Search for resistance to olive quick decline syndrome caused by X. fastidiosa

The olive quick decline syndrome (OQDS) is a novel disease recently emerged in southern Italy and currently threating the Mediterranean olive-growing area. The disease was found to be associated with infections caused by the exotic bacterium X. fastidiosa, well known in the Americas as the causal agent of severe diseases of important crops, i.e. grapevine and citrus. In these species, looking for resistance is regarded as one of the most promising long term control strategies. In olives, cultivars displaying differential phenotypes have been observed in the field, with symptoms ranging from virtually no decline and limited desiccation in Leccino and FS-17® to severe decline and death cvs Cellina di Nardo and Ogliarola Salentina. However, the large variability of olive genetic resources, including both cultivated and wild olives remains to be explored. Several experiments are currently ongoing aiming at detecting new sources of resistance in plant materials representative of the genetic and geographical variability of the species, including commercial cultivars, genotypes from other Olea europaea subspecies, and selections from breeding programs. Identified resistant sources could serve as parental for breeding programs, as currently underway for other vascular diseases such as Verticillium wilt. The status and challenges of the currently ongoing activities will be presented.Acknowledgment This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement N. 727987 "Xylella fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy XF-ACTORS"