Abstract: A considerable variation of antioxidative capabilities existed among the fruits from different exposures on a tree depending upon various microenvironments where they grow. In sunny and clear days during growing season, a severer oxidative stress frequently occurred on the fruits from the southwest exposure of the canopy, regardless of bagged or exposed fruits,with O₂ contents in SW fruits being 1.23-1.37 folds as high as those on the other exposures, MDA 1.32-1.75 folds and SOD 1.40-1.69 folds. Generally, bagging could aggravate the extent of fruit stress, thus both O₂ and MDA contents and SOD activity in fruits increased, compared with the control. Furthermore,fruits became more sensitive shortly after bags were removed to harsh fluctuation of ambient temperatures and intense light because of the long-term adaptation to the ″relatively stable and dark environment″ within the bags, showing an abrupt rise of both O₂ content and SOD activity, which implied that a quick response to new stress had been initiated.

Key words: Bagging technique, Apple, Fruit, Antioxidative capability

CLC Number: 

• S661.01