Yan Z.,South China Normal University |
Song B.,South China Normal University |
Liu M.,Lingnan Landscape Co. |
Liu Y.,Lingnan Landscape Co. |
And 6 more authors.
Chinese Journal of Applied and Environmental Biology | Year: 2015
To better understand the allelopathy effect of different macrophytes with different treatments, we studied the allelopathy effect of five submerged plant species (Hydrilla verticillata, Elodea nuttallii, Myriophyllum spicatum, Vallisneria natans and Echinodorus amazonicu) on an eutrophic alga Scenedesmus obliquus by measuring the cell number of S. obliquus and concentration of Chl a in the co-culture systems of the alga and the five macrophytes, as well as those in the culture systems of the alga treated with the culture waters and the plant extractions of the five macrophytes. The co-culture systems exhibited the most obvious inhibition effect on S. obliquus, followed by extraction-treated systems and culture-treated systems, with cell number of S. obliquus significantly lower than in the other two culture systems (P < 0.05). No significant difference existed among the five macrophytes and the alga co-culture systems. The concentration of Chl a in the co-culture systems with H. verticillata was significantly higher than that in the other four (P < 0.05). The extraction treated systems, except those of H. verticillata, showed a significant inhibition effect on the cell number and relative growth rate (RGR) of S. obliquus (P < 0.05). The cell number of S. obliquus and concentration of Chl a showed that the culture water treated systems had a relatively weak effect on S. obliquus. The inhibition effect of culture water treated systems on S. obliquus was better than co-culture systems and extraction culture treated systems at the beginning of the experiment. The RGR of S. obliquus showed that the culture water treated systems of H. verticillata and E. nuttallii exhibited an obvious inhibition effect on S. obliquus, with the RGR of S. obliquus being significantly lower than that in the control group (P < 0.01) and no significant difference among the five macrophytes. The experiment showed that both macrophyte species and treatment may have different inhibition effects on algae. The allelopathy of different treatments requires further research.