bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occurrence of Coffee ringspot virus, a Brevipalpus Miteborne Virus in Coffee in Costa Rica
Authors: Rodrigues J. C. V. , Rodriguez C. M. , Moreira L. , Villalobos W. , Rivera C. , Childers C. C. 
Published: May 2007

Coffee ringspot virus (CoRSV) (family Rhabdoviridae) is transmitted by Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae). Coffee ringspot disease was first reported in coffee plants from Brazil in 1939 (1). In August 2000, severe symptoms of concentric ringspots and “oak leaf” patterns on coffee leaves (Coffea arabica L. cv. Catuai) were observed during field inspections conducted in two areas of San Gabriel de Desamparados, Costa Rica. The disease caused premature fruit and leaf drop in the affected plants. Some areas within the ringspot lesions remained green on senescent leaves. Because CoRSV particles remain restricted to lesion areas (1), this virus has not been purified, and antiserum for virus detection is not available. Therefore, leaves with symptoms were collected and examined by transmission electron microscopy. In ultrathin sections of symptomatic leaves, arrays of rhabdovirus-like particles were associated with the nucleus as described for CoRSV (2). Healthy tissues did not contain similar arrays of bacilliform and bullet-shaped particles. Twenty mites collected from the infected plants at the same locations and time were slide-mounted and identified as B. phoenicis. High populations of this mite were also observed infesting plants of Cajanus cajan L. that were intercropped with coffee at the same location. Sweet orange trees growing in the same fields as shade for the coffee did not show symptoms of citrus leprosis, a disease caused by another Brevipalpus-transmitted virus that was recently reported in Panama (3). To our knowledge, this is the first report of a virus similar to CoRSV in Costa Rica. The spread of this virus, presumably CoRSV, could seriously affect the coffee industry throughout Central America by increasing production costs. It may be necessary to apply one or more foliar acaricides to effectively control the mite vector. References: (1) A. Bitancourt. O. Biol. 5:33, 1939. (2) C. M. Chagas et al. Phytopathol. Z. 102:100, 1981. (3) F. S. Dominguez et al. Plant Dis. 85:228, 2001.
Mefenoxam-Resistant Isolates of Pythium irregulare in an Ornamental Greenhouse in California
Authors: Aegerter B. J. , Greathead A. S. , Pierce L. E. , Davis R. M. 
Published: May 2007

Root rot, caused by Pythium species, is a common malady in ornamental greenhouses in Monterey County, CA. In 2001, a root rot of Gerbera daisy (Gerbera jamesonii) and lisianthus (Eustoma grandiflora) caused plant losses in excess of 15 and 75%, respectively, in one greenhouse. Some plantings were total losses. Although mefenoxam was used repeatedly, no disease control was reported. P. irregulare was identified based on morphological structures produced on grass blades in water (1) and on the sequence of the rDNA internal transcribed spacer (ITS) region. Four isolates from each host were tested for sensitivity to mefenoxam in a laboratory bioassay. Using corn meal agar amended with mefenoxam at 0, 0.1, 1, 10, 50, or 100 μg a.i./ml, no inhibition of growth of any isolate occurred at concentrations of 10 μg/ml or less. At 50 and 100 μg/ml, radial growth of colonies was inhibited by approximately 20%. In contrast, 26 isolates of P. ultimum from various agricultural soils in California were completely inhibited by mefenoxam at 100 μg a.i./ml. At 0.1, 1, 10, and 50 μg/ml, growth of these isolates was inhibited by 33, 61, 78, and 96%, respectively. Each treatment was replicated three times, and the experiment was repeated with similar results. Mefenoxam was introduced in 1996 to replace metalaxyl. While metalaxyl contains a mixture of active and inactive enantiomers, mefenoxam contains only the active enantiomer. The intensive use of metalaxyl and mefenoxam in this greenhouse may have resulted in selection for resistant isolates. A resistant isolate (8-007 from Gerbera) has been submitted to the American Type Culture Collection: Manassas, VA. Reference: (1) A. J. van der Plaats-Niterink. Monograph of the Genus Pythium. Stud. Mycol. No. 21. Centraalbureau voor Schimmelcultures, Baarn, the Netherlands, 1981.
Pathogens Associated with Necrosis of Cactus Pear Cladodes in South Africa
Authors: Swart W. J. , Kriel W.-M. 
Published: May 2007

