PHYSIOLOGICAL AND MORPHOLOGICAL ALTERATIONS INDUCED BY CARBARYL AND 1-NAPHTHOL COMBINATIONS IN NOSTOC-LINCKIA ISOLATED FROM SOIL

Carbaryl and its major hydrolysis product, 1-naphthol, were tested sin gly and together at concentrations ranging from 2 to 20 mug/ml towards photosynthesis, in vivo nitrate reductase activity and nitrogen fixat ion, and ultrastructure of a diazotrophic cyanobacterium, Nostoc linck ia, isolated from soil. All three physiological processes tested were drastically affected and correlated well with the alterations in the u ltrastructure of the organism. Combination of carbaryl and 1-naphthol, at different concentrations, interacted significantly, yielding addit ive, antagonistic, and synergistic responses.