bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Mundulla Yellows on Eucalyptus spp. Outside Australia
Authors: Hanold D. , Randles J. W. 
Published: May 2007

Mundulla Yellows (MY) is a newly recognized lethal dieback of unknown etiology affecting Eucalyptus spp. in Australia (1). Progression of symptoms, unlike other disorders described for eucalypts, starts as foliar interveinal chlorosis on one branch followed by branch dieback advancing toward the main trunk. Epicormic shoots with symptomatic leaves typically develop proximal to the dying zone. Continuing dieback leads to tree death in 5 to 20 years. MY trees occur singly or in small foci and do not recover even if affected branches are removed. MY-like symptoms developed on seedlings grafted with bark patches from MY trees (1). There is no evidence for a fungal, phytoplasma, or other bacterial etiology. In a search for a putative virus-like agent we have identified an electrophoretic pattern (2) of several single-stranded RNAs with apparent size of 200 to 600 nt that is consistently associated with MY and absent from disease-free trees (unpublished). The RNAs are not yet characterized, but the pattern can be used as a preliminary confirmatory “fingerprint” for MY. We report here that MY-like symptoms occur in southern Spain and the Spanish island of Ibiza. RNA fingerprints closely resembling those of MY, were detected in symptomatic trees (4 of 4 of E. camaldulensis and 1 of 1 of E. globulus) from Valencia, Spain. MY therefore, appears not to be limited to Australia. References: (1) D. Hanold et al. Landscope 17(4):41, 2002. (2) J. W. Randles. Strategies for implicating virus-like pathogens as the cause of diseases of unknown etiology. Pages 315–332 in: Diagnosis of Plant Virus Diseases, CRC Press, Boca Raton, FL, 1993.
First Report of Leaf and Sheath Spot Caused by Rhizoctonia zeae Affecting Panicum tennesseense in Rhode Island
Authors: Mitkowski N. A. 
Published: May 2007

Panicum tennesseense Ashe is a perennial, coarse-textured, cool-season grass (similar in appearance to many warm-seasoned grasses), which grows in the southern coastal areas of New England and is commonly found in home lawns, roadsides, and meadows. In August 2002, a large stand of P. tennesseense with significant leaf spotting was identified in Washington County, RI. Lesions were excised, surface sterilized with 0.6% sodium hypochlorite, and plated on one-half-strength potato dextrose agar (PDA). Cultures were incubated at 25°C, and mycelia quickly covered plates within 3 days. After 2 weeks in darkness, plates were covered with white, aerial mycelium. When placed under near-UV light, no aerial mycelium was produced, and mycelia were a salmon color. After 5 weeks, separate, spherical, 0.5-mm-diameter beige sclerotia were produced submerged throughout the media and turned red within a few days. Sclerotia were not produced in the absence of near-UV light. Spores were not produced, and right-angled branching, characteristic of Rhizoctonia spp., was observed. Monilioid hyphae were also produced in culture. At the optimal growth temperature of 32°C, mycelia grew an average of 33.6 mm/day. Cells were stained using safranin, and the number of nuclei observed within young hyphal cells was five or seven. On the basis of the described mycelial and sclerotial characterisitics, the isolated fungus was identified as Rhizoctonia zeae (1,2). To demonstrate pathogenicity, plugs of isolated fungi were cut from PDA plates, placed on leaf blades at the junction with leaf sheaths, and incubated in a greenhouse humidity chamber at an average temperature of 32°C and 80% humidity. After 3 days, significant disease was observed and included blighting of newly emerged shoots, blighting and spotting on leaf sheaths, and severe spotting on leaf lamina. Whereas Rhizoctonia solani has been reported as a pathogen on P. tennesseense, to our knowledge, this is the first report of R. zeae induced leaf and sheath spot on this host (1). References: (1) H. Couch. Diseases of Turfgrasses. Krieger Publishing Co., Malabar, FL, 1995. (2) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St. Paul, MN. 1991.
First Report of Association of Tomato leaf curl virus-New Delhi with Yellow Mosaic Disease of Luffa cylindrica in India
Authors: Sohrab S. S. , Mandal B. , Pant R. P. , Varma A. 
