Inhibitory effect of Arundo donax and Nymphaea tetragona on Microcystis aeruginosa.

Lab-scale experiment was conducted to study the inhibitory effects of tissues and tissue extracts of Arundo donax and Nymphaea tetragona on Microcystis aeruginosa from south Lake Taihu.Inhibitory effects on growth of the algae were showed in different ways.According to the experimental results,leaves and haulm of A.donax as well as leaves and stems of N.tetragona exerted stronger inhibitory effects than their extracts at the similar concentrations.In addition,A.donax showed better inhibitory capacity than A.donax,and different tissues of A.donax and N.tetragona exerted different inhibitive effects on Microcystis aeruginosa.Inhibitive effect of haulm of A.donax was stronger than that of the leaves,while leaves of N. tetragona exerted stronger inhibition than the stems.The fact that autoclaved tissues and extracts of A.donax and N.tetragona showed remarkable algae inhibiting effects indicated that the allelochemicals excreted by both plants were thermally stable.