Identification and characterization of volatile organic compounds active against barley pathogens
Abstract: Barley is threatened by various edaphic fungal diseases. Today, since most of the chemicals used for crop protection are being forbidden, there is a growing need of sustainable ways to control these diseases. In this paper, the volatile interactions that take place below ground between barley roots and two pathogenic fungi, Cochliobolus sativus and Fusarium culmorum were investigated and the effect of fungal volatiles on barley growth and the effect of barley root volatiles on fungal growth were evaluated by cultivating both organisms in a shared atmosphere without any physical contact. We show that the blend of VOCs emitted by infected barley roots decreased C. sativus growth by 13 to 17% while having no significant effect on F. culmorum. Methyl acrylate and methyl propionate were afterwards identified as the two molecules of the blend responsible for the growth reduction observed. The efficiency of these organic esters on a large panel of pathogens was tested and complete growth inhibition was obtained for five of them. Our results open promising perspectives concerning the biological control of edaphic diseases.