Preliminary results on the canopy distribution of Xylella fastidiosa in the Apulian olive cultivars

Pathogen detection in the Italian outbreak area of X. fastidiosa is carried out using samples from symptomatic olive twigs and leaves. Conversely detection from asymptomatic trees is difficult due to the uneven pathogen distribution in olive cultivars. In this study the incidence and canopy distribution of the infection is under assessment in 4 olive cultivars (EU H2020 project ‘Xf-Actors’) grown in a field (about 1.5 Ha) in the infected area of Apulia. All trees were tested in March for the presence of X. fastidiosa using real time LAMP (Loop Mediated Isothermal Amplification). The highest infection rate was detected in ‘Cellina di Nardò’ (74%) and ‘Cima di Melfi’ (76%), whereas the lowest was recorded in ‘Leccino’ (61%) and ‘Frantoio’ (63%). Based on these results, 5 trees were selected from ‘Cellina di Nardò’ (highly susceptible) and ‘Leccino (less susceptible). About 4 twigs were randomly collected from 3 levels of the asymptomatic sector of the canopy and each twig was divided in 3 portions. About 180 samples/cultivar are collected 3 times from March to July and tested by DTBIA and real time LAMP. After the first 2 samplings a preliminary difference was noticed on the infection distribution: the whole canopy in the case of ‘Cellina di Nardò’ and the lower part of the canopy in the case of ‘Leccino’. However, final results will be achieved after the 3rd sampling in July and data analysis by Univariate and Multivariate ANOVA test.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"