Allelopathy in aquatic macrophytes: Effects on growth and physiology of phytoplanktons

Abstract

The present review discussed allelophatic effects of aquatic macrophytes on phytoplankton with emphasis on growth and physiology; and also indicates implication for control of invasive aquatic macrophyte and phytoplankton species. In view of the fact, inhibition of phytoplankton by allelochemicals released by macrophytes is supposed to be one of the mechanisms that contribute to stabilisation of clear-water states in shallow lakes. This is achieved through the effects of allelochemicals on growth, photosynthesis and enzymatic activities of the phytoplanktons. The reciprocal/counter act mechanisms of target phytoplankton to allelochemicals are still ill defined. Reciprocal allelopathic responses between macrophytes and other phytoplankton species would have implications for management of eutrophic waters. Therefore, understanding the molecular mechanisms and the genetic bases of such effect is important. In addition to these, the molecular and genetic bases of allelopathy of invasive species of aquatic macrophytes are not well studied and utilizing the outputs to develop potential control is done through engineering.   Key words: Allelopathy, enzymatic activity, macrophytes, phytoplanktons.