@article{quesada-ocampo_withers_butler_birdsell_schultheis_2015, title={First Report of Plectosporium Blight on Pumpkin and Squash Caused by Plectosporium tabacinum in North Carolina}, volume={99}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-07-14-0770-pdn}, abstractNote={HomePlant DiseaseVol. 99, No. 5First Report of Plectosporium Blight on Pumpkin and Squash Caused by Plectosporium tabacinum in North Carolina PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Plectosporium Blight on Pumpkin and Squash Caused by Plectosporium tabacinum in North CarolinaL. M. Quesada-Ocampo, S. Withers, S. Butler, T. Birdsell, and J. SchultheisL. M. Quesada-OcampoSearch for more papers by this author, S. WithersSearch for more papers by this author, S. ButlerSearch for more papers by this author, T. BirdsellSearch for more papers by this author, and J. SchultheisSearch for more papers by this authorAffiliationsAuthors and Affiliations L. M. Quesada-Ocampo S. Withers S. Butler , Department of Plant Pathology, North Carolina State University, Raleigh 27695 T. Birdsell , Cooperative Extension, North Carolina State University, Raleigh 27695 J. Schultheis , Department of Horticulture, North Carolina State University, Raleigh 27695. Published Online:29 May 2015https://doi.org/10.1094/PDIS-07-14-0770-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Cucurbits are among the most important vegetable crops in North Carolina. Plectosporium blight, caused by Plectosporium tabacinum, can significantly reduce marketable fruit in squash and pumpkin (1). Since 1988, when Plectosporium blight was first reported in the United States in Tennessee, the disease has been confirmed in New York, Alabama, Louisiana, Virginia, and Illinois (4). In July of 2013, approximately15% of zucchini squash (Cucurbita pepo ‘Zephyr’ and ‘Senator’) grown in an organic commercial field in Davidson County, NC, showed spindle-shaped, corky, sunken, tan lesions on the stems and petioles; and circular, corky, raised, tan lesions on the leaves and fruit. In September of 2013, approximately 10 to 20% of the pumpkin plants (C. pepo ‘Field Trip’) at research station fields in Ashe and Haywood Counties, NC, also showed stem, leaf, and fruit lesions characteristic of Plectosporium blight (4). After surface-sterilization with 70% ethanol, four to five lesions were excised from petioles and fruit of each cultivar, placed on potato dextrose agar, and incubated under constant fluorescent light at room temperature (21°C). Tan to light pink colonies with white aerial mycelium grew on the plates after a week, and after single-sporing, one representative isolate from each of three cultivars, Zephyr, Senator, and Field Trip, was retained for analysis. One- and two-celled, hyaline, elongate, ellipsoid, slightly curved conidia (n = 10), each with a narrow base that measured 7.4 to 10.2 × 2.1 to 3 μm were observed for the three isolates at 100× magnification. Branched, hyaline conidiophores (n = 5) with elongate, slightly sinuous, apical phialides and conidia in mucilaginous heads at the tip of each conidiophore identified the isolates as P. tabacinum (synonyms Microdochium tabacinum, Fusarium tabacinum, and Plectosphaerella cucumerina) (2). To confirm the identity of the isolates, the internal transcribed spacer (ITS) region of ribosomal DNA was amplified and sequenced with the ITS4 and ITS5 primers (3). The sequence was compared with sequences in GenBank using a BLAST alignment, which revealed that the isolates had 98% identity with ITS sequences of P. cucumerina (AB266250.1), the teleomorph of P. tabacinum. The ITS sequences of the three isolates were deposited in GenBank under accession numbers KJ130026, KJ130027, and KJ130028. No official report has been published of P. tabacinum on C. pepo in NC; however, Plectosporium blight can be misidentified as mechanical injury, e.g., from sand blasting, and it is likely that the pathogen has previously been encountered but not yet reported officially in NC. While it is uncommon for Plectosporium blight to result in devastating yield losses, the disease can cause significant reduction in marketable fruit, which may warrant applications of effective fungicides in fields where the pathogen has been found.References:(1) Mullen, J. M., and Sikora, E. J. 2003. Plant Dis. 87:749. https://doi.org/10.1094/PDIS.2003.87.6.749A Link, ISI, Google Scholar(2) Palm, M. E., et al. 1995. Mycologia 87:397. https://doi.org/10.2307/3760837 Crossref, ISI, Google Scholar(3) White, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA. Crossref, Google