Validation of the chlorophyll fluorescence imaging method (CFI) for early detection of herbicide resistance in weeds

Abstract

The increasing number of herbicide tolerant weed populations is illustrating the increasing demand for reliable methods for an accelerated detection of herbicide tolerance compared to greenhouse studies. Several methods for resistance quick detection have been published in previous years. One of the recent methods is the Chlorophyll Fluorescence Imaging Method (CFI). For this method changes in photosynthetic activity of the target organisms, caused by herbicides, are determined. General assumption of this method in terms of herbicide resistance detection is that each herbicidal compound, independent of the mode of action, will cause changes within the photosynthetic apparatus of the target organisms. This effect already could be confirmed for several modes of action (PSII, ALS, ACCase, EPSPS, synth. Auxins). Aim of this study is to validate this novel method on the basis of greenhouse experiments and single nucleotide polymorphisms (SNP) analysis. The resistance profiles of 10 black-grass populations (Alopecurus myosuroides Huds.) have been determined in greenhouse herbicide efficacy trials and constitutive SNP analyses of the survivors. With the CFI-method it was possible to detect the resistance profile as well as the resistance frequency within the populations. The results from the greenhouse experiments could be reproduced with conformity of 94%. This result is valid for the tested herbicides mesosulfuron, pyroxsulam as well as clodinafop and pinoxaden.

Keywords

• ACCase
• Alopecurus myosuroides Huds.
• ALS
• blackgrass
• herbicide resistance
• resistance quick detection