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Title: Mexican papita viroid and tomato planta macho viroid belong to a single species in the genus Pospiviroid

item VERHOEVEN, J - Plant Protection Research Institute
item ROENHORST, J - Plant Protection Research Institute
item Owens, Robert

Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2011
Publication Date: 3/25/2011
Citation: Verhoeven, J.J., Roenhorst, J.W., Owens, R.A. 2011. Mexican papita viroid and tomato planta macho viroid belong to a single species in the genus Pospiviroid. Archives of Virology. 156:1433-1437.

Interpretive Summary: Viroids are the smallest known agents of infectious disease – small, circular RNA molecules whose presence in susceptible ornamental and crop plants can cause disease. In recent years, repeated disease outbreaks affecting tomatoes and related ornamentals growing in greenhouses have been reported around the world. Because infected plants do not always show strong symptoms, the initial source of infection is often unclear, and eradication may require destruction of entire lots of valuable plants. In this study we demonstrate that two of the viroids responsible for these outbreaks cannot be distinguished by their ability/inability to infect commonly-used experimental host plants. Although they should no longer be considered as separate species, these two tomato planta macho viroid variants are easily distinguished by the molecular methods currently used for viroid detection. This publication will be of greatest interest to APHIS scientists and other regulatory officials responsible for quarantine and eradication of plant pathogens.

Technical Abstract: Tomato planta macho viroid (TPMVd) and Mexican papita viroid (MPVd) are two closely-related (>90% sequence identity) members of the genus Pospiviroid. Their current status as separate species is based upon the reported ability of TPMVd to replicate in Gomphrena globosa and the inability of this viroid to evoke flower break in N. glutinosa. Characterization of a viroid recently isolated from diseased tomato plants grown in Mexico (identical to GenBank Accession GQ131573) casts doubt on this earlier report and indicates that both viroids should be classified as a single species. Giving priority to the oldest name, we propose TPMVd as the species name.