bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Occurrence of White Rust of Arugula, Caused by Albugo candida
Authors: Scheck H. J. , Koike S. T. 
Published: May 2007

In California, arugula (Eruca sativa) is grown commercially as a component of specialty mixed green salads. In 1999, white rust was observed on arugula in the central coast county of Santa Barbara. Symptoms consisted of white, blisterlike sori beneath the raised host epidermis on the underside of leaves from the seedling stage onward. Secondary infection of flower heads led to staghead development. Affected plantings were severely diseased and were not harvested. The pathogen was confirmed to be Albugo candida (Pers.) Kunze (2). Sporangia diameters ranged from 19.5 to 22.2 μm. Inoculum for pathogenicity tests was prepared by scraping sporangia from infected leaves and incubating them in sterile, distilled water for 12 h at 5°C to induce zoospore formation (1). The following plants were then spray inoculated: arugula, cauliflower (Brassica oleracea subsp. botrytis), Chinese cabbage (Brassica campestris subsp. pekinensis), Japanese mustard (Brassica campestris subsp. nipposinica), red mustard (Brassica juncea subsp. rugosa), and tah tsai (Brassica campestris subsp. narinosa). Twelve plants of each species were inoculated with 1.5 × 104 spores per ml at the six- to eight-leaf stage. Plants were incubated in a dew chamber for 48 h at 18°C and then maintained in a greenhouse at 20 to 24°C. After 10 to 12 days, white rust pustules similar to the original symptoms observed in the field developed only on arugula. The experiment was conducted three times and the results were the same. Distinct biological races of A. candida have been described for some Brassicaceae hosts of white rust (1). This is the first report of white rust of arugula in California caused by A. candida. References: (1) R. S. Pidskalny and S. R. Rimmer. Can. J. Plant Pathol. 7:283, 1985. (2) G. S. Pound and P. H. Williams. Phytopathology 53:1146, 1963.
Coriander: A New Natural Host of Groundnut Ring Spot Virus in Brazil
Authors: Lima M. F. , de Ávila A. C. , da G. Wanderley L. J. , Nagata T. , da Gama L. J. W. 
Published: May 2007

Coriander plants (Coriandrum sativum L. ‘Palmeira’), showing stunting, chlorotic ring spots, necrosis, and malformation of apical leaves were observed on 50-day-old-plants in July 1998 in one seed production field at Petrolina, State of Pernambuco, Brazil, but not in nearby fields. Leaf samples were collected and tested by double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) with a panel of polyclonal antibodies made against the nucleocapsid protein (N) of tomato spotted wilt virus (TSWV), tomato chlorotic spot virus (TCSV), groundnut ring spot virus (GRSV), and impatiens necrotic spot virus (INSV) (1). All symptomatic samples reacted only with the GRSV antisera. Coriander leaf extracts from infected plants were mechanically inoculated onto potential indicator hosts. The virus induced systemic infection with vein clearing, chlorotic and necrotic spots, necrotic ring spots, mosaic, top distortion, and stunting within 21 days after inoculation on Capsicum annuum cv. Ikeda, C. chinense PI 159236, Physalis floridana, Nicandra physaloides, Nicotiana tabacum cv. TNN, N. benthamiana, Lycopersicon esculentum cv. Rutgers, Phaseolus vulgaris cv. BT2, and Gomphrena globosa. The symptomatic indicator plants tested positive for GRSV by DAS-ELISA. P. vulgaris, Chenopodium amaranthicolor, C. quinoa, and Cucurbita pepo (zucchini) cv. Caserta showed only small, necrotic, local lesions on inoculated leaves. Citrullus lanatus cv. Charleston Gray was asymptomatic. This is the first report of natural occurrence of GRSV on coriander in Brazil. Reference: (1) A. C. de Ávila et al. J. Gen. Virol. 71:2801, 1990.
First Report of Soilborne Wheat Mosaic Virus in the United Kingdom
Authors: Clover G. R. G. , Wright D. M. , Henry C. M. 
Published: May 2007

