Lotus tenuis maintains high arbuscular mycorrhizal diversity in grasslands regardless of soil properties or management

Abstract

This study aimed to evaluate the root colonization and diversity of arbuscular mycorrhizal fungi (AMF) associated with Lotus tenuis grown in natural and L. tenuis-promoted grasslands (by herbicide application, which consists in removing above-ground biomass to favor the establishment and growth of L. tenuis) in the Salado River Basin (Argentina). Soils ranged from saline and/or sodic to neutral and non-saline. AMF colonization was slightly higher in natural grasslands than in L. tenuis-promoted sites (93% and 86%, respectively). A total of 22 AMF species were identified in root-associated soil. The Glomeraceae was the only family present in all sites, and Funneliformis mosseae was the only species found in all the sites studied, regardless of the soil properties and management. Claroideoglomus etunicatum and Septoglomus constrictum were present in all sites except in one of the L. tenuis-promoted sites studied. The PCR-Single-Strand Conformation Polymorphism analysis showed that amplicons of AMF-Glomeraceae did not cluster in a site-specific or management-specific way. The sequences obtained were highly similar to sequences of Glomeraceae detected by morphological spore taxonomy. L. tenuis promotion by herbicide application did not negatively affect AMF colonization or diversity. L. tenuis contributed to maintaining AMF diversity through high root colonization, regardless of soil properties or management. This should be considered for the maintenance of L. tenuis and AMF-associated communities.