The commercial cultivation of spineless cactus (Opuntia ficus-indica (L.) Miller) for its fruit is a relatively recent undertaking in South Africa but has been shown to possess huge export potential. To date, only one fungal pathogen, Didymosphaeria opulenta (De Not.) Sacc., has been officially reported on the genus Opuntia in South Africa, but the report is from O. stricta Haw. and not O. ficus-indica (1). The need for research on diseases of O. ficus-indica in South Africa has recently become important since local growers are increasingly reporting disease-related yield losses. Surveys conducted over a period of 3 years indicated that stems or cladodes are particularly prone to various forms of tissue necrosis, caused primarily by three fungi, which can ultimately lead to death of entire cladodes. Alternaria tenuissima was isolated from a dry superficial necrosis of the cuticle and underlying tissue as much as 3 mm deep. Symptoms include small chlorotic spots on the cuticle, which coalesce to form raised gray scabs. Fusarium sporotrichoides was isolated more commonly from dry necrotic lesions that were darker, larger, and less superficial, sometimes extending through the tissue to the opposite side of the cladode. Lasiodiplodia theobromae (teleomorph Botryosphaeria rhodina) was isolated from roundish black cankers (15 to 50 mm diameter) on cladodes and characterized by black gum exudation from the perimeter of the canker. Pycnidia were often evident on the surface of the canker. The fulfillment of Koch's postulates demonstrated that an isolate of each respective species was very aggressive in colonizing cladodes following artificial inoculations in the glasshouse. Mean lesion diameters measuring 15, 27, and 44 mm for A. tenuissima, F. sporotrichoides, and L. theobromae, respectively, were recorded 14 days after inserting wooden toothpick tips that had been colonized by the three pathogens into each of five cladodes of 18-month-old potted plants of O. ficus-indica (cv. Morado). Alternaria sp. and B. rhodina have been reported on Opuntia sp. in the United States (2), but no records of the above three fungi occurring on O. ficus-indica were found. References: (1) P. W. Crous et al. Phytopathogenic Fungi from South Africa. University of Stellenbosch, Department of Plant Pathology Press, Stellenbosch, South Africa, 2000. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.
Report of Colletotrichum coccodes Associated with Mentha
Authors: Johnson D. A. , Douhan L. I. , Geary B. 
Published: May 2007

Colletotrichum coccodes (Wallr.) Hughes is a pathogen of tomato and potato and occurs worldwide on plants primarily from the Solanaceae. It has not been previously reported for Mentha. C. coccodes was isolated from rhizomes and lower portions of above ground stems of symptomless Mentha × piperita L. (peppermint) plants collected from commercial fields in central Washington and Wisconsin (central sands). Three isolates from mint were evaluated for pathogenicity on mint and potato. Rooted cuttings of eight plants each of M. × piperita, M. spicata L. (native spearmint), and M. × gracilis Sole (Scotch spearmint) were dipped into a conidial suspension (1 × 106 conidia per ml) of each isolate of C. coccodes for 10 min. Plants were transplanted into a sterilized potting mix and moved to a greenhouse. After 50, 90, and 185 days, pieces of rhizomes and roots were thoroughly washed in running water, soaked in 1.5% NaOCl for 7 min, and plated on NPX agar medium (1). C. coccodes was reisolated from 25 of 36 plants at 50 days, 14 of 18 plants at 90 days, and 10 of 18 plants at 185 days. Disease symptoms were not observed on roots, rhizomes, or aboveground plant parts. C. coccodes was not isolated from rhizomes and roots of eight noninoculated plants of each mint species. In pathogenicity tests on potato, the isolates from mint produced cortical root rotting and sclerotia on cv. Russet Burbank and did not differ in their aggressiveness from three potato isolates. (Conidial suspensions at 106 were applied to soil surface of potted plants at 10 cm of shoot growth and assessed for disease severity at plant maturity.) All tests were repeated with similar results. Mint is often rotated with potato in central Washington and appears to be a bridging host for C. coccodes. Reference: (1) E. J. Butterfield and J. E. DeVay. Phytopathology 67:1073, 1977.
First Report of Bacterial Deep Bark Canker of Walnut Caused by Brenneria (Erwinia) rubrifaciens in Europe
Authors: González R. , López-López M. J. , Biosca E. G. , López F. , Santiago R. , López M. M. 
Published: May 2007

