Comparative Study on Heat-resistance of Wild Red Clover in Chongqing Region
QIN Xiao-peng et al(Department of Grassland Science,Sichuan Agricultural University,Yaan,Sichuan 625014)
[Objective] The study aimed to compare difference on the heat-resistantce between of wild red clover and the existing varieties at home and abroad.[Method] With 9 wild red clover(CQ1-9),2 foreign varieties(Rider and Dory) and a domestic variety(Wuxi) as the tested materials,the physiological indicators and heat-resistance of 12 accessions of red clover were evaluated through the pot test and under the artificial simulation high-temperature.[Result] With the delay of the heat stress time,the survival rate of field plants of 12 accessions was decreased gradually,the relative electrical conductivity and free proline contents in leaves were all increased gradually,total chlorophyll content was decreased gradually and SOD activity showed a trend of first increasing and then decreasing.The heat resistance of 12 red clover accessions in order was: CQ8 Rider CQ5 Dory CQ1 CQ2 CQ4 CQ6 CQ9 Wuxi CQ7 CQ3.[Conclusion] According to clustering analysis,12 accessions were divided into 3 groups.CQ8 had stable physiological indicators,highest survival rate and best heat resistance,the following was CQ2,CQ4,CQ5,Rider and Dory and the worst was CQ1,CQ3,CQ6,CQ7,CQ9 and Wuxi.