bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Phytophthora cactorum on Strawberry Plants in Spain
Authors: Santos B. de los , Porras M. , Blanco C. , Barrau C. , Romero F. 
Published: May 2007

Crown rot of strawberry (Fragaria × ananassa Duch. cv. Camarosa) was observed in three and two production fields in 2000 and 2001, respectively, in Huelva, southwestern Andalucia, Spain. Affected plants did not exhibit typical symptoms of red stele. Instead, there was an internal red-brown discoloration of the upper crown, a bluish discoloration of leaves, and the plants were wilted. Eventually, plants collapsed and died. Fungi were isolated from surface-disinfested necrotic crown tissue on P5ARPH medium (1). Plates were placed at 21°C for 5 to 10 days. One species was isolated consistently from symptomatic tissue. Microscopic observations revealed spherical oogonia with thin walls. Antheridia were paragynous and were attached to the oogonium near the oogonial stalk. Single oospores were spherical and had double-layered, yellow-brown walls (20 to 25 μm in diameter). Sporangia were usually borne terminally and were colorless and papillate (22 to 30 μm in diameter). Based on these characteristics, the causal agent was identified as Phytophthora cactorum (Lebert & Cohn) J. Schröt. (2). The fungus was transferred to V8 juice agar and maintained at 21°C in the dark. Disks (9-mm diameter) were removed from 7-day-old cultures of P. cactoru and used to inoculate five 2-month-old ‘Camarosa’ strawberry plants grown in sterilized peat in the greenhouse. Three disks were placed in the crown of each plant at soil level. Five noninoculated plants were similarly treated with sterile V8 juice agar disks only. After 2 weeks, the pathogen was reisolated from red-brown lesions visible on crowns of all inoculated plants. Noninoculated plants did not show any symptoms. To our knowledge, this is the first report of P. cactorum attacking strawberry plants in Spain. References: (1) S. N. Jeffers and S. B. Martin. Plant Dis. 70:1038, 1986. (2) G. M. Waterhouse and J. M. Waterston. No. 111 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, UK, 1996.
Chrysomyxa weirii on Colorado Blue Spruce in Wisconsin
Authors: Stanosz G. R. , Cummings-Carlson J. 
Published: May 2007

In early June 2002, yellow spots and bands with erumpent telia on previous year's needles of Colorado blue spruce (Picea pungens) were noted in landscape tree nurseries in both northern (Sawyer County) and southern (Dane County) Wisconsin. Many 1 to 2 m tall trees were symptomatic at each location. Based on the age of affected needles, time of year of telium development, and telial characteristics including the size and shape of teliospores, the pathogen was identified as Chrysomyxa weirii, the cause of Weir's cushion rust (1,2). Identification of the pathogen was confirmed by Dale Bergdahl, (School of Natural Resources, University of Vermont), who also observed basidiospores. C. weirii is an autoecious microcyclic rust pathogen known to affect P. englemanii, P. glauca, P. mariana, P. pungens, and P. sitchensis. Although this fungus has been reported in the western United States from the Black Hills of South Dakota to Washington State, in the eastern United States from the southern Appalachian Mountains (Tennessee and West Virginia) to Vermont, and in most Canadian provinces and territories (1,2), to our knowledge, this is the first report from the Great Lakes Region of the United States. The occurrence of Weir's cushion rust in Wisconsin has direct implications for the economically important nursery and Christmas tree industry in this region. References: (1) D. Bergdahl and D. Smeltzer. Plant Dis. 67:918, 1983. (2) W. Ziller. The Tree Rusts of Western Canada. Canadian Forestry Service, Victoria, BC, 1974.
First Report of Charcoal Rot of Sugar Beet Caused by Macrophomina phaseolina in Greece
Authors: Karadimos D. A. , Karaoglanidis G. S. , Klonari K. 
Published: May 2007

