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An infectious particle, similar to but smaller than a virus, that consists solely of a strand of RNA and is capable of causing disease in plants.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Biochemistry) any of various infective RNA particles, smaller than a virus and known to cause some plant diseases
[C20: from vir(us) + -oid]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈvaɪ rɔɪd)

an infectious agent of plants similar to a virus but consisting of only a short, single strand of RNA without a protein coat.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.viroid - the smallest of viruses; a plant virus with its RNA arranged in a circular chromosome without a protein coat
plant virus - a plant pathogen that is a virus consisting of a single strand of RNA
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
However, many of these effects may be due to the presence of exocortis viroid complex or poor adaptation to certain soil conditions, especially sandy soils where P.
benthamiana expression and influence of Potato spindle tuber viroid movement in 4/1-silenced plants were demonstrated [30, 31].
Development of a real-time RT-PCR assay for the detection of Potato spindle tuber viroid. J.
Development of the molecular methods for potato virus and viroid detection and prevention.
[26.] Grasmick ME and SA Slack Detection of potato spindle tuber viroid in true potato seed by bioassay on Rutgers tomato.
[section] 7702(14) (2006) (defining plant pests as "any living stage of any of the following that can directly or indirectly injure, cause damage to, or cause disease in any plant or plant product: (A) A protozoan (B) A nonhuman animal (C) A parasitic plant (D) A bacterium (E) A fungus (F) A virus or viroid (G) An infectious agent or other pathogen (H) Airy article similar to or allied with any of the articles specified in the preceding subparagraphs"); id.