bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Clover Proliferation Phytoplasma in Strawberry
Authors: Jomantiene R. , Maas J. L. , Dally E. L. , Davis R. E. , Postman J. D. 
Published: May 2007

In 1996, diseased plants of Fragaria virginiana Duchesne were collected from a native population in Quebec, Canada, and sent to the National Clonal Germplasm Repository in Corvallis, OR, where grafting onto disease-free plants of F. chiloensis (L.) Duchesne (4) was performed. Plants of both species were sent to Beltsville, MD, for identification of a phytoplasma possibly associated with the disease symptoms of dwarfing and multibranching crowns. A phytoplasma was found in both species and characterized as the strawberry “multicipita” (SM) phytoplasma, which is representative of subgroup 16SrVI-B, a new subgroup of the clover proliferation (CP) group (2). In 1999, we observed commercial strawberry (Fragaria × ananassa Duchesne) plants collected in California and Maryland that were stunted and chlorotic or exhibited these symptoms in addition to small, distorted leaves. Infected F. × ananassa plants, as well as diseased F. virginiana and grafted F. chiloensis plants previously infected by the SM phytoplasma, were assessed for phytoplasma infection by nested polymerase chain reactions primed by phytoplasma universal primer pairs R16mF2/R1 and F2n/R2 (1) or P1/P7 (3) and F2n/R2 for amplification of phytoplasma 16S rDNA (16S rRNA gene) sequences. Phytoplasma-characteristic 1.2-kbp DNA sequences were amplified from all diseased plants. No DNA sequences were amplified from healthy plants. Restriction fragment length polymorphism patterns of rDNA digested with AluI, KpnI, HhaI, HaeIII, HinfI, HpaII, MseI, RsaI, and Sau3A1 endonucleases indicated that all plants were infected by a phytoplasma that belonged to subgroup 16SrVI-A (CP phytoplasma subgroup) and that diseased F. virginiana and grafted F. chiloensis plants were infected by both SM and CP. This is the first report of the CP phytoplasma, subgroup 16SrVI-A, infecting strawberry. This report also indicates that the occurrence of the CP phytoplasma in strawberry may be widespread in North America and that F. chiloensis, F. virginiana, and F. × ananassa plants are susceptible to infection by the CP phytoplasma. References: (1) D. E. Gunderson and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (2) R. Jomantiene et al. HortScience 33:1069, 1998. (3) R. Jomantiene et al. Int. J. Syst. Bacteriol. 48:269, 1998. (4) J. D. Postman et al. Acta Hortic. 471:25, 1998.
First Report of Pepper Powdery Mildew Caused by Leveillula taurica in Oklahoma
Authors: Damicone J. P. , Sutherland A. J. 
Published: May 2007

During April 1999, bell peppers (Capsicum annuum L.) from a commercial hydroponics greenhouse in Oklahoma County, OK, were severely affected by powdery mildew caused by Leveillula taurica (Lév.) Arnaud (anamorph Oidiopsis taurica (Lév.) Salmon). Defoliation levels (50 to 75%) were similar for cvs. Valencia, Lavender Islander, Sweet Chocolate, Aladdin, Purple Beauty, Golden Summer, Chocolate Beauty, Early Sunsation, Fat N'Sassy, Lilac, Sweet Rainbow Mix, and Ivory. Fruit from infected plants were small and unmarketable. Newly infected leaves exhibited light powdery colonies that were visible on abaxial leaf surfaces. On older leaves, abaxial leaf surfaces were completely covered by powdery mildew. Severely infected leaves developed chlorotic and necrotic patches on adaxial leaf surfaces prior to leaf drop. L. taurica was identified by the presence of endophytic mycelia, often-branched conidiophores, and dimorphic conidia borne singly or in short chains (1). In 50 measurements of each type, pyriform conidia averaged 67.8 ± 5.3 × 17.9 ± 2.2 μm and cylindrical conidia averaged 62.7 ± 6.2 × 15.7 ± 2.0 μm. Although conidia were slightly longer and narrower than those reported for isolates of L. taurica from pepper in California (2), dimensions were within the range reported for the species (1). The teleomorph of this powdery mildew pathogen was not observed. Peppers were grown from seed on the site. The source of L. taurica for the outbreak and the potential impact of powdery mildew on field production of peppers are unknown. Tomatoes in another hydroponics greenhouse within 100 m were not affected. This is the first report of L. taurica in Oklahoma. References: (1) H. J. Boesewinkel. Bot. Rev. 46:167, 1980. (2) J. C. Correll et al. Plant Dis. 71:248, 1987.
First Report of Clover Yellow Edge and STRAWB2 Phytoplasmas in Strawberry in Maryland
Authors: Jomantiene R. , Maas J. L. , Dally E. L. , Davis R. E. 
Published: May 2007

