Drivers of Arbuscular Mycorrhizal Fungal Diversity Across 1,000 km of Chilean Vineyards

Arbuscular mycorrhizal fungi (AMF) communities associated to several grapevine cultivars were analyzed from 1,000 km long of crop area in Chile. The effect that different cultivars of Vitis vinifera L. may have on AMF communities has been scarcely studied, especially in non-organic managements. Our objective was to describe the AMF communities and quantify the arbuscular mycorrhizal root colonization associated to several grapevine cultivars in different grapevine ages along a 1,000 km long cropping surface and to test whether factors such as grapevine cultivar and grapevine age, as well as soil chemical factors shapes AMF communities. The vineyards were distributed along 1,000 km across Chile, passing through several administrative regions of the country. The different grapevines ranged from 1 to 41 years old. AMF identification and taxonomy was performed based on spore morphological analyses. AMF spores abundance, root colonization and extraradical mycelium (ERC) were also evaluated. More than 94,000 AMF spores were identified in the 34 vineyards investigated. In total, 15 AMF species were identified in this study. The AMF community was mainly represented by species belonging to the families Acaulosporaceae, Entrophosporaceae and Glomeraceae, dominated by the genera Acaulospora, Claroideoglomus, Septoglomus and Simiglomus. Regardless of grapevine age, soil chemistry and geographic location, the AMF community structure was influenced by grapevine cultivar. Grapevine age, soil chemistry and geographic location no affect AMF richness, AMF spores abundance, root colonization and extraradical mycelium (ERC). The AMF species identified in our work could be indicators of agricultural systems exposed to biotic and abiotic stresses in different grapevine age, soil chemistry and geographic location, according to the transect investigated. A role of vineyard cultivar in determining the structure of the AMF community was revealed. The use of AMF species target in regenerative vineyards management could be determining factors for the AMF community establishment.