The impact of the symbiont genotype on the effect of arbuscular mycorrhizal symbiosis on grapevine growth and physiology

The challenge of maintaining grapevine yields and quality under unrelenting climate change is a priority in viticulture nowadays. This challenge can be addressed by investigating and utilizing sustainable agricultural practices that promote ecosystem services. Examples of eco-sustainable approaches to this challenge include the use of new eco-friendly management strategies (such as cover crops and beneficial microbes that restore soil biodiversity) and the selection of stress-adapted grapevine genotypes (such as rootstocks that confer stress tolerance traits to the grafted scion). Grapevine establishes mycorrhizal symbioses with arbuscular mycorrhizal fungi (AMF), which naturally occur in roots of most of the studied vineyards. The colonization of grapevine root system by AMF affects its architecture and functioning and leads to beneficial effects on host growth, nutrition and health. Here, three out of the most widespread rootstocks (110R, 1103P, Kober 5BB), exhibiting specific traits in terms of vigor, stress tolerance and adaptability to particular soil conditions, have been selected and evaluated for their ability to interact with different AMF (both commercial and custom inocula) to verify the efficiency of symbiosis. Results showed that all the tested inocula led to a root colonization on the selected rootstocks, although at different extent.