Published: May 2007

Sponge gourd (Luffa cylindrica), an important cucurbitaceous vegetable in India, is affected by a disease (2) causing yellow spots on newly emerged leaves, mosaic, mild leaf curling and distortion, small leaves, and misshapen fruits. Nearly 100% of sponge gourd plants were symptomatic in Delhi. Geminivirus-like particles were observed with electron microscopy of uranyl acetate-stained leaf-dip preparations of the diseased plants collected from experimental fields at the Indian Agricultural Research Institute in New Delhi during May and June of 2002. The virus was transmitted by the whitefly (Bemisia tabaci) to sponge and ridge gourd (L. acutangula) after an acquisition and inoculation access period of 24 h each. Whitefly-inoculated plants produced typical yellow mosaic symptoms and contained geminate particles. Nucleic acid extracted from the field-infected and experimentally infected plants hybridized with 32P-labeled probe to DNA-A of Indian cassava mosaic virus, suggesting association of a begomovirus. The viral DNA, isolated by the alkali denaturation method (1) from the experimentally infected sponge gourd plants, was cloned in pBS SK+ at the EcoRI site. A clone with an insert of 2,658 bp was sequenced (GenBank Accession Nos. AJ557219, AJ555488, and AY309957) which shared 89.6 to 95.1% identity with the DNA-A of different strains of Tomato leaf curl virus-New Delhi (ToLCV-NDe). The highest sequence identity (95.1%) was with the severe strain of ToLCV-NDe (GenBank Accession No. U15015). The data suggest that the begomovirus associated with the yellow mosaic disease of L. cylindrica in India is a putative strain of ToLCV-NDe. Reference: (1) K. M. Srivastava et al. J. Virol. Methods 51:297, 1995. (2) A. Varma and B. K. Giri. Virus diseases. Pages 225–245 in: Cucurbits. N. M. Nayar and T. A More, eds. Oxford and IBH Publishing House Private Ltd., New Delhi, India, 1998.
Occurrence of the Root-Knot Nematodes Meloidogyne incognita and M. hapla in Slovenia
Authors: Širca S. , Urek G. , Karssen G. 
Published: May 2007

The root-knot nematode Meloidogyne incognita (Kofoid & White) Chitwood is one of the most harmful species within the genus Meloidogyne. It has been detected regularly in greenhouses throughout Europe, while in the field it is restricted to the southern parts of Europe (4). M. incognita is able to parasitize more than 700 plant species and varieties, including the majority of our economically important crops (1). It has been recorded in most parts of the world, including former Yugoslavia; however, there is no data about its presence in Slovenia. In late summer of 2002, large galls were observed on roots of pepper, Capsicum annuum L., grown in a greenhouse located in Portorož near the Adriatic Coast of Slovenia. Different root-knot nematode stages, i.e., males, females, and second-stage juveniles, were isolated and morphologically identified as M. incognita (2). Additional isozyme gel electrophoresis confirmed this (3). To our knowledge, this is the first report of M. incognita from Slovenia. In addition, M. hapla Chitwood was found for the first time in a field in Slovenia. Previously, it had been detected on different host plants, all restricted to greenhouses. In October 2002, M. hapla was isolated and identified from relatively small galls of sweet pepper, C. annuum L., grown in a field near Ljubljana, located in central Slovenia. Additional resampling of the soil comfirmed the presence of M. hapla in this field. References: (1) J. D. Eisenback. Root-Knot Nematode Taxonomic Database. CD-ROM, CABI, Wallingford, UK, 1998. (2) J. D. Eisenback and H. Hirschmann Triantaphyllou. Root-knot nematodes: Meloidogyne species and races. Pages 191–274 in: Manual of Agricultural Nematology. W. R. Nickle, ed. Marcel Dekkers, Inc., New York, 1991. (3) P. R. Esbenshade and A. C. Triantaphyllou. J. Nematol. 17:6, 1985. (4) G. Karssen. Revision of the European root-knot nematodes III on mono- and dicotyledons. Pages 119–121 in: The Plant-Parasitic Nematode Genus Meloidogyne Göldi, 1892 (Tylenchida) in Europe. Koninklijke Brill NV, Leiden, the Netherlands, 2002.
