Proposal of A New Bois Noir Epidemiological Pattern Related to ‘<i>Candidatus</i> Phytoplasma Solani’ Strains Characterized by A Possible Moderate Virulence in Tuscany
Roberto Pierro,
Alessandra Panattoni,
Alessandro Passera,
Alberto Materazzi,
Andrea Luvisi,
Augusto Loni,
Marco Ginanni,
Andrea Lucchi,
Piero Attilio Bianco,
Fabio Quaglino
Affiliations
Roberto Pierro
Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
Alessandra Panattoni
Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
Alessandro Passera
Department of Agricultural and Environmental Sciences, Production, Landscape, Agroenergy (DiSAA), University of Milan, via Celoria 2, 20133 Milano, Italy
Alberto Materazzi
Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
Andrea Luvisi
Department of Biological and Environmental Sciences and Technologies, University of Salento, via Provinciale Monteroni, 73100 Lecce, Italy
Augusto Loni
Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
Marco Ginanni
Agro-Environmental Research Center “Enrico Avanzi” (CiRAA), University of Pisa, via Vecchia di Marina 6, 56122 Pisa Italy
Andrea Lucchi
Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
Piero Attilio Bianco
Department of Agricultural and Environmental Sciences, Production, Landscape, Agroenergy (DiSAA), University of Milan, via Celoria 2, 20133 Milano, Italy
Fabio Quaglino
Department of Agricultural and Environmental Sciences, Production, Landscape, Agroenergy (DiSAA), University of Milan, via Celoria 2, 20133 Milano, Italy
Bois noir (BN), associated with ‘Candidatus Phytoplasma solani’ (CaPsol), is the most widespread disease of the grapevine yellows complex worldwide. In this work, BN epidemiology was investigated in a case study vineyard where an unusual CaPsol strain, previously detected only in other host plants, was found to be prevalent in grapevine. Experimental activities included: symptom observation; sampling of symptomatic vines, Auchenorrhyncha specimens, and weeds; molecular detection and typing of CaPsol strains; statistical analyses for determining possible relationships between CaPsol relative concentration, strain type, and symptom severity. Among insects, Reptalus quinquecostatus was the most abundant and was found to be highly infected by CaPsol, while Hyalesthes obsoletus, the main CaPsol vector, was not caught. Moreover, R. quinquecostatus harbored CaPsol strains carrying uniquely the stamp sequence variant St10, also identified as prevalent in vines and in the majority of weeds, and all the secY variants identified in the vineyard. Statistical analyses revealed that CaPsol strains carrying the St10 variant are not associated with severe symptoms, suggesting their possible moderate virulence. Based on such evidence, a new BN epidemiological pattern related to these CaPsol strains and involving grapevine, R. quinquecostatus, and/or weeds is proposed. Furthermore, the possible presence of other players (vectors and weeds) involved in CaPsol transmission to grapevines was highlighted.
