磷亏缺芦苇对氮梯度变化的生理响应

Physiological Effect of Phragmites Australis by Phosphorus Staraved under Different Concetration of Nitrogen Supply

研究了磷亏缺芦苇在不同氮浓度梯度下(0mg/L、2 mg/L、5 mg/L、15 mg/L)干重、鲜重、叶面积等形态学指标和叶片叶绿素、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)等生理学指标的变化,研究结果表明:芦苇形态学指标和叶片叶绿素含量均随氮浓度的增加呈现先增加(低浓度范围:0～5mg/L)后减小(高浓度范围:5-15 mg/L)的趋势。MDA及活性氧清除系统指标则呈现先降低(低浓度范围:0～5mg/L)后升高(高浓度范围:5-15 mg/L)的趋势。表明在低浓度范围内,氮浓度增加可以缓解芦苇磷亏缺胁迫症状,而当氮浓度超过了芦苇的耐受阈值之后(5 mg/L),芦苇在磷亏缺和氮过量的双重胁迫下,体内活性氧清除系统被破坏。与正常磷供给相比(10 mg/L),磷亏缺芦苇对氮的耐受阈值下降了96.8%—90.6%。研究结果可为富营养化水体水生态环境的改善提供科学依据。

The effects of dry weight, fresh weight, the content of chlorophyll, the MDA, SOD, CAT and POD activites in the leaves of Phragmites australis by phosphorus strayed under different concentration of nitrogen （0mg/L, 2 mg/L,5 mg/L,15 mg/L） were investigated. The index of configuration and the content of chlorophyll increased at the lower concentration of nitrogen range （0-5 mg/L）, while decreased at the higher concentration of nitrogen range （5-15 mg/L）. The content of MDA, SOD, CAT and POD decreased at he lower concentration of nitrogen range （0-5 mg/L）, while increased at the higher concentration of nitrogen range （5-15 mg/L）. The results showed that at the lower concentration of nitrogen range, nitrogen alleviate the inhibitory effect of Phragmites australis growth and its oxidative damage by phosphorus strayed, while higher concentration nitrogen could provoke a major oxidative insult.