bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathogenic Isolates of Rhodococcus fascians from New Hosts in the United States
Authors: Putnam M. L. , Miller M. 
Published: May 2007

Rhodococcus fascians is important to the nursery industry due to its broad host range (68 genera) (2) and potential for horizontal gene transfer of plasmid-borne virulence genes. Since 2001, many herbaceous ornamental plants with symptoms of leafy galls or basal or axillary shoot proliferation suggestive of infection by R. fascians have been submitted to the Oregon State University Plant Clinic for diagnosis. R. fascians was isolated from symptomatic plants by placing affected tissues into saline or liquid D2 medium (1) for 30 to 120 min and then dilution plating onto D2 agar. Orange colonies were purified by dilution streaking and identified as R. fascians by substrate utilization (Biolog, Hayward, CA) and fatty acid analysis (L. Barnes, Texas A & M University, College Station, TX). Pathogenicity was confirmed by inoculation of 10 newly germinated Pisum sativum ‘Laxton Progress’ and ‘Sugar Pod’ seedlings with bacteria from 2-day-old cultures (107 CFU/ml) or water (controls). Our isolates produced shoot proliferations typical of R. fascians infection of peas, confirming pathogenicity. Control plants remained healthy. Pathogenic R. fascians isolates were associated with and isolated from eight species not previously reported as hosts: Acanthus mollis, Campanula sarastro, Heliopsis helianthoides ‘Loraine Sunshine’, Nemesia × ‘Natalie’, Hosta × ‘Blue Umbrella’, Verbascum ‘Sierra Sunset’, Veronica spicata ‘Minuet’ and Viola × ‘Purple Showers’. References: (1) N. W. Schaad et al. Laboratory Guide to Plant Pathogenic Bacteria. The American Phytopathological Society, 2001. (2) D. Vereecke et al. Mol. Plant-Microbe Interact. 6:53, 2003.
First Report of Cladocolea cupulata on Pinus douglasiana and P. herrerai in Northern Mexico
Authors: Kenaley S. , Howell B. , Mathiasen R. 
Published: May 2007

The mistletoe Cladocolea cupulata Kuijt (Loranthaceae) has previously been reported parasitizing pines (Pinus spp., Pinaceae) in central Mexico (3). As of today, reported pine hosts have been Pinus jaliscana Pérez de la Rosa and P. lumholtzii B.L. Rob. & Fernald from the state of Jalisco (1,2). During July 2005, we found this mistletoe parasitizing P. douglasiana Martinez and P. herrerai Martinez along Route 40 in Durango approximately 8 km east of El Palmito (23°35′54″N, 105°50′45″W, elevation 2,000 m). We also found the mistletoe on P. douglasiana along Route 40 at approximately 18 km west of El Palmito (23°27′51″N, 105°49′58″W, elevation 1,780 m) in the state of Sinaloa. Additional populations of this mistletoe were observed along the roadside of Route 40 in the Sinaloa-Durango border region. Infected trees had one to five mistletoe plants on them. Comparing infected hosts with neighboring noninfected hosts, the mistletoe appeared to have no effect on the growth of the infected trees. No mortality associated with mistletoe infection was observed for either of these mistletoe-host combinations. C. cupulata can be distinguished from its closest relatives, C. grahami Kuijt and C. pringlei Kuijt, by its longer, narrower, opposite leaves, parallel venation, and the saddle-like peduncles that hold four flowers (3). The other taxa have predominantly alternate leaves with pinnate venation and lack the saddle-like peduncle. To our knowledge, this is the first report of C.cupulata parasitizing P. douglasiana and P. herrerai and the first report of this mistletoe from the states of Durango and Sinaloa (2,3). Specimens of C. cupulata and host material were collected and have been deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession Nos. 79532, 79533, and 79536). References: (1) B. Chazado. Biosphera 1:3, 1990. (2) B. Geils et al. USDA For. Serv. Gen. Tech. Rep. RMRS-GTR-98, 2002. (3) J. Kuijt. J. Arnold Arbor. Harv. Univ. 56:265, 1975.
First Report of Southern blight of Formosan Michelia Seedlings in Taiwan
Authors: Hsiao W. W. , Fu C. H. , Chen C. Y. 
Published: May 2007

