Investigation of the resistance of Amaranthus retroflexus L. to atrazine through the method of leaf fluorescence

Abstract

 It has been investigated the resistance of various of Amaranthus retroflexus L. to atrazine by the method of leaf fluorescence and the determination of quantum yield. Effects of varying concentrations of atrazine and intervals of its incubation with leaves on secondary kinetics of chlorophyll a fluorescence and quantum yield in both treated and untreated plants, were evaluated. It was shown that atrazine produced a significant infibitory effect on photosynthesis, depressed the quantum yield markedly, and blocked the transport of electrons, thus promoting the yield of chlorphyll a fluorescence and reducing O2 evolution from the susceptible biotype. The resistant biotype of Amaranthus retroflexus L. behaves like an untreated plant.