Assessment method for leaf litters allelopathic effect on cyanobacteria.
Abstract
A new bioassay technique combining leaf disk and soft-agar over-layer methods was developed to investigate the allelopathic effect of deciduous leaf litters on the growth of cyanobacteria (Microcystis aeruginosa). Bioactive substances exuded from leaf disks caused inhibitory plaques on the agar plate containing cyanobacteria, and the rate of diffusion depended on the specific leaf disk area. Most of the leaf litters collected around reservoirs in Japan showed inhibitory activity to M. aeruginosa, with Rhus trichocarpa, Quercus variabilis and Mallotus japonicus being the strongest among the 22 tested species.