Commercial strawberry (Fragaria × ananassa Duchesne) plants that were either chlorotic and severely stunted or exhibiting fruit phyllody were collected in Maryland. The plants were assessed for phytoplasma infection by nested polymerase chain reactions primed by phytoplasma universal primer pairs R16mF2/R1 and F2n/R2 (2) or P1/P7 (3) and F2n/R2 for amplification of phytoplasma 16S ribosomal (r) DNA (16S rRNA gene) sequences. Phytoplasma-characteristic 1.2-kbp DNA sequences were amplified from all diseased plants. No phytoplasma-characteristic DNAs were amplified from healthy plants. Restriction fragment length polymorphism patterns of rDNA digested with AluI, KpnI, HhaI, HaeIII, HpaII, MseI, RsaI, and Sau3A1 endonucleases indicated that chlorotic and stunted plants were infected by a phytoplasma that belonged to subgroup 16SrIII-B (clover yellow edge [CYE] subgroup) and that the plant exhibiting fruit phyllody was infected by a phytoplasma that belonged to subgroup 16SrI-K (STRAWB2 subgroup). The STRAWB2 phytoplasma was first reported from strawberry plants grown in Florida and characterized as representative of a new subgroup of the aster yellows group, 16SrI (3); this is the first report of this phytoplasma occurring in strawberry outside of Florida. A STRAWB2-infected plant produced phylloid fruits in two consecutive years of observation in the greenhouse; the plant previously had been field-grown in a breeder's evaluation plots in Beltsville, MD. The CYE phytoplasma was first experimentally transmitted by leafhopper to commercial strawberry and F. virginiana Duchesne in Ontario Canada (1); this is the first report of natural CYE phytoplasma infection of strawberry in Maryland. CYE phytoplasma-infected plants, representing ≈5% of the total number of plants of one advanced sselection, were located in a breeder's evaluation plots in Beltsville. References: (1) L. N. Chiykowski. Can. J. Bot. 54:1171, 1976. (2) D. E. Gunderson and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (3) R. Jomantiene et al. Int. J. Syst. Bacteriol. 48:269, 1998.
First Report of Gray Leaf Spot (Pyricularia grisea) on Perennial Ryegrass (Lolium perenne) in New England
Authors: Schumann G. L. , Jackson N. 
Published: May 2007

