Disease Notes

Molecular Characterization of and Chili Leaf Curl fields in Owyhee County in southwestern Idaho near Grand View. The Begomoviruses from Pakistan. S. L. Shih, W. S. Tsai, and S. K. Green, perfect stage was widespread and easily found, and in one field the The Asian Vegetable Research and Development Center (AVRDC), surfaces of leaves collected from 50 randomly sampled were Shanhua, Tainan 741, Taiwan, R.O.C.; S. Khalid and I. Ahmad, Crop between 10 and 90% covered with ascomata. Subsequently, the Disease Research Institute, National Agricultural Research Centre, ascigerous stage was found in September and October in multiple fields Islamabad, Pakistan; M. A. Rezaian, Commonwealth Scientific and in three additional counties in southwestern and south-central Idaho and Industrial Research Organization (CSIRO), Adelaide, Australia; and J. two counties in northern Colorado. Ascomata were found on 12 Smith, CABI Bioscience, Surrey, UK. Dis. 87:200, 2003; published commercial varieties in the two states and six breeding lines in Colorado. on-line as D-2002-1204-02N, 2003. Accepted for publication 18 Asci contained one to four hyaline or yellow-to-golden pigmented November 2002. ascospores per ascus. Ascomata observed in Idaho and Colorado are similar to those described from Europe (2). Ascospores appeared intact Leaf curl or yellowing symptoms, typical of those caused by after leaves were dried and stored at 4 to 7°C more than 4 weeks. begomovirus infection, are commonly observed in chili ( However, after leaves with ascomata were dried and stored at 24 to 27°C annuum) and tomato (Lycopersicon esculentum) plantings in Pakistan. for 1 week or more, ascomata and asci appeared intact microscopically, One chili sample with leaf curl symptoms was collected in 1998 in but ascospores were no longer delineated and appeared desiccated or Multan (Punjab Province), and two tomato samples with leaf curl and degraded. Because the ascigerous stage provides a means of genetic yellowing symptoms were collected from Islamabad and Dargai (North recombination, there is the potential for races of the pathogen to arise West Frontier Province) in 2000 and 2001, respectively. DNA was with greater frequency. This has serious implications for managing first amplified by polymerase chain reaction using the degenerate primer fungicide resistance and breeding for disease resistance to sugar beet pair PAL1v1978/PAR1c715 (3). The expected 1.4-kb PCR products were powdery mildew. obtained from the three samples. Based on the sequences of the 1.4-kb DNA products, specific primers were designed to complete each of the References: (1) D. L. Coyier et al. (Abstr.) Proc. Am. Phytopathol. Soc. 2:112, 1975. DNA-A sequences. Two primer pairs, DNABLC1/DNABLV2 and (2) S. Francis. Mol. Plant Pathol. 3:119, 2002. DNABLC2/DNABLV2, were used for the detection of DNA-B (2). The of the tomato leaf curl isolate from Islamabad contained a DNA- A of 2,739 nucleotides (GenBank Accession No. AF448059), a DNA-B First Report of Cucumber in fruticans. L. of 2,728 nucleotides (GenBank Accession No. AY150304), and had 94% Cardin, A. Poupet, and J. P. Onesto, IPSMV Phytopathologie, Villa nucleotide identity in the common region. The genome of the tomato leaf Thuret, BP2078, F-06606 Antibes Cedex, France. Plant Dis. 87:200, curl isolate from Dargai contained a DNA-A of 2,740 nucleotides 2003; published on-line as D-2002-1202-01N, 2003. Accepted for (GenBank Accession No. AF448058), a DNA-B of 2,686 nucleotides publication 12 November 2002. (GenBank Accession No. AY150305), and had 96% nucleotide identity in the common region. Each of the tomato isolates contained eight predicted Teucrium fruticans (shrubby germander), family , is a hardy open-reading frames (ORFs) (AV1, AV2, AV3, AC1, AC2, AC3, AC4, and . Being drought tolerant, it is widespread in the Mediterranean area. AC5) in the DNA-A and two predicted ORFs (BV1 and BC1) in the Because it is readily propagated through cuttings, it is also planted in DNA-B. The DNA-A nucleotide sequence identity of the Islamabad hedges. In 1997 and 2000, respectively, yellow chlorotic areas were isolate and Dargai tomato isolate is 96% and that of DNA-B is 88%. observed on the foliage of T. fruticans in Saint Jean Cap Ferrat (France) Sequence comparisons with begomovirus sequences available in the and San Remo (Italy). These symptoms were distinct from those GenBank sequence database showed that these two