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ARS Home » Research » Publications at this Location » Publication #231527

Title: Russian isolates of Potato spindle tuber viroid exhibit low population diversity

item Owens, Robert
item Lee, Ing Ming

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2009
Publication Date: 7/1/2009
Citation: Owens, R.A., Girsova, N.V., Kromina, K.A., Lee, I., Mozhaeva, K.A., Kastalyeva, T.B. 2009. Russian isolates of Potato spindle tuber viroid exhibit low population diversity. Plant Disease. 93:752-759.

Interpretive Summary: In Russia and other regions of the former Soviet Union, the widespread occurrence of potato spindle tuber viroid (PSTVd) poses significant problems for seed potato production. There are no regional seed potato certification laboratories in Russia, and farmers lack access to reliable methods of viroid identification. This publication reports small differences between 17 strains of PSTVd collected from locations throughout the Russian Federation. Only two of these strains appear to be widely distributed in Russia, and all but one were previously unknown. Both widely-distributed strains of PSTVd can both be traced back to a single source. Information about strain distribution is critical to the success of ongoing efforts to control (and eventually eliminate) this important disease from Russian seed potatoes. The primary users of this information will be plant quarantine officials (for example, APHIS) and research scientists interested in the pathways by which plant diseases are spread. Our results also have certain important implications for fundamental studies of viroid molecular biology.

Technical Abstract: Potato spindle tuber viroid (PSTVd) is currently wide-spread in seed potatoes grown in Russia. Characterization of 39 PSTVd isolates collected from widely separated areas in Russia over a 15-year period revealed the presence of 17 different sequence variants, all but one of which were previously unknown. Most variants were recovered only once, but two others were more widely distributed; one was a mild variant previously isolated in Germany, the second a novel variant inducing symptoms similar to those of the type strain in tomato. Despite this apparent lack of population diversity, several novel and informative PSTVd variants were recovered. Sequence changes in the pathogenicity and variable domains were particularly common, but previously unknown changes were also detected within the loop E motif in the central domain, a structural motif known to play a key role in PSTVd replication and host range determination.