A Survey of Viruses Affecting Faba Bean (Vicia faba) in Tunisia Includes First Record of Soybean dwarf virus
Authors: Najar Asma , Kumari Safaa G. , Makkouk Khaled M. , Daaloul Abderazzek 
Published: May 2007

A survey was conducted in April 2003 to identify viruses infecting faba bean (Vicia faba L.) in six regions (Beja, Bizerte, Cap-bon, Le Kef, Siliana, and Zaghouan) in Tunisia. A total of 292 faba bean samples with symptoms of viral infection (leaf rolling, yellowing, and mosaic) were collected. The samples were tested at the virology laboratory of the International Center for Agricultural Research in the Dry Areas (ICARDA), Syria, for 11 viruses using the tissue-blot immunoassay procedure (3). Specific rabbit polyclonal antisera were used to test for Chickpea chlorotic dwarf virus (CpCDV) (provided by H. J. Vetten, BBA, Braunschweig, Germany), Alfalfa mosaic virus (AMV), Bean yellow mosaic virus (BYMV), Broad bean mottle virus (BBMV), Broad bean stain virus (BBSV), Cucumber mosaic virus (CMV), and Pea seedborne mosaic virus (PSbMV) (ICARDA, Aleppo, Syria). In addition, four specific monoclonal antibodies were used to detect Bean leaf roll virus (BLRV) (4B10) (2), Beet western yellows virus (BWYV) (ATCC PVAS-647; American Type Culture Collection, Manassas, VA), Faba bean necrotic yellows virus (FBNYV) (3-2E9) (1), and Soybean dwarf virus (SbDV) (ATCC PVAS-650). Serological tests showed that BBMV, a beetle-transmitted and seedborne virus identified in 23.3% (68 samples) of the samples tested, was the most common. BLRV, FBNYV, BWYV, BYMV, SbDV, and PSbMV were detected in 56, 33, 31, 10, 5, and 1 sample(s) of 292 samples tested, respectively. AMV, BBSV, CMV, and CpCDV were not detected in any samples tested. In Tunisia, BLRV, BWYV, BYMV, FBNYV, and PSbMV have previously been reported in faba bean (4), but to our knowledge, this is the first record of SbDV affecting faba bean in Tunisia, where it was detected in two fields in the Cap-bon Region. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by western blots, extracts from SbDV-infected plants were observed to contain 23-kDa structural proteins, which reacted strongly with SbDV monoclonal antibodies. Transmission tests showed that the samples, which reacted with SbDV monoclonal antibodies, were transmitted to faba bean plants by the pea aphid (Acyrthosiphon pisum Harris) in a persistent manner. To our knowledge, this is the first report of SbDV naturally infecting faba bean in Tunisia and it could cause a serious problem to other leguminous crops grown in Tunisia, such as French bean and peas, which are hosts for the virus. References: (1) A. Franz and K. M. Makkouk Ann. Appl. Biol. 128:255, 1996. (2) L. Katul. Characterization by serology and molecular biology of bean leaf roll virus and faba bean necrotic yellows virus. PhD thesis. University of Gottingen, Gottingen, Germany, 1992. (3) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994. (4) A. Najar et al. Phytopathol. Mediterr. 39:423, 2000.
First Report of Peronospora farinosa f. sp. spinaciae Race 5 Causing Downy Mildew on Spinach in Florida
Authors: Irish B. M. , Correll J. C. , Raid R. N. , Morelock T. E. 