tomato virus isolates produced by a rust that frequently affects T. fruticans in these areas. had the highest sequence identity with Tomato leaf curl New Delhi virus- from both locations were identified as Cucumber mosaic virus Severe (GenBank Accession No. U15015) from northern (more than (CMV) based on the following: (i) symptoms after mechanical 95% for DNA-A and less than 90% for DNA-B). The DNA-A of the virus inoculation of Nicotiana tabacum cv. Xanthi nc, N. tabacum cv. Samsum, associated with chili leaf curl from Pakistan (GenBank Accession No. Chenopodium quinoa, C. amaranticolor, Vigna unguiculata cv. Black, AF336806) consists of 2,754 nucleotides, containing six predicted ORFs and Cucumis sativus cv. Poinsett; (ii) the morphology of particles (AV1, AV2, AC1, AC2, AC3, and AC4). The chili virus was unrelated to observed in electron microscopy of uranyl acetate stained leaf dips from the two tomato begomovirus isolates from Pakistan, with which it shares tobacco; and (iii) positive result from leaves of diseased T. fruticans and less than 75% nucleotide identity. Sequence comparisons show highest mechanically inoculated host plants cited above based on enzyme-linked sequence identity (87%) with Tomato leaf curl Bangladesh virus immunosorbent assay (ELISA) using CMV antisera. On tobacco cv. (GenBank Accession No. AF188481). DNA-beta of 1.3 kb was detected Xanthi nc, the French (F) and Italian (I) isolates first induced essentially in the chili begomovirus isolate using Beta01/Beta02 primers (1). There necrotic rings on the inoculated leaves followed by the same systemic was no evidence for the presence of a DNA-B in the chili begomovirus symptoms as described above. The two isolates were cloned from local isolate when tested by the two DNA-B specific primer pairs. Based on lesions after two successive inoculations in V. unguiculata cv. Black, DNA sequence comparisons, the chili leaf curl virus from Pakistan, to our multiplied in tobacco, purified with the citrate-chloroform method, and knowledge, constitutes a distinct, new monopartite begomovirus. stabilized with formaldehyde (1). The serotype determination was made by double immunodiffusion in agar gel with the CMV-D and CMV-To References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:315, 2002. (2) S. K. Green et strains and homologous antisera (1,2). The formation of spurs and al. Plant Dis. 85:1286, 2001. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993. antigen-antibody lines indicated that both isolates belonged to the ToRS serotype (1). Thirty plants of T. fruticans cv. Azureum, first tested negative for CMV using ELISA, were mechanically inoculated with the F The Perfect Stage of Powdery Mildew of Sugar Beets Found in Idaho isolate (25 plants) and the CMV-D strain (five plants) and cultivated in a and Colorado. J. J. Gallian, University of Idaho, Twin Falls Research hydroponic system. Three months later, plants inoculated with the F and Extension Center, P.O. Box 1827, Twin Falls 83303-1827; and L. E. isolate were positive for CMV using ELISA and displayed clear Hanson, USDA-ARS, Crops Research Laboratory, 1701 Center Ave., Fort symptoms with chlorotic spots, which were sometimes ring-shaped. As Collins, CO 80526. Plant Dis. 87:200, 2003; published on-line as D- plants mature, symptoms tend to disappear on young shoots. For the 2002-1213-01N, 2003. Accepted for publication 21 November 2002. CMV-D strain, three plants of five were ELISA positive, but did not show any typical symptoms. This report demonstrates the infection of T. Powdery mildew (Erysiphe polygoni DC [synonym E. betae {Vanha} fruticans by CMV and the symptom induction by some CMV isolates. In Weltzien]) of sugar beet (Beta vulgaris L.) has been a significant problem September 2002, two CMV isolates were collected from T. fruticans in in many sugar beet growing areas of the United States since the first public gardens in Menton (France) and Genoa (Italy). These new isolates serious epidemic in 1974. Disease has been attributed solely to the have the same characteristics as those described in this report. asexual stage of the pathogen in the United States, except for one report of the perfect stage in a single field in Washington coincidental with the References: (1) J. C. Devergne and L. Cardin. Ann. Phytopathol. 7:225, 1975. (2) M. 1974 epidemic (1). In August 2001, ascomata were observed in several H. V. van Regenmortel. Adv. Virus Res. 12:207, 1966.