In April 1999, severe soilborne wheat mosaic virus (SBWMV) symptoms were observed in five fields of winter wheat (Triticum aestivum, cvs. Consort, Equinox, and Savannah) on one farm in Wiltshire, UK. Affected plants were markedly stunted and had a pale mosaic on their leaf sheaths that developed into bright yellow, parallel streaks on the leaves as they unfolded. Symptomatic plants were found in discrete, elliptical patches ranging in size from a few square meters to nearly a hectare. During May and June, symptoms became less marked as temperatures increased and were restricted to lower leaves. SBWMV was positively identified in all five fields (60 to 170 plants per field) by double (W. Huth, BBA-Braunschweig, Germany; Sanofi Phyto-Diagnostics, Paris) and triple (T. Wilson, SCRI, Dundee, UK) antibody sandwich enzyme-linked immunosorbent assay and by reversetranscription polymerase chain reaction (2). Identification was confirmed by immunoelectron microscopy, including protein-A gold labeling, which revealed bipartite, rod-shaped particles typical of SBWMV. Neither wheat spindle streak mosaic virus nor barley yellow dwarf virus was detected in the field samples, nor was SBWMV detected in any other field subsequently sampled, despite a survey of the surrounding area. Wheat is the most important economic crop in the United Kingdom (≈1.9 million hectares are grown annually, yielding ≈16 million tonnes), but its position is threatened by the economic impact of SBWMV, which has decreased yields by up to 50% in the United States (1). References: (1) T. A. Kucharek and J. H. Walker. Plant Dis. Rep. 58:763, 1974. (2) R. E. Pennington et al. Plant Dis. 77:1202, 1993.
First Report of Rhizosis Caused by Ceratocystis radicicola on Date Palms in South Africa
Authors: Linde C. , Smit W. A. 
Published: May 2007

During late summer (February to March) of 1997, a sudden loss of large date palms (Phoenix dactylifera L. ‘Medjool’) and adjacent suckers was observed in the Pofadder area of South Africa. The palms were planted in sandy soil, with flood irrigation from the adjacent Orange River. Initial symptoms included wilting of leaves, chlorosis of young leaves, and root necrosis. Ceratocystis radicicola (D.E. Bliss) C. Moreau (synamorph Ceratostomella radicicola; anamorph Chalara) was consistently isolated from necrotic roots and lower crown portions of diseased palms. Dark colored spores were observed in root sections. Pathogenicity studies were performed in a shadehouse on 5-year-old Medjool clones. Two experiments were conducted in which Medjool plants were inoculated with 2-week-old C. radicicola cultures grown on corn meal agar (CMA). In the first experiment, a 7-mm wound was made at the leaf base of 15 plants and inoculated with an agar plug of C. radicicola culture. The same number of control plants was inoculated with CMA. Wounds were sealed with Parafilm, and lesions were measured after 3 months. In the second experiment, conidial suspensions and pieces of mycelia from five C. radicicola cultures were harvested in 1.5 liters of water, and 100 ml of inoculum was added to each of 15 plants. Control plants (15 total) each received 100 ml of sterile water. Plants were examined after 3 months. In the first experiment, all leaves inoculated at the base with C. radicicola became necrotic at the point of inoculation, wilted rapidly, and died. In the second experiment, roots showed severe necrosis resembling rhizosis observed in the field. In each experiment, only three plants died, and C. radicicola was successfully isolated from all inoculated plants. No symptoms developed on control plants, and C. radicicola could not be isolated from them. Rhizosis of date palms caused by C. radicicola has been described in the United States (1) and differs from the disease of date palm stems, leaves, buds, and inflorescences caused by C. paradoxa (Dade) C. Moreau. This is the first report of rhizosis on date palms in South Africa. Reference: (1) D. E. Bliss. Phytopathology 31:1123, 1941.
First Report of Pythium paroecandrum on Lupinus havardii
Authors: Fernández-Pavía S. P. , Valenzuela-Vazquez M. 
Published: May 2007

Lupinus havardii Wats. (Big Bend Bluebonnet), a plant native to Texas, has been tested extensively for greenhouse production as a cutflower crop (1). Disease symptoms were observed on L. havardii plants grown in Las Cruces, NM, during two consecutive years. Plants were grown in Metro Mix 200 and watered by an automatic irrigation system every 3 days. During the growing season, which extended from September through February, 6% of mature plants (10-week-old plants) became chlorotic, wilted, and died. The first symptoms were observed during December 1998, when greenhouse temperatures were from 10 to 13°C. During the rest of the growing season, from February to July, only one plant became diseased, during May 1999, and the plant died within 1 week after greenhouse temperatures reached 20 to 25°C. Diseased plants were examined, and root, crown, and stem rot were found. Pythium paroecandrum Drechs. (2) was isolated routinely from infected tissues. Koch's postulates were fulfilled after plants were inoculated with oospores and mycelia of P. paroecandrum. Inoculum was applied next to the crown of 6-week-old plants in the form of water-agar plugs and a suspension that contained P. paroecandrum oospores and mycelia. Plants were maintained at 20 to 25°C. After 10 days, symptoms were similar to those previously observed, and the pathogen was reisolated from necrotic lesions observed on stems and crowns. Disease developed slower on 6-week-old plants (inoculated) than on 10-week-old plants (naturally infected). This is the first report of P. paroecandrum on L. havardii. References: (1) W. A. Mackay and T. D. Davis. HortScience 33:348, 1998. (2) A. J. Van der Plaats-Niterink. Monograph of the genus Pythium. Studies Mycol. 21:1, 1981.
Outbreak of False Smut of Rice in Louisiana
Authors: Rush M. C. , Shahjahan A. K. M. , Jones J. P. , Groth D. E. 
Published: May 2007

