bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Fomitiporia punctata Infecting Kiwifruit
Authors: Elena K. , Paplomatas E. J. 
Published: May 2007

During 2000 and 2001, a wood discoloration and decay of 10- to 12-year-old kiwifruit vines (Actinidia deliciosa (Chev.) Liang & Ferguson) was observed in vineyards in all major kiwifruit-growing areas of Greece. Leaves became chlorotic or necrotic, dry, and abscised prematurely. Fruits dropped before reaching full maturity. Necrosis of shoots and twigs progressed from the shoot tips toward the trunk. If the infected twigs were pruned early, the vine occasionally produced new shoots. Cross sections of infected trunks and shoots revealed a light-colored soft rot in the center, surrounded by brown, hard, necrotic wood resembling the esca disease of grapevine, caused by Fomitiporia punctata. From the white rotted areas, a fungus was isolated that formed a dense aerial mycelium with cream-yellow to light-brown colonies on potato dextrose agar (PDA). The fungus was identified as F. punctata (Fr.) Murrill by M. Fischer, Weinbauinstitut, Freiburg-Germany, (personal communication). Pathogenicity tests were performed by artificially inoculating 2-year-old healthy kiwifruit (cv. Hayward) plants. The inoculum consisted of a 7-mm diameter mycelial plug taken from the margin of a 10-day-old culture of F. punctata growing on PDA. A portion of the bark was partially raised from the trunk, and the inoculum was inserted under the bark. The bark was tied with adhesive tape to keep the inoculum in place and sealed with Vaseline to prevent dehydration. Ten plants were inoculated while 10 were used as nonincoculated controls. Wilting of lower leaves was first observed 15 days after inoculation. In longitudinal sections, a brown discoloration on the stem wood was observed 46 days after inoculation in all inoculated vines, while control plants remained healthy. However, the same fungus was isolated from only one infected plant. Low frequency in reisolating F. punctata is often mentioned in the literature (3). Although esca on kiwifruit has been reported in Italy, the fungus initially was identified as Phellinus conchatus and subsequently as F. punctata (1,2). To our knowledge, this is the first published report of F. punctata causing wood decay of kiwifruit. References: (1) F. Calzarano et al. Inf. Fitopatol. 49:12, 1999. (2) S. Di Marco et al. N. Z. J. Crop Hortic. Sci. 28:69, 2000. (3) L. Sparapano et al. Phytopathol. Mediterr. 39:46, 2000.
First Occurrence of Downy Mildew on Digitalis purpurea (Common Foxglove), Caused by Peronospora digitalidis, in California and the United States
Authors: Tjosvold S. A. , Koike S. T. 
Published: May 2007

In California, Digitalis purpurea (common foxglove) and D. grandiflora (yellow foxglove) are grown as cutflower, potted, and landscape plant commodities. In the spring of 2002, after seasonably wet and cool weather, severe downy mildew was observed on potted common foxglove plants in commercial nurseries in coastal California (Santa Cruz County). Initial symptoms on leaves consisted of light green, rectangular areas that were vein-delimited and measured 2 to 5 × 8 to 12 mm. Such spots later became chlorotic. As disease progressed, chlorotic spots coalesced and turned necrotic. The purple-gray sporulation of the pathogen could be seen primarily on abaxial leaf surfaces. However, in some cases, extensive fungal growth developed on adaxial surfaces of lower leaves. Conidiophores branched dichotomously and measured 278 to 520 μm long from the lower end to the first branches and 11 to 14 μm across at the widest part of the swollen base. Branch ends were slender with curved tips that measured 11 to 22 μm long. Conidia were hyaline, ellipsoid to ovoid, and measured 22 to 31 μm × 17 to 19 μm. Oospores were not observed. The pathogen was identified as Peronospora digitalidis (1,2). Pathogenicity tests were not conducted. However, the consistent association of sporulation with symptoms, the internal hyphal growth giving rise to conidiophores, and the obligate nature of Peronospora pathogens clearly indicated that P. digitalidis was the causal agent of this disease. Field observations indicated that D. purpurea cvs. Alba and Apricot and Foxy hybrids were very susceptible, D. × mertonensis ( = D. grandiflora × D. purpurea) appeared to be moderately susceptible, and D. grandiflora grown in the same area was symptomless. One planting of Foxy hybrid was 100% infected, and the entire lot of several hundred plants was discarded. The disease also was found on Foxy hybrid seedlings grown in propagation greenhouses. To our knowledge, this is the first report of downy mildew caused by P. digitalidis on cultivars of D. purpurea in California and the United States. This disease has been reported previously in Europe, Asia, and New Zealand (1,2). References: (1) G. Hall. Mycopathologia 126:47, 1994. (2) E. H. C. McKenzie and J. M. Dingley. N. Z. J. Bot. 34:263, 1996.
Identification of the Fungal Endophyte Epichloe festucae in the Fine Fescue Festuca ampla
Authors: Zabalgogeazcoa I. , Criado B. García , Bony S. 
Published: May 2007

