A high-sensitivity chlorophyll fluorescence assay for monitoring herbicide inhibition of photosystem II in the chlorophyte Selenastrum capricornutum: Comparison with effect on cell growth
Jay, Aicha El; Ducruet, Jean-Marc; Duval, Jean-Claude; Pelletier, Jean Pierre
published: Sep 25, 1997
ArtNo. ESP141014002007, Price: 29.00 €
A pulse amplitude modulated fluorometer (PAM) was used to measure the chlorophyll fluorescence induction kinetics (OIDP). The increase of I level, recorded at two different excitation light intensities, was used to monitor atrazine, simazine, diuron and isoproturon. The methods used were applied to a sensitive chlorophyte, Selenastrum capricornutum. Concentrations of about 0.01 μM of diuron, 0.04 μM of isoproturon and atrazine and 0.08 μM of simazine can be detected significantly. I50-values obtained by the most sensitive method, corresponding to an excitation lightintensity of 130 μmol photon·m-2.sec-1, are 0.3 μM for atrazine, 0.5 μM for simazine, 0.05 μM for diuron and 0.2 μM for isoproturon. The inhibition of S. capricornutumgrowth over a 4 days period was also studied and the I50 obtained were about 0.4 μM for triazines, 0.03 μM for diuron and 0.2 μM for isoproturon.