硒、锌及其交互作用对夏茶多酚氧化酶活性的影响

通过配合喷施不同浓度亚硒酸钠（Na2SeO3）和醋酸锌(CH3COO)2Zn·2H2O]，研究硒（Se）、锌（Zn）及硒锌交互（Se-Zn）作用对夏茶叶片多酚氧化酶（PPO）活性的影响。结果表明，单施Se（100~200 μg/mL）和单施 Zn（0.4%~0.8%）处理，茶叶叶片PPO活性相对较高；高浓度Se（400 μg/mL）和 Zn（1.2%）处理对PPO活性的提高效应不明显，甚至有一定的抑制作用。同一Se、Zn处理喷施16 d后，茶叶叶片PPO活性相对较高。中浓度Zn（0.4%~0.8%）与中浓度Se（100~200 μg/mL）配合喷施，夏茶叶片多酚氧化酶活性较高；而高浓度的硒锌配施对PPO活性无明显促进效应。同一配施处理，喷施16 d后PPO活性变化趋于稳定，且比喷施8d活性增幅较大。高浓度的Zn与不同浓度的Se配施，PPO活性的时间效应不甚明显，而低中浓度Zn与不同浓度Se配合喷施后，PPO活性的时间效应明显。

Effects of Se, Zn and theit interaction on polyphenol oxidase activity of tea leaves in summer season

Different levels of Na2SeO3(0, 50, 100, 200 and 400 μg/mL) and (CH3COO)2Zn·2H2O(0, 0.2%, 0.4%, 0.8% and 1.2%) was applied by foliar spraying to determine the effects of Se, Zn and the their interaction on polyphenol oxidase (PPO) activity of tea leaves in summer season. The result showed that: (1) The PPO activity of tea leaves was higher when spraying apply Se at 100-200 μg/mL and Zn was 0.4%-0.8% compared to other treatments. Applying high-concentration of Se (>400μg/mL) or Zn (>1.2% ) alone did not significantly improve PPO activity. Higher PPO activity was observed at 16 days after Se or Zn spraying application. (2)Combined applying middle-concen-tration of Se (100-200 μg/mL) and Zn (0.4%-0.8% ) increased PPO activity, but combine applying high-concentra-tion of Se and Zn had no significant effects on PPO activity. The PPO activity after 16 days of spraying became stable. When applying high concentration of Zn combined with different concentration of Se, the temporal effect on PPO activity was not significant, but when low concentration of Zn was combined with different concentrations of Se, the temporal effect on PPO activity was significant.