First report of Australian grapevine viroid in grapevine in Greece

Abstract

In 2017 and 2018, grapevine leaves and stems were collected from symptomatic and symptomless vines from various cultivars of prefecture of Heraklion and the vineyard of the Greek Institute of Grapevine in Likovrisi (Attica). Total RNA extractions were performed according to Maliogka et al. (2015) and multiplex RT-PCR method (Hajizadeh et al. 2012) revealed the presence of Australian grapevine viroid (AGVd) in 13 out of 298 samples tested (11 from Crete and 2 from Attica). The full-length genome of the viroid was verified with Sanger sequencing for two isolates from Crete, AGVd S122 (369 bp; GenBank accession No. MT227864) and AGVd Her75 (370 bp; MT227865). In symptomatic AGVd positive plants showing bright yellow and chlorotic discolorations, pathogens such as grapevine fanleaf virus (GFLV), grapevine leafroll-associated virus-3 (GLRaV-3) and grapevine yellow speckle viroid-2 (GYSVd-2) were detected, in different combinations in each plant, making it difficult for the observed symptoms to be directly correlated with the AGVd presence.