bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Ascochyta Blight of Chickpea in Latin America
Authors: Kaiser W. J. , Coca W. F. , Vega O. S. 
Published: May 2007

Chickpea (Cicer arietinum L.) has been cultivated in different regions of Bolivia for hundreds of years. In the highlands (2,400 to 3,000 m above sea level) of the Department (state) of Chuquisaca in southern Bolivia, chickpea is an important cash crop for small farmers. During March through April 1999, a blight was observed infecting local chickpea landraces in Chamicle, Escana, Kullpa Ckasa, Presto, Q'ara Puncu, Santa Rosalia, Sucre, and Yotala in Chuquisaca, and its cause was tentatively identified as Ascochyta rabiei (Pass.) Labrousse (teleomorph Didymella rabiei (Kovachevski) v. Arx) based on disease symptomatology. Stems, leaflets, and pods of infected plants exhibited abundant necrotic lesions. Isolations were made from lesions on leaflets, stems, pods, and seeds of infected plants on 2% water agar and potato dextrose agar. The fungus was isolated from the foliar and reproductive tissues of infected plants. Koch's postulates were fulfilled by inoculating the foliage of 15-day-old seedlings of a local chickpea landrace with spore suspensions of three isolates of the pathogen from Escana, Santa Rosalia, and Sucre. Inoculated and control (sterile water) plants were incubated in moist chambers for 4 days in the laboratory at ambient temperatures and under natural daylight. The fungus was reisolated from lesions that developed on the leaflets, petioles, and stems of all inoculated seedlings but not from tissues on any of the noninoculated control plants. The fungus was identified as A. rabiei based on symptoms, cultural and morphological characteristics (2), and pathogenicity tests. Above average rainfall and cool weather during March and April favored development and spread of the disease in many chickpea-growing areas. Severe infection usually resulted in dieback and death of plants and reduced yields. Additionally, A. rabiei was isolated from chickpea seeds purchased in the markets of Sucre and Monteagudo and in seeds used by farmers in Escana to plant the 1999 crop (which had supplied the plants previously observed with blight). The teleomorph did not develop on naturally infested chickpea debris from five locations when incubated over the winter on the soil surface in Sucre. Based on farmers' reports, it appears that Ascochyta blight of chickpea has been present in the Department of Chuquisaca and possibly other Bolivian departments for many years. This is the first report of the disease in either Bolivia or other countries of Latin America (Mexico and Central and South America) (1). References: (1) CAB. 1991. CAB Distribution Maps of Plant Diseases: Ascochyta rabiei. Map No. 151. CAB International Mycological Institute, Wallingford, England. (2) E. Punithalingham and P. Holliday. 1972. Ascochyta rabiei. Descriptions of Pathogenic Fungi and Bacteria No. 337. Commonwealth Mycological Institute, Kew, England.
A Severe Outbreak of Fire Blight in Woody Ornamental Rosaceae Plants in North Florida and South Georgia
Authors: Momol M. T. , Momol E. A. , Dankers W. 