200 Plant Disease / Vol. 87 No. 2

First Report of Fusarium oxysporum on Eruca vesicaria and in the Northern Hemisphere (1). Samples were deposited in the Diplotaxis spp. in Europe. A. Garibaldi, G. Gilardi, and M. L. Gullino. Plant Pathology Mycotheca at the University of Córdoba, Spain (MIC- DIVAPRA—Patologia vegetale, Via Leonardo da Vinci 44, 10095 888 to MIC-897). To our knowledge, this is the first report of T. quercina Grugliasco, Italy. Plant Dis. 87:201, 2003; published on-line as D-2002- on Q. canariensis and the first report of this pathogen in Spain. 1204-01N, 2003. Accepted for publication 19 November 2002. Reference: (1) P. F. Cannon. Mycopathologia 135:69, 1996. Two types of rocket are available on the market in Italy: (i) Eruca vesicaria (synonym E. sativa) known as ruchetta or cultivated garden rocket; and (ii) several species of Diplotaxis (Diplotaxis erucoides, D. First Report of Rhizomania Disease of Sugar Beet Caused by Beet muralis, and D. tenuifolia), which are wild plants now widely cultivated. necrotic yellow vein virus in the Great Lakes Production Region. Rocket is increasingly used in the mediterranean cuisine as salad and or William M. Wintermantel, USDA-ARS, 1636 East Alisal Street, Salinas, to decorate dishes. In spring 2002, plants of the cultivated (E. vesicaria) CA 93905; Teresa Crook, Michigan Sugar Company, 725 South Almer, and wild (Diplotaxis spp.) rocket showing symptoms of a wilt disease P.O. Box 107, Caro, MI 48723; and Ralph Fogg, Monitor Sugar were observed in several commercial plastic greenhouses near Bergamo, Company, 2600 South Euclid, Bay City, MI 40706. Plant Dis. 87:201, in northern Italy. Wilted plants were first observed during the spring and 2003; published on-line as D-2002-1209-01N, 2003. Accepted for summer of 2001 when temperatures were between 26 and 35°C. In May publication 23 November 2002. 2002, symptoms were again observed in the same area, on the same farm as well as other farms. Although the distribution of the disease was Rhizomania, caused by Beet necrotic yellow vein virus (BNYVV) and generally uniform, symptoms were more severe in the central part of the vectored by the soilborne fungus Polymyxa betae Keskin, is one of the greenhouses where temperatures were warmest (30 to 60% of plants were most economically damaging diseases affecting sugar beet (Beta vulgaris affected). Diseased plants were stunted and chlorotic with brown or black L.). The virus likely originated in Europe and was first identified in streaks in the vascular system. Vascular tissues of affected plants California in 1983 (1). It has since spread among American sugar beet appeared red or brown. Vascular streaks in the chlorotic leaves extended production regions in spite of vigorous sanitation efforts, quarantine, and from the crown and were continuous with a red-brown discoloration in disease monitoring (3). In the fall of 2002, mature sugar beet plants the vascular system of the crown and upper taproot. Fusarium oxysporum exhibiting typical rhizomania root symptoms, including proliferation of was consistently and readily isolated from symptomatic vascular tissues hairy roots, vascular discoloration, and some root constriction (2) were when plated on a Fusarium-selective medium (2). Microconidia measured found in several fields scattered throughout central and eastern Michigan. 8.8 × 3.0 µm. E. vesicaria and Diplotaxis spp. were grown in steam- Symptomatic beets were from numerous , all susceptible to sterilized soil, and 10 days after emergence they were artificially rhizomania. Two to five sugar beet root samples were collected from each inoculated by root dipping in a spore suspension (1 × 105 CFU/ml) of field and sent to the USDA-ARS in Salinas, CA for analysis. Hairy root three F. oxysporum strains collected from infected plants. Uninoculated tissue from symptomatic plants was used for mechanical inoculation of plants served as control. Plants (60 per treatment) were grown at 25 to indicator plants. Mechanical inoculation produced necrotic lesions on 28°C in growth chambers. Wilt symptoms developed on all plants 20 Chenopodium quinoa and systemic infection of Beta vulgaris ssp. days after inoculation, and F. oxysporum was consistently reisolated from macrocarpa, both typical of BNYVV and identical to control inoculations infected plants. The pathogenicity test was conducted twice. To our with BNYVV. Symptomatic sugar beet roots were washed and tested knowledge, this is the first report of F. oxysporum on cultivated rocket in using double antibody sandwich-enzyme linked immunosorbent assay Europe and the first on wild rocket (Diplotaxis spp.) in the world. A wilt (DAS-ELISA) for the presence of BNYVV using standard procedures and of E. sativa attributed to F. oxysporum f. sp. erucae was previously antiserum specific for BNYVV (3). Sugar beet roots were tested reported in India in 1973 (1). Studies are being carried out to determine if individually, and samples were considered positive when absorbance the Italian isolates of F. oxysporum belong to the same formae speciales. values were at least three times those of greenhouse-grown healthy sugar beet controls. Samples were tested from 16 fields, with 10 confirmed positive for BNYVV. Positive samples had mean absorbance values References: (1) C. Chatterjee and J. N. Rai. Indian Phytopathol 28:309, 1973. (2) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. ranging from 0.341 to 1.631 (A405nm) after 30 min. The mean healthy control value was 0.097. Fields were considered positive if one beet tested positive for BNYVV, but in most cases, all beets tested from a field were uniformly positive or uniformly negative. In addition, soil-baiting Quercus canariensis, a New Host of Trabutia quercina. A. Trapero and experiments were conducted on seven of the fields. Sugar beet seedlings M. E. Sánchez, Departamento Agronomía, ETSIAM, Universidad de were grown in soil mixed with equal parts of sand for 6 weeks and were Córdoba, Apdo. 3048, 14080-Córdoba, Spain. Plant Dis. 87:201, 2003; subsequently tested using DAS-ELISA for BNYVV. Results matched those of the root sampling. Fields testing positive for BNYVV were published on-line as D-2002-1205-01N, 2003. Accepted for publication 2 22 November 2002. widely dispersed within a 100 square mile (160 km ) area including portions of Gratiot, Saginaw, Tuscola, and Sanilac counties in the central and eastern portions of the Lower Peninsula of Michigan. The Quercus canariensis Willd. is an oak species endemic to northwestern confirmation of rhizomania in sugar beet from the Great Lakes Region Africa and the Iberian Peninsula. This species is particularly abundant in marks the last major American sugar beet production region to be the southwestern Andalucía Region of southern Spain. During a disease diagnosed with rhizomania disease, nearly 20 years after its discovery in survey in this area from 1997 to 1998, we observed Q. canariensis trees California (1). In 2002, there were approximately 185,000 acres affected by a tar spot disease. Tar spot lesions were clearly differentiated (approximately 75,00 ha) of sugar beet grown in the Great Lakes Region, by a black, crustose, and shiny stromata (10 to 20 mm in diameter) on the (Michigan, Ohio, and southern Ontario, Canada). The wide geographic upper surface of leaves mainly arranged along leaf veins but also distribution of infested fields within the Michigan growing area suggests scattered randomly over the leaf surface. On most leaves there was little the entire region should monitor for symptoms, increase rotation to necrosis, and on most trees the damage was not serious, although some nonhost crops, and consider planting rhizomania resistant sugar beet trees located in the most humid areas were severely affected with leaf cultivars to infested fields. chlorosis and heavy defoliation. Other Quercus species in the area, such as Q. ilex and Q. suber, did not show signs of tar spot. One fungus References:(1) J. E. Duffus et al. Plant Dis. 68:251, 1984. (2) J. E. Duffus. species was consistently associated with tar spots. The fungus formed Rhizomania. Pages 29-30 in: Compendium of Beet Diseases and Insects, E. D. ascomata, 250 to 400 µm in diameter, embedded in the stromata. Asci Whitney and J. E. Duffus eds. The American Phytopathological Society, St. Paul, MN, were clavate or saccate, 45 to 55 × 17 to 22 µm, eight spored, and short 1986. (3) G. C. Wisler et al. Plant Dis. 83:864, 1999. stalked. The ascus apex was acute to obtuse. Ascospores were arranged irregularly, 20 to 25 (-30) × 5 to 8.5 µm, fusiform to ellipsoidal fusiform, often curved and flattened on one side, thin walled, hyaline, aseptate, and smooth without a gelatinous sheath or appendage. Based on these characteristics, the fungus was identified as Trabutia quercina (Rudolphi ex Fr.) Sacc. & Roum., a pathogen causing tar spot in several Quercus (Disease Notes continued on next page)

Plant Disease / February 2003 201 Disease Notes (continued )

First Report of Fusarium denticulatum from Sweet Potato in DNAStar software, Madison, WI) with the GenBank database. Analysis Venezuela. M. S. González, F. Fuenmayor, F. Godoy, and R. Navas, of the PCR products confirmed the begomovirus nature of the sequence. Instituto Nacional de Investigaciones Agrícolas, Centro Nacional de The first 64 amino acids of the CP had 89% identity with Squash leaf Investigaciones Agropecuarias, Apdo Postal 4653, Maracay 2101, curl virus while the intergenic region had 85% identity with Sida golden Venezuela. Plant Dis. 87:202, 2003; published on-line as D-2002-1127- mosaic virus. To our knowledge, this is the first report of a begomovirus 02N, 2003. Accepted for publication 11 November 2002. infecting okra in .

During 2001and 2002, 53 accessions of sweet potato ( batatas Reference: 1) J. T. Ascencio et al. Plant Dis. 86:692, 2002. L.) from a germ plasm collection maintained in the field at Centro * The e-Xtra logo stands for “electronic extra” and indicates this Disease Note online Nacional de Investigaciones Agropecuarias, Maracay, Venezuela, were contains supplemental material not included in the print edition. evaluated for diseases. Sweet potato accessions Catemaco and 2878 were symptomatic for chlorotic leaf distortion with deformation of young leaves and stunted vines. Symptomatic nodes and shoot tips were First Report of Charcoal Rot (Macrophomina phaseolina) on Soybean excised, surface disinfested in 0.5% sodium hypochlorite, cultured on in Minnesota. M. E. ElAraby and J. E. Kurle, Department of Plant potato dextrose agar (PDA), and incubated at 28°C. Pale pink colonies Pathology, 495 Borlaug Hall, University of Minnesota, 1991 Upper with white aerial mycelium developed from symptomatic tissues. At Buford Circle, St. Paul, MN 55108; and S. R. Stetina, Southwest 20°C, pure cultures on PDA developed slow-growing, aerial, white-to- Research