| Abstract [eng] |
One of the measures assumed to potentially help controlling cyanobacterial blooms is the use of aquatic plants and their allelochemicals. We studied effects of one of the most allelopathically active aquatic plants Myriophyllym spicatum on the potentially toxic cyanobacterium Microcystis aeruginosa. Cyanobacteria chlorophyll a concentrations were consistently lower in macrophyte treatments throughout the mesocosm experiment. The percentage of microcystin- and non-microcystin-producing M. aeruginosa genotypes in macrophyte treatments with respect to control treatments at the end of the experiment was not significantly different. For the laboratory single strain bioassay tests, both chlorophyll a concentrations and maximum quantum yields of the photosystem II were significantly diminished in non-microcystin producing relative to microcystin-producing M. aeruginosa strains. Our results indicate that although the use of M. spicatum could potentially lower cyanobacteria biomass, however, due to the allelopathic effect, it would potentially increase toxin producing M. aeruginosa genotype ratio, that would increase M. aeruginosa bloom toxicity. |