Published: May 2007

Woody ornamentals including ‘Bradford’ and ‘Aristocrat’ pears (Pyrus calleryana), Indian hawthorn (Rhaphiolepis sp.), and cotoneaster (Cotoneaster spp.) developed blossom and shoot blight symptoms suggestive of fire blight caused by Erwinia amylovora. Disease was observed in several counties in north Florida and south Georgia and samples were sent to Florida Extension Plant Diagnostic Clinic-Quincy (FEPDC-Q). The incidences in individual ‘Bradford’ pear were as high as 30 to 40 strikes per tree. This level of severe E. amylovora infections on ‘Bradford’ pear has not been seen in Florida for the last 10 years based on FEPDC-Q data. Symptomatic plants first appeared in the landscape and nurseries around the first week of April 2000 in the following counties: Bay, Holmes, Washington, Gadsden, Leon, Jefferson (north Florida), and Decatur (south Georgia). Severely infected ‘Bradford’ pear trees were also observed in Georgia cities of Cairo, Thomasville, Moultrie, and Tifton. The presence of E. amylovora in samples was verified by pEA29-polymerase chain reaction (PCR) (2,4), fatty acid methyl ester analysis (MIDI, Newark, DE), and colony type on semi-selective modified Miller-Schroth (MMS) medium (3). Of the 16 samples tested by PCR, E. amylovora was present in all. Actively growing shoots of Cotoneaster salicifolius (a susceptible host) were inoculated with a bacterium isolated from ‘Bradford’ pears that was identified as E. amylovora by PCR. Dark brown necrotic tissues with typical fire blight appearance developed within 10 days. E. amylovora was reisolated on MMS medium from inoculated shoot tissues of C. salicifolius and confirmed by PCR. The presence of E. amylovora from ornamental pears, Indian hawthorn, and cotoneasters was previously reported in Florida (1). Cool spring temperatures in the Florida panhandle and several rain events during the bloom period may have stimulated the severe outbreak of fire blight. This severe outbreak highlights the importance of using a forecasting model such as Maryblyt 4.3 to predict unexpected infection periods so that preventive control measures can be taken. References: (1) S. A. Alfieri, Jr. et al. Florida Department of Agriculture and Consumer Services, Bulletin No. 14, 1994. (2) S. Bereswill et al. Appl. Environ. Microbiol. 58:3522, 1992. (3) W. Brulez and W. Zeller. Acta Hortic. 117:37, 1981. (4) M. T. Momol et al. Plant Dis. 82:646, 1998.
Cyclanthera pedata var. edulis: New Host of Papaya ringspot virus-type W in Brazil
Authors: Rezende J. A. M. 
Published: May 2007

Stuffing cucumber (Cyclanthera pedata var. edulis Schrad.) is native to the Americas, where it often occurs as an escape. The species is monoecious, with small flowers and large and deeply palmately lobed leaves. Fruits are puffy, partially hollow, and measure 5 × 15 cm long. The plant has soft spines, a tapered neck, and black seeds. The species has long been cultivated in Asia, where fruits are eaten raw as a substitute for cucumber or cooked (1). One plant showing intense mosaic, without leaf malformation, was found near a squash crop (Cucurbita moschata) in Anhembi County, State of São Paulo. Electron microscopic examination of a negatively stained sap preparation from leaves of this plant showed that it contained numerous flexuous rod-shaped particles, approximately 700 × 760 nm long, similar to those of potyviruses. Extracts from symptomatic leaves were rub-inoculated to zucchini squash (Cucurbita pepo), Carica papaya, Chenopodium amaranticolor, C. quinoa, Gomphrena globosa, and Phaseolus vulgaris cv. Black Turtle 2. Only zucchini squash was infected and developed severe mosaic with intense leaf malformation. Extracts from field infected stuffing cucumber and experimentally inoculated zucchini squash were tested by plate-trapped antigen enzyme linked immunosorbent assay (PTA-ELISA) with antisera against the following potyviruses: Papaya ringspot virus-type W (PRSV-W), Zucchini yellow mosaic virus (ZYMV), and Watermelon mosaic virus-2 (WMV-2). Samples were also tested with antisera against a tospovirus (Zucchini lethal chlorosis virus) and a cucumovirus (Cucumber mosaic virus). Both samples were positive in PTA-ELISA only with PRSV-W antiserum. This is the first report of C. pedata var. edulis as a natural host for PRSV-W in Brazil. References: (1) R. W. Robinson and D. S. Decker-Walters. 1997. Cucurbits. CAB International, UK.
Cucurbit yellow stunting disorder virus (Genus Crinivirus) Associated with the Yellowing Disease of Cucurbit Crops in Portugal
Authors: Louro D. , Vicente M. , Vaira A. M. , Accotto G. P. , Nolasco G. 
