Diversity of arbuscular mycorrhizal fungi associated with Triticum aestivum L. plants growing in an Andosol with high aluminum level

Arbuscular mycorrhizal (AM) fungi contribute to agricultural productivity by improving plant nutrient and water acquisition, and modifying some physiological traits under various environmental stresses. Notwithstanding, there is a lack of knowledge about the ecology and behavior of AM fungi in acidic soils with high levels of exchangeable aluminum (Al). Therefore, we have carried out a preliminary research based on the taxonomic identification of AM fungal species associated to winter wheat habitually cropped in an Andosol from Southern Chile. Rhizosphere soils from six winter wheat cultivars ("Bakan", "Porfiado", "Maxi", "Crac", "Invento" and "Otto") were collected from field plots. AM fungal species identification was performed based on spore morphological analyses. In this study, we additionally observed AM fungal propagules (spore density and colonization levels) at two crop stages (grain filling and postharvest). At grain filling stage, "Bakan", "Porfiado" and "Maxi" cultivars showed higher colonization levels than "Otto", "Crac" and "Invento" ones. Spore density increased at postharvest stage and "Maxi", "Otto" and "Invento" cultivars presented higher spore densities than other three cultivars. Twenty-four AM fungal species were identified and subsequently classified into genera Acaulospora, Pacispora, Claroideoglomus, Glomus, Funnehformis, Septoglomus, Simiglomus, Scutellospora, Cetraspora, Ambispora, Archaeospora and Paraglomus. The Shannon-Wiener values showed no significantly difference in AM fungal diversity associated to wheat cultivars, but species richness was significant different among cultivars. Simpson's index was significantly different among AM fungal communities being Acaulospora and Scutellospora the most dominant genera. In this study, AM fungal community structure was different for specific wheat cultivar; hence the use of target AM fungal species could be determinant factor for the appropriate AM community establishment in potential inoculation assays, especially in Andosols with high aluminum levels. (c) 2014 Elsevier B.V. All rights reserved.