变温对寒富苹果枝条生理代谢的影响OA

The apple producing area in the cold region of Northeast China is a characteristic apple producing area in China.In recent years,affected by global warming,the diurnal temperature difference between late winter and early spring has increased,and frequent alternating temperature freeze-thaw cycles cause combined freezing-drought injury to one-year-old apple branches,which severely restricts the sustainable development of the industry.In this study,one-year-old branches of'Hanfu'apple were used as materials to explore the changes of branch water content,proline content,soluble protein content,sugar content,reactive oxygen species content and antioxidant enzyme activities under three alternating temperature cycle treatments,aiming to clarify the influence mechanism of alternating temperature stress on the physiological metabolism of branches.The results showed that alternating temperature treatment promoted the accumulation of osmotic regulatory substances such as soluble protein and soluble sugar,and aggravated reactive oxygen species burst and the damage degree of branch membrane lipids.Among them,the soluble protein content and soluble sugar content of branches after 5 alternating temperature cycles were both significantly higher than those of the control;relative conductivity,malondialdehyde content,superoxide anion content,hydrogen peroxide content and catalase activity were all significantly higher than those of the control.There were significant correlations among relative conductivity,hydrogen peroxide content,sucrose content,catalase activity and other indicators,which further revealed that membrane lipid damage was closely related to reactive oxygen species burst and accumulation of osmotic regulatory substances.This study clarified the physiological strategy of apple branches adapting to alternating temperature environment in cold regions,and provides an important theoretical basis for optimizing the ecological adaptability of apple production in cold regions.