A known ilarvirus is associated with a novel viral disease in pepper

Abstract

AbstractIn 2020, a new pepper disease was recorded in a greenhouse crop in Drama, Greece, exhibiting mild concentric chlorotic rings and deformation on the fruits. High‐throughput sequencing (HTS) of total RNA from a plant with symptoms revealed three viral RNA segments closely related (>90% nucleotide identity) to those of four recently identified Ilarvirus species, Solanum nigrum ilarvirus 1 (SnIV1), surrounding legume associated ilarvirus (sLaIV), Erysiphe necator associated ilar‐like virus (ENaIlV1) and grapevine associated ilarvirus (GaIV). Nucleotide comparisons indicated that SnIV1, sLaIV, ENaIlV1, GaIV and the herein detected ilarvirus are isolates of the same virus species. All these ilarviruses were also discovered with the aid of HTS on different hosts; however, no data existed so far regarding their putative association with a disease. To fulfil Koch's postulates, we conducted mechanical inoculation to indicator plants and cultivated solanaceous species. The virus was transmitted only to Nicotiana benthamiana and Capsicum annuum ‘Arlequin’ plants; mild concentric rings, like the original symptoms, also appeared in the fruits of the pepper plants. We suggest that the new ilarvirus isolate PD be classified as SnIV1. However, the nomenclature of the species, including all the recently determined ilarviruses, should be ultimately addressed by the relevant ICTV group. Finally, a small‐scale survey revealed that SnIV1‐PD is currently not present in other geographical regions; nonetheless, more surveys are needed in Greece and abroad to unravel the geographical distribution, the biological characteristics and the evolutionary history of this virus.