Some olive species less susceptible to tree pathogen
Some tree species have been found to be more resistant than others to a dangerous pathogen that is spreading across Europe.
Xylella fastidiosa, a plant pathogen which has affected olive plantations across southern Italy, could pose a serious threat to Europe’s olive oil industry if it continues to spread, but new test results suggest that some species may be more tolerant to the bacterium.
The tests were done under the Horizon 2020-funded Pest Organisms Threatening Europe (POnTE) project, which was co-funded by the European Food Safety Agency (EFSA). The head of the EFSA’s Plant and Animal Health unit, Giuseppe Stancanelli, told BBC News that the discovery of trees more tolerant to the pathogen was crucial: “They grow in infected orchards but do not show strong symptoms, as seen in more susceptible varieties. They are still infected by the inoculation, but this infection is much slower so it takes longer for the infection to spread, and the concentration of the bacterium in the plant is much lower.”
It is not yet known whether the bacterium will affect the crop yield of the resistant trees, but in any case the results offer new insight into the spread of the pathogen and may help to reduce the potential damage to Italy’s orchards.
X. fastidiosa is responsible for a number of diseases in trees, including leaf scorch in several species and citrus variegated chlorosis disease. Infections are often asymptomatic in certain hosts, meaning that they are difficult to detect, and this has contributed to the rapid spread of the disease since it was first detected in Italy in October 2013. According to commission figures, the EU produces almost three quarters of the world’s olive oil, meaning that tackling the pathogen is a priority for the EFSA.