Published: May 2007

During autumn 1998, chlorotic mottling, yellowing, and stunting symptoms were observed on cucumber (Cucumis sativus L.) plants in an experimental plot, in Algarve, southern Portugal. The first symptoms appeared 3 weeks after planting, associated with a heavy infestation of Bemisia tabaci (Gennadius). Plants affected early produced few and small fruits. Analysis of double-stranded RNA (dsRNA) extracted from symptomatic cucumber leaves revealed the presence of two dsRNAs of about 8 and 9 kbp, not present in healthy cucumber plants. Reverse-transcription polymerase chain reaction (RT-PCR) using dsRNA or total RNA extracts as template and the oligonucleotide primers 410L and 410U (1), specifically amplified a fragment of expected size of the HSP70-homolog gene of Cucurbit yellow stunting disorder virus (CYSDV). The RT-PCR-amplified fragment was sequenced (Acc. No. AF287474) and showed 99% sequence identities with the corresponding sequences (GenBank accessions AJ223619 and U67170) from two CYSDV isolates belonging to group I (2), confirming CYSDV detection. CYSDV was also detected in samples of cucumber, melon (Cucumis melo L.) and watermelon (Citrullus lanatus [Thunb.] Matsun.) collected during the summer of 1999 in commercial greenhouses. CYSDV is an emerging and important virus of cucurbits in the Middle East and Mediterranean Europe (2). This is the first report of CYSDV infecting cucurbit crops in Portugal. References: (1) A. Célix et al. Phytopathology 86:1370, 1996. (2) L. Rubio et al. Phytopathology 89:707, 1999.
Occurrence of Stem Rot of Basil, Caused by Sclerotinia sclerotiorum, in Coastal California
Authors: Koike S. T. 
Published: May 2007

In January and February 1999, extensive dieback was observed on commercial basil (Ocimum basilicum) being grown in shadecloth greenhouses in coastal California's Salinas Valley. Symptoms were associated with stems that were high in the plant canopy and had cut ends resulting from multiple harvests of the foliage. Stems had brown discoloration extending from the cut ends toward the crown of the plant. Attached petioles and leaves turned brown and wilted. Profuse white mycelia were generally present externally on symptomatic stems, and occasionally large (>5 mm long) black sclerotia were found inside affected stems. In some shade houses approximately 20 to 25% of the plants were diseased. Isolations from mycelia, sclerotia, and symptomatic stems produced colonies of Sclerotinia sclerotiorum. Inocula for pathogenicity tests were produced by growing isolates on potato-dextrose agar, removing the resulting sclerotia, air drying them for 12 h, and placing them onto sterilized sand saturated with sterile distilled water. Sand cultures were incubated at 24 to 26°C in the light. After 4 to 6 weeks, apothecia containing asci with eight uniform ascospores developed from the sclerotia. Apothecial cultures were placed at the base of potted basil plants that had been trimmed to simulate harvest and placed in a humidity chamber. After 4 weeks, stem dieback was observed on test plants and S. sclerotiorum was recovered from symptomatic tissue. This pathogenicity test was repeated and the results were similar. Though this disease has occurred in the state prior to 1999, this is the first report of S. sclerotiorum on basil in California. This disease has been reported in North America from Canada and Louisiana (2,3). In contrast with reports from Europe (1), basal infections were not observed in the California greenhouses. References: (1) A. Garibaldi et al. Plant Dis. 81:124, 1997. (2) G. E. Holcomb and M. J. Reed. Plant Dis. 78:924, 1994. (3) T. C. Paulitz. Plant Dis. 81:229, 1997.
Natural and Augmented Spread of Rose Rosette Disease of Multiflora Rose in Maryland
Authors: Tipping P. W. , Sindermann A. B. 
