultivars

Alfalfa(Medicago sativa L.) is one of the most important legume forages in China.In the course of adjusting agricultural structure,alfalfa is considered to be the most important forage because of its versatile functions.The resistance of alfalfa is the crucial factor to select and distribute alfalfa varieties.It is useful for alfalfa industrial development to evaluate drought resistance and salt tolerance of several representative alfalfa species introduced from homeland and abroad in this paper.1.Study on salt tolerance of different alfalfa varieties.This research evaluate salt-tolerant identification results of different alfalfa were not constantly consistent by using different salt-tolerant indexes.By analysis several salt-tolerant indexes,partial indexes were selected.Cluster analysis on them showed that order of salt tolerance degree was:Medicago sativa L.cv.'Ningxia No.1',Medicago sativa L.cv.'Longmu No.801', Medicago sativa L.cv.'WL-525'＞Medicago sativa L.cv.'Longmu No.803'＞Mcdicago sativa L.cv.'Gongnong No.2'＞Medicago sativa L.cv.'Gongnong No.3'＞Mcdicago sativa L.cv.'Gongnong No.1', Medicago sativa L.cv.'Vector',Medicago sativa L.cv.'Runner'＞Mcdicago sativa L.cv.'Aohan'＞Medicago sativa L.cv.'Jacklin',Medicago sativa L.cv.'Zhongrnu No.1'＞Medicago sativa L.cv.'Leafldng'＞Medicago sativa L.cv.'Farmers Treasure'＞MagnumV-wet.2.Study on drought-resistance of different varieties of Medicago sativa:Artificial soil drought stress were carded out on 15 different alfalfa varieties in laboratory,and the drought resistance index of membrane relative permeability,proline content and leaf water saturation deficit were measured.A comprehensive evaluation on drought resistance of different alfalfa varieties was given based on subordinate function values analysis.By using the method of cluster analysis the alfalfa varieties were classified into three types:high drought resistant varieties:Medicago sativa L.cv.'Aohan',Medicago sativa L.cv.'Gongnong No.2',Medicago sativa L.cv.'Ningxia No.1',Medicago sativa L.cv.'Longmu No.801',medium drought resistant varieties: Medicago sativa L.cv.'Gongnong No.1',Medicago sativa L.cv.'Longmu No.803',MagnumV-wet,Medicago sativa L.cv.'Farmers Treasure',Medicago sativa L.cv.'Runner',Medieago sativa L.cv.'Leafking',Medicago sativa L.cv.'Zhongrnu No.1',low drought resistant varieties:Medicago sativa L.cv.'Gongnong No.3',WL-525, Medicago sativa L.cv.'Jacklin',Medicago sativa L.cv.'Vector'.3.The study of salt-tolerant and drought resistance of 15 alfalfa varieties show both of them cannot as a single indicator to identify varieties.Different indicators reflect different force of drought resistance and salt tolerance,it relate to different alfalfa varieties adapt to the environment in different ways.So,it is necessary to analysis some indicators when identify the salt-tolerant and drought resistance of alfalfa variety.