Study On Cold Resistance Of Three Phoebes

Phoebe zhennan,Phoebe chekiangensis andPhoebe bourneiare famous "gold-rimmed nanmu" key members of China.They are not onlyquality inmaterial but very beautiful,which can well use asornamental plants or for materials.But they are sensitive to low temperature,so they cann't resist the low temperature in the North,which limited their production and promotion.Two types of Phobe zhennan(large-leave type and small-leave type),two provenances of Phoebe chekiangensis(Hangzhou,Qingyuan)and three provenances of Phoebe bournei were used as materials to determinate the effect of low temperature stress on physiological and biochemical characters,and we also investigate the Phoebe bournei's freeze injury of five cities in Zhejiang province under extreme low temperature in early 2016.The main results are as follows:1.As the temperature decreases: the relative conductivity increased,while the activity of POD,SOD and the content of soluble sugar,soluble protein,proline increased at frist and then decreased in all these three kinds of Phoebe.The content of MDA content in Phoebe chekiangensisincreased all the time,while the content of MDA in Phoebe zhennan and Phoebe bournei increased at frist and then decreased.2.Their ability of low temperature resistance was,Phoebe zhennan of large-leave type >small-leave type;Phoebe chekiangensis of Hangzhou provenance> Qingyuan provenance;Phoebe bournei of Wuyuan provenance>Suichuan provenance>Wuping provenance.3.Comprehensive evaluation by principal components analysis and membership function method,we can conclude that there was a negative correlation between the relative conductivity and content of MDA,while there was a positive correlation between the activity of SOD,content of soluble sugar.4.Take the evaluation results and activity of POD,content of prolineinto consideration,we can infer the stable type(provenance)of POD activity has stronger cold resistance ability,and proline's content has no obvious correlation with cold resistance ability.5.Phoebe bournei freezing injury occurred at different levels under different site conditions,mixed forestation shows a lower level freezing injury occur thansingle Phoebe bournei afforestation,consistent with other conditions,Phoebe bournei in wind minor localfreezing injured less than windy places;southfacing slope injured less than that on the north slope;and top of the slopewere hurt more severely than that in the bottom.6.Choose appropriate family and provenance,Phoebe bournei can live through the winter in zhejiang province without any protection.