False smut, caused by Ustilaginoidea virens (Cooke) Takah., has been occurring in Louisiana rice since at least 1906 (4). A color plate (no. 69) of the disease was published in the Compendium of Rice Diseases published by the American Phytopathological Society (3). The slide for this plate was taken by M. C. Rush in 1976 of rice grown at the Rice Research Station at Crowley, LA. Since that time, the disease has been sporadic and light in Louisiana. In 1997, however, incidence was high. False smut was present on many germ plasms at the Rice Research Station in Crowley and was observed on commercial cultivars in several growers' fields in southwestern Louisiana. Incidence ranged from 1 to 15% of tillers infected with at least two to three spore balls per infected panicle. The disease occurred on both long- and medium-grain cultivars. False smut of rice occurs in the field at the hard dough to mature stages of the crop. A few spikelets in a panicle transform into globose, yellowish green, velvety spore balls that are 2 to 5 cm in diameter and covered by a thin orange membrane. The membrane bursts open and releases powdery dark green spores. The chlamydospores formed in the spore balls are spherical to elliptical, warty, olivaceous, and 3 to 5 × 4 to 6 μm in dimension. Some of the spore balls develop one or more sclerotia, which are the overwintering structure, in the center. False smut has been considered a minor disease of rice that occurs sporadically in Louisiana. The recent discovery of ustilotoxin, a phytotoxin and mycotoxin, produced by this pathogen on diseased tissues suggests that the fungus may be of concern as a contaminant on rice products consumed by livestock and humans (1,2). This increases the need to monitor the incidence of this disease. References: (1) Koiso et al. Ustiloxin: A phytotoxin and a mycotoxin from false smut balls on rice panicles. Tetrahedron Lett. 33:4157, 1992. (2) Koiso et al. Ustiloxins, antimitotic cyclic peptides from false smut balls on rice panicles caused by Ustilaginoidea virens. J. Antibiot. 47:765, 1994. (3) F. N. Lee and P. S. Gunnel. 1992. Compendium of Rice Diseases. The American Phytopathological Society, St. Paul, MN. p. 28. (4) W. A. Orton. 1907. Plant diseases of 1906. Yearbook U.S. Department of Agriculture. U.S. Government Printing Office, Washington, DC, pp. 499–508.
First Report of Cucurbit Yellow Stunting Disorder Virus (Genus Crinivirus) in North America
Authors: Kao J. , Jia L. , Tian T. , Rubio L. , Falk B. W. 
Published: May 2007

In late summer 1999, field- and greenhouse-grown melon plants (Cucumis melo) showing severe stunting and yellowing symptoms were observed near Donna in southern Texas and near the town of Reynosa in northern Mexico. Symptoms were typical of those caused by viruses in the genus Crinivirus, family Closteroviridae. High populations of Bemisia spp. whiteflies were associated with these plantings, with many plants showing heavy infestation. Laboratory analyses showed that melon plants from both locations were infected by the whitefly-transmitted Cucurbit yellow stunting disorder virus (CYSDV). Positive hybridization reactions with digoxigenin-UTP-labeled transcript probes corresponding to the CYSDV heat shock protein 70 (HSP70) homolog coding region (1) were obtained for RNAs extracted from symptomatic plants. Similar probes for the related Lettuce infectious yellows virus (LIYV) and Beet pseudo-yellows virus (BPYV), two whitefly-transmitted viruses previously reported from North America (2), did not hybridize with the RNAs. Definitive confirmation of CYSDV was obtained by performing reverse-transcription polymerase chain reaction (RT-PCR) analyses for two distinct CYSDV coding regions. RT-PCR with primers corresponding to CYSDV, but not LIYV or BPYV HSP70 homolog coding regions, gave specific (≈500 bp) products from corresponding test plants. RNAs from healthy control plants gave no RT-PCR product. Because the HSP70 coding region is highly conserved (2), we also performed RT-PCR with primers designed for the Spanish CYSDV capsid protein gene (GenBank accession AJ243000). Positive RT-PCR products of ≈700 bp were obtained only from the Texas and Mexico melon plants. CYSDV is a widespread and damaging virus of cucurbits in southern Europe and the Middle East (2). This is the first report of this important virus in North America. References: (1) Tian et al. Phytopathology 86:1167, 1996. (2) Rubio et al. Phytopathology 89:707, 1999.
Evidence that Watermelon Leaf Curl Disease in Pakistan Is Associated with Tomato Leaf Curl Virus-India, a Bipartite Begomovirus
Authors: Mansoor S. , Khan S. H. , Hussain M. , Mushtaq N. , Zafar Y. , Malik K. A. 
Published: May 2007

