滨海区黄花鸢尾的耐盐碱性及氮磷去除效果

The Iris Pseudoacorus' tolerant ability and removal efficiency for nitrogen and phosphorus in saline-alkaline water of coastal region

为探究黄花鸢尾（Iris pseudoacorus）在滨海区的耐盐碱程度及对盐碱污染水体中氮磷的去除能力,采用水培实验,分析其幼苗在盐碱交互胁迫下的生长状况、生理响应及其对水体中氮磷的去除效果.结果表明,黄花鸢尾耐盐碱范围：p H值为7、8、9时,盐度分别低于9‰、6‰、3‰.在其耐盐碱范围内,植株的含水量和叶绿素含量与对照相差在5.0%以内,而Na＋、Cl-与甜菜碱、可溶性糖含量随盐度和p H值的升高而增加,但增幅均低于130.0%.在低盐弱碱（p H 7、盐度为3‰、6‰与p H 8、盐度为3‰）条件下,黄花鸢尾幼苗相对生长速率比对照高0.6~6.1%,对水体中总氮、总磷的最大去除率分别为0.046mg/（g？d）、0.020mg/（g？d）.在其耐盐碱范围外,Na＋与脯氨酸含量与对照相比增幅高达14.0倍和91.4倍;黄花鸢尾生长受阻,对水体中氮磷的去除效果较差.因此,黄花鸢尾仅适用于滨海低盐弱碱水体的生态修复.

The study investigated the saline-alkaline tolerant ability of Iris pseudoacorus seedlings in coastal regions as well as the nitrogen and phosphorus removal capability under hydroponic culture. The growth characteristics, physiological response of I. pseudoacorus and the removal efficiency for nitrogen and phosphorus by I. pseudoacoruswere analyzed in saline-alkaline water. The results showed the limits of salinities that I. pseudoacorus could tolerate were less than 9‰, 6‰ and 3‰, corresponding the p H values of the water were 7, 8, 9, respectively. Within the limits, the differences of water content and leaf chlorophyll content between the plants in salt-alkali treated groups and those in control group（without salt or p H stress） were less than 5.0%. The concentrations of Na＋, Cl-, betaine and soluble carbohydrates increased by 130% at most within the limits. At low salinities and low alkalinities（salinities were 3‰ and 6‰ while the p H was 7and salinity was 3‰ while the p H was 8）, the relative growth rate of the plants in treated groupswas 0.6~6.1% higher than those in control group, and I. pseudoacorus removed 0.046mg/（g·d） and 0.020mg/（g·d） of total nitrogen and total phosphorus, respectively. Beyond the limits, however, the concentrations of Na＋ and proline of I. pseudoacorus were 14.0 and 91.4 times higher than those in control group in response to salt-alkali stresses. In addition, the growth of I. pseudoacorus were inhibited and the removal efficiency for nitrogen and phosphorus reduced significantly. In summary, I. pseudoacorus could be chosen to purify the coastal water with low salinity and low alkalinity.