The genus Coleviroid, family Pospiviroidae, comprises six known viroids, all infecting Plectranthus scutellarioides (Coleus blumei; coleus). In 2017, a novel viroid-like RNA sequence that shares ca. 65% identity with Coleus blumei viroid 1 (CbVd-1) was identified in a coleus cultivar infected by multiple coleviroids. Further sequence and secondary structure analyses are consistent with the discovery of a seventh viroid in the genus Coleviroid: tentatively named "Coleus blumei viroid 7" (CbVd-7). The viroid appears to be the product of a natural recombination event between CbVd-1 and Coleus blumei viroid 5. We prove CbVd-7 to be infectious and in turn demonstrate the ability of all known coleviroid left- and right-arm segments to recombine. With a length of 234 nucleotides, this is the smallest viroid described to date.

属Coleviroid，家庭马铃薯纺锤形块茎类病毒科，包括六个已知类病毒，感染所有彩叶草（彩叶草;彩叶）。2017 年，一个新的类病毒 RNA 序列共享约。在被多种类类病毒感染的锦紫苏栽培品种中鉴定出与 Coleus blumei 类病毒 1 (CbVd-1) 的 65% 同一性。进一步的序列和二级结构分析与在类病毒属中发现的第七个类病毒一致: 暂定名为“Coleus blumei viroid 7”（CbVd-7）。该类病毒似乎是 CbVd-1 和 Coleus blumei 类病毒 5 之间自然重组事件的产物。我们证明 CbVd-7 具有传染性，反过来又证明了所有已知类病毒的左臂和右臂节段重组的能力。长度为 234 个核苷酸，这是迄今为止描述的最小的类病毒。