Published: May 2007

Downy mildew, caused by Peronospora farinosa f. sp. spinaciae, is an economically important disease in most areas where spinach is grown. This disease has become increasingly important in production fields for prepackaged salad mixes where plant densities typically are very high. In Florida, spinach production for these markets has reached approximately 200 ha. Currently, seven physiological races of the downy mildew pathogen have been described (1). Downy mildew was observed in several commercial spinach fields in the Everglades agricultural area of Palm Beach County, Florida in January 2003 on cvs. Unipak 151 and Merlo Nero. Symptoms appeared as chlorotic and necrotic leaf spots. Disease incidence reached approximately 25% in some field locations. Economic losses were significant, since entire plantings in several fields were not harvested as a result of diminished quality. The race of a field isolate recovered from the cv. Unipak 151 was determined following greenhouse inoculation procedures and using differentials outlined by Irish et al (1). Greenhouse inoculation tests were conducted twice. Disease reactions on a U.S. and international set of differentials indicated that the isolate was race 5. To our knowledge, this is the first report of race 5 occurring outside of the California/Arizona spinach production area in the United States. There are commercial spinach lines with resistance to race 5, as well as the other described races (1). References: (1) B. M. Irish et al. Plant Dis. 87:567, 2003.
First Report of Basal Stem Rot of Golden Barrel Cactus Caused by Fusarium oxysporum f. sp. opuntiarum in Italy
Authors: Polizzi G. , Vitale A. 
Published: May 2007

Golden barrel cactus (Echinocactus grusonii Hildm.) is the most common landscape cactus in southern Italy. During 2000, 2001, and 2002, a basal stem rot of golden barrel cactus was observed in several plastichouses located in eastern Sicily with disease levels of nearly 100% on young plants (up to 15 cm in diameter). On the basal crown area, the plants showed pale brown or yellow-orange, sunken lesions bordered by a reddish orange strip up to 1 mm wide. A water-soaked rot or white mycelium at the soil line was also observed. Thirty pieces (0.5 to 1 cm) from the edge of symptomatic tissues were surface disinfected for 2 min in 0.8% (wt/vol) NaOCl, washed with sterile distilled water (SDW), and placed on potato dextrose agar (PDA). In addition, 20 pieces of affected tissue were ground in 400 μl of SDW (1:3, wt/wt), and the resulting suspensions were streaked by loops on PDA supplemented with 1.1 μl/ml of lactic acid (pH 4.4). A Fusarium sp. was consistently isolated from affected tissue pieces and streaks. Koch's postulates were performed at 25°C by inoculating 24 golden barrel cactus plants in 12-cm-diameter pots (12 plants previously sterile needle wounded) with 10 ml per plant of three suspensions (106 CFU/ml) of three isolates sprayed onto the basal stem. One milliliter per ten g of soil of each suspension was also added in the crown portion of golden barrel cacti. Twelve control cacti (six wounded) were sprayed only with SDW. Further pathogenicity tests were carried out on Thanksgiving cactus (Schlumbergera truncata (Haw.) Moran), devil's tongue barrel cactus (Ferocactus latispinus (Haw.) Britton & Rose), peruvian old man cactus (Espostoa lanata (Kunth) Britton & Rose), and Parodia spp. by inoculating eight plants for each host (four wounded) by placing 9-day-old 6-mm mycelial plugs at the base of the healthy cacti. An equal number of plants (four wounded) was inoculated only with a PDA plug. All cacti were maintained in polyethylene bags (90 to 95% for 72 hr) at 25°C. After 12 to 15 days, all wounded inoculated golden barrel, devil's tongue barrel, and peruvian old man cacti exhibited similar symptoms observed in the plastichouses. Typical symptoms were visible also in nonwounded and inoculated cacti 15 days later. Yellow-orange, tan, sunken, and roughly circular lesions were observed on the wounded and inoculated Thanksgiving and Parodia sp. cacti. Control plants were symptomless. The causal fungus was always reisolated from infected cacti. On the basis of 3-septate macroconidia (27 to 35 μm long × 3 to 4 μm wide [average 31.45 × 3.18 μm]), microconidia aseptate, single or double chlamydospores, and monophialide conidiophores observed on carnation leaf agar, and considering the susceptibility of all other inoculated hosts, the fungus was identified as F. oxysporum Schlechtend. f. sp. opuntiarum (Speg.) (1). To our knowledge, this is the first report of basal stem rot of golden barrel cactus in Italy. Reference: (1) W. Gerlach. Phytopathol. Z. 74, 197, 1972.
