Vessels occlusion frequency as cultivar-associated xylem trait in Olea europaea.

Constitutive vessel occlusion frequency is a stable, cultivar-specific anatomical trait in Olea europaea that varies consistently among genotypes despite environmental differences.

• Why it matters: Understanding phenotypic traits linked to vascular resistance is crucial for selecting olive cultivars with improved tolerance to vascular pathogens like Xylella fastidiosa, especially under Mediterranean conditions.
• What they did: The study quantified occlusion frequency in 97 olive cultivars using microscopy, classified them from low to high occlusion, and analyzed 40 representative cultivars with 1H-NMR profiling to explore associated metabolic traits.
• The result: Readiness for vessel occlusion formation is a consistent cultivar-specific feature that may predict biotic stress tolerance, supporting its use as a phenotypic marker in breeding strategies for vascular pathogen resilience.