Comparison of Photosynthetic Functions and Antioxidase System of Apple Leaves between Two Orchard Ground Managements

摘要

In order to explore the physiological mechanism of photosynthetic decline of apple leaves under different orchard ground managements,the study had compared the changes of net photosynthetic rate (Pn),the contents of chlorophyll,soluble protein,superoxide anion (O2ˉ),hydrogen peroxide (H2O2) and malondialdehyde (MDA),and the activity of superoxide dismutase (SOD) and peroxidase (POD) in the process of leaf senescence under two kinds of orchard managements,i.e.natural grassing and clean cultivation,using 5 year old Hanfu apple as material The results showed that natural grassing treatment kept the contents of O2-,n2O2 and MDA at a relatively low level by enhancing the activities of SOD and POD during leaf senescence.Comparing with clean cultivation treatment,natural grassing treatment delayed leaf senescence and improved photosynthetic functions,through reducing the degradation rate of chlorophyll and soluble protein.In conclusion,natural grassing management could delay leaf senescence and keep higher photosynthetic functions of Hanfu apple leaves than that of clean cultivation management.