The unspecificity of the relationships between the invasive Pennisetum setaceum and mycorrhizal fungi may provide advantages during its establishment at semiarid Mediterranean sites

Abstract

The involvement of mutualistic plant-fungal interactions in invasion processes, especially in some climatic regions including semiarid areas, has not been sufficiently investigated. We compared the arbuscular mycorrhizal fungi (AMF) communities hosted by the invasive plant Pennisetum setaceum with those from the co-occurring native Hyparrhenia hirta at five Mediterranean semiarid locations with different edaphic characteristics. Illumina technology was used to investigate the AMF communities in the roots. The subsequent multivariate analysis showed that native and non-native host plants shared a similar AMF community, whereas the invaded locations differed in AMF communities harbored in the plant roots. The indicator species analysis revealed the absence of indicator virtual taxa for the fungal communities of the roots of native or invasive plants. In contrast, different numbers of indicator species were recorded in different sampling locations. According to the canonical correspondence analysis, the variability in the AMF communities between sampling sites was related to changes in soil total carbon, electrical conductivity, respiration, and protease and urease activities. These findings reveal the unspecificity of P. setaceum in relation to its association with the AMF community encountered in the invaded locations, which could have facilitated its successful establishment and spread.