During the summer of 2000 in the Amyndeon area of northern Greece, sugar beet (Beta vulgaris L.) roots with rot symptoms were observed in many fields. Initially, the plants wilted, and leaves soon turned brown and died. Diseased plants appeared in patches in the field. Brown-black lesions were observed in the external part of the root crown while yellow-mustard colored lesions occurred internally. In advanced stages of decay, masses of sclerotia formed in rotted cavities and roots became mummified. Macrophomina phaseolina (Tassi) Goid. (1) was isolated on potato dextrose agar (PDA) from 30 rotted roots collected in five fields. Cultures produced dark multi-septate mycelium and sclerotia, which were black, smooth, spherical to irregular in shape, and varied in size from 100 μm to 1mm in diameter. Five isolates were evaluated for pathogenicity on surface-sterilized 16-week-old sugar beet roots (cv. Rizor) by placing a 5-mm-diameter PDA plug of actively growing mycelium in wounds made with a sterile knife. Sterile PDA plugs were placed in wounds made in control beet roots. Ten roots were inoculated per isolate. Roots were kept at 25°C in the dark for 10 days. Extensive decay of inoculated roots developed, similar to decay observed in the field, and M. phaseolina was reisolated from rotted tissue. Control roots showed no decay. This pathogen has been previously reported as a root rot pathogen of sugar beet in California, India, and countries of the former USSR. Charcoal rot is of minor economic importance since M. phaseolina attacks mainly weakened plants under conditions of high temperature (2). To our knowledge, this is the first report of charcoal root rot of sugar beet in Greece. References: (1) Anonymous. Macrophomina phaseolina. No. 275 in: Descriptions of Plant Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1970. (2) J. E. Duffus and E. G. Ruppel. Diseases. Page 347 in: The Sugar Beet Crop. Science into Practice. D. A. Cooke and R. K. Scott eds. Chapman and Hall, NY, 1993.
First Report of Fusarium oxysporum on Lettuce in Europe
Authors: Garibaldi A. , Gilardi G. , Gullino M. L. 
Published: May 2007

In spring 2001, plants of the lettuce cv. Salad Bowl showing symptoms of a wilt disease were observed in several commercial plastic greenhouses near Bergamo, in northern Italy. Wilted plants were first observed during the spring and summer of 2001 when temperatures were between 26 and 35°C. Symptoms were observed in the same area and the same farms in March 2002, in concomitance with a period of high temperatures. Although the distribution of the disease was generally uniform, symptoms were more severe in the central part of the greenhouses where temperatures were warmest. Symptoms were first observed at thinning, when seedlings (30 days old) appeared wilted. Vascular tissues of affected seedlings appeared red or brown. Affected plants were stunted and developed yellow leaves and brown or black streaks in the vascular system. The vascular streaks in the yellow leaves extended from the crown and were continuous with a red-brown discoloration in the vascular system of the crown and upper taproot. Symptoms were typically not visible on the outside of the crowns or roots. Fusarium oxysporum was consistently and readily isolated from symptomatic vascular tissues on a Fusarium-selective medium (2). Seeds of cv. Salad Bowl were planted in steam-sterilized soil artificially infested with 1 × 104 CFU/g soil of each of two isolates of F. oxysporum obtained from infected plants. Plants grown in noninfested soil served as noninoculated control treatments. Plants (25 per treatment) were grown at 25 to 28°C in growth chambers. Wilt symptoms and vascular discoloration of the roots, crown, and veins developed 20 days after seeding for all plants grown in the infested soil, and F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of F. oxysporum on lettuce in Europe. A wilt of lettuce attributed to F. oxysporum f. sp. lactucae was reported in Japan in 1967 (3) and in the United States in 1993 (1), in the latter case the incitant organism was described as F. oxysporum f. sp. lactucum. References: (1) J. C. Hubbard and J. S. Gerik. Plant Dis. 77:750, 1993. (2) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (3) T. Matuo and S. Motohashi. Trans. Mycol. Soc. Jpn. 8:13, 1967.
First Report of a Disease of Peony Caused by Alfalfa mosaic virus
Authors: Bellardi M. G. , Rubies-Autonell C. , Bianchi A. 
Published: May 2007

