bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Fusarium verticillioides on Kenaf in South Africa
Authors: Swart W. J. , Tarekegn G. 
Published: May 2007

Kenaf (Malvaceae; Hibiscus cannabinus L.) is being commercially cultivated in Winterton, South Africa for its high-quality cellulose fibers with approximately 2,000 ha currently under cultivation. In 2004, 25% of 1-month-old kenaf plants grown from seed were observed in the field with severe wilting followed by lodging and mortality within 1 week. Isolations from diseased stem and root tissue on malt extract agar (MEA) consistently yielded Fusarium verticillioides (Sacc.) Nirenberg (2). Pathogenicity tests were conducted by inoculating kenaf seedlings with inoculum prepared from barley grains that had been colonized by the pathogen in vitro for 2 weeks prior to being finely ground in a laboratory mill. Fifty seeds from each of eight kenaf cultivars were incubated at 25°C on sterile filter paper to ensure germination and the absence of pathogens. Germinated seeds were sown in pots (400 cm3) containing steam sterilized loam soil (200 g) by placing 20 germinated seeds from each cultivar, with four replicates (5 seeds per pot), on the soil in each pot and covering them with 100 g of the same soil. Inoculum powder was sprinkled on the surface of the soil in each pot and covered by 100 g of soil. Pots were maintained in a glasshouse at an ambient temperature of 25°C. Sterile ground barley seeds served as the control treatment. Pots were watered daily with 20 ml of water and observed periodically for seedling emergence. The percentage of diseased seedlings was recorded after 3 weeks and the experiment was repeated. Wilting had occurred in 85% of seedlings when they were approximately 4 cm high and all diseased seedlings had died within 1 week thereafter. Subsequent examination revealed dark brown lesions girdling the stem and decayed roots in all instances. No symptoms developed on control plants. From means of combined data, the greatest seedling mortality was observed for cv. Gregg (65%) and the least for cv. Cuba108 (5%). Mean mortalities for the remaining six cultivars ranged from 30 to 55%. The pathogen was reisolated on MEA from all diseased seedlings. To our knowledge, this is the first report of F. verticillioides occurring on kenaf in South Africa. The only other report of Fusarium sp. causing serious damping-off of kenaf is from Iran (1). The potential impact of the pathogen on kenaf production in South Africa must be considered in the implementation of disease control measures. References: (1) J. M. Dempsey. Kenaf. In: Fiber Crops. The University Press of Florida, Gainesville, 1975. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006.
Basal Rot of Hylocereus undatus Caused by Fusarium oxysporum in Buenos Aires, Argentina
Authors: Wright E. R. , Rivera M. C. , Ghirlanda A. , Lori G. A. 
Published: May 2007

Night-blooming cereus (Hylocereus undatus A. Berger) is generally used as rootstock of ornamental cactus because of its rapid growth and tolerance to humid substrates. Since 2002, in Gran Buenos Aires, a new disease has been observed in grafted crops in all production stages. Incidence was as much as 30% in many greenhouses. Symptoms consisted of soft rot that started near the soil line and developed upward until it affected all the rootstock. The scion was not rotten, but died as a consequence of rootstock infection. All the roots were symptomless. For pathogen isolation, symptomatic tissues were surface disinfected by a 1-min immersion in 0.2% NaOCl, placed on potato dextrose agar (PDA), and incubated at 22 ± 2°C. Only a Fusarium spp. was consistently isolated in pure culture. Twenty healthy potted night-blooming cereus plants, 10 of them previously injured with needles on the rootstock near the soil line, were gently removed from the substrate and inoculated by a 1-min immersion of their base in a suspension of 1.4 × 106 conidia per ml of sterile distilled water, prepared from 15-day-old cultures. Ten control plants, five of them previously injured, were immersed in sterile distilled water. Inoculated and noninoculated plants were replanted in the original substrate, placed in a climatic chamber at 22 ± 2°C, and monitored for disease expression. Basal rot was observed on all injured inoculated plants 12 days after inoculation. Symptoms on undamaged plants appeared 22 days after inoculation. After 72 days of incubation, all inoculated plants were totally rotten. Control plants remained symptomless. The same pathogen was reisolated to fulfill Koch's postulates. For species identification, single-spore cultures were grown on PDA and carnation leaf agar in a climatic chamber at 23 ± 2°C with a 12-h darkness/near ultraviolet light regimen. The micromorphology and culture features, mainly conidial ontogeny, were consistent with descriptions of Fusarium oxysporum Schlechtend.:Fr. (1). The pathogen was able to penetrate undamaged tissues. Needle injuries accelerated infection. To our knowledge, this is the first report of Fusarium oxysporum on H. undatus in Gran Buenos Aires, Argentina. A culture of the pathogen was deposited at the fungal collection of PRHIDEB-CONICET (University of Buenos Aires) as BAFCult 3158. Reference: (1) P. E. Nelson et al. Fusarium species. An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, PA, 1983.
First Report of the Pale Cyst Nematode, Globodera pallida, in the United States
Authors: Hafez S. L. , Sundararaj P. , Handoo Z. A. , Skantar A. M. , Carta L. K. , Chitwood D. J. 
Published: May 2007