Festuca ampla is native to the Iberian Peninsula (4). Endophytic mycelium was observed by microscopy (2) in stem pith samples of two of eight asymptomatic plants of F. ampla collected in one population from a natural grassland in Salamanca, Spain. The fungus could be isolated (2) only from these two plants, and conidiophores and reniform conidia typical of Epichloe species (3) were observed in pure cultures. The two infected plants maintained in pots outside, developed ectostromata in some reproductive stems (choke disease) the year after the field sampling. Six seeds collected from an infected plant were germinated, and all six seedlings were found to be infected based on microscopy (2), implying seed transmission of the endophyte. These observations suggest that this is a pleiotropic symbiont, having both mutualistic and pathogenic states in its host. An ergovaline concentration of 120 ng/g dry weight was detected in a sample of leaves and leaf sheaths of an infected plant. All of the above characteristics are typical of the genus Epichloe, and in particular of the fine fescue endophyte E. festucae (1,3). To determine the species, internal transcribed spacer and 5.8-rDNA sequences as well as a partial sequence of the β-tubulin gene were obtained. These two sequences (EMBL Accession Nos. AJ488497 and AJ488498) showed 100% sequence homology to the corresponding sequences in E. festucae. To our knowledge, this is the first report of this endophyte species in the grass F. ampla. References: (1) L. P. Bush et al. Plant Physiol. 114:1, 1997. (2) E. M. Clark et al. J. Microbiol. Methods 1:149, 1983. (3) A. Leuchtmann et al. Mycologia 86:802, 1994. (4) I. Markgraff-Dannenberg. Festuca. Pages 125–153 in: Flora Europaea, Vol 5. Cambridge University Press, Cambridge, 1980.
First Report of Web Blight Caused by Rhizoctonia solani on Catharanthus roseus in Louisiana
Authors: Holcomb G. E. , Carling D. E. 
Published: May 2007

Web (aerial) blight was observed in field plots of Catharanthus roseus (L.) G. Don (Madagascar periwinkle) during three consecutive summers at the Burden Research Center in Baton Rouge. Leaf spots formed first, followed by a general blighting of leaves and stems that resulted in circular areas of dead plants in the plots. Dead leaves were matted together but remained attached to plants. Mycelia, and occasionally small, brown sclerotia (1 to 3 mm) were observed on blighted foliage. During the first year, only prostrate-growing cultivars belonging to the Mediterranean series of C. roseus were infected, but in 2001 and 2002 upright-growing cultivars as well as those with prostrate growth habit became infected. The disease occurred in July and August during periods of hot, humid, and rainy weather. Among 52 cultivars in the 2001 trial, only ‘Tropicana Pink’, ‘Tropicana Rose’ and ‘Stardust Orchid’ were disease free. A Rhizoctonia sp. was consistently isolated from diseased plants and further characterized as R. solani Kühn AG-1 based on its multinucleate cells and hyphal anastomosis with several AG-1 tester isolates. On potato dextrose agar, colonies displayed morphologies with characteristics of AG-1 IA and AG-1 IB, therefore, identification to AG subgroup was not made. Mature colonies ranged from light tan to brown and produced sclerotia, individually or in clumps, at the edge of the culture dish. Pathogenicity tests were performed by placing agar blocks, taken from the margins of 7-day-old cultures, on stems of eight healthy Madagascar periwinkle plants (15 to 20 cm tall). Inoculated and noninoculated control plants were held in a dew chamber at 26°C for 3 days and then moved to a greenhouse. Leaves on all inoculated plants developed water-soaked spots that turned dark brown or black prior to death, whereas noninoculated plants remained healthy. R. solani was reisolated from inoculated plants and its cultural characteristics were similar to those of the original isolate. Web blight occurs in Louisiana on Madagascar periwinkle used as landscape bedding plants, but has not been observed on container-grown plants. Web blight caused by R. solani AG-1 was previously reported on Madagascar periwinkle from Alabama (1). R. solani AG-1 has been reported previously as causing web blight in Louisiana on rosemary (2), dianthus (4), and verbena (3). To our knowledge, this is the first report of web blight on Madagascar periwinkle (C. roseus) in Louisiana. References: (1) A. K. Hagan and J. M. Mullen. Plant Dis. 77:1169, 1993. (2) G. E. Holcomb. Plant Dis. 76:859, 1992. (3) G. E. Holcomb and D. E. Carling. Plant Dis. 84:492, 2000. (4) G. E. Holcomb and D. E. Carling. Plant Dis. 84:1344, 2000.
First Report of Bacterial Soft Rot of White Flowered Calla Lily Caused by Erwinia chrysanthemi in Taiwan
Authors: Lee Y.-A. , Chen K.-P. , Chang Y.-C. 
Published: May 2007