and Outreach Center, Department of Plant Pathology, pink mycelium. Pigmentation in reverse was light orange. Conidia University of Minnesota, 23669 130th Street, Lamberton, MN 56152. aggregated in false heads, and orange sporodochia were abundant. Plant Dis. 87:202, 2003; published on-line as D-2002-1211-01N, 2003. Conidiophores in aerial mycelium were prostrate, short, and sometimes Accepted for publication 2 December 2002. branched. Sporodochial conidiophores were branched. Phialides were mostly monophialidic but occasionally polyphialidic and averaged 25.0 × In August 1999, soybean (Glycine max (L.) Merr.) plants exhibiting 3.0 µm. Microconidia were abundant, long, oval to allantoid, and 0 to 1 symptoms of charcoal rot were observed near Zumbrota, MN. Symptoms septate. Macroconidia were fusiform to falcate with a beaked apical cell included shrunken, unfilled pods, and brown, wilted leaves attached to and a footlike basal cell, 3 to 5 sepate, and 38 to 45 × 3.6 to 4.0 µm. dead petioles and stems (1). When stems of symptomatic soybean plants Chlamydospores were absent. The fungus was identified as Fusarium were split, areas of gray-to-black discoloration where present in the stem denticulatum Nirenberg and O’Donnell (1). Ten 25-cm-long vine-tip cortex (1). Black, spherical microsclerotia 77 to 90 µm in diameter and cuttings of accessions Catemaco and 2878 were immersed in a conidial elongated microsclerotia 77 to 120 µm long (1) were found in vascular suspension (1 x 106 conidia per ml) of F. denticulatum. As a control, tissue. Stem tissue placed on potato dextrose agar (PDA) yielded fungal vines were immersed in sterile, distilled water. After inoculation, each colonies identified as Macrophomina phaseolina (Tassi) Goid. based on cutting was planted in a 13-cm plastic pot containing a soil/sand (1:1) gray colony color, colony morphology, and the presence of microsclerotia mixture. Inoculated plants were covered with plastic bags for 48 h and 70 to 90 µm in diameter. In 2000, M. phaseolina was isolated from plant grown in a greenhouse at temperatures ranging from 30 to 38°C. After 3 samples gathered from 11 of 90 fields sampled in a statewide soybean months, three inoculated plants of accession Catemaco and two plants of disease survey. More studies are needed to determine the distribution of accession 2878 developed purple terminals and moderate interveinal charcoal rot in Minnesota; however, the occurrence of symptoms at one chlorosis. Leaf distortion was not observed. F. denticulatum was recovered location and the presence of M. phaseolina in soybean-growing areas of from both symptomatic and asymptomatic inoculated plants. To our Minnesota suggest that charcoal rot may occur in susceptible soybean knowledge, this is the first report of F. denticulatum from sweet potato germ cultivars under favorable environmental conditions. plasm in Venezuela. Dried, pure cultures and slides of the fungus are being deposited in the Albert S. Muller Herbario Micologico (VIA). Reference: (1) G. S. Smith and T. D. Wyllie. Charcoal rot. Pages 29-30 in: Compendium of Soybean Diseases, 4th ed. G. L. Hartmann, J. B. Sinclair, and J. C. Reference: (1) H. I. Nirenberg and K. O’Donnell. Mycologia 90:434, 1998. Rupe, eds. The American Phytopathological Society, St. Paul, MN, 1999. e-Xtra* Tobacco mosaic virus in Jalapeno Pepper in New York. J. F. Murphy, First Report of a Geminivirus Inducing Yellow Mottle in Okra Department of Entomology and Plant Pathology, Auburn University, AL (Abelmoschus esculentus) in Mexico. R. De La Torre-Almaráz and A. C. 36849; T. A. Zitter, Department of Plant Pathology, Cornell University, Monsalvo-Reyes, UBIPRO, FESI, UNAM, P.O. Box 54090, Tlalnepantla, Ithaca, NY 14853; and A. Erb, Lake Plains Vegetable Program, Cornell Edo. de México; R. F. Rivera-Bustamante, CINVESTAV-Irapuato, Cooperative Extension, E. Aurora, NY 14052. Plant Dis. 87:202, 2003; Irapuato, Gto., Mexico; and J. Méndez-Lozano, CIIDIR-IPN U., Sinaloa, published on-line as D-2002-1127-01N, 2003. Accepted for publication Guasave, Sin. Mexico. Plant Dis. 87:202, 2003; published on-line as D- 14 November 2002. 2002-1210-02N, 2003. Accepted for publication 22 November 2002. Jalapeno pepper plants (Capsicum annuum cv. Jaladuro) grown in Erie Okra is an annual vegetable species native to Africa. In Mexico, the County, New York expressed chlorotic oak-leaf patterns along the states of Tamaulipas, Guerrero, and Morelos contain the most important primary vein of fully expanded leaves. Fruit had patterns of irregular okra-producing areas. Viral-like diseases have recently affected the fruit ripening with a bumpy surface. Symptom expression was most obvious in production. In the field, the most common symptoms encountered August 2002, when leaf and fruit abscission occurred. Symptomatic fruit include yellow streak, distortion of fruits, and foliar yellow mottle. Total samples were tested by western blot analysis for the presence of DNA extracts from symptomatic okra plants were used as a template for Cucumber mosaic virus (CMV), Potato virus Y (PVY), Pepper mottle polymerase chain reaction (PCR)-based detection using begomovirus- virus (PepMoV), Tobacco etch virus (TEV), and Tobacco mosaic virus specific primers. RepMot and CPMot primers (1) were used for the (TMV). A positive reaction for TMV, but none of the other viruses, was amplification of DNA fragments that included the Rep and coat protein