bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mycosphaerella dearnessii, a Needle-cast Pathogen on Mountain Pine (Pinus mugo) in Italy
Authors: La Porta N. , Capretti P. 
Published: May 2007

The pathogen Mycosphaerella dearnessii Barr. (syn. Scirrhia acicola; anamorph Lecanosticta acicola), the causal agent of brown spot needle blight, was observed on Pinus mugo in the Botanical Garden in Gardone (Brescia), on the western side of Garda Lake in northeastern Italy. Symptoms were first noticed in the spring of 1997 by Klaus Lang (University of Freising, Germany). Two years later, all 12 of the P. mugo present in the Garden exhibited extensive necrosis, and defoliation of the crown starting from the bottom upward was more prevalent on the shaded portion of infected trees. The trees were about 50 years old and 2.0 to 2.5 m in height. Symptomatic needles were confined to the 2- and 3-year old internodes. Infected needles had several dark to purplish-brown spots surrounded by green tissue and usually had dead tips. Pycnidia and conidia of Lecanosticta acicola were observed. Conidia were 4-celled, curved, pointed at one end and blunt at the other, pale olive-brown and 20 to 30 × 3 to 4 μm. The fungus was isolated in pure culture. The pathogen causes serious losses in China, eastern United States, and central and South America, but was observed for the first time in Europe only 30 years ago. It is a major cause of needle blight on several European pine species, especially P. sylvestris, P. nigra, and P. mugo. In the last 7 years, there have been reports of the fungus in pine stands, first in France, Aquitaine, and the western Pyrenees on P. radiata (3), and more recently on P. mugo in the Alps in Austria (1), Switzerland (2), and southern Germany (4). This record of the fungus near Lake Garda poses a new serious threat especially for the pine plantations of P. nigra and P. sylvestris in the more humid locations in the Alps, Apennines, and elsewhere in the mountains of southern Europe where the climatic conditions are similar to that of central Europe. This is the first report of M. dearnessii on the southern slopes of the Alps and in Italy. References: (1) M. Brandstetter and T. Cech. Oesterreichische Forstzeitung 110:35, 1999. (2) O. Holdenrieder and T. N. Sieber. Eur. J. For. Pathol. 25:293, 1995. (3) A. Levy and C. Lafaurie. Phytoma 463:33, 1994. (4) L. Pehl L. Nachrichtenbl. Dtsch. Pflanzenschutzdienstes 47:305, 1995.
First Report of a Leaf Blight of Onion Caused by Xanthomonas campestris in Colorado
Authors: Schwartz H. F. , Otto K. 
Published: May 2007

Sweet Spanish onion (Allium cepa L.) cultivars in southern Colorado (Otero and Prowers counties) have been found with symptoms of a foliar blight since 1996, and the same symptoms have been observed in northern Colorado (Weld County) since 1997. This onion disease appears to be identical to that reported from Barbados in 1971, Hawaii in 1978, and Texas in 1998 (1). Leaf blighting in scattered fields began as linear, tan to brown, water-soaked lesions that rapidly coalesced and were often surrounded by chlorotic areas, causing a general discoloration and tip die-back of affected foliage. The disease occurs generally after periods of heavy rainfall or storms. Bulb size may be reduced, and 10 to 15% yield losses have been recorded from control plots in copper-based bactericide screening nurseries naturally infected primarily by this pathogen at Rocky Ford during 1996 to 1998. Disease progression into bulbs has not been observed. Gram negative, rod-shaped, yellow bacteria were consistently recovered from infected foliar and bulb tissues on nutrient agar. The bacterial isolates utilized glucose in an oxidative manner, were catalase positive, oxidase negative, and negative for the tetrazolium salt tolerance test (0.1 and 0.02%). Two strains, one recovered during 1996 and the other in 1997, were identified by Microbe Inotech Laboratories (St. Louis, MO) as Xanthomonas campestris based on fatty acid methyl ester analysis (similarity indices of 0.81 and 0.82). A literature search indicated that classification to pathovar is lacking (2). To prove pathogenicity, a suspension (108 CFU/ml sdw) of one of the strains was sprayed to runoff onto a flat of approximately 100 8-week-old plants. Inoculated plants were placed in a dew chamber for 24 h, and then transferred to a bench and maintained at 25 to 28°C with a 12-h photoperiod and misting period for 14 days. A sample of 10 randomly selected plants with symptoms of water-soaking and discoloration was collected from which X. campestris was reisolated. No symptoms developed on seedlings sprayed with water only. This is the first report of X. campestris from onions grown in Colorado and the western continental United States. References: (1) T. Isakeit et al. Plant Dis. 84:201, 2000. (2) M. Van Den Mooter and J. Swings. Int. J. Syst. Bacteriol. 40:348–369, 1990.
First Report of Anemone Plants Infected by Ranunculus white mottle virus
Authors: Vaira A. M. , Vecchiati M. , Lisa V. , Milne R. G. 
Published: May 2007