Pyricularia grisea (Cooke) Sacc. causing significant damage in perennial ryegrass (Lolium perenne L.) was first observed on a golf course in eastern Maryland in 1985 by P. H. Dernoeden, but there is no published account. The first published report of the problem was from southeastern Pennsylvania in 1991 (1). There were scattered reports of gray leaf spot in several other states in 1991. A more severe and widespread epidemic occurred under similar environmental conditions throughout the mid-Atlantic region in 1995 and has reoccurred to some extent annually since then in an expanding area throughout the United States. This report documents the expansion of the northern range of the epidemic into New England. Samples of perennial rye-grass with gray leaf spot from golf courses in three towns in Connecticut (Norwich, Stratford, and Willamantic) and one in Rhode Island (West Warwick) were submitted to the diagnostic labs at the universities of Massachusetts and Rhode Island beginning on 22 September 1998. Severe gray leaf spot was observed in perennial ryegrass fairways and roughs, especially where new seedlings were present, causing turf loss exceeding 50% in some areas. Diagnosis of this now familiar disease is based on the presence of abundant sporulation of the pathogen on infected tissue, distinctive leaf symptoms, and rapid foliar blighting of only perennial ryegrass in plantings of mixed turfgrass species. Golf course superintendents in New England with perennial ryegrass may have to extend their late-season fungicide applications to accommodate this new and destructive late-summer and fall disease. Reference: (1) P. J. Landschoot and B. F. Hoyland. Plant Dis. 76:1280, 1992.
First Occurrence of Alternaria alternata on Gypsophila paniculata in Bulgaria
Authors: Margina A. F. , Bobev S. G. , de Gruyter J. 
Published: May 2007

During late summer 1996 to 1997, 27 to 30% of Gypsophila paniculata (baby's-breath) plants were noted as diseased in an experimental field (Kazanlak, Bulgaria). Symptoms on lower and middle leaves consisted of small circular spots, with light brown centers and reddish purple margins. Development of numerous spots (which grew larger) and, especially, damage to the midrib led to withering of leaflets. Conidiophores of the isolated fungus were dark, formed singly or in clusters, were unbranched with three to eight septa, and were 40 to 120 µm long. Conidia, produced in branched chains (four to six conidia or longer), were brown, globose, and ovate to pyriform with short beaks, contained four to five transverse and zero to two longitudinal septa, and were 36.6 to 46.6 × 10.0 to 13.3 µm. The fungus was identified as Alternaria alternata. Pathogenicity was confirmed by artificial inoculation of potted G. paniculata and Dianthus caryophyllus plants. Conidia (2 weeks old) produced on potato dextrose agar were sprayed on plants in a 5 × 103 suspension, and plants were incubated at 20 to 24°C in a moist chamber for 2 days. Lesion development in both plant species was observed and recorded at 4 to 5 and 6 to 7 days after inoculation, respectively. Lesions were most numerous on G. paniculata. This is the first report of A. alternata on baby's-breath in Bulgaria. References: (1) M. B. Ellis. 1971. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, U.K. (2) E. G. Simmons. Alternaria themes and variations. Mycotaxon 37:79, 1990.
First Report of Thyronectria austroamericana Canker on Thornless Honey Locust in North Carolina
Authors: Grand L. F. , Vernia C. S. , Hodges C. S. 
Published: May 2007

Specimens from a thornless honey locust (Gleditsia triacanthos var. inermis ‘Shade Master’) with cankers were submitted in May 1999 to the North Carolina State University Plant Disease and Insect Clinic by staff from the North Carolina Zoological Park (Asheboro). Abundant stromata of Gyrostroma austroamericana, the anamorph of Thyronectria austroamericana, were associated with the cankers. A visit to the Zoological Park during August 1999 revealed seven additional honey locust trees with multiple branch and stem cankers and dieback. All infected trees had perithecia of T. austroamericana and/or its anamorph. The fungus is distinguished by the large clusters of yellow-brown perithecia with dark brown tips produced on stromata emerging from lenticels, elliptical muriform ascospores, and sparse ascoconidia (1,2). Ascoconidia form as the result of ascospores budding within the ascus. Other trees of the cultivar are an integral part of the landscaping theme of the African Pavilion of the park, and park staff were concerned about disease spread. Infected trees were 8 years old, and several had evidence of sunscald cankers, a common infection court of T. austroamericana (2). Thornless cultivars of honey locust are popular landscape plants in the central and eastern United States and may be seriously affected by T. austroamericana (2). Apparently ‘Shade Master’ is very susceptible to the fungus and should not be used as a landscape tree, especially where the disease has been reported. This is the first report of T. austroamericana in North Carolina on any host. Voucher specimens have been deposited in the National Fungus Collection, Beltsville, MD (BPI 74693), and in the Mycological Herbarium, Department of Plant Pathology, North Carolina State University, Raleigh. References: (1) E. V. Seeler, Jr. J. Arnold Arbor. Harv. Univ. 21:429, 1940. (2) W. A. Sinclair et al. 1993. Diseases of Trees and Shrubs. Cornell University Press, Ithaca, NY.
Gliocladium catenulatum in Association with Sclerotium cepivorum on Onion Leaves in Ghana
Authors: Tsigbey F. K. , Nutsugah S. K. , Ritchie Barbara J. 
Published: May 2007

