European Xylella fastidiosa strains can cause symptoms in blueberry

Beyond Xylella, Integrated Management Strategies for Mitigating Xylella fastidiosa Impact in Europe (BeXyl) (Grant Agreement 101060593). Partner/Coordinador principal: Blanca B. Landa del Castillo, Investigadora Científica del Instituto de Agricultura Sostenible (IAS-CSIC).

Strains of the bacterial pathogen Xylella fastidiosa subspecies multiplex (Xfm) and pauca (Xfp) isolated from symptomatic almond and olive plants in Spain and Italy were used in this study. Due to the risk of host jump and considering the importance of southern highbush blueberry production in Spain, we tested a small set of these strains for their potential to infect and cause disease symptoms in blueberries under greenhouse experiments. Xfm IVIA5901 (isolated from almonds in Alicante, Spain) caused symptoms similar to those caused by Xfm AlmaEM3 (isolated from blueberries in Georgia, USA, and used as a reference strain capable of inducing severe symptoms in blueberry). Nevertheless, bacterial populations of Xfm IVIA5901 in planta were significantly lower than those of Xfm AlmaEm3. Xfm ESVL (isolated from almonds, Alicante, Spain) and Xfp XYL1961/18 (isolated from olives, Ibiza Island, Spain) caused limited symptoms, while Xfm XYL466/19 (isolated from wild olives, Mallorca Island, Spain) and Xfm XF3348 (isolated from almonds, Mallorca Island, Spain), and Xfp De Donno (isolated from olives, Puglia, Italy and representative of the devastating olive quick decline syndrome) did not cause symptoms nor colonize blueberries. This study suggests that certain strains already found in Europe could infect blueberry if conditions conducive for a host jump in this region are met, such as proximity of blueberries to other infected hosts and presence of insect vectors that feed on these crops. Surveys on the presence of X. fastidiosa in blueberries in Spain and other European countries are needed to anticipate possible issues.

Partial funding was obtained from Project BeXyl (Beyond Xylella, Integrated Management Strategies for Mitigating Xylella fastidiosa impact in Europe; Grant ID No 101060593) from European Union’s Horizon Action ‘Food, Bioeconomy Natural Resources, Agriculture and Environment’ Programme, Qualifica Project QUAL21-023 IAS from Junta de Andalucía, Spain and the Interdisciplinary Thematic Platform PTI-SolXyl from CSIC. L.D. was a recipient of a research fellowship awarded by the Organization for Economic Cooperation and Development (OECD), Co-operative Research Programme (CRP), during the writing of this manuscript. M. R.-E. was recipient of a contract financed by the Intramural Project 202240E067 from CSIC. M. R.-E. and M.P.V.-A. were recipients of Short-Term Scientific Missions fellowships at L.D.’s Laboratory financed by European Cooperation in Science and Technology (COST) Action CA16107 Euro-Xanth.

Peer reviewed