|TAN, S - University Of California|
|TALIBOV, THO - Azerbaijan Academy Of Sciences|
|BODAGHI, S - University Of California|
|DANG, T - University Of California|
|CHAO, Y - University Of California|
|GREER, G - University Of California|
|VIDALAKIS, G - University Of California|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2016
Publication Date: 11/1/2016
Citation: Tan, S.H., Talibov, T., Krueger, R., Bodaghi, S., Dang, T., Chao, Y.Y., Greer, G., Vidalakis, G. 2016. First report of citrus exocortis viroid and two citrus variants of the hop stunt viroid on lemon in Azerbaijan. Plant Disease 100:2341. http://dx.doi.org/10.1094/PDIS-05-16-0761-PDN.
Interpretive Summary: Budwood received from a lemon tree growing at the Bioresources Institute Nakhichivan, Azerbaijan, produced symptoms of citrus viroids Citrus exocortis viroid (CEVd) and Hop Stunt Viroid (HSVd) in citrus and herbaceous indicators. Extracts from the ‘S-1’ indicator produced bands corresponding to these viroids in sequential polyacrylamide gel electrophoresis. Extracts from the indicators tested positive for CEVd and HSVd by reverse transcription real-time quantitative polymerase chain reaction, and cloned and sequenced products showed homology with CEVd and HSVd submissions in GenBank. This is the first report of citrus viroids in Azerbaijan and highlights the importance of indexing and certification programs and the necessity of National Clean Plant Network centers for the exclusion of citrus pathogens from the USA.
Technical Abstract: Budwood received from a lemon tree growing at the Bioresources Institute Nakhichivan, Azerbaijan, produced symptoms corresponding with citrus viroids and cachexia on biological indicators ‘S-1’ citron and ‘Parson’s Special’ (PSM) mandarin, respectively. Sequential poly acrylamide gel electrophoresis of RNA extracts from the symptomatic ‘S-1’ citron identified viroid RNAs with mobility similar to citrus exocortis viroid (CEVd) and hop stunt viroid (HSVd). Slash inoculation of herbaceous indicators gynura (Gynura aurantiaca (Blume) DC) and chrysanthemum (Dendrathema morifolia L.) with total nucleic acid extracted from the lemon resulted in symptoms associated with viroids. Reverse transcription real-time quantitative polymerase chain reaction tests for CEVd and HSVD identified both viroids in the source lemon, the inoculated ‘S-1’ and ‘PSM’ indicators, and the slash-inoculated chrysanthemum, whereas the slash inoculated gynura tested positive for CEVd. Cloned and sequenced products showed homology with CEVd and HSVd accessions in GenBank. This is the first report of citrus viroids in Azerbaijan.