Study of physiological change in ‘Dangshansuli’ pear of superficial scald

`Dangshansuli´ pear is one of crisp pears and has a non-climacteric respiratory pattern. With `Dangshansuli´ pears which were in different pathological grades of superficial scald as material, the internal physiological indexes were determined to study the physiological change in superficial scald pears. The results indicated that it was obvious positive correlation between the contents of α-farnesene and the pathological grades, while the content of conjugated trienes in the occurrence of superficial scald had a value of threshold. The contents of total phenols and the PPO activity had significant positive correlation with the pathological grade, as well as the activity of POD, SOD, CAT, the scavenging ability of DPPH, the penetration of cell membrane, and the content of MDA. In all, as the disease get worse, the content of disease-causing substances were increasing and the ability of antioxidant was escalating, the former of which is consistent with the previous, while the latter is different.