In 2002, soft rot symptoms on white flowered calla lily (Zantedeschia aethiopica) were found in some nurseries in the Yang Ming Shan area, Taipei, Taiwan. The disease was characterized by foul smelling rot and collapse of flower stems. Isolations from diseased flower stems consistently yielded bacterial colonies that were translucent, white, and glistening on nutrient agar. Ten representative isolates were chosen for further characterization. All isolates were gram-negative rods, facultatively anaerobic, sensitive to erythromycin (25 μg/ml), negative for oxidase and arginine dihydrolase, and positive for catalase, phosphatase, tryptophanase (indole production), and lecithinase. They fermented glucose and reduced nitrates to nitrites. The maximum temperature for growth was 37°C. The isolates hydrolyzed gelatin and esculin, produced acids from utilizing D(+)-glucose, melibiose, amygdalin, L(+)-arabinose, D-mannitol, and sucrose, but not from trehalose, lactose, D-sorbitol, or maltose. They degraded pectate and rotted potato, carrot, sweet pepper, and onion slices. Bacterial suspensions (108 CFU/ml) were injected in stems of white flowered calla lily to fulfill Koch's postulates. Control plants were inoculated with sterile distilled water. Inoculated plants were kept in a growth chamber at 30°C. Symptoms developed 1 to 2 days in all four inoculated plants and appeared to be identical to those observed on diseased material in nurseries. The four control plants did not rot. The bacterium was readily reisolated from diseased plants, confirmed to be the inoculated pathogen, and identified as Erwinia chrysanthemi. E. carotovora subsp. carotovora has been reported to cause soft rot of other calla lilies, such as Zantedeschia sp. cvs. Black Magic and Pink Persuasion and Z. elliottiana in Taiwan (1). However, to our knowledge, this is the first report of soft rot caused by E. chrysanthemi on white flowered calla lily in Taiwan. Reference: (1) S. T. Hsu and K. C. Tzeng. Pages 9–18 in: Proc. Int. Conf. Plant Path. Bact., 5th. J. C. Lozano, ed. CIAT, Cali, Colombia, 1981.
Occurrence of Potato Powdery Scab Caused by Spongospora subterranea f. sp. subterranea in Costa Rica
Authors: Montero-Astúa M. , Vásquez V. , Rivera C. 
Published: May 2007

Powdery scab of potatoes, caused by Spongospora subterranea (Wallr.) Lagerheim f. sp. subterranea Tomlinson, is important worldwide due to its effect on tuber quality and transmission of Potato mop-top virus. Although powdery scab-like lesions have been observed on potato in Costa Rica (1), the presence of the pathogen has not been confirmed. During a survey in 2001, powdery scab-on was observed from a field and a greenhouse in the high elevation zone of the main potato-producing area of Costa Rica. Commercial potatoes with scab-like lesions were also obtained at a farmers' market. Scraping the lesions, and observing spore balls or cystosori with a honey-comb-like structure under light microscopy confirmed the identity of S. subterranea. The identity of the pathogen was also confirmed by enzyme-linked immunosorbent assay using monoclonal antibodies specific for S. subterranea (BioReba Ag, Reinach, Switzerland). Pathogenicity of S. subterranea was confirmed by a bioassay on tomato plants grown in nutrient solution culture (2). Tomato cv. Supermarmande plants were grown from seed in pots filled with quartz and watered with nutrient solution. Three weeks after planting, the roots were trimmed to 60 mm, and the plants were transferred to the nutrient solution for additional growth. After growing for 1 week in the nutrient solution, tomato seedlings were inoculated by replacing the nutrient solution with nutrient solution containing cystosori (20 mg/liter, wt/vol) that were scraped from the scab lesions. Zoosporangia of S. subterranea were observed in root hairs and epidermal cells of the seedlings 2 weeks after inoculation. To our knowledge, this is the first report that confirms the presence of S. subterranea on potato in Costa Rica. References: (1) R. Amador. Invest. Agri. Costa Rica. 1(1):16, 1987. (2) U. Merz. Bull. OEPP 19:585, 1989.
Report of Bacterial Leaf Spot on Collards and Turnip Leaves in Ohio
Authors: Ivey M. L. Lewis , Wright S. , Miller S. A. 
Published: May 2007

