What is Xylella fastidiosa

The bacterium Xylella fastidiosa is one of the most threatening plant pathogens in the world

 

It disrupts the stream of water and mineral nutrients in the xylem vessels (conducting channels in the wood) of host plants, which is the reason for the name “Xylella”. The adjective “fastidiosa” is due to the difficulty of isolating and culturing it in vitro.

Xylella fastidiosa 

Xylella fastidiosa disrupts the stream of water and mineral nutrients in the xylem vessels (conducting channels in the wood) of host plants, which is the reason for the name “Xylella”. The adjective “fastidiosa” is due to the difficulty of isolating and culturing it in vitro. The bacterium was discovered for the first time in grapevines affected by the Pierce’s disease, a harmful grape disease described in California by Newton Pierce in 1892. 

Several variants and strains of the bacterium are known worldwide, and more than 650 plant species can be colonized by one or more strains of the bacterium. Xylella fastidiosa can remain latent in several plant species. But it is well known as the causal agent of important diseases in a wide range of them, such as grapevine, almond, oleander, orange, peach, citrus, coffee, avocado, olive tree, and oak. The bacterium affects the normal physiological processes of the plants and can lead to their death.

In October 2013, for the first time in the EU and in the Mediterranean countries, scientists reported the presence of Xylella fastidiosa on olive trees in Puglia, southern Italy. Since then, surveillance has led to the discovery of outbreaks in regions of France, Spain and Portugal. Several species of xylem sap-sucking insects, mainly “spittlebugs”, are known to be vectors of the bacterium.

Xylella fastidiosa is a “special observed” pathogen in the EU. The Union includes it in the priority list of the most threatening plant pests.