Scholar(4) Zitter, T. A. 1996. Page 28 in: Compendium of Cucurbit Diseases. T. A. Zitter, D. L. Hopkins, and C. E. Thomas, eds. The American Phytopathological Society, St. Paul, MN. Google ScholarDetailsFiguresLiterature CitedRelated Vol. 99, No. 5 May 2015SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 29 May 2015Published: 29 May 2015First Look: 11 Dec 2014Accepted: 3 Dec 2014 Page: 724 Information© 2015 The American Phytopathological SocietyCited byPlectosphaerella cucumerinaCABI Compendium, Vol. CABI CompendiumDiseases of Chrysanthemum7 January 2018Diseases of Chrysanthemum24 May 2017}, number={5}, journal={PLANT DISEASE}, publisher={Scientific Societies}, author={Quesada-Ocampo, L. M. and Withers, S. and Butler, S. and Birdsell, T. and Schultheis, J.}, year={2015}, month={May}, pages={724–725} }
 @article{scruggs_butler_quesada-ocampo_2014, title={First Report of Cladosporium Leaf Spot of Spinach Caused by Cladosporium variabile in North Carolina}, volume={98}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-05-14-0474-pdn}, abstractNote={ Cladosporium leaf spot of spinach, caused by Cladosporium variabile, can result in significant economic losses in the United States (2). In March 2014, symptoms consistent with Cladosporium leaf spot (4) appeared on the spinach cultivar Tyee in a greenhouse located in Rowan County, NC. Of 1,080 spinach plants, 90 to 100% were infected. Symptoms consisted of small (1 to 3 mm in diameter), circular, tan lesions each outlined with a dark margin on the adaxial surface of the leaf. On severely infected foliage, lesions coalesced to produce relatively large necrotic regions. Profuse fungal sporulation was observed on the lesion surface with a dissecting microscope at 40× magnification. Using a dissecting microscope, conidia were collected with a sterile needle and transferred to petri plates containing potato dextrose agar. Plates were then incubated at 23 ± 2°C under continuous fluorescent light, and fungal growth was apparent after 24 h. Isolations from leaves of six infected plants produced slow-growing, dark green to brown fungal colonies that reached only 31 mm in diameter after 14 days, which is characteristic of C. variabile (4). Colonies contained dense masses of dematiaceous, septate, unbranched conidiophores with conidial chains, each containing up to five conidia. Conidia were ovate to elongate, with some being septate. The length of individual conidia ranged from 10 to 19 μm. Conidial septa were distinctly dark when observed at 100× magnification, which is a defining feature of C. variabile vs. the conidia of C. macrocarpum (4). The surface of the conidia appeared verrucose at 100× magnification, and conidia were each distinctly darkened toward the base. A single isolate obtained through single-spore transfer was used for DNA extraction, and the histone 3 (H3) gene sequence was amplified using the primers CYLH3F and CYLH3R (1). Sequence analysis of the amplified product using BLAST analysis indicated that the H3 sequences had 100% identity to that of a C. variabile isolate (GenBank Accession No. EF679710.1), and 99% identity to a C. macrocarpum isolate (EF679687.1). The H3 sequence from a representative isolate was deposited in GenBank (KJ769146). To our knowledge, this is the first report of Cladosporium leaf spot on spinach in North Carolina based on morphological evaluation and H3 sequencing results. C. variabile is a seedborne pathogen, so it is possible inoculum was introduced into the greenhouses in North Carolina on infected seed (3). Seeds can be treated with hot water or chlorine to reduce the risk of disease outbreaks caused by infected seed (2). Furthermore, Cladosporium leaf spot may be controlled with the use of fungicides (3). }, number={12}, journal={PLANT DISEASE}, publisher={Scientific Societies}, author={Scruggs, A. C. and Butler, S. C. and Quesada-Ocampo, L. M.}, year={2014}, month={Dec} }