During a regular survey of diseases in farmers' fields of onion (Allium cepa L.) in the Upper East Region of Ghana in March 1997, bulbs infected with white rot disease were collected for identification. A portion of the white mycelium present on the onion scale was cultured on potato dextrose agar (PDA). After 2 days of incubation, white fluffy mycelium was observed that later developed black sclerotia on the colony surface to confirm the identity of Sclerotium cepivorum. Ten days later, an unknown fungus was observed growing from the original inoculation point of the S. cepivorum mycelium. Pure cultures of the unknown fungus grown on PDA were sent to CAB International, UK, and identified as Gliocladium catenulatum Gilman and Abbott (1). G. catenulatum grew along the mycelia of S. cepivorum and completely suppressed its growth. In culture, G. catenulatum colonized sclerotia of S. cepivorum and rendered them mushy and easy to crush, whereas the uncolonized sclerotia remained firm and difficult to crush. The uncolonized sclerotia when transferred onto PDA produced the white fluffy mycelial growth typical of S. cepivorum; the colonized did not grow at all. G. catenulatum also reduced colony growth, sclerotia formation, and maturation of S. cepivorum. Cultures of S. cepivorum inoculated with G. catenulatum measured 3 cm in diameter after 3 days of incubation and exhibited sparse mycelial growth, while cultures of S. cepivorum measured 5 cm in diameter after 3 days of incubation and produced a fairly even sheet of abundant, fluffy mycelial growth. Sclerotia were produced profusely in pure cultures of S. cepivorum whereas those of G. catenulatum and S. cepivorum in combination produced only two sclerotia after 6 days and these were later colonized by G. catenulatum. A striking characteristic of G. catenulatum was the production of a yellow pigmentation around the colony margins. Species within the genus Gliocladium are known to be antagonistic to, and parasitic on, other fungi. The antagonistic and/or parasitic nature of G. catenulatum on S. cepivorum suggests a possible role in biological control. This is the first report of G. catenulatum in association with S. cepivorum on onion in Ghana. Reference: (1) J. C. Gilman and E. V. Abbott. Iowa State College J. Sci. 1:225, 1927.
Occurrence of Leaf Blotch and Stem-End Rot of Strawberry in the Central Coast of California
Authors: Gubler W. D. , Feliciano A. J. 
Published: May 2007

