UV-B辐射增强对3种湿地植物叶片紫外吸收物质含量的影响

以香蒲、芦苇、鸢尾3种湿地植物为材料,采用模拟人工湿地的方法,研究植物叶片紫外吸收物质含量对3个UV-B辐射强度的响应。结果表明:3种植物叶片类黄酮含量变化趋势为高辐射处理下先增加后降低,低辐射处理条件下持续增加,高辐射处理显著大于低辐射处理、低辐射处理显著大于对照,增强UV-B处理下叶片类黄酮含量平均增幅为鸢尾(21.88%)>芦苇(14.23%)>香蒲(6.16%)。增强UV-B辐射条件下,香蒲和鸢尾叶片类胡萝卜素(Car)含量显著(p<0.05)低于对照,且高辐射处理低于低辐射处理;芦苇叶片Car含量则表现为低辐射处理大于对照、对照大于高辐射处理,两个辐射剂量之间差异显著(p<0.05)。增强UV-B处理下叶片Car含量平均降幅为香蒲(51.00%)>芦苇(26.63%)>鸢尾(17.95%)。说明3种湿地植物对增强UV-B辐射的防御能力为:鸢尾>芦苇>香蒲。

Effects of Enhanced UV-B Radiation on the Content of Ultraviolet Absorbents in Leaves of Three Wetland Plants

The response of plant leaf ultraviolet absorption substance content to three UV-B radiation intensities was studied by simulating constructed wetland with Iris tectorum Maxim., Phragmites australis Cav.and Typha orientalis Presl.as materials.The results showed that the content of flavonoid increased first and then decreased under high radiation treatment but increased continuously under low radiation condition.The content of flavonoid increased significantly at high radiation level than that at low radiation level,and was significantly higher at low radiation level than that of the control.The average increase of flavonoid content in leaves under enhanced UV-B radiation was:Iris tectorum Maxim.(21.88%)> Phragmites australis Cav.(14.23%)> Typha orientalis Presl.(6.16%).Under the condition of enhanced UV-B radiation,the contents of carotenoid in the leaves of Typha orientalis Presl.and Iris tectorum Maxim.were significantly lower than those of the control ( p <0.05),but the contents under high radiation level were lower than those under the low radiation treatment.The leaf carotenoid content of Phragmites australis Cav.was higher under low radiation treatment than that in the control and higher in the control than that under high radiation treatment,the difference between two radiation levels was significant ( p <0.05).The average decrease of carotenoid content in leaves under enhanced UV-B treatment was:Typha orientalis Presl.(51.00%)> Phragmites australis Cav.(26.63%)> Iris tectorum Maxim.(17.95%).The result showed that the defensive ability to enhanced UV-B radiation of three wetland plants was Iris tectorum Maxim.> Phragmites australis Cav.> Typha orientalis Presl.