No allelopathic effect of the invader Acacia dealbata on the potential infectivity of arbuscular mycorrhizal fungi from native soils

Abstract

The invasion success of the leguminous tree Acacia dealbata Link has been related to the release of novel chemical compounds that affect both native plant performance and native soil bacterial communities. However, the allelopathic effect of A. dealbata on arbuscular mycorrhizal fungi (AMF) has not been explored. We used natural leachates from invasive A. dealbata and native soils to assess the bioactivity of these chemicals on AMF colonization of Plantago lanceolata in native soils. The highly mycorrhizal P. lanceolata was used as a model-test species to estimate the infectivity of AM fungi. Acacia leachates did not affect mycorrhizal colonization in any of the native soils studied. Either the leachates released by A. dealbata do not have an antifungal effect or the analyzed soils contained AMF species resistant to those allelochemicals. Our results appeal for further research to elucidate the role of native AMF in the invasion process of A. dealbata.