Evidence of new viruses infecting freesia hybrids showing necrotic disease

Freesia plants of different cultivars with necrotic symptoms were collected in the Sanremo area, Northern Italy. Symptomatic foliar tissue was used both for mechanical inoculation to Nicotiana benthamiana and virus purification. Total, virus-enriched RNA extract was tested by Sequence-Independent Amplification (SIA) to get preliminary information about the presence of both known and previously undescribed viruses. In parallel, Next Generation Sequencing (NGS) of total RNA extracted from mechanically inoculated N. benthamiana plants was performed, in order to more easily identify the transmissible unknown virus(es). Obtained data led to the identification of a previously undescribed, mechanically transmissible, RNA virus, presumably belonging to the genus Phlebovirus or Tenuivirus, here provisionally named Freesia leaf necrosis associated virus (FreLNaV), likely involved in the necrotic disease. Moreover, novel virus sequences ascribable to DNA viruses belonging to Caulimoviridae family were also identified.