During the summer of 1995 and subsequent years, bark cankers were observed in walnut trees (cv. Hartley grafted on Juglans hindsii) imported from California in 1978 growing in Badajoz, Spain. Two foci were found in an orchard of 200 ha where 80 walnut trees were affected. Cankers were observed on trunks and branches, and dark exudates staining the bark appeared mainly in summer. Isolations were performed from affected tissue using King's B medium, and Brenneria (Erwinia)-like colonies (1) were purified and characterized. Gram reaction, Kovacs' oxidase, O/F metabolism, aesculin hydrolysis, urease activity, and levan production were assayed for five isolates (1). Biochemical characterization was performed by the miniaturized API 20E, API 20NE, and API 50CH systems (BioMérieux, Marcy-l'Etoile, France) as recommended, except for incubations that were made at 25°C for 48 h. Analyses of the cellular fatty acids of selected isolates were performed as described by Sasser (2). They were also tested in indirect enzyme-linked immunosorbent assay (ELISA) using antisera obtained against the reference strain CFBP 1284 and one Spanish isolate. When compared to the reference strain from California, isolates were identified as Brenneria rubrifaciens (1,3) on the basis of physiological and biochemical characteristics, fatty acid profiles, and ELISA. Pathogenicity of two selected Spanish isolates was confirmed using three 2-year-old walnut trees per bacterial isolate by inoculating 108 CFU of each isolate in deep wounds made in the trunk at 40 and 80 cm from the crown. The reference strain and water were also inoculated as controls. Two months later, removal of the outer bark of walnut revealed typical dark lesions in the inner bark at all the inoculation sites on trees inoculated with the Spanish and reference strains, but no external cankers were observed. Four years later, these plants showed internal lesions (20 to 80 cm), from which B. rubrifaciens was reisolated far away from the inoculation site. To our knowledge this is the first report of this bacterium in Europe. References: (1) L. Hauben et al. Syst. Appl. Microbiol 21:384, 1998. (2) M. Sasser. Pages 199–204 in: Methods in Phytobacteriology. Budapest, Hungary, 1990. (3) E. Wilson et al. Phytopathology 57:618, 1966.
First Report of Bleeding Canker Caused by Phytophthora cactorum on Horse Chestnut in Turkey
Authors: Intini M. , Gurer M. , Ozturk S. 
Published: May 2007

Bleeding canker on horse chestnut (Aesculus sp.), caused by Phytophthora cactorum (Lebert and Cohn) Schröeter previously has been reported from the United States and Europe (1). In August 2000, it was found for the first time in a park in Ankara Province, Turkey. Symptoms included sparse yellowish brown foliage with abnormally small leaves, and dark-stained spots or dark brown necrosis of the bark on the trunk and main branches, with or without a reddish black gummy exudate. P. cactorum was isolated from tissues taken from the margins of necrotic bark. Pure cultures were slightly radiate, fluffy but not dense, and had short aerial hyphae when grown on carrot agar, potato dextrose agar, or V8 agar. Sporangia were ovoid, strongly papillate, and averaged 35.6 μm in length and 26.8 μm in width (range: 24 to 55 μm × 19 to 40 μm). The isolates were homothallic with smooth-walled paragynous oogonia ranging from 23.5 to 34.5 μm in diameter. To satisfy Koch's postulates, mycelium of P. cactorum was placed under the bark of six branches of healthy horse chestnut. Noninoculated wounds served as controls. Four months later a reddish black gummy exudate was observed oozing from the inoculated wounds, and the bark tissue was necrotic for 3 to 4 cm around each infection. P. cactorum was successfully reisolated from the necrotic bark tissue. Control wounds remained healthy. To our knowledge, this is the first report of this disease on horse chestnut in Asia Minor. Reference: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996.
A Severe Outbreak of Ascochyta Blight of Chickpeas in Western Nebraska
Authors: Harveson R. M. 
Published: May 2007

