Six Iris Species' Purification Effects On Eutrophicated Water And The Physiological Response

This paper took 3 kind of the Iris L. (Iris pseudacorus,Iris ensata var. hortens and Iris sanquinea) as test materials. With the method of the greenhouse static state experiment and scene experiment ,the paper had studied 3 kind of the Iris L.'s elimination effect regarding the N and P elements of eutrophic water in different seasons and carried the shape observation and the physiological target determination on the 3 kind of plants under different eutrophication levels.The purposes of the study was to provide the scientific basis for Iris L. in governing the eutrophic water and promoting the application. The studying results were as following:1,The purification to the eutrophic water: The purification effects to eutrophic water of 3 kind of Iris L.were different in vegetative seasons. The eutrophic degree in spring was low and the purific effect was Iris ensata var. hortens>Iris pseudacorus>Iris sanquinea. The eutrophic degree in summer was high and reduces much slightly in autumn compared to in summer. These two seasons' purification was Iris pseudacorus>Iris ensata var. hortens>Iris sanquinea. The overall purification effects in different season situations was, the purification was summer> autumn>spring.2,The effect of submerged macrophytes on the N and P in eutrophic water:The Iris pseudacorus and Iris ensata var. hortens in the pollutated river in the school had completely survived with good growing trend. The Iris sanquinea survivalled rate is 95%. The biomas of Iris pseudacorus increases greater than the others with the root cap ratio reduced most. Its N and P cumulantion is much higher than that of other plants. Therefore Iris pseudacorus had the superiority compared to Iris ensata var. hortens and Iris sanquine in elimination of eutrophic water body's nutritive elements.3,The physiological response to different eutrophication levels: Iris pseudacorus like high nutritional conditions. Its chlorophyll content, the soluble protein content, the soluble sugar content and the SOD activeness gradually elevate with water N and P density's elevation in the water. Iris ensata var. hortens adapted the medium nutritional conditions. Its chlorophyll content, the soluble sugar content, the soluble protein content and the SOD activeness had elevated. Beyond the scope, these had declining trend. Iris sanquine was sensitive to the highly nutritional eutrophic water. In later period of the experiment, it even presented a slight rotten phenomenon and each target displays well in the low concentration condition.