Towards a better understanding of cultivar susceptibility to esca disease: results from a pluriannual common garden monitoring

Botrytis cinerea, a fungal pathogen commonly known as grey mold, which under specific climatic conditions can develop into a desirable form known as noble rot. In this process the fungus penetrates the grape skin, allowing water evaporation and concentration of sugars and flavors, while profoundly affects the metabolite composition of grapes, leading to the production of unique and desirable compounds in the resulting wines. The result is a unique and complex wine with a luscious sweetness, heightened aromatics, and a distinct character.

Grapevine vigour, defined as the propensity to assimilate, store and/or use non-structural sugars for allowing fast growth of shoots and producing large canopies[1], is crucial to optimize vineyard management. Recently, a model has been proposed for predicting the vigor of young grapevines through the measurement of the vegetative growth and physiological parameters, such as water status and gas exchange[2]. Our objectives were (1) to explore the influence of the association of two grapevine varieties (Tempranillo and Cabernet Sauvignon, grafted onto R110 rootstocks) with arbuscular mycorrhizal fungi (AMF) on the vegetative vigour of young plants; and (2) to assess the effect of environmental factors linked to climate change on the vegetative vigour of Cabernet Sauvignon.

Drought is one of the main challenges for viticulture in the context of global change. The choice of rootstock could be leveraged for vineyard adaptation to drought as we can improve plant performance without modifying the scion variety. However, most of the existing rootstocks, selected over a century ago, have a narrow genetic background which could compromise their adaptive potential.

Volatile organic compounds (VOCs) are emitted by nearly all plant organs of the plants, including leaves. They play a key role in the communication with other organisms, therefore they are involved in plant defence against phytopathogens. In this study VOCs from grapevine leaves of two varieties of Vitis vinifera infected by Erysiphe necator were analysed. The varieties were selected based on their susceptibility to pathogen, Kishmish Vatkana has the Ren1 resistance gene and Zamarrica showed high susceptibility in previous trials.

Changes in the rainfall and temperature patterns affect the increase of drought periods becoming one of the major constraints to assure agricultural and crop resilience in the Mediterranean regions. Beside the adaptation of agricultural practices, also the microbial compartment associated to plants should be considered in the crop management. It is known that the microbial community change according to several factors such as soil composition, agricultural management system, plant variety and rootstock.