First Report of Petunia Root Rot Caused by Rhizoctonia solani in Argentina
Authors: Wright E. R. , Rivera M. C. , Asciutto K. , Gasoni L. , Barrera V. , Kobayashi K. 
Published: May 2007

Common garden petunias (Petunia × hybrida Hort. Vilm.-Andr.) are herbaceous annual plants with brightly colored flowers up to 10 cm in diameter. During the winter of 2002, crown and root rot were observed on plants (cv. Ultra) growing in five greenhouses in Buenos Aires. Affected plants were randomly distributed in the greenhouses, and mean disease incidence in all the greenhouses was 26%. Basal leaves turned yellow and gradually became necrotic, and infected plants were often killed. Small pieces of affected tissues were disinfested in 2% sodium hypochlorite for 1 min and plated on 2% potato dextrose agar (PDA). Fifteen isolates identified to the genus Rhizoctonia were obtained. Fungal colonies were initially white, turned brown with age, and produced irregularly shaped, brown sclerotia. Hyphal branched at right angles, were constricted at the base of the branch near the union with main hyphae, and septate near the constriction. Basidia were not observed in the greenhouses or on the plates. Isolates were cultivated on water agar and incubated at 25°C for 3 days. Hyphal cells were determined to be multinucleate when stained with 1% aniline blue solution (2) and examined at ×400. Anastomosis group of one isolate was determined by using AG-4 HG II, AG-1 IA, AG-1 IB, AG-1 IC, AG-2 2-1, and AG-2 2IIIB tester strains of Rhizoctonia solani that includes isolates reported to be pathogenic on ornamentals (1). Anastomosis was observed only with strains of AG-4 HG II. Pathogenicity on this isolate was conducted on potted, healthy, adult plants that were 10 to 22 cm high and flowering. Thirty-five plants were inoculated by placing 1 cm2 pieces of PDA from 7-day-old mycelial cultures near the base of the stem. Twelve control plants were treated with 1 cm2 PDA plugs. Plants were kept at 22 to 24°C, >95% relative humidity, and 12 h of fluorescent light. Wilt symptoms due to basal stem rot appeared 7 days after inoculation, and all the inoculated plants died within 27 days. Control plants remained disease free. The pathogen was reisolated from symptomatic tissues, completing Koch's postulates. To our knowledge, this is the first report of R. solani causing disease on petunia in Argentina. References: (1) D. M. Benson and D. K. Cartwright. Ornamental diseases incited by Rhizoctonia spp. Pages 303–314 in: Rhizoctonia species: Taxonomy, Molecular Biology, Ecology, Pathology and Disease Control. B. Sneh et al., eds. Kluwer Academic Publishers, London, England, 1996. (2) C. C. Tu and J. W. Kimbrough. Mycologia 65:941, 1973.
First Report of Tomato chlorosis virus in Israel
Authors: Segev L. , Wintermantel W. M. , Polston J. E. , Lapidot M. 
Published: May 2007

During December 2003, symptoms were observed in greenhouse tomato plants in Bet Dagan, Israel that resembled those of Tomato chlorosis virus (ToCV), a crinivirus common in the southeastern United States and southern Europe (2,3). Middle-aged leaves showed interveinal chlorosis, while more mature leaves showed more intense interveinal chlorosis with some interveinal bronzing. Symptoms were associated with the presence of Bemisia tabaci, an efficient vector of ToCV. Total nucleic acids were extracted (1) from middle-aged and mature leaves from two symptomatic plants, as well as from healthy tomato, Physalis wrightii infected with ToCV, and Nicotiana benthamiana infected with Tomato infectious chlorosis virus (TICV), another crinivirus that produces identical symptoms on tomato. Extracts were tested using hybridization with probes specific to the coat protein (CP) gene of ToCV and the HSP70h gene of TICV. Hybridization results identified the presence of ToCV in all samples from symptomatic tomato plants and ToCV-infected P. wrightii, but not in those from healthy tomato or TICV-infected N. benthamiana. TICV was only detected in TICV-infected N. benthamiana. Extracts were also subjected to reverse transcription-polymerase chain reaction using primers specific to the CP gene of ToCV (GenBank Accession No. AY444872; Forward primer: 5′ ATGGAGAACAGT GCCGTTGC 3′; Reverse Primer: 5′ TTAGCAACCAGTTATCGATGC 3′). All samples from symptomatic tomato and ToCV-infected P. wrightii produced amplicons of the expected size, but no amplicons were produced from extracts of healthy tomato. Laboratory results and observed symptoms confirm the presence of ToCV in symptomatic tomatoes. To our knowledge, this is the first report of ToCV in Israel. References: (1) S. Dellaporta et al. Plant Mol. Biol. Rep. 1:19, 1983. (2) J. Navas-Castillo et al. Plant Dis. 84:835, 2000. (3) G. C. Wisler et al. Phytopathology 88:402, 1998.