Published: May 2007

Rose rosette disease (RRD), a mite-vectored agent of unknown etiology, was first recorded on multiflora rose, Rosa multiflora Thunb. in central Maryland in 1996. This uncharacterized agent is transmitted to some members of rose family by the eriophyid mite Phyllocoptes fructiphilus Keifer, which is common on multiflora rose in Maryland (1). It is also graft-transmissible (2). In 1996, a farmer near Middletown in Frederick County observed one plant with witches'-broom and reddened shoots along a fence row and sent a sample to J. W. Amrine, Jr. at West Virginia University, for confirmation of the disease (J. W. Amrine, personal communication). During 1997, delimiting surveys around this farm failed to detect any other plant with noticeable symptoms in an area heavily infested with multiflora rose. In an attempt to augment the disease, we grafted shield buds from this plant into 10 nearby apparently helathy plants in May and again in June 1997. None of these grafts were successful. More diseased buds were removed from the original infected plant during May 1998 and grafted into another 12 plants. By June of 1999, only the graft-inoculated plants from 1998 had symptomatic shoots arising from the graft sites. During this interval, RRD was observed in sites in western Maryland near Cumberland in Allegany County (May 1997) and Hagerstown in Washington County (May 1998). Initially, the percentage of symptomatic plants at these sites was less than 10%. Surveys 12 months later indicated that approximately 50% of the plants showed symptoms of RRD. At one site, the majority of the larger multiflora rose plants had at least one dead cane and a few were completely dead. Further augmentation of RRD by grafting was conducted in May 1998 at the University of Maryland Research and Education Center in Keedysville in southern Washington County, and by June 1999 only treated plants were symptomatic. In August 1998, one multiflora rose and one ornamental rose, Rosa hybrida ‘Scarlet Meidiland’ Meikrotal, exhibited RRD symptoms on a farm in northern Washington County near the Pennsylvania border. We found numerous symptomatic multiflora roses in May 1999, at a farm in northern Frederick County, also near the Pennsylvania border. Symptomatic plants have been observed during 2000 in Montgomery, Carroll, and Baltimore Counties as RRD continues to spread rapidly east and north through the state. This is the first documentation of the occurrence and rate of spread of RRD in Maryland. References: (1) W. B. Allington et al. J. Econ. Entomol. 61:1137, 1968. (2) E. A. Thomas and C. E. Scott. Phytopathology 43:218, 1953.
First Report of Fusarium Wilt of Babaco (Carica × heilbornii var. pentagona) in Ecuador
Authors: Ochoa J. , Fonseca G. , Ellis M. A. 
Published: May 2007

Babaco, Carica × heilbornii V.M. Badillo var. pentagona (Heilborn) V.M. Badillo, is a fruit native to Ecuador that has great potential as a cultivated crop. Local market demand and strong potential as an export crop have greatly increased interest in babaco production in Ecuador. Although the crop can be produced in open fields, the majority of crop production is in plastic greenhouses. In 1996, a serious wilt disease developed on babaco in several greenhouses, resulting in up to 100% loss of plants. Symptoms first appeared as chlorosis of the lower leaves, followed by defoliation progressing up the stem until the entire plant was defoliated. When cut in cross section, vascular discoloration was observed in the stem. Eventually necrosis and soft rot of the stem occurred and entire plants collapsed. Fungal isolations were conducted from fine feeder roots of diseased plants by soaking root pieces (2 cm long) in a 0.5% solution of sodium hypochlorite for 3 min. Root pieces were cut into smaller sections and placed on potato dextrose (PDA) or corn meal (CMA) agar in petri dishes. Isolations from larger roots, crowns, stems and fruits were made by soaking tissue sections of each plant part in a 2.87% solution of sodium hypochlorite for 3 min. Tissue sections were rinsed three times in sterile distilled water. Smaller tissue sections (≈0.125 cm3) were cut from surface-disinfested pieces and placed on PDA and CMA in petri dishes. Cultures were incubated at 20°C. A fungus resembling Fusarium sp. was isolated consistently from infected tissues from all infected plant parts. Based on the morphology of the fungal colony and conidia from monosporic isolations, the fungus was identified as Fusarium oxysporum Schlechtend:Fr. (1). Pathogenicity tests were conducted by growing babaco plants in pots containing an equal mixture of sterilized soil, compost, and sand in the greenhouse. Eight 7-month-old plants were inoculated by placing 40 ml of a suspension (106 conidia per ml) of F. oxysporum in four plastic straws placed in the soil (5 cm depth) at equal distances (5 cm) from the base of each plant. Straws around noninoculated control plants received sterile water. Plants were watered with 400 ml of sterile water daily. Pathogenicity tests were repeated once as described. All inoculated plants developed typical wilt symptoms within 45 days after inoculation. No symptoms developed on uninoculated control plants. F. oxysporum was successfully reisolated from infected stem tissues of inoculated plants. Incidence of Fusarium vascular wilt of babaco has continued to increase since 1996 and is currently the major constraint to production. References: (1) P. E. Nelson et al. 1981. Fusarium: Diseases, Biology, and Taxonomy. The Pennsylvania State University Press, University Park.
