Relation of composition in peel to color development in satsuma mandarin.

温州蜜柑果皮中总糖随着脱脂的开始大量积累，而果皮中的氮含量则有所下降。果皮含糖量与色泽发育呈显著正相关，含氮量与果皮色泽呈显著负相关。果皮的颜色发育与糖分状态的关系比与果汁的关系更为密切。在体外，果皮的颜色发育受琼脂基质中糖和氮的供应控制，在琼脂上培养果皮。基质中高浓度的蔗糖促进脱色，而氮素通过抑制脱色而抑制蔗糖脱色。抑制脱脂诱导的高温是由于果皮中糖的积累较少所致。在此基础上，认为温州蜜柑的变色是由于果皮中糖含量的升高和含氮量的降低所致。果皮内源GA类物质活性随脱脂开始而减弱，ABA类物质活性随脱脂开始而增加。通过外源处理，赤霉素抑制果皮颜色发育，乙烯利和NAA促进果皮颜色。

Total sugar in peel of satsuma mandarin was greatly accumulated as degreening was initiated, whereas content of nitrogen in peel was decreased. There was significant active correlation between sugar content of peel and color development, whereas negative one between nitrogen content and peel color. Color development was more closely related with sugar status in peel than that in juice.Color development of peel was controled in vitro by sugar and nitrogen supplies in agar media upon which peel segments were cultured. High concentrations of sucrose in media promoted degreening, whereas nitrogen acted in opposition to sucrose by inhibiting degreening.Inhibition of degreening induced high temperature was due to low accumulation of sugar in peel.Based on these observation, it was suggested that coloring of satsuma mandain was attributed to elevated sugar content and reduced nitrogen content in peel. Activity of endogenous GA-like substance in peel was disapeared as degreening was initiated, whereas ABA-like substance was increased. By exogenous treatment, gibberellin inhibited color development, ethrel and NAA promoted peel color.