Formosan michelia (Michelia compressa (Maxim.) Sargent) is a native, giant evergreen tree in Taiwan. This species is used for afforestation, provision of shade in domestic situations, used in parks, and also for furniture. During the summer of 2004, a sudden wilt of 1-year-old plants was observed in a nursery of northern Taiwan. Initial symptoms included stem necrosis at the soil line, yellowing, and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues were covered with whitish mycelium that differentiated into reddish brown spherical (1 to 2 mm in diameter) sclerotia. Sclerotium rolfsii was consistently recovered from the surface of symptomatic stem sections that were disinfected for 1 min in 0.5% NaOCl and then plated on potato-dextrose agar amended with 100 ppm ampicillin. Pathogenicity of two S. rolfsii isolates was confirmed by inoculating 1-year-old Formosan michelia seedlings grown in pots. Inoculum consisted of mycelium and sclerotia of the pathogen placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were kept in a growth chamber at 25 to 35°C with relative humidity >95%. Inoculated plants developed symptoms within 14 days while control plants remained symptomless. Sclerotia developed on infected tissues, and S. rolfsii was reisolated from symptomatic tissues. This disease has been observed on many species of plants (1), but to our knowledge, this is the first report of southern blight of Formosan michelia seedlings caused by S. rolfsii in Taiwan. Reference: (1) Y. P. Tsai, ed. List of Plant Diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China, 1991.
First Report of Gladiolus Rust Caused by Uromyces transversalis in Michoacán, México
Authors: Rodríguez-Alvarado G. , Fernández-Pavía S. P. , Valenzuela-Vázquez M. , Loya-Ramírez J. G. 
Published: May 2007

During October 2005, rust lesions were observed on leaves of gladiolus (Gladiolus sp.) plants being grown for flower production in a 20-ha field in eastern Michoacán, México. Disease incidence was near 100% in the field. Five symptomatic plants were collected on 11 and 25 October 2005, from each of 10 farms for further examination. Uredinia were scattered, orange, elliptical to irregular, and arranged transversely across the leaf. The sori were covered by the epidermis initially and later were erumpent and pulverulent. Urediniospores were bright yellow gold, ovate to oblong, and measured 15 × 19 μm (average). The urediniospore wall was hyaline and minutely echinulate. Telia were scattered, dark brown, elliptical, arranged transversely across the leaf, and were covered by the epidermis. Teliospores were irregularly pyriform, ovate, irregular or angular, light to dark brown with a conical or truncate apex and measured 17 × 23 μm (average). The teliospore wall measured 1 μm (average) thick at the sides and 3 μm (average) thick at the apex. Pedicels were light yellow and measured as much as 60 × 3 μm (average). On the basis of these characters, the rust was identified as Uromyces transversalis (Thüm.) G. Winter (1). To our knowledge this is the first report of U. transversalis causing gladiolus rust in Michoacán, México. Originally reported from Africa, the disease has been reported from Argentina, Brazil, southern Europe, and Oceania (1). Gladiolus rust caused by Uromyces transversalis is a quarantine disease for Europe and the United States. There have been unpublished reports of interceptions of this rust on cut flowers of gladiolus going from México into the United States (1). References: (1) J. R. Hernández. Invasive Fungi. Gladiolus Rust. Systematic Botany and Mycology Laboratory, Online publication. ARS, USDA, 2004.
Sclerotinia Petiole and Crown Rot of Celery Caused by Sclerotinia minor in California
Authors: Koike S. T. , Daugovish O. , Downer J. A. 
Published: May 2007