Ranunculus white mottle virus (RWMV) (1), genus Ophiovirus, has been reported in crops of several cultivars of commercial ranunculus (Ranunculus asiaticus hybrids) during the 1990s in Liguria in Northwest Italy. Symptoms associated with RWMV in ranunculus are not clear-cut owing to the presence of mixed viral infections. During autumn 1999, a severe disease in commercial crops of anemone (Anemone coronaria) was noted in the same area. Plants appeared stunted with young leaves showing curling, deformation, and necrotic spotting. Disease incidence in some fields reached 40 to 50%. DAS- and TAS-enzyme-linked immunosorbent assays (ELISAs) for presence of RWMV and for the viruses most frequently infecting anemone in Italy were run on 24 field samples. Seven proved to be infected by RWMV in mixed infection with Cucumber mosaic virus subgroup II or with Tobacco necrosis virus. Ophiovirus-like particles were detected by negative staining and electron microscopy from sap extracts of field plants that were RWMV-positive by ELISA. Sap from these plants was also mechanically inoculated to indicator plants. Total RNAs were extracted from RWMV-infected field samples and from inoculated Nicotiana benthamiana and N. clevelandii and used in molecular tests. A DIG-DNA probe targeting the 1.8-kb RNA2 of RWMV was used in Northern blots and dot blots of total RNAs, confirming the infection in field samples and multiplication of the virus in test plants, unfortunately still in mixed infection. At present, it is difficult to evaluate RWMV symptomatology in anemone, but the presence of this virus in mixed infection seems to produce serious effects. This is the first report of RWMV in anemone. Reference: (1) A. M. Vaira et al. Arch. Virol. 142:2131, 1997.
First Report of Cucumber mosaic virus in Garlic Mustard in Ohio
Authors: Boehm M. J. , Nameth S. T. 
Published: May 2007

Garlic mustard (Alliaria officinalis) is a common weed species associated with woodland borders, hedge rows, and suburban gardens. Garlic mustard plants expressing foliar symptoms of leaf mosaic and vein banding were collected from Franklin and Cuyahoga counties in Ohio. Analysis of symptomatic tissue using viral-associated double-stranded RNA (dsRNA) analysis on 5% polyacrylamide gels and stained with ethidium bromide resulted in the production of a banding profile (four dsRNA bands with molecular weights of 2.6, 2.0, 1.5, and 0.7 × 106 daltons) similar to that of Cucumber mosaic virus (CMV) (1). Symptomatic tissue suspected of being infected with CMV was analyzed with an indirect enzyme-linked immunosorbent assay (iELISA) employing commercially produced antiserum (Agdia Inc.) against the common strain of CMV antiserum confirmed the presence of CMV. Nonsymptomatic tissue reacted negatively to CMV. This is the first report of CMV in garlic mustard in Ohio. Due to the extensive range of this weed and the wide host range of CMV in ornamental and food-plant species, garlic mustard could serve as an alternate host for CMV in many commercially important plant species. Reference: (1) T. J. Morris et al. Plant Mol. Biol. Rep. 1:27–30, 1983.
Basal Rot of Geraldton Waxplant Caused by Phytophthora boehmeriae
Authors: Wolcan S. , Lori G. 
Published: May 2007