Interest in chickpea (Cicer arietinum L.) production as an alternative crop to sugar beets and dry beans has rapidly increased in the Nebraska Panhandle. Production (concentrated near Alliance in Box Butte County) has increased from 80 ha in 1999 and 800 ha in 2000, to almost 4,000 ha in 2001. In mid-July 2001, symptoms in fields consisted of circular, dark brown lesions (0.5 to 1.0 cm) on leaves and pods containing pycnidia (225 to 240 μm) arranged in concentric rings. Symptom appearance followed unusually high rainfall events (over 25 cm the previous week), and the epidemic affected virtually all chickpeas planted in the area. Infected leaves incubated in humidity chambers in the laboratory produced nonseptate, hyaline, oval to oblong conidia measuring 8.5 to 10.0 × 4.0 to 4.5 μm that oozed out of pycnidia in a mucilaginous mass. Based on symptoms and fungal morphology (1), the pathogen was identified as Ascochyta rabiei (Pass.) Labr. Because of the seedborne nature of the disease, pathogen identity was further verified by planting seeds from infected pods in the greenhouse. Emerging plants exhibited similar symptoms to those from field infections, and the pathogen was identified from newly developed lesions. A section 18 emergency exemption was obtained for the use of the fungicide Quadris (azoxystrobin) on 2,400 to 2,800 ha in Nebraska. This measure averted serious losses, but 15 to 20% reductions in yield and quality were still recorded from treated fields. Infected plants collected from untreated fields had almost 60% losses in both pod number and total seed weight compared with uninfected plants. Disease occurrence in the Western Hemisphere was first reported from Canada in 1974, followed by other chickpea-growing states in the United States, including California, Washington, Idaho, and North Dakota (2–4). To my knowledge, this is the first report of the disease in Nebraska, and its presence poses a significant threat to the developing chickpea industry in the state, as the planted area is expected to increase in the foreseeable future. References: (1) D. J. Allen. The Pathology of Tropical Food Legumes. John Wiley and Sons, New York, 1983. (2) M. L. Derie et al. Plant Dis. 69:268, 1985. (3) P. Guzman et al. Plant Dis. 79:82, 1995. (4) W. J. Kaiser and F. J. Muelbauer. Phytopathology 74:1139, 1984.
First Report of a Root Rot Caused by Rosellinia necatrix on Camellia in Spain
Authors: Mansilla J. P. , Aguín O. , Salinero M. C. 
Published: May 2007

Camellias are widely cultivated in gardens and grown in nurseries for plant and flower production in northwestern Spain. Camellia japonica L. is most frequently grown, but many other camellia species and hybrids are also produced. In spring 1998, plants of Camellia sp. from a garden were observed to be affected by a root fungal pathogen, that formed a white mycelium that covered most of the roots, while aboveground plant parts showed a general decline. Infected roots were macerated and discolored. Fragments of the infected roots were surface-sterilized and placed in petri dishes containing potato dextrose agar and incubated at 24°C in the dark. The fungus formed a white mycelium that turned black in 1 week, developing pyriform swellings characteristic of Rosellinia necatrix Prill (1). To confirm pathogenicity, inoculum of the isolate was produced on wheat (Triticum aestivum L.) seeds autoclaved in glass vessels for 30 min at 120°C. Wheat seed cultures were started from disks of R. necatrix mycelium and grown at 24°C in the dark for 30 days. Pathogenicity tests were conducted on 48 2-year-old plants of the hybrid Camellia × williamsii cv. Mary Phoebe Taylor, which had been grown in 1.5-liter pots (one plant per pot) filled with soil in a glasshouse. The R. necatrix isolate was inoculated by adding 30 g of infected wheat seeds to each pot. The inoculum was mixed thoroughly with the substrate before potting. Another set of pots was left uninoculated, and served as a control. All pots were randomly arranged in a growth chamber at 22 to 24°C with a 12-h photoperiod. Seventeen days after inoculation, aerial symptoms of chlorosis and leaf fall were observed, while control plants remained symptomless. Inoculated plants died 3 months after inoculation. R. necatrix was reisolated from roots of all infected plants. To our knowledge, this is the first report of a root rot of camellia caused by R. necatrix, a pathogen causing white root rot mainly in deciduous fruit crops. Reference: (1) S. Freeman and A. Sztejnberg. Pages 71–73 in: Methods for Research on Soilborne Phytopathogenic Fungi. The American Phytopathological Society, St. Paul, MN, 1992.
First Report of Musk Thistle Rust (Puccinia carduorum) in California and Nevada
Authors: Woods D. M. , Pitcairn M. J. , Luster D. G. , Bruckart W. L. 
Published: May 2007