Celery (Apium graveolens) is grown extensively in the coastal counties (Ventura, Santa Barbara, San Luis Obispo, Monterey, and Santa Cruz) of California. In 2004 and 2005, field plantings of celery in Ventura and Monterey counties showed symptoms of a petiole and crown rot. Initial symptoms consisted of a light tan discoloration at the crowns and on outer petioles that were in contact with soil. These discolored areas developed a soft, brown, watery rot. Affected petioles wilted and later collapsed. White mycelium and small (0.5 to 3.0 mm in diameter), irregularly shaped, black sclerotia formed on diseased tissues. Isolations from symptomatic petioles, crowns, mycelium, and sclerotia produced colonies of Sclerotinia minor. Eight-week-old celery transplants (cv. Conquistador) grown in a peat-moss based rooting medium in 10-cm2 pots were used to test pathogenicity. Colonized agar plugs (one plug per plant) from eight celery isolates were inserted into slots made in the potting mix adjacent to the crowns and lower petioles of the transplants. Noncolonized plugs were placed in slots for control celery plants. Twenty plants were used for each isolate and control, and all test plants were incubated in a greenhouse at 21 to 23°C. Disease development was rapid, and after 4 days, inoculated celery plants exhibited brown necrosis at inoculation points. After 9 days, celery crowns were decayed and petioles collapsed. S. minor was reisolated from necrotic crown and petiole tissues. Noninoculated plants were asymptomatic. The experiment was repeated and results were similar. To our knowledge, this is the first report of celery as a host of S. minor in California (2). In the United States, S. minor has been reported on celery in Florida (1). Celery in California is only occasionally infected by S. minor and is more often infected by S. sclerotiorum. Reference: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society. St. Paul, MN, 1989. (2) M. S. Melzer et al. Can. J. Plant Pathol. 19:272, 1997.
Occurrence of Bacterial Fruit Blotch of Watermelon Caused by Acidovorax avenae subsp. citrulli in the Eastern Mediterranean Region of Turkey
Authors: Mirik M. , Aysan Y. , Sahin F. 
Published: May 2007

Turkey has the second highest production level of watermelon (Citrullus lanatus L.) in the world, with 3.8 million tons produced in 2005. In the spring of 2005, a severe outbreak of a disease resembling bacterial fruit blotch was observed on watermelon cv. Crispy growing in a production area of 35,000 ha in Adana Province in the eastern Mediterranean Region of Turkey. In 13 commercial watermelon fields surveyed in this study, incidence of symptomatic fruit ranged from 30 to 45%. Characteristic symptoms were dark, gray-green stains or blotches on the surface of fruits. Cracks developed in the rind and released an amber-colored substance. Bacteria were consistently isolated from affected fruits and they formed nonfluorescent colonies on King's medium B. Identification of isolated bacterial strains was based on the methods described by Schaad et al. (2). All strains were oxidase positive, gram negative, arginine dyhydrolase negative, and produced a hypersensitive response on tobacco leaves (Nicotiana tabacum cv. Samsun). Strains were identified as Acidovorax avenae subsp. citrulli (1,2) on the basis of the results of biochemical tests (1,2) and sole carbon substrate utilization (BIOLOG GN; Biolog Inc., Hayward, CA) with 75 to 93% similarity indices. A pathogenicity test was performed for nine identified strains by injecting a bacterial suspension (108 CFU/ml of saline) under the rind of three harvested watermelon (cv. Diyarbakir) fruits and into the stems of three seedlings. Saline was used as the negative control. The fruits and seedlings inoculated with each strain were incubated in polyethylene bags for 48 h at 25°C. Dark green water-soaked lesions developed on inoculated fruits and water-soaking and stem necrosis were observed on the seedlings 3 to 5 days after inoculation. The bacterium was readily reisolated from inoculated fruits and seedlings and identified as A. avenae subsp. citruli on the basis of BIOLOG GN. In 1995, bacterial fruit blotch of watermelon has been observed and eradicated in the Marmara Region of western Turkey (1). Therefore, to our knowledge, this is the first outbreak of bacterial fruit blotch on watermelon in the eastern Mediterranean Region of Turkey. References: (1) G. Demir. J. Turk. Phytopathol. 25:43, 1996. (2) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria. The American Phytopathological Society, St Paul, MN, 2001.
First Report of Powdery Mildew Caused by Erysiphe (Golovinomyces) orontii on Veronica spicata in Italy
Authors: Garibaldi A. , Bertetti D. , Minerdi D. , Gullino M. L. 
Published: May 2007