First Record of Hop stunt viroid in Canada
Authors: Michelutti R. , Al Rwahnih M. , Torres H. , Gomez G. , Luffman M. , Myrta A. , Pallás V. 
Published: May 2007

“Tissue-printing” hybridization (3) for Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd) was used to assess the sanitary status of stone fruit accessions in the Canadian Clonal Genebank (CCG) located in Harrow (Ontario). The Prunus spp. accessions in the CCG are primarily of Canadian origin; other countries of origin include the United States, the United Kingdom, Hungary, the Czech Republic, the Former Soviet Union, Spain, New Zealand, and Italy. All Prunus spp. accessions were donated to the Genebank from Canadian or American sources. Leaves were harvested in November 2003 from 336 trees (116 peach and nectarine, 84 sweet and sour cherries, 54 plum, 44 apricot, and 38 of other cherries) representing 267 accessions. No visible symptoms were observed during the collection of the accessions to be evaluated. The petioles were excised at the base and imprinted on a nylon membrane in triplicate for each sample. The membranes were air dried and submitted by mail to the laboratory. The digoxigenin-labeled riboprobes used for hybridization were obtained by T7 RNA polymerase transcription of the linearized plasmids pHSVd (1) and pPLMVd (2). Thirty stone fruit samples were infected by viroids. PLMVd occurred in 28 peach and nectarine samples, representing the following cultivars and selections: Harblaze Hardired, Harko, Earlyvee, Harbelle, Harken, Harland, Harrow Beauty, Harrow Rubirose, HW264, Redhaven, Silver Gold, Suncling, V68101, Vanity, Veeglo, Velvet, Vesper, Villa Doria, and Vulcan. PLMVd-infected samples represented 24.1% of the tested peaches and nectarines. PLMVd finding confirms previous reports of the viroid in Canada from British Columbia and Ontario. Two CCG apricot accessions, ‘Bulida’ and ‘Velkopavlovicka’, were found to be infected with only HSVd, representing 4.5% of tested apricot samples. These samples, determined to be positive by tissue-printing hybridization, were also positive by reverse transcription-polymerase chain reaction (RT-PCR) (1). In addition, nucleotide sequences of the PCR products were obtained. The ‘Bulida’ isolate showed 100% homology to a Spanish isolate, apr9, while the ‘Velkopavlovicka’ isolate showed 99% homology to an Italian isolate. Since HSVd has not been previously reported in Canada (4), to our knowledge, this report documents its first detection in the country. This report may prompt the inclusion of regular testing for HSVd in existing Prunus spp. virus testing programs in Canada. References: (1) N. Astruc et al. Eur. J. Plant Pathol. 102:837, 1996. (2) M. Badenes et al. Acta Hortic. 472:565, 2001. (3) V. Pallás et al. Page 135 in: Virus and Virus-Like Diseases of Stone Fruits, with Particular Reference to the Mediterranean Region. A. Myrta et al., eds. CIHEAM-IAMB, 2003. (4) R. Singh et al. Page 255 in: Viroids. A. Hadidi et al., eds. CSIRO Publishing, Australia, 2003.