First Report and Molecular Characterization of Yam mild mosaic virus in Dioscorea alata on the Island of Martinique
Authors: Bousalem M. , Dallot S. 
Published: May 2007

Naturally infected Dioscorea alata plants showing mild mosaic were collected in 1998 on the island of Martinique in the Caribbean. Isolates were first screened by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies raised against Yam mosaic virus (YMV) and antigen-coated plate ELISA with universal potyvirus monoclonal antibodies (Agdia, Elkhart, IN). A positive reaction was obtained only with the universal potyvirus antiserum. Immunocapture reverse-transcriptase polymerase chain reaction was performed for specific detection of Yam mild mosaic virus (YMMV [3]) and YMV. A product with the predicted size of 249 bp was obtained with YMMV primers. YMMV is a recently recognized distinct potyvirus infecting D. alata in West Africa and the South Pacific (2–4). It was originally described as Yam virus I and is synonymous with Dioscorea alata virus (4). To characterize the YMMV Martinique isolate, total RNA was extracted, and universal potyvirus degenerate primers (1) were used to amplify a 700-bp fragment that included the core and C-terminal region of the coat protein (CP) and 3′ untranslated region (3′UTR). Sequence information generated (EMBL AJ250336) from the cloned fragment was compared with sequences of other yam potyviruses. Sequence comparisons of the partial CP (453 nt) showed a similarity of 94.6% (amino acids [aa]) with the YMMV isolate from Papua New Guinea (EMBL AB022424 [2]); 72.2% (aa) with the Japanese yam mosaic virus (JYMV) isolate (EMBL AB016500); and 67 to 73% (aa) with 27 YMV isolates. These sequences are most diverse in the 3′UTR, which showed a similarity of 72.8% with the YMMV Papua New Guinea isolate, 30% with the JYMV isolate, and 26% with the YMV isolates. These results confirm, as previously shown by S. Fuji et al. (2), that YMMV should be classified as a new potyvirus of yam. This is the first report of the natural occurrence of YMMV in the Caribbean. References: (1) Colinet et al. Phytopathology 84:65, 1994. (2) S. Fuji et al. Arch Virol. 144:1415, 1999. (3) R. A. Munford and S. E. Seal. J. Virol. Methods 69:73, 1997. (4) B. O. Odu et al. Ann. Appl. Biol. 134:65, 1999.
Yellow Leaf Disease of Cantaloupe and Wax Gourd from Thailand Caused by Tomato leaf curl virus
Authors: Samretwanich K. , Chiemsombat P. , Kittipakorn K. , Ikegami M. 