Veronica spicata (spike speedwell) is a perennial garden species belonging to the family Scrophulariaceae. During the summer through fall of 2004 and 2005, severe outbreaks of a previously unknown powdery mildew were observed in several gardens near Biella (northern Italy). Upper surfaces of leaves were covered with a white mycelium and conidia, and as the disease progressed, infected leaves turned yellow and died. Very rarely was the mycelium observed on the lower surface of leaves or on petioles and flowers. Foot cell was cylindric and measured 19.2 to 25.7 × 10.8 to 14.3 μm (average 21.9 × 12.0 μm). Conidia were hyaline, ellipsoid, brought in short chains (three conidia per chain), and measured 22.2 to 40.8 × 13.6 to 21.6 μm (average 30.1 × 17.0 μm). Conidiophores measured 45.5 to 74.0 × 10.4 to 11.0 μm (average 59.4 × 10.6 μm). Fibrosin bodies were absent. Cleistothecia were never observed on the samples collected. The ITS region (internal transcribed spacer) of rDNA was amplified using the primers ITS4/ITS6 (3) and sequenced. BLASTn analysis (1) of the 504 bp obtained showed an E-value of 0.0 with Erysiphe (Golovinomyces) orontii (2). The nucleotide sequence has been assigned GenBank Accession No. DQ386696. Pathogenicity was confirmed by gently pressing diseased leaves onto leaves of five healthy Veronica spicata plants. Five noninoculated plants served as controls. Inoculated and noninoculated plants were maintained in a greenhouse where temperatures ranged between 15 and 28°C. After 15 days, typical powdery mildew symptoms developed on inoculated plants. Noninoculated plants did not show symptoms. The pathogenicity test was carried out twice. To our knowledge, this is the first report of the presence of powdery mildew on V. spicata in Italy. Sphaerotheca fuliginea has been reported as the causal agent of powdery mildew on V. spicata (4). Specimens of this disease are available at DIVAPRA Collection, University of Torino. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) U. Braun. Nova Hedwigia 89:166, 1987. (3) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (4) B. Ing. Mycologist 4:125, 1990.
First Report of Lethal Yellowing Disease of Coconut Palms Caused by Phytoplasma on Nevis Island
Authors: Myrie W. A. , Paulraj L. , Dollet M. , Wray D. , Been B. O. , McLaughlin W. 
Published: May 2007

Coconuts (Cocos nucifera) are an important small-holder's crop in many tropical countries and are used to enhance esthetics of coastal areas. Lethal yellowing (LY) is the single most important plant disease affecting the coconut industry in Jamaica. It affects many palm species in Jamaica, Florida, and Guatemala. This coconut disease was first recorded in Grand Cayman Island in 1834 and Jamaica in 1884. Symptoms of LY disease include premature nut fall, necrosis of the inflorescence, yellowing of the leaves, and defoliation. Thirty-eight coconut palms displaying symptoms indicative of LY disease were sampled in April, 2005 at several locations in Nevis. Immature leaf tissues (leaf bases adjacent to the apical meristem) and nondestructive (boring with a bit and braces) samples were collected from disease and healthy control coconut trees. DNA was extracted (2). The first round of polymerase chain reaction (PCR) with phytoplasma universal primer pair P1/P7 (1,3) resulted in an rDNA fragment of 1.8 kb, and a subsequent nested PCR using LY16-23Sr/LY16Sf primers yielded an amplicon of 1.74 kb (4). Purified product was cloned for sequencing. Sequences obtained were analyzed with Vector NTI Software Suite. The sequence of LYN 18-3 was entered in Genbank and Accession No. DQ378279 was assigned. LYN 18-3 has approximately 99% homology with LY Phytoplasma U18747 from Florida (Manila palm [Veitchia merrillii]). The disease-associated phytoplasma was reliably detected in immature tissues and trunk phloem at the onset of foliar symptoms in palms by PCR. On the basis of the results obtained from this study, it is clear that LY phytoplasma (16SrIV group) was found in the samples collected from Nevis. To our knowledge, this is the first report on lethal yellowing disease in Nevis. References: (1) S. Deng and C. Hiruki. J. Microbiol. Methods 14:53 1991. (2) J. J. Doyle and J. L. Doyle. Focus 12:13, 1990. (3) N. A. Harrison et al. Ann. Appl. Biol. 141:183, 2002. (4) C. D. Smart et al. Appl. Environ. Microbiol. 62:2988, 1996.
First Report of Thielaviopsis Trunk Rot of Date Palm in Italy
Authors: Polizzi G. , Castello I. , Vitale A. , Catara V. , Tamburino V. 
Published: May 2007