Whitefly-transmitted geminiviruses (begomoviruses) have emerged as major constraints on food and fiber crops worldwide, and there are several examples of begomovirus mobilization in previously unknown host plants. Here we report on evidence that leaf curl disease of watermelon in Pakistan is caused by Tomato leaf curl virus-India (TLCV-India). Leaf curl disease of watermelon, characterized by leaf curling and mottling and stunted plant growth, was observed at several locations in the Punjab Province of Pakistan. Symptomatic and asymptomatic leaf samples were collected from three locations, and total DNA was isolated by the cetyltrimethylammoniumbromide method and resolved in agarose gel. A full-length clone of Cotton leaf curl virus DNA A was labeled with [32P]dCTP and used as a general probe in Southern hybridization. The probe detected characteristic geminivirus DNA forms in infected watermelon plants, whereas no signal was detected in asymptomatic plants. The association of a begomovirus was confirmed further by polymerase chain reaction (PCR) amplification with degenerate primers PAL1V and pAR1c (2). Samples were screened for infection by TLCV-India, because of symptom similarity. A full-length clone of DNA B of TLCV-India (1) was labeled with [32P]dCTP by random priming and was used as a specific probe in Southern hybridization. The probe detected geminivirus DNA forms, showing that the disease is associated with TLCV-India. Primers TLCV1 (GAGGTACCAAAACTTGTCGTTTTGATTCGG), in the virion-sense, and TLCV2 (GCCCATGGTTCTTTGCTCGGAGAACAAGAA), in the complementary-sense, were designed based on the sequence of DNA A of TLCV-India. These primers were used in PCR and amplified a product of the expected size from infected plants. Similarly, primers TLCVBC1 (GCGGATCCTTATTCCGTAATTATATCTGCA), in the virion-sense, and TLCV BC2 (CACCATGGCAATAGGAAATGATGGTATGGG), in the complementary-sense, were designed based on the sequence of DNA B of TLCV-India (1). These primers amplified a product of expected size when used in PCR. The results show that watermelon leaf curl disease in Pakistan is associated with TLCV-India. This the first report of detection of a begomovirus in watermelon in Pakistan and the first report of detection of TLCV-India on a plant other than tomato from Southeast Asia. References: (1) M. Padidam et al. J. Gen. Virol. 76:25, 1995. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993.
First Report of Gray Leaf Spot Caused by Pyricularia grisea on Lolium perenne in Illinois
Authors: Pedersen D. K. , Kane R. T. , Wilkinson H. T. 
Published: May 2007

Each year from 1991 to 1999, a disease matching the description of gray leaf spot (1) was observed in the central and north central regions of Illinois. Disease severity was low (<10% blight) from 1991 to 1994 and 1999 and was severe (>50% blight in some areas) from 1995 to 1998. The disease was observed on Lolium perenne (perennial ryegrass) golf course fairways and sports fields. Isolations of Pyricularia grisea were made from L. perenne collected from golf courses in Bloomington, Decatur, Kankakee, Pekin, Urbana, and Moline, IL. All isolates were collected from surface-sterilized, symptomatic leaves. Cultures were maintained on one-fifth strength potato-dextrose agar (PDA) and induced to sporulate on full-strength oatmeal agar. All isolates in culture displayed vegetative and conidial characteristics similar to those previously described for P. grisea (1). Twenty-five different L. perenne germ plasms were inoculated with isolate WF9826 (Kankakee) using a suspension of 1 × 105 conidia per milliliter. The 4-week-old lawns (100 plants per 3-cm-diameter cone-tainer) of each ryegrass germ plasm were inoculated by spraying foliage with the conidial suspension until runoff. Inoculated and uninoculated lawns were enclosed in plastic bags and placed in an incubator (16 h light; 28°C) for 7 days. Disease severity was rated using a scale of 0 to 10 (10 = 100% blight). Each treatment was replicated three times, and all experiments were repeated four times. Small blue-gray, water-soaked lesions with dark brown borders were observed on leaves of all inoculated ryegrass germ plasms. Advanced symptoms included blighting of much of the leaves. The mean disease severity rating was 3.8 (range 2 to 7) for all experimental units and all 25 germ plasms. P. grisea was isolated from leaves that were inoculated with WF9826. This is the first report of gray leaf spot of perennial ryegrass caused by P. grisea in Illinois. Reference: (1) P. J. Landschoot et al. Plant Dis. 76:1280, 1992.
Gaeumannomyces graminis var. graminis Isolated from Emerald Zoysiagrass in Texas
Authors: Tomaso-Peterson M. , Trevathan L. E. , Gonzalez M. S. , Colbaugh P. F. 
Published: May 2007

