Effects of pre-harvest and post-harvest applications of gibberellin (GA3) on appearance quality of 'Guifei' mangoes

The effects of pre-harvest and post-harvest applications of gibberellin (GA3) at different concentrations of 0.0, 0.5, 1.0, 2.0 and 3.0 g L-1 on appearance quality of 'Guifei' mango were investigated. The results showed that: (1) When application with GA(3) during pre-harvest, lower GA(3) treatments could delay the change of a* value, inhibit degradation of chlorophyll and the accumulation of carotenoid and anthocyanin, and decrease the activities of chlorophyllase (Chlase) and chalcone isomerase (CHI). However, higher concentration (>1.0 g L-1) treatment could result in incomplete change in peel color until ripening. (2) When application with GA(3) during post-harvest, the degradation of chlorophyll, the synthesis of anthocyanin and carotenoid, and the change of peel color were retarded greatly by GA(3) treatment. Thus, the higher concentration (>2.0 g L-1) could make mangoes not turning color completely at the end of storage period. Therefore, it is suggested that unsuitable GA(3) concentration applied during pre-harvest (>1.0 g L-1) or post-harvest (>2.0 g L-1) had a negative influence on the appearance quality of 'Guifei' mangos.