UV-B辐射对两种海洋微藻生长的影响

THE EFFECT OF UV-B IRRADIATION ON GROWTH OF TWO MARINE MICROALGAE

研究了两种微藻──小新月菱形藻与青岛大扁藻在各自的抑制剂量范围内（小新月菱形藻0～3．00J／m2；青岛大扁藻0～11．25J／m2）UV－B辐射对其相对增长率（K）、蛋白质含量、类胡萝卜素含量以及超氧化物歧化酶（Superoxidedismutase，SOD）活性的影响。结果表明，（1）随着辐射剂量的升高，两种微藻的相对增长率（K）逐渐下降，其各自的半数有效抑制浓度48h·EC50分别为：小新月菱形藻1．79J／m2；青岛大扁藻7．80J／m2。（2）蛋白质与光合色素含量的变化趋势基本类似于相对增长率的变化。相对增长率是灵敏指示微藻生长变化的优选指标。（3）超氧化物歧化酶（SOD）的活性也受到影响，在其各自的最大实验剂量下小新月菱形藻SOD活性下降21％；青岛大扁藻SOD活性下降17％。

Two species of marine microalgae: Ntzschia closterlum f minutissma and Platymonas helgolamdica var.Tsingtaoensis were exposed to various agent of UV-B irradiation. The relative growth rate(K),contents of protein,chlorophyll a, cartenoid as well as the activity of superoxide dismutase (SOD) were analysed. The results showed that: (1)The relative growth rate (K) decreased gradually with the increment of UV-B agent.Their respective 48h·EC50 were Nitzschia closterlum, 1. 79J/m2;Platymonas helgolamdica var.Tsingtaoensis, 7. 80J/m2. Nitzschia closterlum was more sensitive to UV-B effect. (2)The contents of protein , cartenoid changed with the similar trend of the relative growth rate(K). (3)The Nitzschia closterlum and Platymonas helgolamdica var. Tsingtaoensis's activity of superoxide dismutase (SOD) decreased by 21 % and 17% respectively.