东方水韭对人工污水胁迫的生理响应

Physiological Response of Isoetes orientalis to Artificial Sewage Water Stress

采用不同浓度的污水对长势基本相同的成熟东方水韭（Isoetes orientalis）植株进行处理,研究其在5,10,20倍浓度污水胁迫2~14 d的6项生理指标,即叶片的保护酶系统、渗透调节物质、叶绿素和丙二醛含量、相对电导率和光和速率的变化规律。结果表明,东方水韭在5倍和10倍浓度污水胁迫下的耐受性较好,在20倍污水胁迫下的耐受性较差,各项生理指标均显示出较大的损伤。根据污水胁迫强度及生态实际,笔者认为,污水胁迫不是造成东方水韭营养体濒危的主要原因。

Isoetes orientalis is a wild national protective endangered aquatic pteridophyte. It is an endemic ancient relict plant inhabited in the middle and lower reaches of Yangtze River. The relationship between pollution of water body and endangerment of I. orientalis had never been reported. Mature I. orientalis plants with similar growth vigor were treated for 2- 14 days with different concentrations（ 5 times,10 times and 20 times）of sewage water to observe the change of 6 physiological indexes of the plants,i. e.,protective enzyme system,osmotic substance,chlorophyll content,malondialdehyde content,relative conductance and photosynthetic rate.I. orientalis was found to have a better tolerance to the stress of the sewage water under 5 and 10 times of the concentration but poor tolerance to the stress under the 20 times of concentration with comparatively obvious physiological injury. According to the sewage stress and the ecological conditions,the authors believe that the sewage water stress might not be the main reason for endangerment of I. orientalis.