Broad associations between Pennisetum setaceum and arbuscular mycorrhizal fungi support invasions
Pennisetum setaceum (EPPO List of Invasive Alien Plants) is a mycorrhizal C4 Poaceae, native to Northeast Africa and the Middle East. This perennial bunch grass has a rapid growth and high tolerance to drought and arid conditions. In Spain, its ornamental use in gardens has caused its naturalization and spread to the surrounding ruderal habitats. It is a very aggressive plant forming monospecific stands and outcompeting native plants by reducing available space and taking scarce water and nutrients. It also increases fuel loads, and becomes extremely inflammable in winter, increasing the intensity and spread of fire, resulting in severe damage to native dry forest species which are adapted to less extreme fire regimes. The present study compared the arbuscular mycorrhizal fungi (AMF) communities hosted by P. setaceum with those from the co-occurring native Hyparrhenia hirta at five sites with different edaphic characteristics. Illumina technology was used to investigate AMF colonisation in the roots and a subsequent multivariate analysis showed that although there were differences in AMF communities between sites, native and non-native host plants shared a similar AMF composition. The results suggest that in the invaded range, P. setaceum is flexible in its association with local AMF and this may support the species in finding suitable niches in a variety of ecosystems outside its native range.
Sources
Rodríguez-Caballero, Roldan FCA (2018) The unspecificity of the relationships between the invasive Pennisetum setaceum and mycorrhizal fungi may provide advantages during its establishment at semiarid Mediterranean sites. Science of the total environment 630, 1464-1471.