Response of multiple herbicide resistant strain of diazotrophic cyanobacterium, Anabaena variabilis, exposed to atrazine and DCMU.

Effect of two photosynthetic inhibitor herbicides, atrazine (both purified and formulated) and [3-(3,4-dichlorophenyl)-1,1-dimethyl urea] (DCMU), on the growth, macromolecular contents, heterocyst frequency, photosynthetic O2 evolution and dark O2 uptake of wild type and multiple herbicide resistant (MHR) strain of diazotrophic cyanobacterium A. variabilis was studied. Cyanobacterial strains showed gradual inhibition in growth with increasing dosage of herbicides.