observed. Symptomatic leaf samples were tested by Agdia, Inc. (Elkhart, (CP) genes of begomoviruses. PCR results suggested the presence of a IN) for Alfalfa mosaic virus, CMV, Impatiens necrotic spot virus, Pepper begomovirus in symptomatic plants. Southern and dot blot hybridization mild mottle virus, PepMoV, PVY, TEV, TMV, Tobacco ringspot virus, analysis were performed using a DNA fragment containing the CP gene Tomato ringspot virus, and TSWV and for using a group- of Pepper huasteco virus as a probe. Hybridization conducted under low specific test. The Agdia test confirmed that the pepper plants were stringency conditions confirmed the presence of a geminivirus. infected with TMV. The pepper field where the original samples were Additionally, transmission by grafting and biolistic (total DNA extracts collected was surveyed for TMV-infected plants. Fifty symptomatic from symptomatic plants) inoculations induced consistently severe streak plants expressing foliar and fruit symptoms similar to those originally fruits and yellow mottle symptoms in okra plants. Cloning of the PCR tested, and 50 asymptomatic plants were sampled by collection of three products (approximately 632-bp fragment) was performed in the leaves per plant and tested using enzyme-linked immunosorbent assay for PCRTopo vector (Invitrogen, San Diego, CA). Cloned viral inserts were the presence of TMV. All symptomatic plants and 18% of asymptomatic sequenced (Genbank Accession No. AF349113). Nucleotide sequence plants tested positive for TMV. To our knowledge, this is the first occurrence comparisons were performed using the Clustal Method (MegAlign, of TMV causing losses in commercially grown pepper in New York.

202 Plant Disease / Vol. 87 No. 2

First Report of a Leaf Spot Disease of Bells-of-Ireland (Moluccella strands, and alignment revealed that all three isolates were identical for laevis) Caused by Cercospora apii in California. S. T. Koike, University both regions. A BLAST search of the NCBI database with the ITS of California Cooperative Extension, Salinas, 93901; S. A. Tjosvold, sequence revealed P. tritici-repentis accessions AY004808 and AF071348 University of California Cooperative Extension, Watsonville, 95076; J. Z. and D. tritici-repentis accession AF163060 as the closest matches with Groenewald, Department of Plant Pathology, University of Stellenbosch, 100, 99.8, and 98.8% sequence similarity, respectively. A similar search Stellenbosch 7602, South Africa; and P. W. Crous, Centraalbureau voor with the gpd sequence revealed P. tritici-repentis accessions AY004838 Schimmelcultures, Utrecht, Netherlands. Plant Dis. 87:203, 2003; and AF081370 and P. bromi accession AY004839 as the closest matches published on-line as D-2002-1203-01N, 2003. Accepted for publication with 100, 100, and 99.0% sequence similarity, respectively. These results, 19 November 2002. coupled with the morphological identification and inoculation results, confirm the identity of the fungus as P. tritici-repentis. Although reported on other grass hosts in the region (3), to our knowledge, this is the first Bells-of-Ireland (Moluccella laevis) (Lamiaceae) is an annual plant report of tan spot of wheat in the Pacific Northwest. This disease has that is field planted in coastal California (Santa Cruz County) for been of little concern to wheat producers in the Pacific Northwest due to commercial cutflower production. In 2001, a new leaf spot disease was low rainfall and relative humidity during the growing season. found in these commercially grown cutflowers. The disease was most serious in the winter-grown crops in 2001 and 2002, with a few plantings having as much as 100% disease incidence. All other plantings that were References: (1) M. L. Berbee et al. Mycologia 91:964, 1999. (2) M. B. Ellis, surveyed during this time had at least 50% disease. Initial symptoms Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK. 1971. (3) R. Sprague. Diseases consisted of gray-green leaf spots. Spots were generally oval in shape, of Cereals and Grasses in North America (Fungi, Except Smuts and Rusts). Ronald often delimited by the major leaf veins, and later turned tan. Lesions were Press Co. New York, 1950. (4) T. J. White et al. Pages 315-322 in: PCR Protocols: A Guide to Methods and Applications. Academic Press Inc., New York, 1990. apparent on both adaxial and abaxial sides of the leaves. A cercosporoid fungus having fasciculate conidiophores, which formed primarily on the abaxial leaf surface, was consistently associated with the spots. Based on morphology and its host, this fungus was initially considered to be Cercospora molucellae Bremer & Petr., which was previously reported First Report of Phytophthora ramorum on Viburnum bodnantense in on leaves of M. laevis in Turkey (1). However, sequence data obtained Belgium. D. De Merlier, A. Chandelier, and M. Cavelier, Department of from the internal transcribed spacer region (ITS1, ITS2) and the 5.8S Biological Control and Plant Genetic Resources, Agricultural Research gene (STE-U 5110, 5111; GenBank Accession Nos. AY156918 and Centre, Rue de Liroux, 4, B-5030 Gembloux, Belgium. Plant Dis. AY156919) indicated there were no base pair differences between the 87:203, 2003; published on-line as D-2002-1210-01N, 2003. Accepted bells-of-Ireland isolates from California, our own reference isolates of C. for publication 25 November 2002. apii, as well as GenBank sequences deposited as C. apii. Based on