Characterization of the root and soil mycobiome associated with invasive Microstegium vimineum in the presence and absence of a native plant community

Abstract

The potential role of fungal root endophytes (including mycorrhizae) in the invasiveness of Microstegium vimineum (Trin.) A. Camus, was researched using automated ribosomal intergenic spacer analysis (ARISA) and brightfield microscopy. Fungal communities of roots from two native plants (Onoclea sensibilis L. and Amphicarpaea bracteata (L.) Fernald) were compared with those found in Microstegium. Fungal communities from the bulk soils also were examined in terms of their potential influence on the root mycobiomes. All three plants occurred in natural communities as monocultures and together in one mixed community in Northern Virginia where Microstegium has recently invaded. Principal coordinate analysis of ARISA data identified fungal communities unique to roots from each monoculture. When the three plants co-occurred in a mixed setting, Microstegium was found to maintain its distinct fungal community while the fungal communities of the two native plants overlapped. In contrast, soil fungal communities showed no specific plant associations. Brightfield microscopy confirmed the presence of endophytic fungi in all three plants. The results recorded here suggest a positive contribution by the root mycobiome in promoting the invasive ability of Microstegium, providing a basis for future experiments testing this hypothesis.