Survival of Egeria densa Under the Combined Effect of Salinity and Allelopathy of Microcystis Aeruginosa

The study elucidates the survival of Egeria densa under increasing salinity and the allelopathic effects of the cyanobacterium Microcystis aeruginosa during co-existence. E. densa exhibited a consistent decline in growth with increasing salinity, with the lowest growth observed in a combined culture with M. aeruginosa. Lower salinity levels (up to 2.5 ppt) stimulated chlorophyll pigment synthesis, while higher salinity concentrations inhibited chlorophyll pigment synthesis. E. densa, in monoculture, showed elevated anthocyanin, carotenoid, and H₂O₂ concentrations at higher salinity levels. Conversely, E. densa experienced declining chlorophyll pigment and H₂O₂ concentrations in a combined culture at higher salinity levels. The experiment revealed that freshwater salinity influences the well-being of E. densa co-existing with M. aeruginosa.