In 2006, a cyst nematode was discovered in tare dirt at a potato (Solanum tuberosum) processing facility in eastern Idaho. The nematode was found during a routine survey conducted jointly by the Idaho State Department of Agriculture and the USDA Animal and Plant Health Inspection Service through the Cooperative Agricultural Pest Survey program. Extensive additional sampling from two suspect fields led to the identification of the same nematode in a 45-acre (18.2-ha) field located in northern Bingham County. The morphology of cysts and second-stage juveniles and molecular analyses established the identity of the species as the pale cyst nematode Globodera pallida (Stone 1973) Behrens 1975. Morphological characters used for identification included cyst shape, characteristics of cyst terminal cone including nature of fenestration, cyst wall pattern, anal-vulval distance, number of cuticular ridges between anus and vulva, and Granek's ratio (1,4). The second-stage juvenile morphologies critical for identification were the following: body and stylet length, shape of stylet knobs, shape and length of tail and hyaline tail terminus, and number of refractive bodies in the hyaline part of tail (1,4). Diagnosis as G. pallida was clearly confirmed by two molecular tests. First, PCR-RFLP (restriction fragment length polymorphism) profiles of a ribosomal DNA fragment using restriction enzymes RsaI, TaqI, and AluI (2) were consistent with a G. pallida control and not G. rostochiensis. Second, the ribosomal DNA region that extends from the 3′ end of the 18S ribosomal subunit and includes all of ITS1, 5.8S, and ITS2 to the 5′ end of the 28S ribosomal subunit was used to generate sequence for the most accurate species determination. Sequences obtained from three individual juveniles were compared with those from several Globodera species (3), revealing unequivocal similarity to G. pallida. This detection represents a new country record for G. pallida in the United States. Collection of additional information regarding distribution of this nematode within the region is underway. References: (1) J. G. Baldwin and M. Mundo-Ocampo. Heteroderinae, Cyst- and Non-cyst-forming Nematodes. Pages 275-362 in: Manual of Agricultural Nematology. W. R. Nickle, ed. Marcel Dekker, New York, 1991. (2) V. C. Blok et al. J. Nematol. 30:262, 1998. (3) L. A. Pylypenko et al. Eur. J. Plant Pathol. 111:39, 2005. (4) A. R. Stone. Nematologica 18:591, 1973.
First Report of Phakopsora pachyrhizi, Cause of Soybean Rust, on Neonotonia wightii in Paraguay
Authors: Morel W. , Miles M. R. , Hernández J. R. , Stone C. L. , Frederick R. D. 
Published: May 2007

Phakopsora pachyrhizi Syd. & P. Syd., the cause of soybean rust, was first observed on soybean (Glycine max (L.) Merr.) in South America in the district of Itapúa in Paraguay during March, 2001 (2). The disease is now widespread in soybean-production areas in South America on soybean and kudzu (Pueraria lobata (Willd.) Ohwi). On 15 March 2006, leaves of the perennial legume Neonotonia wightii (Graham ex Wight & Arn.) Lackey with lesions and rust sori were observed in the Reserva Biológica de Itabó, Departamento Alto Paraná. Lesions were scattered, most contained a single uredinium, mostly hypophyllous, and appeared to be new infections. Lesions with several uredinia, which are indicative of older infections on soybean, were also observed. Sori (Malupa-type) contained hyaline, peripheral, cylindric to clavate paraphyses measuring 24 to 45 × 6 to 13 μm and urediniospores that were hyaline, ovoid to globose, and measuring 20 to 40 × 14 to 25 μm with an echinulate spore wall, characteristics typical of a Phakopsora sp. DNA extracted from sori from leaves of N. wightii was amplified in a real-time fluorescent polymerase chain reaction with the P. pachyrhizi-specific primers Ppm1 and Ppa2 (1). Sequence alignment of the internal transcribed spacer region 2 further confirmed the identification as P. pachyrhizi (1). The host identification was confirmed by J. Kirkbride, USDA/ARS/SBML, using the Smithsonian Institution Department of Botany, U.S. National Herbarium. To our knowledge, this is the first confirmed report of natural infection of P. pachyrhizi on a host other than soybean or kudzu in South America. Voucher specimens were deposited in the herbarium of the Facultad Ciencias Químicas of the Universidad Nacional de Asunción of Paraguay (FCQ) and the National Fungus Collection (Accession No. BPI 875340). References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) W. Morel and J. Yorinori. Bol. Divulg. No. 44. Ministerio de Agricultura y Ganadería, Centro Regional de Investigación Agrícola, Capitán Miranda, Paraguay, 2002.
First Report on the Natural Occurrence of Beet chlorosis virus in Poland
Authors: Kozlowska-Makulska A. , Szyndel M. S. , Syller J. , Bouzoubaa S. , Beuve M. , Lemaire O. , Herrbach E. 
Published: May 2007