Geraldton waxplant (Chamaelauciun uncinatum Schauer.) is a shrub that produces flowered branches used in bouquets. Waxplant was introduced into Argentina (Buenos Aires province) in the 1990s and currently is cultivated in greenhouses. In the summer of 1995, a previously undescribed disease was observed on plants at different stages of growth. Plants showed a progressive yellowing of the branches from the base to the top of the stems. Leaves of diseased plants became grayish green, then yellow, and finally straw colored. Leaves remained attached to the branches after the plants died. Roots and stem discoloration was observed and the root cortex sloughed off. A Phytophthora sp. was isolated from the roots and lower stems of symptomatic plants. Koch's postulates were completed in a greenhouse at 28 to 34°C using the cvs. Snowflake, Violet, and Orchid. Inoculum was obtained by growing the fungus for 7 days in Petri dishes containing an autoclaved wet mixture of polished rice + wheat bran + V8 juice + perlite (1:1:1:1, by volume). The inoculum was mixed with soil (4:100, wt/wt) in pots, and 15 4-month-old plants per cultivar were transplanted into infested and noninfested soil. Plants of the cv. Snowflake were the most susceptible with symptoms starting 25 days after inoculation. At the end of the trial (five months) 86% of these plants died. Disease development was delayed on plants of cvs. Orchid and Violet and mortality was only 20% on Orchid and 26% on Violet. Control plants remained healthy. The Phytophthora sp. was reisolated from plants showing typical symptoms. The fungus was cultivated on potato-dextrose agar at 25°C and morphological characteristics were recorded. The colony diameter was 3.7 cm after 5 days. Ovoid, obturbinate and obpyriform to limoniform, papillate and caducous sporangia were observed. They averaged 42.1 ± 10.7 × 31.7 ± 9.2 μm (range 25.0 to 65.0 × 18.7 to 55.0 μm) with a length-breadth ratio = 1:1 to 1.81, av. 1.25:1. Many sporangia were distorted in their shapes and averaged 61.7 ± 30.5 × 24.8 ± 4.5 μm (range 27.5 to 125.0 × 20.0 to 32.5 μm) with a length-breadth ratio = 1.31:1 to 4.6:1, av. 2.1:1. After the zoospores were discharged, a narrow exit pore was observed (3.7 to 8.7 μm, av. 6.9 μm). Pedicels were not conspicuous or were short when present. Oogonia and amphigynous antheridia were readily observed in single culture. Spherical oospores nearly filling the oogonium and containing many subcellular inclusions averaged 29.7 ± 8.9 μm (range 17.5 to 47.5 μm). Terminal or intercalary, rounded to ovoid chlamydospores developed in smooth or swollen hyphae. Based on cultural and morphological characteristics, the species infecting waxplant was identified as P. boehmeriae Sawada (1). This is the first record of P. boehmeriae on geraldton waxplant. References: (1) D. C. Erwin and O. K. Ribeiro. 1996. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN.
First Report of Natural Hybrids of Phytophthora nicotianae and P. cactorum on Loquat in Taiwan
Authors: Man in 't Veld W. A. 
Published: May 2007

