Effects on Changes of Dominating Pigment Contents in Peel of Cara Cara(Citrus sinensis Osbesk)and Fruit Colouring after Exogenous ABA and GA₃ Treatments

The dynamic contents of chlorophyll and carotenoid during fruit development and after exogenous ABA and GA₃ treatments before the beginning of colour changing in peel of Citrus Sinensis Osbesk cv. Cara Cara were determined,and the colour and luster appearance of mature peel of Cara Cara after ABA and GA₃ treatments were also determined. The results showed that contents of chlorophyll and carotenoid in the peel of Cara Cara reached maximum on September,20 and December,20,which are 0.1469 mg·g^-1FW and 0.0321 mg·g^-1FW,respectively;exogenous ABA accelerated the degradation of chlorophyll and restrained the accumulation of carotenoid;exogenous GA₃ delayed the degradation of chlorophyll and also restrained the accumulation of carotenoid and prohibited the synthesis of carotenoid seriously;both of exogenous ABA or GA₃ treatment didn’t benefit the colour and luster quality of Cara Cara fruit.