Freie Universitat Berlin, Berlin, Germany.
J Environ Sci Health B. 2010 Feb;45(2):95-101. doi: 10.1080/03601230903471829.
Growth of common duckweed Lemna minor under optimal standard test conditions was compared to growth of L. minor exposed to nutrient-poor water in both a modified standardised test and in oligo- to mesotrophic indoor pond mesocosms in order to test the impact of trophic conditions and test system complexity on the effect of the herbicide metazachlor (2-chloro-N-(pyrazol-1-ylmethyl)acet-2',6'-xylidide) on aquatic macrophytes. In the mesocosms L. minor was replaced by greater duckweed Spirodela polyrhiza after 3 weeks due to high mortality even in the controls. The pond systems contained other macrophytes and biota as well as sediment and were thus more complex than standard test systems. For L. minor front area, the ErC(50) (50% effective concentration related to growth rate) was 2.8 microg L(-1) metazachlor in the standardised and 4.7 microg L(-1) in the modified laboratory test after 7 days (4.9 microg L(-1) and 52.9 microg L(-1) metazachlor when using front number). In the oligo- to mesotrophic pond mesocosms, similar sensitivities to metazachlor (ErC(50) 4.5-6.4 microg L(-1)) were noted for S. polyrhiza after 21 and 28 days of exposure. In comparison with dicotyledonous macrophytes, duckweed species are more sensitive for irreversible enzyme inhibitors of growth such as metazachlor independent of trophic status and complexity of the test system.
为了测试营养贫乏的水质和测试系统复杂性对除草剂甲唑草酮（2-氯-N-（吡唑-1-基甲基）乙酰-2'，6'-二甲氧基苯）对水生植物影响，将最佳标准测试条件下的普通浮萍（Lemna minor）的生长情况与暴露在贫营养水中的浮萍生长情况进行了比较，包括在改良的标准化测试和寡营养到中营养的室内池塘中进行了比较，以测试营养条件和测试系统复杂性对除草剂甲唑草酮的影响。由于即使在对照组中死亡率也很高，因此在 3 周后，大型浮萍（Spirodela polyrhiza）替代了浮萍。池塘系统除了含有其他的大型植物和生物以及沉积物之外，还含有其他的大型植物和生物以及沉积物，因此比标准测试系统更为复杂。在 7 天的标准测试和改良的实验室测试中，浮萍的正面区域的 ErC50（与生长速度相关的 50%有效浓度）分别为 2.8μg/L 的甲唑草酮和 4.7μg/L 的甲唑草酮（当使用正面数量时，分别为 4.9μg/L 和 52.9μg/L 的甲唑草酮）。在寡营养到中营养的池塘中，经过 21 天和 28 天的暴露，大型浮萍对甲唑草酮的敏感性相似（ErC50 为 4.5-6.4μg/L）。与双子叶大型植物相比，浮萍对生长的不可逆酶抑制剂（如甲唑草酮）更敏感，而与营养状态和测试系统的复杂性无关。