In 1995 loquat trees (Eriobotrya japonica [Thunb.] Lindl.) in several orchards in central Taiwan suffered from a severe stemrot and rootrot (2). Two populations of Phytophthora spp. isolates were recovered from diseased trees by placing pieces of plant tissue in a petri dish containing selective medium (2). One group of isolates possessed papillate sporangia, appeared to be heterothallic with amphigynous antheridia, and had a maximum growth temperature of 36°C. Upon mating, isolates of this group produced oogonia and oospores measuring 26.1 and 21.4 μm in diameter, respectively. These isolates were identified as typical strains of P. parasitica (=P. nicotianae) (2). The second group of isolates showed papillate sporangia, was homothallic with predominantly amphigynous antheridia, and had a maximum growth temperature of 34.5°C. However, the sizes of oogonia and oospores were considerably larger (average 34.7 and 30.3 μm in diameter, respectively) than those of P. nicotianae. Amplification of genomic DNA of one isolate (95023) of the second group by polymerase chain reaction (PCR) using P. nicotianae species specific primers PAR1 and PAR2, produced a special 1,000 bp sequence, indicating that the atypical isolates of second group were closely related to P. nicotianae. Isozyme analysis of two isolates (95023 and 95034, provided by L. L. Chern, Taiwan) of the second group, using the dimeric enzymes malic enzyme (MDHP; EC 1.1.1.40) and malate dehydrogenase (MDH; EC 1.1.1.37), was applied as described before (1,3). These two isolates generated the same three banded patterns using either enzyme (genotype: MDHP: 92/100; MDH-2: 93/100); the Mdhp92 allele and the Mdh-293 allele are diagnostic for P. cactorum, whereas the Mdhp100 allele and the Mdh-2100 allele are diagnostic for P. nicotianae. These well-defined heterozygous band patterns were exactly identical to those generated in atypical isolates which were identified earlier as hybrids of P. nicotianae and P. cactorum (1,3). Based on their atypical morphology and isozyme genotyping, it was concluded that these two isolates of the second group represent hybrids of P. nicotianae and P. cactorum. One of the parents, P. nicotianae, was also found closely associated with diseased loquat trees; the other parental species, P. cactorum, was not isolated from loquat in this study. It is the first time that natural hybrids of P. nicotianae and P. cactorum were found on loquat in Asia. References: (1) P. J. M. Bonants et al. Phytopathology 90:867–874, 2000. (2) L. L. Chern et al. Plant Dis. 82:651–656, 1998. (3) W. A. Man in 't Veld et al. Phytopathology 88:922–929, 1998.
First Report of Cassava virus X in Cassava in Venezuela
Authors: Chaparro-Martínez E. I. , Trujillo-Pinto G. 
Published: May 2007

Cassava (Manihot esculenta Crantz) is a vegetatively propagated tropical root crop. Viral infections have been identified as an important biotic component limiting cassava production (2). To survey for virus diseases, symptomatic samples of cassava plants were collected from the Venezuelan cassava production states Amazonas, Aragua, Barinas, Cojedes, Monagas, and Portuguesa. Mechanical transmissions to a differential host (Chenopodium quinoa) and a previously described double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) procedure (3) were used to test for the presence of Cassava virus X (CsVX). The DAS-ELISA procedure used gamma globulin diluted 1/2,000, conjugate diluted 1/2,000, and leaf sap extracts diluted 1/100 (1). CsVX and frog skin disease (detected graft inoculation tests with cultivar Secundina and electron microscopy) were detected in mixed infections in plants collected in Barinas. CsVX was not detected in any of the plants collected in the other surveyed areas. The low incidence of the virus (11.43%; 4 of 35 samples) suggests that CsVX has been introduced only recently via infected planting stock. Transmission of the virus is 100% when infected cuttings are used as propagation material. CsVX caused no symptoms on any of the cultivars examined in the field, and the occurrence of symptomless CsVX in Venezuela may result from the inadvertent use of cuttings from virus-infected plants. This is the first report of CsVX in cassava in Venezuela. References: (1) B. L. Nolt et al. Ann. Appl. Biol. 118:105, 1991. (2) B. L. Nolt et al. Plant Pathol. 41:348, 1992. (3) A. C. Velasco et al. 1994. Prog. Virol. Yuca, CIAT, Cali, Colombia.
First Report of Psittacanthus angustifolius on Psidium guineense and Pinus tecunumanii in Honduras
Authors: Melgar J. , Berrios M. , Mathiasen R. , Howell B. 
Published: May 2007

The mistletoe Psittacanthus angustifolius Kuijt (Loranthaceae) is a common parasite of pines in Central America and southern Mexico (1,2). In August 2000, we observed this mistletoe parasitizing a wild guava tree, Psidium guineense Sw., ≈5 km north of Yamaranguila, Department Intibuca, Honduras, at an elevation of 1,800 m. Only one plant was found on a single tree, and wild guava is apparently a rare host for this mistletoe because we have not observed this host-parasite combination in other areas where Psidium guineense occurs. This is the first report of P. angustifolius on a plant other than Pinus spp. In November 2000, we observed this mistletoe parasitizing Pinus tecunumanii (Schw.) Eguiluz et Perry ≈4 km north of Opatoro, Department La Paz, Honduras, at an elevation of 1,700 m. Several pines were infected, but no trees had more than five mistletoe infections. To our knowledge, this is the first report of P. angustifolius on P. tecunumanii in Honduras, although it is known to occur on this host in Chiapas, Mexico. Specimens of P. angustifolius from these hosts have been deposited at the Herbario, Escuela Nacional de Ciencias Forestales, Siguatepeque, Honduras. References: (1) R. Mathiasen et al. Plant Dis. 84:203, 2000. (2) R. Mathiasen et al. Plant Dis. 84:808, 2000.
First Report of Parietaria mottle virus on Tomato in Spain
Authors: Aramburu J. 
Published: May 2007

