Host plant resistance remains the most practical, efficient, and cost-effective strategy for managing Xylella fastidiosa outbreaks in the EU, top world specialists participating in the 4th European Conference on Xylella fastidiosa confirmed.

So far, scientists have identified two disease-resistant olive cultivars. Good news from the Conference is the presentation of the BeXyl work package leader Ofir Bahar showing encouraging results on a X. fastidiosa resistant almond genotype. The pathogen is the primary agent of Almond Leaf Scorch (ALS). The resistant genotype emerged from a selection of seven and showed minimal symptoms and a significantly lower bacterial population. Data show that the genotype is resistant to X. fastidiosa, and its resistance intensifies over time. 

The conference hosted presentations from the US, showing that research currently focuses on improving the understanding of systemic immunity mechanisms (such as priming) and providing the basics for solutions based on bioengineered rootstocks or lipopolysaccharides. Also, data presented from researchers from the University of Girona indicated that selected or newly designed peptides can hamper biofilm formation, and induce defense responses in the plant

Concluding the meeting, scientists discussed the lengthy process of making progress on resistant varieties. For some plant species, such as olives, this comes from the knowledge gap on the availability of the olive genome compared to other species (such as grapevine). However, breeding the resistant cultivars has considerable potential, as researchers discovered that resistance is transmitted to the progeny.