Changes in Structure and Antioxidant Metabolism in the Fruit Pericarps of Citrus during Sunburn Development

摘要

Fruit sunburn rates of three citrus varieties such as ' Shatangju' (Citrus reticulata Blanco cv. Shatangju) , ' Gonggan' (Citrus reticulata Blanco cv. Gonggan) , and ' An liu' sweet orange (Citrus sinensis Osbeck cv. Anliu) were investigated. Fruits were used as materials to study the changes of cell memberane lipid peroxidation, the activities of antioxidases (SOD, POD, PPO) , the contents of antioxidants (AsA, GSH) and cell structure of fruit pericarp. The result showed that the degree of cell memberane lipid peroxidation enhanced after fruit sunburned. The activity of SOD and the contents of AsA and GSH were significantly decreased, while the activities of POD and PPO were significantly increased. Pericarp was significantly thickened, with larger pericarp cells, which were arranged neatly and compacted orderly. Epicuticular waxes emerged rough.