Plant PathologyVolume 50, Issue 6 p. 805-805 Free Access Identification and isolation of Impatiens necrotic spot virus from prickly pear cactus (Opuntia microdasys) NEW DISEASE REPORT A. L. Blockley, A. L. Blockley Central Science Laboratory, Sand Hutton, York YO41 1LZ, UKSearch for more papers by this authorR. A. Mumford, R. A. MumfordSearch for more papers by this author A. L. Blockley, A. L. Blockley Central Science Laboratory, Sand Hutton, York YO41 1LZ, UKSearch for more papers by this authorR. A. Mumford, R. A. MumfordSearch for more papers by this author First published: 29 December 2001 https://doi.org/10.1046/j.1365-3059.2001.00628.xCitations: 5AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat In February 2001, 15-month-old plants of Opuntia microdasys var. albata were received from a specialist UK cactus grower. Over 80% of the plants (which had been raised as cuttings) of the same stock had necrotic symptoms, ranging from small (2–4 mm) necrotic spots up to large (1–2 cm) necrotic lesions. As the nursery involved had a persistent infestation of Western flower thrips (Frankliniella occidentalis), the samples were tested by ELISA for the two tospoviruses which occur in the UK and which are transmitted by this vector: Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV). INSV, but not TSWV, was detected using both polyclonal (Loewe Biochemica, Saverlach, Germany) and monoclonal (Adgen Auchincruive, KA6 5HW, UK) antibodies; infection by INSV was confirmed by RT-PCR by using INSV-specific primers (Mumford et al., 1996) which generated a PCR product of the correct predicted size (620 bp). The virus was also transmitted mechanically to a range of indicator plants which developed characteristic symptoms of INSV. Infected Chenopodium quinoa leaves with necrotic lesions were shown to be infected by INSV when subsequently tested by both ELISA and RT–PCR. The biological, serological and molecular properties of this Opuntia isolate are very similar to those of previously characterized INSV isolates from the UK and the Netherlands (Weekes et al., 1998). This is the first report of a tospovirus infecting a member of the genus Opuntia. A second virus detected in the Opuntia samples by electron microscopy had flexuous, filamentous particles 520 nm long. Such virus particles were also detected in mechanically inoculated leaves of C. amaranticolor. This virus has yet to be identified, but its experimental host range and the size and morphology of its particles indicate that it is probably Cactus virus X (CVX), a potexvirus previously reported from Opuntia spp. (Brunt et al., 1996). The symptoms, if any, caused by this potexvirus are unknown. However, CVX occurs symptomlessly in cactus species (Bercks, 1971) and thus alone is unlikely to have any significant deleterious effect on infected plants. References Bercks R, 1971. Cactus virus X. CMI/AAB Descriptions of Plant Viruses no. 58. Wallingford, UK: CAB International. Web of Science®Google Scholar Brunt AA, Crabtree K, Dallwitz MJ, Gibbs AJ, Watson L, 1996. Viruses of Plants. Wallingford, UK: CAB International. Google Scholar Mumford RA, Barker I, Wood KR, 1996. An improved method for the detection of tospoviruses using the polymerase chain reaction. Journal of Virological Methods 57, 109– 15.DOI: 10.1016/0166-0934(95)01975-8CrossrefCASPubMedWeb of Science®Google Scholar Weekes RJ, Barker I, Spence NJ, O'Neill T, Wood KR, 1998. A UK isolate of Impatiens necrotic spot virus from glasshouse-grown Cineraria. Journal of Phytopathology 146, 201– 3. Wiley Online LibraryWeb of Science®Google Scholar Footnotes *E-mail: r.mumford@csl.gov.uk Citing Literature Volume50, Issue6December 2001Pages 805-805 ReferencesRelatedInformation