Wilkinson and Kane (3) previously reported diseased zoysiagrass infected by Gaeumannomyces graminis (Sacc.) Arx & Olivier var. graminis in the spring in Illinois. Emerald zoysiagrass (Zoysia japonicum Steud. × Zoysia matrella (L.) Merr var. tenufolia (Willd. ex Thiele) established by sod in a home lawn for one year in Austin, TX, developed irregular, chlorotic, and, subsequently, necrotic patches 30 cm in diameter and larger in late summer of 1999. Patches were restricted to areas of the lawn receiving full sun. The lawn was fertilized, mowed at 2.5 cm, and watered daily during active growth. A thatch layer in excess of 1.9 cm was present. Tillers within diseased patches were removed easily from stolons. Crowns were rotted and colonized by dark brown septate hyphae (4.5 µm wide) and olivaceous brown lobed hyphopodia (25 × 21 µm). Diseased tillers were desiccated and newly developed leaves were chlorotic. Stolons were also chlorotic and developed water-soaked lesions adjacent to crowns. Diseased roots appeared light brown and brittle with strands of dark brown septate runner hyphae along the surface of the root axis and olivaceous brown growth cessation structures within the cortical tissue. Overall, symptoms were more severe on crowns and nodes than roots. A Gaeumannomyces fungus was isolated from root, sheath, and bud tissues. Taxonomy of the fungus was consistent with the description of G. graminis var. graminis by Walker (1,2). Diseased plants were washed free of soil and other debris and maintained in a moist chamber for 14 days. Perithecia were formed on leaf sheaths. Morphology of perithecia, asci, and ascospores was consistent with Walker's description of perithecia, asci, and ascospores of G. graminis var. graminis (2). Leaf buds and root tissue, colonized by G. graminis var. graminis, were plated directly onto potato-dextrose agar containing streptomycin sulfate and rifampicin (100 ppm, respectively). Colonies of sparse white, slightly aerial mycelium turning olive brown with age and producing lobed hyphopodia, developed from plated plant material. Hyphae at the margin of colonies curled back, characteristic of G. graminis var. graminis. Symptoms reported here are similar to those described by Wilkinson and Kane (3); however, the season and prevailing environmental conditions were different. References: (1) J. Walker. Trans. Br. Mycol. Soc. 58:427, 1972. (2) J. Walker. Mycotaxon 11:1, 1980. (3) H. T. Wilkinson and R. T. Kane. Plant Dis 77:100, 1993.
First Outbreak of Banana Streak Badnavirus Infection in Commercial Export Bananas in Costa Rica
Authors: Pasberg-Gauhl C. , Lockhart B. E. , Duran S. 
Published: May 2007

Banana streak badnavirus (BSV) is the most widely occurring virus in banana and plantain (1) but has not been reported to be a significant problem in commercial export bananas. In early 1999, the first severe outbreak of BSV infection in commercial export bananas (Musa AAA cv. Grand Nain) was recorded at Siquirres on the Atlantic coast of Costa Rica. Disease incidence in the plantation was 60% and symptoms included foliar chlorotic streaks, stunting of plants, splitting and internal necrosis of pseudostems and fruits, cigar leaf necrosis, and bunch emergence through the pseudostem. Diseased plants within a 0.8 ha area were eliminated to prevent possible further spread of the disease. The presence of BSV in diseased plants was confirmed by enzyme-linked immunosorbent assay and immunosorbent electron microscopy (1). Cucumber mosaic virus and Banana mild mosaic virus, which also occur in banana and plantain in Latin America (2), were not detected in the plants tested. Other recent accounts of BSV occurrence in commercial banana plantations in South America (our unpublished results) suggest that BSV occurrence in export bananas may be more significant than previously thought. References: (1) F. Gauhl et al. Int. J. Pest Management 45:167, 1991. (2) D. R. Jones, ed. 1999. Diseases of Banana, Abacá and Enset. CABI Publishing, Wallingford, U.K.