擎天树初始外植体总酚含量与PPO活性的关系

Relationship total phenolics contents and polyphenol oxidase activities in explant of preliminary culture in Vitro of Parashorea chinensis

以擎天树当年生嫩枝为材料，分析外植体在消毒及启动培养过程中总酚含量与PPO活性关系，为擎天树褐变机理研究、建立种质资源保存新途径提供参考依据。结果表明：（1）擎天树总酚含量与褐变呈正相关，培养基中添加PVP 2.0g/L及黑暗处理下褐变程度较弱，总酚含量低；不添加抗褐化剂处理褐变最严重，总酚含量最高；（2）外植体材料不同褐化程度下的PPO活性均很低，为0.15～0.3U之间，且不同抗褐化剂及黑暗与否等处理间无明显变化；（3）外植体总酚含量随培养时间增加呈先降后升趋势，各处理下PPO活性随培养时间增加趋于一致。

Using shoots from Parashorea chinensis explants, the regulation of total phenolics contents and polyphenol oxidase activities were studied in the processes of the disinfection and primary culture, which would provide the new references for the browning mechanism and establishment of germplasm conservation. The results were as follows：（1） There was a positive correlation between the total phenolics content and the browning, the browning levels were weaker with both treatments of adding PVP 2.0 g/L into medium and by dark treatment, the total phenolics were lower in the tested explants;while the total phenolics content went up to the top if without any anti-browning agents. （2） The polyphenol oxidase activities were low between 0.15-0.3U and the treatments with different dose of ppo and dark and non-dark, the browning levels had insignificant changest. （3） The total phenolics contents showed a first decreased and then increased trend in 2 days, the changing trends of polyphenol oxidase activities tended to converge with the cultural time after induction. The relation between the total phenolics content and the polyphenol oxidase was not obvious.