Studies on the Relationship between the Changes of Mian Physiological Indices and Cold-resistance in the New Shoots of Dahongpao Zanthoxylum bungeanum under Low Temperature Stress
XIAO Cai-ling et al (Forestry College,Gansu Agricultural University,Lanzhou,Gansu 730070)
[Objective] These studies aimed to discuss the cold-resistant mechanism and capability of the newly germinated shoot of Dahongpao Zanthoxylum bungeanum.[Method] With newly germinated shoots of Dahongpao Z.bungeanum as tested materials,the changes of SOD and POD activities,MDA content and relative conductivity in new shoots and their influences on the injuries of new shoots under different low temperature stresses at 0,-2,-4 and-6 ℃ were analyzed through determining main physiological indices and restoring growth test.[Result] With the temperature decreasing,the activities of SOD and POD in the newly germinated shoots of Z.bungeanum showed the trend of firstly increasing and then decreasing,that were relatively higher and the protective capability was stronger at 0～-4 ℃ and that decreased sharply and the protective capability decreased greatly at-4～-6 ℃.The MDA content and the relative conductivity showed the trend of firstly decreasing and then increasing with the temperature decreasing,that were relatively low and stable and the injury degree of newly germinated shoots was relatively light at 0～-4 ℃ and that increased rapidly and the shoots were injured seriously at-4～-6 ℃.[Conclusion]-4 ℃ was the critical low temperature at which the newly germinated shoots of Dahongpao were injured;-6 ℃ was the critical low temperature which induced the newly germinated shoots of Dahongpao to be died.