Study On Freezing Resistance Of Introduced Camphor Tree In Shandong Province

Camphor tree is a class of evergreen broadleaved trees belong to LauraceaeCinnamomum, which as a representative of the subtropical evergreen broadleaved forest treespecies, is an important material and special economic tree species, in medicine, materials,industrial and landscape has its special status. Camphor tree has clear regional characteristicin the distribution because the influence of climate, so it is not widely grown in the northarea. In this paper, with the introducted camphor trees as test material, studying itsmorphological change in Shandong area during the winter, and determination of the relativeelectric conductivity, protective enzyme activity, MDA content, free praline content, solublesugar and soluble protein content with the leaves after artificial low temperature (0℃～-25℃)treatment, discussing adaptability camphor trees in winter in Shandong area especiallyin Zaozhuang area, the main conclusions are as follows:1. By observing winter morphology of camphor trees planting in different environmentof Zaozhuang, we can discover that camphor trees which perennial, provenance close to theintroduction area, DBH between10-20cm and planted around more buildings, has highercold resistance than others. Meanwhile, to protect trees can also enhance its cold resistancecapacity.2. According to the investigation of8cities in Shandong Province, the cold resistance ofcamphor trees planted in south-eastern and coastal areas of Shandong is higher than whichplanted in the northwest and inland areas of Shandong, and camphor trees planted in theurban area are better than which planted in suburb in winter.3. Selected camphor trees and grouping them by provenance, tree age and differentplanting environment, group including provenance in Jiangxi (camphor tree A, camphor treeB,camphor tree C), provenance in Nanjing(camphor tree D) and provenance inHunan(camphor tree E, camphor tree F). with artificial low temperature treatment, anddetermining its conductivity, then according to the logistic equation, the LT50of camphortree A,camphor tree B,camphor tree C, camphor tree D, camphor tree E, camphor tree F is-19.51℃,-16.71℃,-28.58℃,-23.05℃,-20.74℃,-18.97℃.The results of LT50showed thatthe cold resistance sequence of the six varieties is: camphor tree D＞camphor tree E＞camphor tree A＞camphor tree F. 4. The protective enzyme activity, MDA content, free proline content, soluble sugar andsoluble protein content of camphor trees in different groups increase with the temperaturerising, but variations are different. When the temperature reaches a certain value, eachindicators are showing a declined trend, with different variation range, but has been higherthan contrast.5. Using comprehensive index method evaluating of Physiological Indexes of six leavesof camphor tree, the results showed that the cold resistance sequence is: camphor tree D＞camphor tree E＞camphor tree C＞camphor tree F＞camphor tree B＞camphor tree A.In summary, on one hand, the study make a more accurate evaluation on the applicationof camphor tree in Shandong area especially Zaozhuang area, found a valid parameters forcold resistance; on the other hand, it also guide the introduction of camphor tree in Shandongarea and other winter low temperature region in the north to avoid blind introduction causeslosses.