Associations between fungal root endophytes and grass dominance in arid highlands

Abstract

In arid highland environments harsh conditions for vegetation establishment prevail. Plants in theseenvironments develop different strategies to survive, including associations with fungal root endophytes.These associations may improve plant growth, helping plant resistance to adverse environments. Theaim of this study was to determine the relationship among arbuscular mycorrhizal fungi (AMF), darkseptate endophytes (DSE) and dominance degree of Poaceae in arid highlands of Argentine Puna. Westudied AMF and DSE root colonization, and rhizospheric hyphal densities of dominant and subordinategrass species. Dual and positive associations between AMF and DSE prevailed. Dominant grasses had thehighest levels of AMF and DSE root colonization. Dominant and intermediate grasses were associatedwith the highest values of rhizospheric hyphal density. In Puna highlands, the interactions among AMF,DSE and grasses suggest that fungal root endophytes may play a role in structuring grass communities bydifferentially improving the resistance to harsh conditions.