During the summers of 2001 and 2002, Japanese peony (Paeonia albiflora Pall., synonym P. lactiflora, family Paeoniaceae) plants, cultivated in the Botanical Garden of the University of Parma (Emilia Romagna Region of northern Italy), were found affected by a disease with virus-like symptoms. The oldest leaves showed yellow, mosaic, oak-like arabesques and line-patterns; the remaining leaves and pink flowers were symptomless. A disease of peony, known as peony ring spot disease, has been reported worldwide (Europe, United States, Japan, and New Zeland) for several years and is associated with strains of Tobacco rattle virus (TRV) (1). Electron microscopic observations of peony leaf sap (leaf dip preparations stained with uranyl acetate and phospotungstic acid) did not show the presence of any rod-shaped virus particles, including TRV. Mechanical inoculations of sap from symptomatic leaves caused symptoms typical of Alfalfa mosaic virus (AMV) on Chenopodium amaranticolor Coste & Reyn. (local chlorotic and necrotic lesions and systemic periveinal line-patterns), Ocimum basilicum L. (yellow mosaic), Vigna unguiculata (L.) Walp. (red, local necrotic lesions), and Nicotiana tabacum cv. Samsun (white, necrotic lesions, systemic leaf malformation, and mosaic), and N. glutinosa L. (systemic leaf variegation). Symptomatic leaves of peony and infected herbaceous plants were analyzed for virus presence by protein A sandwich enzyme-linked immunosorbent assay (PAS-ELISA). The polyclonal antisera tested were those to AMV (PVAS 92, American Type Culture Collection, Manassas, VA), AMV-Vinca minor L. (DiSTA collection, Italy), and the nepoviruses Strawberry latent ringspot virus, Tomato ringspot virus, and Cherry leaf roll virus. PAS-ELISA revealed only the presence of AMV. Immunoelectron microscopy and gold-labeled decoration confirmed the identity of the virus. In 2001, five symptomless peony plants (provided by a commercial grower and previously analyzed for AMV and TRV presence) were grafted with shoots from peony showing yellow mosaic on the leaves and maintained in a greenhouse under aphid-proof cage. During the summer of 2002, one of the grafted plants showed a mild mosaic on the leaves; PAS-ELISA revealed this peony was infected by AMV. To our knowledge, this is the first report of AMV in peony. Reference: (1) Chang et al. Ann. Phytopathol. Soc. Jpn. 42:325, 1976.
Sclerotinia Stem and Crown Rot of Corn-Salad Caused by Sclerotinia minor in California
Authors: Koike S. T. 
Published: May 2007

Corn-salad or lamb's lettuce (Valerianella locusta) is a specialty leafy green vegetable that is grown commercially in California and is harvested fresh for use in salads. In 2001, field plantings of corn-salad in coastal California showed symptoms and signs of a previously undescribed disease. Initial symptoms consisted of a light tan discoloration at the crown and lower leaf attachment areas. Once this discoloration was observed, the crown rapidly developed a soft rot, attached leaves wilted, and the entire plant collapsed. White mycelium and small (0.5 to 3.0 mm in diameter), irregularly shaped, black sclerotia formed on the crowns and lower leaves. Isolations from symptomatic crowns, mycelium, and sclerotia produced colonies of Sclerotinia minor (1). Seven-week-old corn-salad plants grown in a peat moss-based rooting medium in pots were used to test pathogenicity. Sclerotia from six corn-salad isolates from the Salinas Valley were inserted into slots made in the potting mix adjacent to the crowns of plants. Sclerotia were not placed in slots for control corn-salad. All test plants were incubated in a greenhouse at 21 to 23°C. After 4 weeks, inoculated corn-salad plants wilted and collapsed, and S. minor was reisolated from necrotic crown and stem tissues. Uninoculated plants were asymptomatic. Using the same method, sclerotia from one lettuce (Lactuca sativa) isolate were used to inoculate corn-salad plants that produced similar symptoms. All experiments were repeated and results were similar. To our knowledge, this is the first report of corn-salad as a host of S. minor in California and the United States. The susceptibility of corn-salad to S. minor from lettuce indicates that this crop might contribute to inoculum levels and lettuce drop incidence for the extensive lettuce plantings in the Salinas Valley. Reference: (1) C. L. Patterson and R. G. Grogan. Plant Dis. 72:1046, 1988.
Fruit Distortion Mosaic Disease of Okra in India
Authors: Krishnareddy M. , Jalali Salil , Samuel D. K. 
Published: May 2007

