2015_06 New Weapons Against Esca

Esca is the Latin word for tinder and describes a complex of diseases, where single, apparently healthy grapes break down within weeks. This mysterious disease, which is also known as Grapevine Trunk or Grapevine Dieback Disease is spreading in all major viticultural regions worldwide. Often, but not always, the leaves bleach in a tiger-like pattern. Since only a small fraction of the infected plants show the symptoms described above, the link between infection and disease outbreak has remained obscure. A couple of wood-decaying fungi that have been detected in affected grape wood are the main suspects. However, due to the long lag phase between infection and outbreak, primary damage is accompanied by secondary damage through „hitchhiking“ fungi that simply live on dead wood. Our cooperation partner Prof. Dr. Christophe Bertsch at the UHA Colmar has developed a "Black&Decker assay" which allows to investigate infection in a standardised manner. The collection of European Wild Grapes established at the KIT has been screened in the Bertsch lab for potential resistance against Esca-fungi. In fact, some of these Vitis sylvestris grapes are almost free of symptoms after inoculation with Neofusicoccum parvum and Diplodia serata and this resistance seems to be correlated with elevated induction of stilbene synthase genes. By using these wild grapes for breeding, it might become possible to develop new grape varieties that are immune against Esca. This work has been a product of the research network BACCHUS - Sustainable Viticulture.

Publication

116. Guan X, Essaki H, Laloue H, Nick P, Bertsch C, Chong J (2015) Mining new resources for grape resistance against Botryosphaeriaceae: a focus on Vitis vinifera ssp. sylvestris. Plant Pathol doi: 10.1111/ppa.12405 - pdf