In 2000, circular water-soaked lesions typical of bacterial leaf spot were observed on leaves of collards (Brassica oleracea L. var. viridis) throughout commercial fields in northwest Ohio. Light brown, rectangular, water-soaked lesions were observed on turnip leaves (Brassica rapa L.). Bacterial streaming from lesions on both crops was observed microscopically. Cream colored, fluorescent colonies were isolated from diseased tissues on Pseudomonas F medium, and eight representative colonies (four from collards and four from turnip) were selected and purified. Fatty acid methyl ester analysis was performed on all of the isolates. Two from collards and two from turnip were identified as Pseudomonas syringae pv. maculicola (mean similarity index = 0.82 [MIDI Inc., Newark, DE]). DNA extracts from pure cultures of the P. syringae pv. maculicola strains were used as template in a polymerase chain reaction (PCR) assay with primers derived from the region of the coronatine gene cluster controlling synthesis of the coronafacic acid moiety found in P. syringae pv. tomato and P. syringae pv. maculicola (CorR and CorF2) (D. Cuppels, personal communication). DNA from P. syringae pv. tomato strain DC3000 and P. syringae pv. maculicola strain 88–10 (2) served as positive controls, while water and DNA from Xanthomonas campestris pv. vesicatoria strain Xcv 767 were used as negative controls. The expected 0.65-kb PCR product was amplified from three of four strains (two from turnip and one from collards) and the positive control DNA, but not from the negative controls. Pathogenicity tests were performed twice on 6-week-old turnip (‘Forage Star’, ‘Turnip Topper’, ‘Turnip Alamo’, ‘Turnip 7’), collard (‘Champion’) and mustard (Brassica juncea L. ‘Southern Giant Curl’) seedlings using the three PCR-positive strains. Premisted seedlings were spray-inoculated separately with each of the three strains (2 × 108 CFU/ml, 5 ml per plant) and a water control. Greenhouse temperatures were maintained at 20 ± 1°C. For both tests, all strains caused characteristic lesions on all of the crucifer cultivars within 5 days after inoculation; the control plants did not develop symptoms. To satisfy Koch's postulates, one of the turnip strains was reisolated from ‘Turnip Topper’ plants, and the collard strain was reisolated from ‘Champion’ plants. The three original and two reisolated strains induced a hypersensitive response in Mirabilis jalapa L. and Nicotiana tabacum L. var. xanthia plants 24 h after inoculation with a bacterial suspension (1 × 108 CFU/ml). The original and reisolated strains were compared using rep-PCR with the primer BOXA1R (1). The DNA fingerprints of the reisolated strains were identical to those of the original strains. To our knowledge, this is the first report of bacterial leaf spot on commercially grown collards and turnip greens in Ohio. References: (1) B. Martin et al. Nucleic Acids Res. 20:3479, 1992. (2) R. A. Moore et al. Can. J. Microbiol. 35:910, 1989.
First Report of Pepper mottle virus in Tomato
Authors: Verhoeven J. Th. J. , Willemen T. M. , Roenhorst J. W. 
Published: May 2007

