Najas are submerged macrophytes and grow in fresh water or
salt water around the world, and some species of Najas have also
been shown to have inhibitory effects on phytoplankton. Gross et al.
[11,12] reported that Najas marina ssp. intermedia has allelopathic
activity on filamentous or chroococcal cyanobacteria. He et al.
[13] showed an inhibitory activity of Najas minor on S. obliquus. But,
even with aforementioned studies, the knowledge to Najas is still
very limited and what effect of these organisms on other planktons
especially on blue–green algae remains unclear. To further provide
insights into the N. minor in its potential application in biological
control of phytoplankton blooms, in this study, we tested the effect
of N. minor All. on four common phytoplankton species: the
cyanobacteria toxic M. aeruginosa, the toxic A. flos-aquae,the
chlorophytes C. pyrenoidosa, S. obliquus (for comparison) and natural
phytoplankton assemblages; and also carried out coexistence experiments
between M. aeruginosa and N. minor. Our findings
suggested that N. minor, a still little known allelochemical-producing
macrophyte, is a useful tool in controlling planktonic blooms, especially
cyanobacteria blooms.