Okra (Abelmoscus esculentus (L.) Moench) is an important vegetable crop of India and other subropical and tropical countries. In 2000 and 2001, in the states of Karnataka and Tamil Nadu, okra was severely affected by a new disease. Since that time, the disease has spread to other states: Andhra Pradesh, Madhya Pradesh, Haryana, and Maharashtra. Chlorotic spots, chlorotic leaf blotches, distortion of leaves, chlorotic streaking, distortion of fruits, and severe yield losses as much as 63% characterize the disease. The causal virus induces local and systemic chlorotic and necrotic lesions on Vigna unguiculata (L.) Walp. cv. C-152 and Chenopodium amaranticolor Coste & Reyne., chlorotic local lesions and mosaic on Cucumis sativus L., necrotic local lesions on Gossypium hirsutum L. and black gram (Vigna mungo L.), and chlorotic local lesions and systemic necrosis on sunflower (Helianthus annuus L.). Host reactions on these species are similar to those described for the ilarvirus Tobacco streak virus (TSV) (3). Electron microscopic observation of leafdip preparations from field samples and partially purified virus preparations revealed the presence of isometric virus particles measuring 25 to 30 nm in diameter. The virus was purified from mechanically inoculated okra by differential and sucrose density gradient centrifugation, and disease symptoms were reproduced in okra mechanically inoculated with the purified virus. In direct antigen coated enzyme-linked immunosorbent assay and immunosorbent electron microscopy tests, the purified virus and sap extracts reacted positively with polyclonal antibodies to TSV, the ilarvirus associated with sunflower necrosis and peanut stem necrosis diseases (1,2), but did not react positively to Turnip mosaic virus and Okra mosaic virus that are previously reported to infect okra. In reverse transcription-polymerase chain reaction (RT-PCR), using oligonucleotide primers designed to amplify the entire coat protein region of TSV, an approximately 800-bp DNA fragment was obtained from purified virus and okra displaying fruit distortion mosaic disease (OFDM) but not from healthy okra. On the basis of host range, serological relationship, electron microscopy, and RTPCR amplification, the virus causing OFDM is an ilarvirus closely related to TSV. To our knowledge, this is the first report of the occurrence of an ilarvirus in okra, and is the third and most recent report of an ilarvirus related to TSV causing disease in crops on the Indian subcontinent (1,2). References:(1). A. I. Bhat et al. Arch. Virol. 147:651, 2002. (2). A. S. Reddy et al. Plant Dis. 86:173, 2002. (3). S. W. Scott. Tobacco streak virus. No 381 in: Descriptions of Plant Viruses. CMI/AAB, Surrey, U.K., 2001.
First Report of Arceuthobium vaginatum subsp. cryptopodum on Pinus mugo
Authors: Mathiasen R. , Haefeli M. , Leatherman D. 
Published: May 2007

