A scientific report has been released on March 23, 2017 by the team of researchers of the CNR-IPSP, DiSSPA-UNIBA and CRSFA “Basile Caramia” about further observations on the presence of resistance traits to Xylella fastidiosa in the olive germplasm. The scientific report, published in the Italian language on the weekly magazine “L’informatore agrario”, is the result of an effective and efficient cooperation among olive growers, farm advisory and researchers.
Field observations for scouting olive trees displaying resistance behavior were conducted in the infected area of the Province of Lecce (southern Italy) by different farm advisories and olive growers. Olive groves were selected and analyzed by the team of researchers involved in the two ongoing H2020 projects on X. fastidiosa: POnTE and XF-ACTORS. The selection was made in the most promising scenarios, i.e. presence of “symptomless trees” within areas with high pressure of inoculum, accompanied by consistent observations on the same cultivar(s) in different locations,
Diagnostic tests were performed to determine the presence and the incidence of the infections and to quantitate the bacterial populations in the trees showing different phenotypes (symptomless, presence of mild or severe symptoms). Among the four olive cultivars analyzed in this work, trees of the cultivars Leccino and FS17® showed the lowest incidence of infections, symptoms and the infected plants of both cultivars were found to harbor the lowest concentration of the bacterium.
These outcomes confirm the preliminary data reported by the same research groups about the finding of resistance mechanisms activated in the cultivar Leccino in response to the infection of X. fastidiosa. Indeed, the cultivar FS17® was identified as an additional useful source of resistance to X. fastidiosa, showing lower incidence of infections and symptoms of the cultivar Leccino, and lower concentration of the bacterium in the trees.
Extensive screening for the olive cultivars susceptibility are currently ongoing in both aforementioned EU projects, to seek for resistant olive cultivars that may reduce the impact of the Xylella-associated disease in the infected olive-growing areas.
These scientific advances provide support to the current decision-making process for transforming scientific research achievement into the implementation of the current EU legislative measures, promoting the adoption of the most appropriate actions and integrated approaches for the containment X. fastidiosa emergence.