As an alternative to Canary Island date palm (Phoenix canariensis Chabaud), date palm (P. dactylifera L.) is being planted in Sicilian landscapes. In January 2006, severe symptoms of trunk rot were noticed on 10 7- to 8-m high mature date palms in the central square of Aci Bonaccorsi (Catania) in eastern Sicily. In June 2004, these palms were transplanted directly from Egypt. In 4 of 13 planted date palms, the canopy suddenly fell off the trunk. The canopy of all palms appeared normal and healthy with no stem bleeding observed before trunk collapse. Cross sections of affected date palms revealed a brown rot of nonlignified or lightly lignified tissues along with a strong odor of fermented fruit (amyl acetate) associated with the presence of Geotrichum candidum Link ex Pers. Brown rot was not detected in three of the date palms examined. Symptoms were not detected on lignified and external fibers. Internal tissue adjacent to the rotted areas was placed on carrot agar amended with 500 μl of streptomycin sulfate and acidified (lactic acid; pH = 3.6) potato dextrose agar. Large sections (10 to 18 cm) of affected palm tissues were maintained in a moist chamber for 8 days. Microscopic examinations of five single-conidia isolates on media and sporulation from affected tissues yielded Thielaviopsis paradoxa De Seyn. (Höhn) (1). Endoconidia measuring 3 to 5.5 × 7 to 11 μm were cylindrical to somewhat oval when mature, hyaline to mid brown and smooth walled. Endoconiodophores were usually straight, colorless to pale brown, as much as 150 μm long, with a terminal spore-bearing cell through which spores are born. Chlamydospores were smooth, thick walled, brown, in chains, and were 7.5 to 13 μm width × 10 to 18 μm length (values referred to 50 examined chlamydospores). T. paradoxa is a pathogen that can infect any part of a palm and its pathogenicity to date palm is well documented (3). T. paradoxa is endemic in northern Italy (Ligurian Riviera) on P. canariensis where it causes a disease known as bud rot (2). To our knowledge, this is the first record of trunk rot caused by T. paradoxa on date palm in Italy and is the first report of the fungus in Sicily. It is recommended to avoid the foreign trade of mature date palms from known infected areas because of the symptomless infections by this pathogen. References: (1) A. R. Chase and T. K. Broschat, eds. Diseases and Disorders of Ornamental Palms. The American Phytopathological Society, St. Paul, MN, 1991. (2) A. Garibaldi et al., eds. Malattie Delle Piante Ornamentali. Calderini Edagricole, Bologna, Italy, 2000. (3) P. Suleman et al. Plant Dis. 85:80, 2001.
First Report of Papaya ringspot virus W in Sponge Gourd from India
Authors: Verma Raj , Baranwal V. K. , Prakash Satya , Tomer S. P. S. , Pant R. P. , Ahlawat Y. S. 
Published: May 2007

During August 2004, symptoms resembling a virus disease were observed in commercial cultivation of sponge gourd (Luffa cylindrica (L.) M. Roem. [cv. Chikni]) in Pune, India. Affected plants exhibited mosaic mottling, vein banding, and downward marginal curling on leaves. The incidence of disease was 10 to 30% based on the symptoms and confirmed using enzyme-linked immunosorbent assay (ELISA). Six fields of sponge gourd were visited, and 30 samples were collected randomly. Samples from affected fields were analyzed for the presence of virus by mechanical inoculation. Symptoms typical of those observed in the original field plants appeared 10 days after inoculation on sponge gourd. The virus isolate produced local lesions on Chenopodium amaranticolor and systemic symptoms on Cucumis melo, Cucumis sativus, Cucurbita maxima, Cucurbita pepo, L. acutangula, and L. cylindrica, but did not produce symptoms on Carica papaya (cvs. CO2 and Red Lady), Nicotiana glutinosa, N. tabacum (cv. White Burley), or Vigna unguiculata. Field-infected sponge gourd and all indicator plants were tested using double-antibody sandwich (DAS)-ELISA. The virus was identified as Papaya ringspot virus-W (PRSV-W) using DAS-ELISA (Agdia, Elkhart, IN). A strong, positive reaction was obtained with antiserum to PRSV-W but not with antisera to PRSV-P, Cucumber mosaic virus, Squash mosaic virus, Zucchini yellow mosaic virus, and Groundnut bud necrosis virus. To ensure virus purity, the isolate was passed through three successive single-lesion transfers on C. amaranticolor. Flexuous filamentous particles 775 nm long were observed with electron microscopy of leaf-dip preparation from symptomatic sponge gourd leaves. The virus particles were then decorated with a second PRSV-W antiserum obtained from the Plant Virology Unit, IARI, New Delhi. PRSV-W on sponge gourd has previously been reported from Taiwan (1). To our knowledge, this is the first report of natural occurrence of PRSV-W on sponge gourd in India. Reference: (1.) C. H. Huang et al. J. Agri. Res. China 36:413, 1987.