 @article{quesada-ocampo_butler_withers_ivors_2014, title={First Report of Fusarium Rot of Garlic Bulbs Caused by Fusarium proliferatum in North Carolina}, volume={98}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-01-14-0040-pdn}, abstractNote={ In August of 2013, garlic bulbs (Allium sativum) of the variety Chesnok Red grown and stored under dry conditions by a commercial producer in Buncombe County showed water-soaked, tan to salmon-pink lesions. Lesions on cloves became soft over time, slightly sunken, and had mycelium near the center of the bulb, which is characteristic of Fusarium rots on garlic (1,2). Approximately 10 to 20% of the bulbs inspected in the drying storage room were affected. Surface-sterilized tissue was excised from the margin of lesions on eight bulbs, plated onto acid potato dextrose agar (APDA), and incubated in the dark at room temperature (21°C). White to light pink colonies with abundant aerial mycelium and a purple pigment were obtained from all samples after 2 to 3 days of incubation. Inspection of colony morphology and reproductive structures under a microscope revealed that isolate characteristics were consistent with Fusarium proliferatum (Matsushima) Nirenberg. Microscopic morphological characteristics of the isolate included hyaline, septate hyphae; slender, slightly curved macroconidia with three to five septae produced in sporodochia; curved apical cell; and club-shaped, aseptate microconidia (measuring 3.3 to 8.3 × 1.1 to 1.3 μm) produced in chains by mono and polyphyalides. To further define the identity of the isolate, the beta-tubulin (Btub), elongation factor 1a (EF1a), and internal transcribed spacer (ITS) regions were amplified and sequenced (3). The resulting sequences were compared against the GenBank nucleotide database by using a BLAST alignment, which revealed that the isolate had 100% identity with F. proliferatum for the Btub, EF1a, and ITS regions (GenBank Accession Nos. AF291055.1, JX118976.1, and HF930594.1, respectively). Sequences for the isolate were deposited in GenBank under accessions KJ128963, KJ128964, and KJ128965. While there have been other reports of F. proliferatum causing bulb rot of garlic in the United States (1), to our knowledge, this is the first report in North Carolina. The finding is significant since F. proliferatum can produce a broad range of mycotoxins, including fumonisins, when infecting its host, which is a concern for food safety in Allium crops. }, number={7}, journal={PLANT DISEASE}, publisher={Scientific Societies}, author={Quesada-Ocampo, L. M. and Butler, S. and Withers, S. and Ivors, K.}, year={2014}, month={Jul}, pages={1009–1010} }
 @article{koenning_frye_butler_creswell_2007, title={First report of Phakopsora pachyrhizi on Kudzu (Pueraria montana var. lobata) in North Carolina and increased incidence of soybean rust on soybean in 2006.}, volume={91}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-91-5-0637A}, abstractNote={ Asian soybean rust, caused by Phakopsora pachyrhizi H. Sydow & Sydow, was first detected in the continental United States in soybean (Glycine max (L.) Merr.) in Louisiana on 6 November 2004 (3) and in kudzu (Pueraria montana var. lobata) in Florida during February 2005 (1). Soybean rust was first confirmed in North Carolina in commercial soybean fields in Brunswick, Columbus, and Robeson counties on 25 October 2005 (2). Subsequently, the disease was detected in soybean in 18 counties, but not in kudzu, even when it was growing adjacent to infected soybean. During 2006, soybean rust was first detected in North Carolina in soybean on 14 September 2006 from a sample from Columbus County that was submitted to the North Carolina State University Plant Disease and Insect Clinic (NCSU-PDIC). Thus, the first detection of soybean rust in North Carolina occurred almost 6 weeks earlier in 2006 than in 2005. Subsequently, in 2006, soybean rust was found in soybean in 42 counties in North Carolina through survey, sentinel plot monitoring, and samples submitted to the NCSU-PDIC. In addition, what appeared to be soybean rust was observed in two samples of kudzu collected on 3 and 6 November 2006 from Moore (35.28313°N, 79.38020°W) and Johnston (35.42742°N, 78.18154°W) counties of North Carolina. The diagnosis of P. pachyrhizi in kudzu was confirmed visually and by ELISA protocol supplied with the EnviroLogix QualiPlate kit (Portland, ME). ELISA tests for each kudzu sample were run in triplicate. PCR was also conducted on infected kudzu samples with a protocol previously reported (1). The PCR master mix that was used came from a dilution scheme based on previous PCR work completed by G. Z. Abad. A total of 24 reactions were run, including four 1-kb molecular markers, four positive controls, four negative controls, and four infected kudzu leaf tissue samples. The results of all diagnostic techniques confirmed the presence of P. pachyrhizi in diseased kudzu. To our knowledge, this is the first report of P. pachyrhizi in kudzu in North Carolina. }, number={5}, journal={PLANT DISEASE}, author={Koenning, S. R. and Frye, J. W. and Butler, S. C. and Creswell, T. C.}, year={2007}, month={May}, pages={637–637} }