Original paper
Direct observation of herbicide action in algae using 10 µs resolved chlorophyll fluorescence induction kinetics
Ruth, B.
Archiv für Hydrobiologie Volume 131 Number 3 (1994), p. 297 - 308
15 references
published: Oct 12, 1994
DOI: 10.1127/archiv-hydrobiol/131/1994/297
ArtNo. ESP141013103002, Price: 29.00 €
Abstract
The chlorophyll fluorescence induction kinetics, excited after a 15 min dark adaptation, was measured with a maximum time resolution of 10 µs to determine the relative time derivative B of its initial increase. Measurements were carried out on the algae Scenedesmus quadricauda, Microcystis aeruginosa, and Navicula pelliculosa after the application of the herbicide terbuthylazine (TA) with concentrations between 0 (control) and 200 µg/l. The effects of the herbicide TA on the induction kinetics are detectable after 20 min and they achieve their final extent about 3 h later. TA causes a significant progressive increase of B beginning with the concentrations 5 or 10 µg/l. As this increase of B directly indicates the action of the herbicide on the secondary electron acceptor Qb of the photosynthetic system, the initial phase of the induction kinetics, measured with the time resolution of 10 µs, provides a sensitive and fast method to determine the herbicide action in algae.
Keywords
algae • chlorophyll