Musk thistle, Carduus nutans L., is an introduced weed of pastures, rangelands, and natural areas in much of North America. Puccinia carduorum Jacky, an autoecious rust fungus from Turkey, has been evaluated for biological control of musk thistle since 1978, including a field study near Blacksburg, VA, from 1987 to 1990. After release of the fungus in Virginia, rusted musk thistle was found in eight eastern states by 1992, in Missouri by 1994 (1), and in Oklahoma by 1997 (2). A rust disease was discovered on musk thistle near Mt. Shasta, CA, on 22 September 1998, and near Mogul, NV, on 12 August 1999. The pathogen was identified as P. carduorum on the basis of pathogenicity on musk thistle and urediniospore morphology (ovate spores, 21 μm diameter, three germ pores equatorial in location, and echinulations over the upper two-thirds to three-quarters of urediniospores). Ribosomal RNA internal transcribed spacer DNA sequences (ITS1 and ITS2) were identical to those from the isolate obtained after the field release in Virginia, verifying that the California isolate is P. carduorum. The initial California infestation was observed on a few plants late in the season, and by September 2000, nearly 100% of plants were infected. The occurrence of P. carduorum in California is apparently the result of natural, unaided spread of the fungus on musk thistle from the East Coast of the United States. References: (1) A. B. A. M. Baudoin and W. L. Bruckart. Plant Dis. 80:1193, 1996. (2) L. J. Littlefield et al. Plant Dis. 82:832, 1998.
European Pines May Be Simultaneously Infected by More Than One Species of Heterobasidion
Authors: Gonthier P. , Garbelotto M. , Nicolotti G. 
Published: May 2007

Heterobasidion annosum (Fr.:Fr.) Bref. sensu lato, one of the most damaging root and butt rot agents on conifers, was recently segregated into three species in Europe based on morphology, intersterility grouping (ISGs), and host preferences (3). These species include: H. annosum (Fr.) Bref. sensu stricto (ISG P) on Pinus, other conifers and some hardwoods; H. parviporum Niemelä & Korhonen (ISG S), primarily on Picea; and H. abietinum Niemelä & Korhonen (ISG F) on Abies. In the summer of 1998, a Swiss stone pine (Pinus cembra L.), growing at 1,900 m in a mixed spruce (Picea) and larch (Larix) forest in the Aosta Valley (northwest Italian Alps), was found infected by H. parviporum and H. annosum sensu stricto. The pine (approximately 14 m tall and at least 75 years old) was without crown symptoms, but the stem, stump, and all the main roots showed internal decay. Disks, 3 to 4 cm thick, were cut consecutively from the roots, stump, and stem, incubated, and examined for conidiophore production. After 8 days, 63 isolates were obtained from all disks taken from the stump and roots, and from disks taken up to 4 m above the collar in the stem. Isolates were identified by polymerase chain reaction (PCR) of mitochondrial and nuclear markers (2) and by sexual compatibility with testers of each European Heterobasidion spp. The stem and one root were colonized by H. parviporum while the other roots and most of the stump was colonized by H. annosum sensu stricto. Somatic incompatibility tests among conspecific isolates suggested that there was only one genet of each species. The coexistence of different Heterobasidion spp. (ISGs) in the same tree has been reported only in Pinus ponderosa Dougl. ex Laws. in California (1) and in Picea abies (L.) Karst. in Europe (4). To our knowledge, this is the first report of H. annosum sensu stricto on P. cembra and of a European pine to be simultaneously infected by more than one species of Heterobasidion. References: (1) M. Garbelotto et al. Phytopathology 86:543, 1996. (2) P. Gonthier et al. Can. J. Bot. 79:1057, 2001. (3) T. Niemelä and K. Korhonen. Taxonomy of the genus Heterobasidion. Pages 27–33 in Heterobasidion annosum, Biology, Ecology, Impact and Control. CAB International, Wallingford, UK, 1998. (4) R. Vasiliauskas and J. Stenlid. Can. J. Forest Res. 28:961, 1998.