Leaf blotch and stem-end rot caused by Gnomonia comari P. Karst. (anamorph, Zythia fragariae Laibach) were observed in a strawberry fruit production field at Watsonville, CA, in 1996. Z. fragariae has been known for years to attack leaves and cause leaf blotch but this is the first time that the perfect stage, G. comari, was identified and documented to infect fruits and cause stem-end rot in California. Symptoms on leaves included pin-point lesions, brownish to purplish blotches, and characteristic large V-shaped lesions. On the fruit, infection showed more frequently on the calyx. Symptoms on the calyx ranged from small lesions on the sepals to a completely infected calyx that turned necrotic and brittle. Calyx infection was observed on seemingly healthy green and ripe fruits. Infected fruits ripened prematurely and turned pale red to brownish in color. They remained firm but were often invaded by secondary organisms including Botrytis cinerea. When infected leaves and fruits were surface sterilized and incubated under humid condition, perithecia and pycnidia readily developed on the lesions. Ascospores oozed from the tip of the perithecial neck while numerous spores oozed out of the pycnidium. The pathogen was identified as G. comari based on size and morphology of the perithecia, asci, and ascospores (1), and the spores were identified as Z. fragariae based on morphology of the conidia and conidiophores (2). Both the spores and ascospores produced pycnidia and perithecia on potato dextroxe agar at room temperature. Inoculation of healthy leaves and fruits with each fungus resulted in development of symptoms of leaf blotch and stem-end rot similar to those observed in the field. G. comari and Z. fragariae were reisolated from newly developing lesions on symptomatic leaves and fruits. Since 1996, stem-end rot has been observed more frequently in fruit production areas in the central coast of California, particularly during wet years. Reference: (1) A. Bolay. Ber. Schweiz. Bot. Ges. 81:398, 1971. (2) J. Fall. Can. J. Bot. 32:172, 1954.
First Report of Sweetpotato Scurf Caused by Monilochaetes infuscans in Italy
Authors: Di Lenna P. , Mascarello N. , Xodo E. 
Published: May 2007

In the last few years, in the Treviso area, the incidence and severity of a sweetpotato (Ipomoea batata) disease has increased to become a serious economic threat to this crop. The symptoms are small, dark brown to black spots on the surface of fleshy storage roots that under high relative humidity coalesce to completely cover the root surface. Affected roots may also develop small cracks and shrink in storage. In the past, the same symptoms were observed, but the low incidence of the disease did not cause significant economic losses, and therefore it was not considered worthy of investigation. In August 1998, an investigation was initiated to determine the causal agent of the disease and to provide growers with effective control strategies. Since the symptoms were similar to those incited by Monilochaetes infuscans, agent of sweetpotato scurf (1), samples of roots were collected and examined for the presence of the pathogen. Even though it is difficult to isolate, M. infuscans was consistently present in infected tissues. In pure culture on potato dextrose agar the pathogen formed typical, raised, domelike, dark gray to black colonies. Conidiophores were brown to black, unbranched, and support straight or curled chains of hyaline conidia. Traditional cultivation methods that ignore sanitary conditions probably caused the gradual increase in the incidence and severity of the disease. Sweetpotato scurf is common in the U.S., Japan, and some Pacific islands, but it has not been previously recorded in Italy. Reference(1): C. A. Clark and J. W. Moyer. 1988. Compendium of Sweet Potato Diseases. American Phytopathological Society, St. Paul, MN.
Occurrence of Colletotrichum acutatum, Causal Organism of Strawberry Anthracnose in Southwestern Spain
Authors: de los Santos G de Paredes B. , Romero Muñoz F. 
Published: May 2007

A wilting disease of strawberry (Fragaria × ananassa Duchesne ‘Oso Grande’) was observed in production fields in Huelva, southwestern Andalucía, Spain. Crowns of wilted plants developed a reddish brown, firm rot. Longitudinal sections of roots of diseased plants showed a black coloration of the cortex. Symptons also included blighting of flowers due to floral infection and rotting of green and ripening fruits. On the fruit, the round, firm sunken lesions were covered with masses of salmon-colored spores. Lesions on the leaves were round, ranged in diameter from 5 to 10 mm, and were light brown with purple edges. Infected tissues were surface disinfected in 20% sodium hypoclorite, blotted dry, and plated on water agar. Dishes were incubated at 25°C; hyphal tips made of fungi growing from lesions were transferred to potato dextrose agar (PDA) and incubated under cool-white fluorescent light at 25°C. One fungus was isolated consistently from lesions on different tissues. It was identified as Colletotrichum acutatum by morphological characteristics (2) and enzyme-linked immunosorbent assay (1). On PDA, the mycelium of the fungus was white to gray and covered with salmon spore masses. Colony diameters on PDA averaged 45 mm after 7 days at 25°C. Hyaline, aseptate conidia were cylindrical, fusiform, and intermediate in shape and averaged 12.8 × 4.2 μm in size. The fungus produced setae on infected fruit. Inoculations of strawberry cvs. Oso Grande and Chandler with conidial suspensions (106 conidia per ml) of C. acutatum produced lesions on the fruit, petioles, and crowns, and caused wilt. The pathogen was reisolated from lesions on the inoculated plants. This is the first report of C. acutatum causing strawberry anthracnose in Huelva. References: (1) T. A. Cooke et al. EPPO Bulletin 25:57, 1995. (2) B. C. Sutton. The Coelomycetes. CMI, Kew, England, 1980.
First Report of Powdery Mildew of Pepper in North-Central Mexico
Authors: Velásquez-Valle R. , Valle-Garcia P. 
Published: May 2007

