Comparison of sensitivity of grasses (Lolium perenne L. and Festuca rubra L.) and lettuce (Lactuca sativa L.) exposed to water contaminated with microcystins.

The effects of aqueous extracts from Microcysts aeruginosa strains (both microcystin-producers and non-microcystin producers) on germination and root growth were investigated for three economically important plant species: Festuca rubra L., Lolium perenne L., and Lactuca sativa L. There was a clear inhibition of root growth for L. sativa exposed to strains containing microcystins (5.9-56.4 microg L(-1)). The strain that produced the most pronounced effects contained the lowest concentration of microcystin suggesting that other cellular compounds may also affect growth.