Southwestern dwarf mistletoe (Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens, family Viscaceae) is a serious and common pathogen of ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) in Colorado, Utah, Arizona, New Mexico, and northern Mexico (1). In July 2002, this dwarf mistletoe was observed parasitizing a 1.4-m tall mugo pine (P. mugo Turra) in the Black Forest north of Colorado Springs, CO (39°02.118′N, 104°36.028′W, elevation 2,250 m). The infected mugo pine was planted as an ornamental approximately 6 m from a ponderosa pine infected with A vaginatum subsp. cryptopodum. Dwarf mistletoe shoots were produced on the only infected branch observed but this was sufficient for a positive identification of the dwarf mistletoe. Although J. Weir successfully inoculated mugo pine with western dwarf mistletoe (A. campylopodum Engelm.) and lodgepole pine dwarf mistletoe (A. americanum Nutt. ex Engelm.) (2), to our knowledge, this is the first report of a dwarf mistletoe occurring naturally on P. mugo, as well as the first report of A vaginatum subsp. cryptopodum on P. mugo (1). Specimens of A vaginatum subsp. cryptopodum from P. mugo have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 73761). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: biology, pathology, and systematics. USDA Agric. Handb. 709, 1996. (2) J. Weir. Bot. Gaz. 56:1, 1918.
First Report of a Geminivirus Associated with Leaf Curl in Baja California Peninsula Tomato Fields
Authors: Holguín-Peña R. J. , Vázquez Juárez R. , Rivera-Bustamante R. F. 
Published: May 2007

Since November 2001, geminivirus-like symptoms (stunting, reduced leaf size, and leaf curling “chino”) have been observed in tomato (Lycopersicon esculentum Mill.) plantings in Baja California Sur, Mexico. Samples of symptomatic plants were collected from commercial fields and analyzed by traditional and molecular methods for the presence of geminiviruses. Inocula prepared from infected plants were experimentally transmitted to tomato seedlings and Datura stramonium by mechanical inoculation and whitefly transmission. Leaf curling and interveinal chlorosis symptoms similar to those found in the field were observed in inoculated tomato and D. stramonium. DNA from infected plants was extracted and analyzed by polymerase chain reaction (PCR) and electrophoresis using degenerate primers PALIv1978/PARIc494 (1). PCR fragments of the expected size (1.1 kb) for the common region (CR) were obtained from 28 of 64 plants, cloned and sequenced (GenBank Accession No. AY336088). Comparisons of CR sequences with the NCBI database by using BLAST and MegAlign (DNASTAR, London) indicated that the Baja Californian isolates were New World bipartite begomoviruses sharing the highest nucleotide sequence identity (93%) with a partially characterized geminivirus (Tomato severe leaf curl virus (ToSLCV); GenBank Accession No. AF130415) from Guatemala. References: (1) M. R. Rojas et al. Plant Dis. 77:340, 1993.
First Report of Beet pseudo yellows virus in Strawberry in the United States: A Second Crinivirus Able to Cause Pallidosis Disease
Authors: Tzanetakis I. E. , Wintermantel W. M. , Martin R. R. 
Published: May 2007

