Arbuscular Mycorrhizal Fungi Improve Growth, Photosynthetic Activity, and Chlorophyll Fluorescence of Vitis vinifera L. cv. Ecolly under Drought Stress

Drought stress has become a limiting factor for viticulture with climate change. The influence of arbuscular mycorrhizal fungi (AMF) on grapevine Vitis vinifera L. cv. Ecolly’s leaf water content, chlorophyll concentration, photosynthesis activity, and chlorophyll fluorescence under drought stress was studied in the greenhouse. The experiment was designed as a randomized complete block with four treatments: AMF colonization, well-watered; non-AMF colonization, well-watered; AMF colonization with drought stress; and non-AMF colonization with drought stress. The grapevines inoculated with mycorrhiza had a higher water content in the leaves and higher chlorophyll concentration under drought stress than those without mycorrhiza inoculation. AMF colonization increased the dry biomass of shoots and roots, photosynthetic rate, stomatal conductance, and transpiration rate and decreased intercellular CO2 concentration. Mycorrhizal grapevines had higher non-photochemistry efficiency, higher photochemistry efficiency, and higher actual quantum yield than non-mycorrhizal grapevines. The results show that AMF alleviated the negative effects of drought stress on grapevines. The alleviation improved leaf water status, chlorophyll concentration, and photosynthetic capacity. Altogether, the results of our study indicate that AMF inoculation has the potential to protect grapevines under drought stress.