these data, the fungus was subsequently identified as C. apii sensu lato. Pathogenicity was confirmed by spraying a conidial suspension (1.0 × In the past decade, a new Phytophthora species inducing shoot canker 105 conidia/ml) on leaves of potted bells-of-Ireland plants, incubating the on Rhododendron and dieback of Viburnum has been observed in Europe, plants in a dew chamber for 24 h, and maintaining them in a greenhouse mainly in Germany and the Netherlands, and California. This new (23 to 25°C). After 2 weeks, all inoculated plants developed leaf spots pathogen has been named Phytophthora ramorum (3). In May 2002, a that were identical to those observed in the field. C. apii was again diseased Viburnum plant (Viburnum bodnantense) from the Plant associated with all leaf spots. Control plants, which were treated with Protection Service (Ministry of Agriculture, Belgium) was submitted to water, did not develop any symptoms. The test was repeated and the our laboratory for diagnosis. Symptoms included wilting, leaves turning results were similar. To our knowledge this is the first report of C. apii as from green to brown, discolored vascular tissues, and root necrosis. The a pathogen of bells-of-Ireland in California. plant came from a Belgian ornamental nursery that obtained supplies of stock plants from the Netherlands. Pieces of necrotic root tissue were excised, surface-disinfected, and transferred aseptically to a Reference: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Cornell Phytophthora selective medium. P. ramorum was identified based on University Press, Ithaca, New York, 1954. morphological characteristics, including the production of numerous, thin-walled chlamydospores (25 to 70 µm in diameter, average 43 µm) and deciduous, semi-papillate sporangia arranged in clusters. Radial growth after 6 days at 20°C on V8 juice agar was 2.8 mm per day. Random amplified microsatellite markers (RAMS) (2) from the total First Report of Tan Spot of Wheat Caused by Pyrenophora tritici- genomic DNA of the Belgian strain (CBS 110901) were similar to those repentis in the Pacific Northwest. T. L. Peever and T. D. Murray, of P. ramorum reference strains (CBS 101330, CBS 101332, and CBS Department of Plant Pathology, Washington State University, Pullman, 101554). Using PCR primers specific for P. ramorum, the identification WA 99164-6430. Plant Dis. 87:203, 2003; published on-line as D-2002- was confirmed by W. A. Man in't Veld (Plantenziektenkundige Dienst, 1202-02N, 2003. Accepted for publication 15 November 2002. Wageningen, the Netherlands) (1). A pathogenicity test was carried out on three sterile cuttings of Rhododendron catawbiense (3). Brown lesions were observed on the inoculated cuttings after 6 to 7 days. None of the In late May 2001, lesions resembling tan spot were observed on lower three uninoculated cuttings showed symptoms of infection. P. ramorum leaves of winter wheat (Triticum aestivum L.) in early boot stage in Nez was reisolated from lesion margins on the inoculated cuttings. To our Perce County, ID. Abundant sporulation was observed from tan lesions knowledge, this is the first report of the fungus from Belgium. Since our with chlorotic haloes after 2 days incubation in a moist chamber at room initial observation, we have found P. ramorum in other Belgian nurseries temperature. Conidia were multicelled, straw colored, approximately 100 on R. yakusimanum. × 15 µm, rounded at the apex, and borne singly on dark brown conidiophores. The fungus fit the morphological description of Drechslera tritici-repentis (Died.) Shoemaker, the anamorphic state of References: (1) M. Garbelotto et al. US For. Ser. Gen. Tech. Rep. PSW-GRT. 184:765, Pyrenophora tritici-repentis (Died.) Drechs. (2). Three single-conidial 2002. (2) J. Hantula et al. Mycol. Res. 101:565, 1997. (3) S. Werres et al. Mycol. Res. isolates were sampled from infected plants in a 5 × 1 m area of the 105:1155, 2001. affected field and induced to sporulate. Two of the isolates were used to spray-inoculate 3-week-old susceptible wheat (cv. Madsen) in the greenhouse (one plant per isolate, 1 × 105 conidia/ml), and tan spot lesions were apparent 3 to 5 days after inoculation with both isolates. DNA was extracted from all three isolates, and the entire nuclear ribosomal internal transcribed spacer (ITS) was amplified with ITS1 and ITS4 primers (4). Similarly, 610 bp of the 5‡ end of the glyceraldehyde-3- phosphate-dehydrogenase gene (gpd) was amplified with gpd-1 and gpd- 2 primers (1). ITS and gpd amplicons were direct-sequenced on both (Disease Notes continued on next page)

Plant Disease / February 2003 203 Disease Notes (continued )

First Report of Infecting Papaya Plants in Saxena et al. Plant Dis. 82:126, 1998. (3) S. Saxena et al. Biochem. Mol. Biol. Int. Taiwan. L.-S. Chang, Department of Horticulture, National Taiwan 45:101, 1998. University, Taipei 106, Taiwan; Y.-S. Lee, H.-J. Su, and T.-H. Hung, Department of Plant Pathology and Microbiology, National Taiwan First Report of Septoria Leaf Spot on Cornus sericea in Italy. A. University, Taipei 106, Taiwan. Plant Dis. 87:204, 2003; published on- Garibaldi, D. Bertetti, and M. L. Gullino, DIVAPRA—Patologia line as D-2002-1216-01N, 2003. Accepted for publication 22 November vegetale, Via Leonardo da Vinci 44, 10095 Grugliasco, Italy. Plant Dis. 2002. 87:204, 2003; published on-line as D-2002-1129-01N, 2003. Accepted for publication 12 November 2002.

