Journal of General Plant Pathology (2004) 70, 181-187

Teruo Sano, Hiroshi Yoshida, Masafumi Goshono, Takayuki Monma, Hideto Kawasaki and Keiichiro Ishizaki (2004)
Characterization of a new viroid strain from hops: evidence for viroid speciation by isolation in different host species
Journal of General Plant Pathology 70 (3), 181-187
Abstract: A new viroid was detected in hops cultivated in Akita Prefecture, Japan where it is prevalent in many hops fields. In a survey of hop samples collected during the 1986-2002 growing seasons, the new viroid was present in the major Japanese hop-cultivating areas as early as the 1980s. A single-stranded circular RNA of 368-372 nucleotides that assume a highly basepaired, stable, rod-like secondary structure, shares 93%-98% sequence homology with Apple fruit crinkle viroid (AFCVd) isolated from apple and 85%-87% with Australian grapevine viroid (AGVd) isolated from grapevine. Taking into account the present concept of viroid species, we conclude that the viroid is AFCVd. Circumstantial evidence suggests that AFCVd from apples and hops were endemic in Japan only where cultivation of the two host plants overlapped, thereby strongly supporting the possibility that AFCVd (or an ancestral viroid) was transmitted across the species barrier from apples to hops or hops to apples somewhere in the region. Phylogenetic analysis of AFCVd from hops, AFCVd from apples, and AGVd together with the other members of the genus Apscaviroid revealed that the Akita isolates of AFCVd from hops (AFCVd-hop) formed a cluster that is distinct from AFCVd-apple and AGVd. Accumulation of host-specific sequence variation following their isolation in different host species may be leading to the formation of two viroid species from a common ancestor.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Teruo Sano

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
identification/taxonomy

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Apple fruit crinkle viroid	Hop (Humulus lupulus)	Japan