Update of the Xylella spp. host plant database – systematic literature search up to 31 December 2020

Abstract

Following a request from the European Commission, EFSA was asked to create and regularly update a database of host plant species of Xylella spp. Complying with an extension of the previous mandate, which now covers the period 2021-2026, the current version of Xylella spp. host plant database updates the previous release dated April 2020. Informative data have been extracted from 86 recent publications retrieved through an extensive literature search. This report is related to the fourth version of the database published in Zenodo in the EFSA Knowledge Junction community, covering articles selected from: a systematic literature review conducted up to 31 December 2020, Europhyt outbreak notifications up to 18 March 2021 and communications from research groups and national authorities. Forty-three new host plant species of X. fastidiosa, identified through the data extracted from the selected publications, have been added to the database. Those plant species were reported as naturally or artificially infected by subsp. fastidiosa, multiplex, pauca or unknown (i.e. not reported in the publication) subspecies of X. fastidiosa. New information on the tolerant/resistant response of plant species or varieties to X. fastidiosa infection is also reported. No additional data were retrieved for X. taiwanensis. This new version of the database includes no update on the number of Sequence Types (STs) identified so far, which remains unchanged. The overall number of Xylella spp. host plants determined with at least two different detection methods or positive with one method (between: sequencing, pure culture isolation) reaches now 385 plant species, 179 genera and 67 families. Such numbers rise to 638 plant species, 289 genera and 87 families if considered regardless of the detection method applied. The database will be issued twice per year, with the aim to provide information and scientific support to risk assessors, risk managers and researchers dealing with Xylella spp.

Landscape and Vegetation Patterns Zoning Is a Methodological Tool for Management Costs Implications Due to Xylella fastidiosa Invasion

“…Since Xf vectors are known to be highly polyphagous [2,5,6], crop diversity was considered another indicator for zoning. In fact, it represents the diversity of the agricultural landscape and provides a quantitative and measurable value of the presence of an agro-ecomosaic that is identifiable with a sustained diversity of the crops present in the study area.…”

“…The ecology and biology of Xf vectors require a relative density of agricultural landscape elements (dry stone walls, hedges, rows of trees). This zoning indicator reflects an indication of the complexity of the agricultural landscape, captures any differences in the characterization of the agroecosystem, and represents the capacity of the agricultural territory to provide shelter, food, and movement for Xf vectors [2][3][4][5][6]. As such, we initially extracted the linear agricultural landscape elements (dry stone walls, hedges, and rows of trees) from the Regional Technical Cartography of the Apulia region.…”

“…Similarly, the cultivation intensity of olive groves corresponds to high costs due to narrower planting distances and a higher number of plants per hectare. In the same way, the presence of an ecomosaic vegetation [28][29][30][31] increases the likelihood of harboring Xf vector species and, consequently, increases monitoring management costs on account of the Xf vector(s) is/are polyphagous [2,5,6]. On the contrary, a monoculture patho-system may positively influence cost reduction.…”

“…and Coffea spp., and recently on olives in Italy [2,3], and on Polygala myrtifolia in France [4]. Xf is highly polyphagous and affects 683 host plants without causing any apparent disease symptoms in many cases [2,5,6].…”

Fast and Reliable Electronic Assay of a Xylella fastidiosa Single Bacterium in Infected Plants Sap

“…Studies on a single‐bacterium are relevant as, even in clonal populations, bacterial cell‐to‐cell variability at the microbiological (metabolism profile, response to stimuli, survival ability, [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ] etc.) and biochemical level, can be significant.…”