Metabolism and action of plant growth regulators during ripening and storage of firethorn fruit

The firethorn(Pyracantka Roem)fruits were sprayed with 80mg／L gibberellic acids(GA₃)and 50mg／kg 6-benzyladenine(6-BA)two months before harvest or after harvest．The changes of respiratory rate，peroxidase，catalase，polyphenol oxidase，ascorbic acid oxidase and their nutritional components were investigated．The results showed that GA₃ treatment before harvest induced the increase of respiratory rate and catalase activity，and the soluble sugar，free amino acids significantly increased while the pectin and total acids significantly decreased．If 6-BA was sprayed，the respiratory rate decreased，polyphenol oxidasc activity increased，the content of soluble sugar fell but the storage life was prolonged without any significant effect on quality of the fruit When GA₃ alld 6-BA were used to treat the fruits after harvest，the treatment of 6-BA slightly increased the respiratory rate and kept much more,soluble sugar and vitamin C than the control one．Both (GA₃ and 6-BA treatments had not significant effect on the storage life．