Sucrose metabolism in Irwin mango (Mangifera indica L.) during maturation.

Sucrose metabolism of Irwin mango(Mangifera indica L.) during maturation was studied.The results showed that the content of sucrose was the highest(81.79 mg/g),the next was fructose(30.15 mg/g),and the lowest was glucose(9.95 mg/g) in the soluble sugar of mango.Although the activites of acid invertase(AI),neutral invertase(NI),sucrose synthase(SS),sucrose phosphate synthase(SPS) were no difference before the harvest of mango,the activities of AI,SS,SPS increased significantly and NI increased slightly during the postharvest period,especially SPS activity got to the maximum.The glucose increased and later decreased during the postharvest period,fructose increased slightly before harvest and sharply at postharvest,which was the same as the changes of sucrose,and sucrose had a maximum at harvest.Sugar of mango metabolized at the postharvest period mainly,and sucrose of which were accumulated mainly,SPS was a key to contribute significantly to sucrose metabolism.