Newly identified host range of viruses infecting species of the genus Allium and their distribution in six habitats in the Czech Republic

Abstract

AbstractStudies on plant viruses are concentrated mainly towards crop diseases and little is known about viruses in wild and ornamental species. We surveyed viruses infecting 65 vegetable, wild, and ornamental Allium species cultivated or naturally occurring in the Czech Republic. Allium plants were collected from six habitat categories (botanical gardens, private gardens, cultivated fields, ornamentals from markets, cultivated plants of wild origin, wild origin). Samples were tested by ELISA and/or reverse transcription‐PCR for the presence of 15 viruses belonging to the genera Allexivirus, Carlavirus, Potyvirus, and Orthotospovirus. Of the 883 sampled plants, 63.4% were infected by at least one or more viruses. The infection rate of Allium samples differed depending on the habitat origin and phylogenetic relatedness of the hosts. Viruses were most frequently detected in cultivated species, with a high incidence of leek yellow stripe virus (LYSV), garlic common latent virus (GCLV), shallot virus X (ShVX), garlic virus A (GarV‐A), and garlic virus B (GarV‐B). Low infection rates and virus‐free samples were detected in species of wild origin. Composition of viruses belonging to the genus Allexivirus significantly differentiated the subgenus Melanocrommyum from other Allium subgenera. Mixed infections (51.1% of analysed plants) were widespread in most species. New host associations were observed for some viruses previously recorded in the Czech Republic. In addition, three viruses, shallot yellow stripe virus (SYSV), Impatiens necrotic spot virus (INSV), and iris yellow spot virus (IYSV), were detected for the first time on Allium species in the Czech Republic.