Discovery of a locus associated with susceptibility to esca in grapevine.

Esca is the most destructive and predominant of grapevine trunk disease. The chronic infections and vine mortality caused by esca syndrome leads to huge economic losses and threatens the sustainability of vineyards worldwide. Esca is caused by numerous wood-decay and wood-decay associated fungi, but its full etiology remains unclear due to the grapevine trunk disease complex, making effective control methods challenging. As differences in esca susceptibility have already been observed among grapevine varieties, we investigated the presence of genetic factors that can explain theses variations using a Riesling x Gewurztraminer progeny. Thanks to the destructive phenotyping of a 16-year-old vineyard plot, we discovered that the Gewurztraminer variety carries on chromosome 1 a locus linked to variations in trunk necrosis associated with esca, which we have named Esca Necrosis Susceptibility 1 (ENS1). Our study also suggests that there is a partial link between trunk vigor and necrosis due to esca. To our best knowledge, ENS1 is the first instance of genetic factor identified as involved in the limitation of necrosis associated to grapevine esca. While the identification of ENS1 alone may not provide a complete resolution of the issue, this discovery nonetheless represents a first step towards a genetic solution and paves the way for broader genetic investigations in the future.