Yellowing symptoms on sugar beet (Beta vulgaris L.) are caused by several viruses, especially those belonging to the genus Polerovirus of the family Luteoviridae, including Beet mild yellowing virus (BMYV) and Beet western yellows virus (BWYV), and recently, a new species, Beet chlorosis virus (BChV), was reported (2). To identify Polerovirus species occurring in beet crops in Poland and determine their molecular variability, field surveys were performed in the summer and autumn of 2005. Leaves from symptomatic beet plants were collected at 26 localities in the main commercial sugar-beet-growing areas in Poland that included the Bydgoszcz, Kutno, Lublin, Poznań, Olsztyn, and Warszawa regions. Enzyme-linked immunosorbent assay (ELISA) tests (Loewe Biochemica GmbH, Sauerlach, Germany) detected poleroviruses in 23 of 160 samples (approximately 20 samples from each field). Multiplex reverse-transcription polymerase chain reaction (RT-PCR) (1) (GE Healthcare S.A.-Amersham Velizy, France) confirmed the presence of poleroviruses in 13 of 23 samples. Nine of twenty sugar beet plants gave positive reactions with BChV-specific primers and three with primers specific to the BMYV P0 protein. Two isolates reacted only with primer sets CP+/CP, sequences that are highly conserved for all beet poleroviruses. Leaf samples collected from three plants infected with BChV were used as inoculum sources for Myzus persicae in transmission tests to suitable indicator plants including sugar beet, red beet (Beta vulgaris L. var. conditiva Alef.), and Chenopodium capitatum. All C. capitatum and beet plants were successfully infected with BChV after a 48-h acquisition access period and an inoculation access period of 3 days. Transmission was confirmed by the presence of characteristic symptoms and by ELISA. Amino acid sequences obtained from each of four purified (QIAquick PCR Purification kit, Qiagen S.A., Courtaboeuf, France) RT-PCR products (550 and 750 bp for CP and P0, respectively) were 100% identical with the CP region (GenBank Accession No. AAF89621) and 98% identical with the P0 region (GenBank Accession No. NP114360) of the French isolate of BChV. To our knowledge, this is the first report of BChV in Poland. References: (1) S. Hauser et al. J. Virol. Methods 89:11, 2000. (2) M. Stevens et al. Mol. Plant Pathol. 6:1, 2005.
First Record of the Perfect Stage Calonectria pauciramosa on Mastic Tree in Italy
Authors: Vitale A. , Polizzi G. 
Published: May 2007

