褐变是导致青钱柳组织培养失败的主要原因之一。研究维生素C（VC）、植酸（PA）和柠檬酸（CA）3种抗氧化剂对青钱柳愈伤组织生长、褐化及其生理生化特性的影响。结果表明，适当浓度的抗氧化剂处理能有效抑制愈伤组织褐化率，促进愈伤组织生长，抑制培养过程中细胞质膜透性的增加。其中VC的处理效果较为明显，PA其次；最适浓度分别为VC 100 mg·L-1、PA 250 mg·L-1和CA 50～100 mg·L-1。VC 100 mg·L-1处理的愈伤组织鲜重增长率比对照增加73.88%，褐化率和细胞膜透性分别比对照低56.52%和45.75%，均达到显著或极显著水平。适当浓度的抗氧化剂使苯丙氨酸解氨酶(PAL)的活性在一定程度上受到抑制，但对多酚氧化酶(PPO)活性的抑制作用总体上不明显。总之，适当浓度的3种抗氧化剂处理能有效降低青钱柳愈伤组织褐化及其产生的伤害，促进生长，对PPO活性的调控可能不是其控制褐化的主要方式，有关机制尚待进一步探讨。
In order to control callus browning and provide theoretical and technical basis for tissue culture of Cyclocarya paliurus, the effects of three antioxidants on the callus growth, browning and physiological and biochemical characteristics were studied. The results showed that an appropriate concentration of antioxidants could effectively restrain callus browning rate, promote callus growth and prevent the increase of cytoplasmic membrane permeability in the process of cultivation. Among the three antioxidants, vitamin C (VC) was the most effective, and phytic acid (PA) came next. The optimal concentration was 100 mg/L for VC, 250 mg/L for PA, and 50 -100 mg/L for citric acid (CA).The growth rate of callus fresh weight with 100 mg/L VC treated group increased by 73.88%, and browning rate and membrane permeability decreased by 56.52% and 45.75%, respectively as compared with the control and the difference was statistically significant. The appropriate concentration of antioxidants could inhibit PAL activity in callus to some degree, while it had no obvious effect on PPO activity. Altogether, it was suggested that appropriate concentrations of three antioxidants could effectively reduce the callus browning, promote the growth. The regulatory effects may be associated with PAL activity. The regulation of PPO activity may not be the main pathway of browning control by antioxidants. The mechanism of PPO regulation need to be further studied.