Ph. D. Ludovic FAESSEL

Acibenzolar-Smethyl-induced resistance on soybean and effects on rhizosphere

Defended in 2007

Under the direction of Bernard Walter and Thierry Lebeau.

Abstract

Research in crop protection is actually focused on the development of new tools for controlling plant diseases, alternative or complementary to traditional fungicides. Induction of resistance by using plants own defence mechanisms is emerging as a promising strategy for controlling plant diseases. The aim of this study was to test seed treatment with acibenzolar-S-methyl (ASM) on soybean for its ability to induce an effective induced resistance to hypocotyl rot and to investigate the effect of this treatment on two symbioses of soybean: Bradyrhizobium japonicum-soybean and Glomus mosseae-soybean. Our results show that seed treatment with ASM decreases significantly the severity of the hypocotyl rot caused by Rhizoctonia solani AG-4. This protective effect of ASM against R. Solani AG-4 is probably due to combination of induced resistance and its effect on growth of the pathogen. However, this strategy can also cause side-effects, by modifying root morphology or by the inhibition of soybean symbioses establishment.