Leaf spots, stem lesions, crown rot, and root rot, caused by heterothallic fungus Cylindrocladium pauciramosum C.L. Schoch & Crous,, on young plants in a nursery represent an important problem in many representative ornamental plant-growing areas of Italy since the disease was first reported in 1993 (2). Symptoms observed during surveys in Italy from 1993 to 2005 were attributed solely to the asexual stage, and the teleomorph (Calonectria pauciramosa C.L. Schoch & Crous) was never found. In October 2005, orange-to-red brown fungal fruiting bodies pertaining to the genus Calonectria were observed in belowground regions and at the soil line on collar and stem tissues of seedlings of the mastic tree (Pistacia lentiscus L., Anacardiaceae) affected by damping off in two nurseries of eastern Sicily. The sexual structures were solitary or in groups, orange-to-red brown, subglobose to ovoid. On the basis of 50 microscopic observations of leaf tissues, they ranged from 180 to 280 μm in diameter and from 270 to 400 μm high. In the presence of adequate moisture, ascospores were discharged from mature perithecia in visible, viscous, and white droplets. Asci containing eight ascospores were clavate and tapering to a long thin stalk. Fusoid ascospores were hyaline and guttulate with rounded ends, slightly curved, 1-septate, not or slightly constricted at the septum, and measured 33 to 39 μm long and 6 to 8 μm wide. However, measurements show that perithecia, asci, and ascospores also fall within the range described by Schoch et al. (3). Single ascospore cultures did not produce perithecia. On the basis of these descriptions and the ability of single-ascospore cultures to mate with two Italian (DISTEF-G87 and DISTEF-G128) and two South African (STE-U 971 and STE-U 1670) selected tester strains of Cylindrocladium pauciramosum (2), the perithecia were identified as C. pauciramosa. To our knowledge, this is the first natural occurrence of the perfect stage of Cylindrocladium pauciramosum in Italy. The presence of the teleomorph is very important because it represents a second means of spread after conidia. Furthermore, the occurrence of the teleomorph also could lead to a 1:1 mating type ratio. In this case, lower percentages of hermaphrodites should be expected (1,4). References: (1) G. Polizzi et al. J. Plant Pathol. 80:262, 1998. (2) G. Polizzi and P. W. Crous. Eur. J. Plant Pathol. 105:413, 1999. (3) C. L. Schoch et al. Mycologia 91:286, 1999. (4) C. L. Schoch et al. Plant Dis. 85:941, 2001.
First Report of Cephalosporium gramineum, Causal Agent of Cephalosporium Stripe of Wheat, in a Commercial Winter Wheat Field in Virginia
Authors: Schmale D. G. , Wood-Jones A. K. , Hansen M. A. , Stromberg E. L. , Roane C. W. 
Published: May 2007

Cephalosporium stripe (CS) (2) was identified in a commercial field of winter wheat (Triticum aestivum) near Riner, Montgomery County, Virginia in May 2006. Nearly 15% of the field was severely affected. Broad, yellow-brown stripes were observed on the leaf blades of affected plants, and many plants were stunted and had ripened prematurely. Symptomatic plants were associated with low acidic (pH 5.2), wet spots of the field. Leaves and nodes of affected plants were surface disinfested for 1 min in 5% sodium hypochlorite, plated on corn meal agar (CMA), and incubated at 20°C for 5 days. Cephalosporium gramineum was isolated from numerous plants. Cultures of the fungus produced hyaline conidiophores approximately 5 μm long and unicellular conidia 3 to 7 μm long. Aqueous suspensions of mycelia and conidia were prepared from pure cultures. Several spring wheat cultivars were wounded by severing the root mass and were inoculated when the fifth stem node was detectable (35 on Zadoks scale). Noninoculated plants were wounded as controls. Plants were kept in the greenhouse at temperatures of 22 to 27°C. After 14 days, inoculated plants produced symptoms of CS, and the fungus was reisolated from the leaves of these plants. No symptoms were observed on noninoculated control plants. Though CS had been observed in Virginia in research nurseries (1), to our knowledge, this is the first confirmed report of the disease in a commercial wheat field in Virginia. References: (1) J. B. Jones et al. Plant Dis. 64:325, 1980. (2) C. M. Stiles and T. D. Murray. Phytopathology 86:177, 1996.
First Report of Impatiens necrotic spot virus in Ornamental Plants in Hungary
Authors: Tóth E. K. , Kriston É. , Takács A. , Bajtek M. , Kazinczi G. , Horváth J. 
Published: May 2007

