Allelopatrhic effect of Acorus tatarinowii upon algae

Article type: Research Article

Authors: He, Chi-Quan | Wang, Chang-ke

Affiliations: The Department of Environmental Science & Engineering, Shanghai University; Shanghai 200072, China. E-mail: [email protected] | Changchun Institute of Geography, Chinese Academy of Sciences,Changchun 130021, China

Abstract: Besides competing with algae for light and mineralnutrients (i.e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in "A. tatarinowii water", some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A.tatarinowii on algae were obvious and planting A. tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 µl/disc, the inhibitory rate was negative; if it was over 45 µl/disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 µl/disc and 45 µl/disc.

Keywords: Acorus tatarinowii, allelopathy, algae, wetlands

Journal: Journal of Environmental Sciences, vol. 13, no. 4, pp. 481-484, 2001