硒、锌及其交互作用对不同季节茶叶多酚氧化酶活性的影响

通过喷施不同浓度的亚硒酸钠和醋酸锌,研究了硒、锌及硒锌交互作用对不同季节茶叶叶片硒、锌含量以及多酚氧化酶活性的影响。结果表明:(1)茶叶硒、锌含量均在春季最高,夏季次之,秋季最低。3季茶叶硒含量都在中高浓度(200~400μg/ml)的硒和低中浓度(0.2%~0.4%)的锌处理下相对较高;而锌含量在中高浓度(0.8%~1.2%)的锌和低中浓度(50~100μg/ml)的硒处理下较高;各季节茶叶硒、锌含量都在中浓度的硒(100~200μg/ml)和锌(0.4%~0.8%)配比下较高。(2)茶叶多酚氧化酶活性在夏季最高,春季次之,秋季最低。3季茶叶该酶活性均在中浓度的硒(100~200μg/ml)和锌(0.4%~0.8%)处理及其配比下相对较高;而高浓度的硒(400μg/ml)和锌(1.2%),以及低浓度(0.2%)的锌处理对春茶和夏茶多酚氧化酶活性的提高效应不甚明显,秋茶多酚氧化酶活性则在低浓度的硒(50μg/ml)和低浓度的锌(0.2%)以及高浓度的硒(400μg/ml)、锌(1.2%)处理下均无明显提高效应,同时低硒与低锌配比、高硒与中高浓度(0.2%~0.8%)的锌配比对春、夏、秋3季茶叶PPO活性的促进效应均不明显。

EFFECTS OF Se, Zn AND THEIR INTERACTION ON POLYPHENOL OXIDASE ACTIVITY OF TEA LEAVES IN DIFFERENT SEASONS

Foliar spraying at different levels of Na_2SeO_3 (0, 50, 100,200 and 400μg/ml) and (CH_3COO)_2 Zn ·2H_2O (0, 0. 2% , 0.4% , 0. 8% and 1.2%) were carried out to determine the effects of Se, Zn and their interaction on the contents of Se, Zn and polyphenol oxidase (PPO) activity of tea leaves in different seasons. The results showed that:(1) The contents of Se in tea leaves was much higher in spring than that in summer, and the content of Se in autumn was the lowest. The content of Se in tea leaves in spring, summer and autumn was relatively high when the spraying concentration of Se was in the range of 200 ～ 400μg/ml and Zn was in the range of 0.2% ～ 0. 4%. The content of Zn in tea leaves was relatively high with treatments of Se (50 ～ 100μg/ml)or Zn (0. 8% ～ 1.2%). The content of Se and Zn in different seasons were also relatively high when Se (100 ～200μg/ml) and Zn (0.4%～0. 8%) were sprayed together.(2) The PPO activities of tea leaves was much higher in summer than those in spring and in autumn, and the PPO activity was the lowest in autumn. The PPO activity of tea leaves in spring, summer and autumn were relatively high when the spraying concentration were 100 ～200μg/ml for Se, 0.4% ～0. 8% for Zn and their interaction. But there were no obvious improvement in the PPO activities of tea leaves in spring and summer with foliar spray at the concentration of Se(400μg/ml)or Zn(0.2%、1.2%). However, the PPO activity of tea leaves in autumn had not obviously increased when the concentrations of Se were 50μg/ml, 400μg/ml and Zn were 0.2% , 1.2%. At the low concentration of Zn (0.2%) combined with the low level of Se (50μg/ml) and the high concentration of Se combined with the different concentrations of Zn (0.2%～0.8%) ,the Se-Zn interaction had no obvious effects on PPO activity.