Studies On The Mechanism Of Low Temperature Tolerance And Winter Survival Technology For Eulaliopsis Binata

With the expansion of planting region,the winter survival problem of Eulaliopsis binata was more and more serious in recent years.A field investigation and field experiment with one-year-old seedlings and adult biennial seedlings with different low temperature and stress time was conducted to explore low-temperature-resistant capacity and low temperature resistant mechanism by winter survival,semi-lethal temperature,chlorophyll content,antioxidant enzyme activities of POD,CAT and SOD.While potassium application, mowing time and mowing height was studied to understand the ability of low-temperature-resistant and low-temperature-resistant mechanism of Eulaliopsis binata, then a winter safety technology system was built.It was valuable to provide advisory for planting of Eulaliopsis binata in the hilly areas in Hunan Province.The results of this study as follows:1 The Eulaliopsis binata has little ability to adapt to low temperature,which would be stressed no more than 0℃,and the semi-lethal temperature was about -2.9℃.The cold hardness of Eulaliopsis binata was significantly improved by application of potassium fertilizer,then the semi-lethal temperature reduced by 1～2℃.2 With 7℃and 2℃stress,the chlorophyll content of Eulaliopsis binata leaf reduced with the lower temperature and extended stress time.The cell protective enzyme activity had significantly changed in the short-term temperature,however little change was observed with extended stress time.The activity of POD and CAT was sensitive more than that of SOD with low temperature.3 The chlorophyll content and protective enzyme activity changed during the first growing stage by application of potassium fertilizer for Eulaliopsis binata leaves.The chlorophyll content reduced 13.5～15.7%less compared to CK with 2℃and 48 hours stress, and POD and CAT activity decreased by 10.1～19.6%and 4.8～15.0%less,respectively.4 Mowing time had more effect on winter survival than that of mowing height for Eulaliopsis binat.The appropriate mowing time was form December to next January. Winter survival was significantly improved by application of potassium fertilizer.5 Total N,P and K content of leaves increased significantly by application of potassium fertilizer,which could promote growth,thereby improving low temperature resistant stress for Eulaliopsis binata.