Update and New Epidemiological Aspects about Grapevine Yellows in Chile

• Main Authors: Nicolás Quiroga, Camila Gamboa, Daniela Soto, Ana Maria Pino, Alan Zamorano, Juan Campodonico, Alberto Alma, Assunta Bertaccini, Nicola Fiore
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Pathogens
• Subjects: insects vector; nested-PCR/RFLP; sequencing; weeds
• Online Access: https://www.mdpi.com/2076-0817/9/11/933

To date, phytoplasmas belonging to six ribosomal subgroups have been detected to infect grapevines in Chile in 36 percent of the sampled plants. A new survey on the presence of grapevine yellows was carried out from 2016 to 2020, and 330 grapevine plants from the most important wine regions of the country were sampled and analyzed by nested PCR/RFLP analyses. Phytoplasmas enclosed in subgroups 16SrIII-J and 16SrVII-A were identified with infection rates of 17% and 2%, respectively. The vineyards in which the phytoplasma-infected plants were detected were further inspected to identify alternative host plants and insects of potential epidemiological relevance. Five previously unreported plant species resulted positive for 16SrIII-J phytoplasma (<i>Rosa</i> spp., <i>Brassica rapa</i>, <i>Erodium</i> spp., <i>Malva</i> spp. and <i>Rubus ulmifolius</i>) and five insect species were fully or partially identified (<i>Amplicephalus ornatus</i>, <i>A. pallidus</i>, <i>A. curtulus</i>, <i>Bergallia</i> sp., <i>Exitianus obscurinervis</i>) as potential vectors of 16SrIII-J phytoplasmas. The 16SrVII-A phytoplasmas were not detected in non-grape plant species nor in insects. This work establishes updated guidelines for the study, management, and prevention of grapevine yellows in Chile, and in other grapevine growing regions of South America.