In 2000, a breeding company submitted a tomato (Lycopersicon esculentum) sample from Guatemala for diagnosis. The plants showed necrotic lesions on leaves surrounded by some chlorosis, necrotic streaks on stems, and large superficial necrotic lesions on fruits. By mechanical inoculation of plant sap to different plant species, symptoms appeared in Capsicum annuum ‘Westlandse Grote Zoete’, Lycopersicon esculentum ‘Money-maker’, Nicotiana benthamiana, N. bigelovii, N. glutinosa, N. hesperis-67A, N. occidentalis-P1, N. tabacum ‘White Burley’, and Physalis floridana. Systemically infected leaves from N. occidentalis-P1 were used for all further experiments. Leaf dip preparations were analyzed by transmission electron microscopy and revealed the presence of filamentous virus particles typical of a potyvirus. Double-antibody sandwich enzyme-linked immunosorbent assay tests for Potato virus A, V, and Y, Tobacco etch virus, and Wild potato mosaic virus were negative. An antiserum (PepMoV/DSMZ As 0186) to Pepper mottle virus (PepMoV), however, gave a positive reaction. To obtain further evidence for the presence of this virus, the nucleotide sequence of the complete 3′ nontranslated region (3NTR) and the 3′ terminal part of the coat protein gene (3CPG) was determined using the set of degenerate primers P9502/CPUP (1). The obtained nucleotide sequence (approximately 700 bp) was deposited in GenBank under Accession No. AF440801. It showed 93 to 94% 3NTR and 90 to 93% 3CPG homology with the three sequences of PepMoV from pepper already present in GenBank. The two viruses with the next closest nucleotide sequence homology were Potato virus V and Potato virus Y showing up to 80 and 75% homology with the 3CPG and up to 53 and 48% homology with the 3NTR, respectively. Based on these results, we concluded that the virus isolated from the symptomatic tomato plants was PepMoV. Because of the relatively low homologies with the pepper isolates of PepMoV, this tomato isolate might be a separate strain of the virus. To our knowledge, this is the first report of the occurrence of PepMoV in tomato. Reference: (1) R. A. A. van der Vlugt et al. Phytopathology 89:148, 1999.
First Report of Gray Leaf Spot Caused by Cercospora zeae-maydis on Corn in Ontario, Canada
Authors: Zhu X. , Reid L. M. , Woldemariam T. , Tenuta A. , Schaafsma A. W. 
Published: May 2007

During an annual corn disease survey in mid-September 2001, sporadic symptoms typical of gray leaf spot (causal agent Cercospora zeae-maydis Tehon & E.Y. Daniels) (4), consisting of long, narrow, rectangular, 0.3 to 0.5 × 2 to 5 cm, tan or gray-to-tan spots, were found in nine fields in southern Ontario. Leaf samples with symptoms were placed in petri dishes containing moistened filter paper to maintain high humidity and stored at room temperature for 48 h. Clustered conidiophores arose from stomata on both leaf surfaces. Slightly curved, hyaline conidia, 4 to 8 × 25 to 88 µm long with 3 to 5 septa appeared on the tops of conidiophores, similar to those described by Kingsland (3). When single-spore isolates were cultured on carrot leaf decoction agar (2) at room temperature, aerial mycelia were rare, but slightly larger conidia were produced in 3 weeks. When single-spore isolates were cultured on V8 agar (1) at room temperature, aerial mycelia were abundant, and conidiophores and conidia were produced on the tops of mycelia in 1 to 2 weeks, but conidia were slightly smaller. Greenhouse-grown plants of two commercial corn hybrids (Pioneer 32Y52 and Zimmerman NX7208) were inoculated at the 8- to 10-leaf stage by injecting a suspension of 5 × 103 conidia per ml (washed from a V8 agar culture with sterile water) into the whorl and by spraying the suspension on the leaves. High moisture was maintained in the greenhouse by a misting system. After 14 to 21 days, typical symptoms of gray leaf spot and typical conidiophores and conidia were observed. Gray leaf was reisolated from inoculated plants, fulfilling Koch's postulates. We have suspected that gray leaf spot has been present in Ontario for a few years based on unconfirmed reports from the seed corn industry, but to our knowledge, this is the first confirmed report of this pathogen in Canada. Voucher specimens of field material, dried cultures, and greenhouse-inoculated leaves have been deposited in the National Mycological Herbarium (DAOM 229597 to 229600) in Ottawa, ON, Canada; and the isolate has been deposited with the Canadian Collection of Fungal Cultures (CCFC). References: (1) S. T. Coates et al. Plant Dis. 78:1153, 1994. (2) O. D. Dhingra and J. B. Sinclair. Page 287 in: Basic Plant Pathology Methods. CRC Press, Inc., Boca Raton, FL, 1985. (3) G. C. Kingsland. Plant Dis. Rep. 47:724, 1963. (4) G. P. Munkvold and C. A. Martinson. Page 6 in: Iowa State University Extension Publication Pm-596, Iowa State University Press, Ames, 1994.