Published: May 2007

Cantaloupe (Cucumis melo var. reliculatus) and wax gourd (Benincasa hispida Cogn.) plants showing a yellow leaf disease have been observed in central Thailand since 1993. The disease has been transmitted to cantaloupe and wax gourd plants by grafting and whiteflies (Bemisia tabaci Genn.) (K. Kittipakorn, unpublished data). Because of the leaf yellowing symptoms and transmission by whiteflies, a geminivirus was suspected. Three naturally infected cantaloupe and four naturally infected wax gourd plants showing leaf yellowing were collected from fields at Kamphaengsaen, Nakorn Pathom, Thailand. Virus cultures were maintained in cantaloupe and wax gourd plants. Inoculations were done with a whitefly vector. Symptoms in cantaloupe and wax gourd plants were the same as those observed in the field. Virus DNA associated with yellow leaf disease of cantaloupe and wax gourd plants was amplified by polymerase chain reaction with geminivirus-specific degenerate primers, described by Rojas et al. (2), that anneal within the AC1 open reading frame (ORF; replication associated protein gene) and the AV1 ORF (coat protein gene) of bipartite geminiviruses and the C1 and V2 ORFs of monopartite geminiviruses (2). Fragments (1.2 kbp) were amplified and cloned from affected cantaloupe and wax gourd plants. Three independent clones were sequenced and analyzed, and identical 32-base stem loop regions were found in the amplified fragments from both isolates, including the conserved nonanucleotide sequence TAATATTAC, which is present in all geminiviruses. The iterative sequence GGCGTC also was found in the intergenic region (IR) (434 bp) of the amplified fragments from both isolates. The B component could not be detected. The nucleotide sequences of the IR and V1 were compared with 28 well-studied whitefly-transmitted geminiviruses and revealed ≈96% sequence identity with DNA A of Tomato leaf curl virus of the genus Geminivirus from India (ToLCV-In 2) (1) for both isolates. The iterative sequence GGCGTC in the IR also was identical to the sequence in ToLCV-In 2. These results establish the provisional identity of the pathogen causing yellow leaf disease on cantaloupe and wax gourds in Thailand as ToLCV or closely related strains. References: (1) M. Padidam et al. J. Gen. Virol. 76:249, 1995. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993.
Outbreak of Potato Y potyvirus and Tobacco mosaic tobamovirus in Georgia's Flue-Cured Tobacco
Authors: Pappu H. R. , Bertrand P. F. 
Published: May 2007

Flue-cured tobacco is an economically important crop in Georgia. During the 1999 growing season, tobacco plants showing various degrees of mottling (mild to severe), mosaic, and vein clearing were observed in most counties in Georgia. In most cases, symptoms were not clearly those associated with Potato Y potyvirus (PVY) or Tobacco mosaic tobamovirus (TMV). The incidence of symptomatic plants in individual fields ranged from 0 to 90%. A survey was conducted in several tobacco-growing counties to ascertain the causal agent(s) of the disease. Symptomatic plants were collected from 11 counties: Appling, Atkinson, Bacon, Berrien, Coffee, Colquitt, Echols, Grady, Lowndes, Tattnall, and Ware. Leaf samples were tested by enzyme-linked immunosorbent assay (ELISA) for Cucumber mosaic cucumovirus (CMV), PVY, TMV, Tobacco etch potyvirus (TEV) and Tobacco vein mottling potyvirus. On the basis of ELISA, TMV and PVY were the most prevalent viruses, followed by CMV. From a total of 50 samples tested, 28 were doubly infected with TMV and PVY, 3 were positive for only TMV, and 5 were positive for only PVY. Eight samples were infected only with CMV, and one sample was doubly infected with PVY and TEV. The causal agent(s) in the remaining five samples could not be determined. Although PVY, TMV, TEV, and CMV occur to some degree every year, they have not been economically important in the past few years. It is interesting that the recent epidemic on tobacco and pepper in northern Florida was associated with CMV (1). Considering the predominance of double infections observed, diagnosis of virus-like symptoms in tobacco may require use of ELISA or other specific detection methods. Reference: (1) T. A. Kucharek et al. Plant Dis. 82:1172, 1998.