Papaya leaf curl disease was first reported in India in 1939 (1). Caused Cornus sericea (synonym C. stolonifera), family Cornaceae, is by begomovirus, Papaya leaf curl virus (PaLCV) (2), this disease was becoming widely used in Italy as ground cover in parks and gardens. In discovered in the papaya orchards of southern Taiwan in 2002. Infected spring 2001, severe outbreaks of a previously unknown disease were papaya developed symptoms such as downward curling of leaves, twisted observed in several gardens located in northern Italy (Biella Province). petioles, vein enation, and stunting. Diseased plants produced small and Infected leaves displayed small, circular, angular, or irregular necrotic distorted fruits that tend to fall prematurely. Typical twin virion was lesions measuring 1 to 3 mm in diameter. Lesions were olivaceous to observed in the diseased papaya cells by electron microscopy. In dark brown with a distinct reddish-to-black margin and surrounded by a addition, our -transmission test demonstrated that the sweet chlorotic halo. Lesions eventually coalesced. Under favorable conditions, potato whitefly (Bemisia tabaci) could transmit this virus. For further infected leaves become heavily spotted, dulling their appearance; severe molecular identification, two opposing primers were selected for the infections resulted in premature defoliation. Pycnidia occurred on polymerase chain reaction (PCR) detection of PaLCV from the published diseased leaves, and a fungus identified as Septoria cornicola (1) was nucleotide sequences of PaLCV (Genbank Accession No. NC004147) consistently isolated on potato dextrose agar (PDA). Dark mycelium (3). The primer pair, composed of the forward primer 5‡-GCT AGA AAT grew slowly on PDA and produced abundant pycnidia and conidia. TAT GTC GAA GCG-3‡ and the reverse primer 5‡-TCA ACT ACA ACC Conidia were holoblastic, hyaline, 2 to 6 septate, 22 to 48 µm (average TGA GGA AAG C-3‡, was designed to amplify a PaLCV-specific 1,031- 35) × 2.2 to 3.6 µm (average 2.5). Pathogenicity tests were performed by bp fragment containing 774 bp of the coat protein gene open reading inoculating leaves of healthy plants of C. sericea (cv. Flaviramea) with a frame (CP-ORF) using PCR. Five diseased papaya samples with typical conidial suspension (1 × 106 CFU/ml). Noninoculated plants served as leaf-curl symptoms tested positive in the PCR-based assay with this controls. Plants were covered for 72 h with plastic bags and maintained specific primer pair, whereas five healthy papaya samples tested negative. in a growth chamber at 20°C. The first lesions developed on leaves of However, the sequencing results of the PCR product from five PaLCV- inoculated plants after 15 days. From such lesions, S. cornicola was infected papayas indicated the CP-ORF of PaLCV in Taiwan (PaLCV- consistently reisolated. No symptoms occurred on control plants. The Tw) was somewhat different from PaLCV in India (PaLCV-Id). The DNA presence of S. cornicola on C. sericea cv. Flaviramea has been reported sequences (Genbank Accession No. AY183472) of CP-ORF of PaLCV- in the United States (2) and was observed in 1905 in northeastern Italy on Tw were 80% identical to those of PaLCV-Id, and their translated amino Cornus sanguinea (1), but to our knowledge, this is the first report of acid sequences were 77% identical. This indicates that PaLCV-Tw and septoria leaf spot on C. sericea in Italy. PaLCV-Id are two different species or strains. References: (1) D. F. Farr. Mycologia, 83:611, 1991. (2) D. Neely and D. S. Nolte. J. References: (1) K. M. Thomas and C. S. Krishnaswamy. Curr. Sci. 8:316,1939. (2) S. Arboric. 15:263, 1989.

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