Economically important viruses such as Tomato spotted wilt virus, genus Tospovirus, are transmissible mechanically and mainly by two thrips species (Thrips tabaci and Frankliniella occidentalis) in Hungary (1). Samples (31) of eight ornamental plant species (Catharanthus roseus, Cyclamen persicum, Dendranthema × grandiflorum, Eustoma grandiflorum, Gerbera sp., Impatiens walleriana, Ocimum basilicum, and Verbena hybrida) were studied. Symptoms including color breaking on flowers and necrotic symptoms on leaves were observed on four samples (C. persicum, I. walleriana, O. basilicum, and E. grandiflorum). Infection by Impatiens necrotic spot virus (INSV) was determined by double-antibody sandwich-ELISA and triple-antibody sandwich-ELISA using antisera obtained from Loewe (Sauerlach, Germany) and the DSMZ. Back inoculation with the F. occidentalis vector was also carried out to Lycopersicon esculentum as indicator plants. Back inoculation was also positive for INSV by symptoms and ELISA. The high amount of ornamental plant production together with the use of virus-infected propagation material and the increasing thrips vector populations may result in significantly increased establishment and distribution of INSV in Hungary. References: (1) M. L. Daughtrey et al. Plant Dis. 81:1220, 1997.
Verticillium Wilt Incited by Verticillium dahliae in Lupinus polyphyllus in Italy
Authors: Garibaldi A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Lupinus polyphyllus Lindl., a perennial ornamental belonging to the Leguminosae family, is grown in gardens for flower beds and borders. During the summer of 2006, in several gardens located in the Biella Province (northern Italy), a new wilt of Lupine was observed in 20 to 30% of the plants. The vascular tissue in stems of affected plants appeared brown. These plants were stunted and developed yellow leaves with brown or black streaks in the vascular tissue. Verticillium dahliae was consistently isolated from symptomatic vascular tissue and leaves when cultured on potato dextrose agar (PDA) (3). Microscopic observations revealed hyaline hyphae, with many irregular, dark microsclerotia, ranging from 17 to 61 μm. Conidiophores showed two verticils of three elements. Conidia were hyaline, elliptical, single-celled, measuring 3.4 to 6.0 × 1.8 to 3.1 μm (average 4.5 × 2.4 μm). The ITS region (internal transcribed spacer) of rDNA was amplified using the primers ITS4/ITS6 (2) and sequenced. BLASTn analysis (1) of the 521 bp obtained showed an E-value of 0.0 with V. dahliae. The nucleotide sequence has been assigned GenBank Accession No. EF015891. Healthy 30-day-old plants (10 per treatment) of L. polyphyllus were inoculated by root dip with a conidial suspension (0.5 × 106 CFU/ml) of V. dahliae isolated from infected plants. Ten noninoculated plants served as control treatments. All plants were transplanted into pots filled with a mix of sphagnum peat/pomix/pine bark/clay (50:20:20:10) and grown outdoors at temperatures ranging from 15 to 25°C. First wilt symptoms and vascular discoloration in the roots, crown, and veins developed within 20 days on each inoculated plant and become evident after 50 days. V. dahliae was consistently reisolated from infected plants. Noninoculated plants remained healthy. The pathogenicity test was conducted twice. To our knowledge, this is the first report of V. dahliae on L. polyphyllus in Italy. A wilt caused by V. dahliae on L. polyphyllus was observed in the Netherlands in 1925 (4). References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (3) G. F. Pegg and B. L. Brady. Verticillium Wilts. CABI Publishing, Wallingford, UK, 2002. (4) J. H. H. Van der Meer. Meded. Landbouwhogesch. Wagening. 28, 1925.
First Report of Root Rot of American Ginseng (Panax quinquefolium) Caused by Ditylenchus destructor in China
Authors: Zhang G. Z. , Zhang H. W. 
Published: May 2007

During the summer of 2004, a root rot was observed on 3- and 4-year-old American ginseng cultivated in the Beijing area, and in 2006, the root rot was also found in the Hebei Province. The root epidermis appeared light brown with irregular lesions in the early stage. Sometimes the lesions had defined edges and were striped. In the later stages of the disease, the roots had splits in the epidermis and a rotted cortex causing them to lose commercial value. Plants wilted when the roots were severely damaged. The diseased roots were assayed for plant parasitic nematodes. A plant parasitic nematode was identified as Ditylenchus destructor on the basis of the following characteristics (1): stylet length ranged from 9.2 to 13.3 μm with rounded knobs; a single anterior outstretched ovary extended toward the base of the esophagus; the developing oocytes existed in two rows, changing to one near the middle of the ovary, and the vulva was thick and elevated, with the posterior uterus extending approximately three-quarters of the distance to the anus; the bursa extended from opposite the anterior end of the spicules approximately three-fourths of the tail length; and the tail was rounded and the lateral field had six incisures. Pathogenicity was tested by inoculating with a 2-ml suspension (approximately 2,000 nematodes) extracted from diseased roots to each of seven intact American ginseng roots. The roots were in a polyethylene bag surrounded by sterile soil and incubated at 25 ± 2°C. On five roots after 60 days, symptoms were similar to those observed in the field, and D. destructor was isolated from the infected parts. The control, inoculated only with sterile water, remained healthy. To our knowledge, this is the first report of D. destructor causing root rot of American ginseng. Reference: (1) G. Thorne. Proc. Helminthol. Soc. Wash. 12:27, 1945.