During efforts to characterize strawberry pallidosis disease, we identified a single strawberry plant that indexed positive for pallidosis disease by grafting but it was not infected with the Strawberry pallidosis associated virus (SPaV) based on reverse transcription-polymerase chain reaction (1). Leaves of this plant were grafted onto Fragaria vesca UC-4 and UC-5 and F. virginiana UC-10 and UC-11 indicator plants. The F. vesca plants remained asymptomatic, while the F. virginiana plants gave typical pallidosis symptoms that included marginal leaf chlorosis and epinasty. The combination of these symptoms on F. virginiana and lack of symptoms on F. vesca is used to define pallidosis disease (1). We extracted dsRNA from the original plant, and synthesized and cloned cDNA as previously described (2). Sequence analysis revealed several clones that corresponded to the published sequence of the Beet pseudo yellows virus (BPYV) heat shock protein 70 homolog gene (HSP70h). We transferred the isolate to Nicotiana benthamiana by using the whitefly vector, Trialeuroides vaporariorum, and then reisolated and cloned dsRNA from the infected N. benthamiana. Here we present the complete sequence of the HSP70h and minor coat protein (CPm) genes of the strawberry isolate of BPYV (GenBank Accession Nos. AY 267369 and AY 268107, respectively). Oligonucleotide primers BP CPm F (5′ TTCATATTAAGGATGCGCAGA 3′) and BP CPm R (5′ TGAAAG- ATGTCCACTAATGATA 3′) were designed to amplify a 334-nucleotide fragment of the CPm gene of the strawberry isolate of BPYV. Using this primer set, we were able to verify the presence of BPYV in 1- to 3-year-old plants from the major strawberry producing areas of the United States, including California, Oregon, and the Mid-Atlantic States. Infection rates were highest near Watsonville, CA where more than 20% of plants tested were infected with BPYV. To our knowledge, this is the first report of BPYV infecting strawberry. BPYV and the closely related SPaV (2) pose new concerns for the U.S. strawberry industry. Studies are currently underway to determine the effects of these two viruses on strawberry vigor and productivity. References: (1) N. W. Frazier and L. L. Stubbs. Plant Dis. Rep. 53:524, 1969. (2) I. E. Tzanetakis et al. (Abstr.) Phytopathology 92:S82, 2002.
First Report of Bronze Leaf Disease on Hybrid Poplar (Populus × canescens ‘Tower’) Caused by Apioplagiostoma populi in Manitoba, Canada
Authors: Northover P. R. , Desjardins M. 
Published: May 2007

Poplars (Populus alba × P. tremula (P. × canescens) (Aiton) Smith cv. Tower) are common ornamental and windbreak trees in Manitoba and across the Canadian prairie provinces because of their rapid growth and columnar growth habit. Bronze leaf disease symptoms have been reported on five poplar species (P. alba, P. canescens, P. grandidentata, P. tremula, and P. tremuloides) (2), and the disease presents a significant barrier to the development and continued use of poplars (1). Elimination of tower poplars would represent a significant loss to the Canadian horticultural industry, and the costs incurred in the replacement of existing windbreaks would be high. In August 2002, we observed symptoms of bronze leaf disease on approximately 20-year-old tower poplars, ranging in height from 8 to 12 m at a tree nursery and golf course near Carman, Manitoba (49°30′N, 98°0′W). The leaf laminae of affected plants were chocolate brown, and the petioles and veins were yellow to light green. In the nursery windbreak, 70 trees had foliar symptoms on 30 to 80% of the canopy. At the golf course, eight trees had foliar symptoms on approximately 5 to 20% of the canopy. No fruiting structures were visible on leaf or shoot tissue, and no staining of vascular tissues was observed. Attempts to isolate the causal fungus of bronze leaf disease on artificial media have been unsuccessful (2). In October 2002, branches with symptomatic leaves were covered with netting, and the trapped leaves were left to overwinter. In March 2003, symptomatic leaves were brought to the laboratory and surface sterilized in 1% NaOCl for 1 min, rinsed with sterile water, and incubated at 18°C in moist chambers. After 2 weeks, dark brown, beaked, single perithecia that were 150 to 200 μm long × 150 μm wide emerged from the upper and lower leaf surfaces. Asci were fusoid clavate with a conspicuous apical ring and contained 4 or 6 spores. The two-celled, hyaline ascospores varied from 10.5 to 14.5 × 2 to 3 μm, the basal cell shorter than the apical cell. Leaf symptoms and microscopic fungal features matched those of Apioplagiostoma populi (Cash & A.M. Waterman) Barr, the cause of bronze leaf disease (1,2). Voucher specimens have been deposited in the U.S. National Fungus Collections (BPI 843385). To our knowledge, this is the first report of this fungus in western Canada, and the first confirmed report of this pathogen on tower poplar in Canada. References: (1) E. K. Cash and A. M. Waterman. Mycologia 49:756, 1957. (2) J. A. Smith et al. Plant Dis. 86:462, 2002.