PHOTOSYNTHETIC PERFORMANCE OF HEALTHY AND VIRUS-INFECTED FELDMANNIA-IRREGULARIS AND F-SIMPLEX (PHAEOPHYCEAE)

The filamentous brown algae Feldmannia simpler and F. irregularis are attacked by aquatic viruses, which propagate in deformed sporangia of the host plants. In order to evaluate a possible detrimental effect of the pathogen, photosynthesis-irradiance response curves and pigment c oncentrations of healthy and infected plants were compared. Photosynth etic performance of infected plants was significantly reduced and asso ciated with a decrease in chlorophyll a and c content. In Feldmannia i rregularis, which had a relatively low photosynthetic capacity, the vi rus infection produced a more severe effect than in F. simpler.