Pepper plants showing general yellowing and white spots on the lower surface as well as brown spots on the upper surface of the lowest leaves were observed during the 1998 crop season in the states of Chihuahua, Zacatecas, and Aguascalientes (north central area of México). Light defoliation was observed. Samples were collected in Chihuahua and Zacatecas to identify the pathogen, which showed navicular conidia. A conidial suspension was sprayed on pepper varieties, but only Hungarian Yellow Wax showed powdery mildew lesions. The average size of the conidia from Zacatecas was 61.2 × 18.2 μm while those from Chihuahua measured 58.2 × 17.6 μm, which is coincident with the description given for an Oidiopsis sp. The perfect stage is Leveillula taurica (1). Cleistothecia were not observed. In Zacatecas the disease was not detected in tomato fields or in sowthistle (Sonchus oleraceae) plants contiguous to, or within, infected pepper fields. Powdery mildew incidence ranged from 35 to 80% in Ancho type and from 0 to 55% in Mirasol type pepper fields in Zacatecas. The number of powdery mildew lesions per leaf in most cases varied from 1 to 3. Incidence was higher in fields where the canopy was closed and warmer and wetter conditions may have allowed the disease to progress. Reference: (1) J. B. Jones et al. 1991. Compendium of Tomato Diseases. American Phytopathological Society, St. Paul, MN.
First Report of Pea Enation Mosaic Virus Affecting Lentil (Lens culinaris) in Syria
Authors: Makkouk Khaled M. , Kumari Safaa G. , Bayaa Bassam 
Published: May 2007

Symptoms suggestive of virus infection in lentil (Lens culinaris Medik.) fields in Dara'a in southern Syria have been observed, in epidemic proportions, almost annually since 1994. A similar epidemic was observed on many lentil genotypes at the ICARDA farm, near Aleppo, as well as in other locations in northern Syria during 1998. Symptoms included growth reduction and rolling of leaves, accompanied by mottling with tip wilting or necrosis. Field symptoms were reproduced on lentil cv. Syrian Local upon mechanical inoculation of plants with inoculum from symptomatic field plants. Transmission tests showed that the disease agent can be transmitted from lentil to lentil, pea (Pisum sativum L.), and faba bean (Vicia faba L.) plants by the pea aphid (Acyrthosiphon pisum Harris) in a persistent manner. More than 500 symptomatic lentil plants were collected and tested for the presence of 14 different viruses by the tissue-blot immunoassay (TBIA) (2). Around 80% of the samples reacted only with antiserum to pea enation mosaic virus (PEMV), a Dutch isolate (E1540) provided by L. Bos, Wageningen, The Netherlands (1). Surveys conducted during the 1997/1998 growing season showed that PEMV was widely distributed in the major lentil-growing areas of Syria: some lentil fields had more than 50% virus incidence. This is the first record of PEMV naturally infecting lentil in Syria. References: (1) K. Mahmood and D. Peters. Neth. J. Plant Pathol. 79:138, 1973. (2) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994.