Increased Copper Concentrations in Soil Affect Indigenous Arbuscular Mycorrhizal Fungi and Physiology of Grapevine Plantlets

Continuous use of fungicides in vineyards leads to soil copper (Cu) accumulation, adversely affecting plants and soil organisms. Arbuscular mycorrhizal fungi (AMF) provide adaptative mechanisms for plant survival and growth in environments with high Cu contents. Using a low-Cu soil from a young vineyard, we evaluated how increasing additions of this element (0, 50, 100, and 150 mg kg-1) affected the AMF community and growth and physiology of grapevine (Vitis berlandieri x Vitis rupestris) rootstock, in greenhouse conditions. Mycorrhizal colonization and AMF richness decreased linearly with increased soil Cu additions. Stomatal conductance and transpiration increased with Cu additions, affecting plant growth. Increasing Cu additions to the soil decreased mycorrhizal root colonization and diversity, with no adverse effects on grapevines.