During spring 2001, plants of different tomato (Lycopersicon esculentum) cultivars grown in several commercial fields in the eastern Catalonia Region of Spain had fruit with brown patches and young leaves with rings and a bright necrotic mosaic that progressed to stem necrosis of the apex, which might die and later develop new symptomless shoots. The symptoms were similar to those of Cucumber mosaic virus (CMV) and Tomato spotted wilt virus (TSWV). Sap of tomato sample R1 (in buffered saline [0.02 M sodium phosphate, 0.15 M NaCl at pH 7.2, containing 0.2% 2-mercaptoethanol]) was infective to Cucumis sativus (local necrosis), tomato cv. Marmande (systemic infection consisting of chlorotic local lesions and necrotic mosaic), Nicotiana clevelandii and N. benthamiana (chlorosis and rosetting), and Chenopodium quinoa (chlorotic local lesions, systemic mottle, and leaf distortion). The sap was not infective to N. glutinosa, N. tabacum cv. Xanthi, Datura stramonium, or Gomphrena globosa. The host range data indicated that the infective agent in sample R1 could be Parietaria mottle virus (PMoV) (1). Symptomatic plants inoculated in a greenhouse with the R1 isolate and symptomatic from tomato plants from the field were analyzed by indirect enzyme-linked immunosorbent assay (ELISA) and had minimum ELISA values at least 10-fold higher than healthy controls, using a polyclonal antiserum (provided by P. Roggero) of a tomato strain of PMoV denoted tomato virus 1 (2). The R1 isolate of PMoV was negative in ELISA when analyzed with commercial antisera to TSWV, CMV, Tomato mosaic virus, Tomato bushy stunt virus, Potato Y virus, Tobacco etch virus, Pelargonium zonate spot virus, and Tobacco streak virus. References: (1) P. Caciagli et al. Plant Pathol. 38:577, 1989. (2) P. Roggero et al. J. Plant Pathol. 82:159, 2000.
Occurrence of Diaporthe phaseolorum var. meridionalis on Soybean in Illinois
Authors: Gravert C. E. , Li S. , Hartman G. L. 
Published: May 2007

Both Diaporthe phaseolorum var. caulivora and D.phaseolorum var. meridionalis cause stem canker on soybean, with D. phaseolorum var. caulivora reported in the northern regions and D. phaseolorum var. meridionalis reported in the southern regions of the United States (1). During the 1999 and 2000 growing seasons, fungi were isolated from soybean plants from growers' fields exhibiting stem canker symptoms. Stem tissue along the margin of the canker was cut into 1- to 5-mm3 pieces, surface-disinfected for 4 min in 0.5% NaOCl solution, rinsed twice, and plated on water or potato dextrose agar (PDA). Fungi of interest were hyphal tipped, grown on PDA at 21°C with 24 h of light, and identified by culture and spore morphology after 3 to 4 weeks. Typical D. phaseolorum var. meridionalis isolates produced white, lanose colonies that turned tan with age. Most of the D. phaseolorum var. meridionalis isolates produced pycnidia with alpha spores and beaked perithecia after 25 to 30 days (2). Brown to black stromata formed in irregular shapes. Of the 16 D. phaseolorum var. meridionalis isolates identified, 11 were from Illinois, 1 each from Indiana and Ohio, and 3 from Kentucky. In Illinois, four isolates were from the northern part of the state, and the rest were from the central and southern areas of the state. In addition to D. phaseolorum var. meridionalis, other isolates obtained from soybean plants included D. phaseolorum var. caulivora, D. phaseolorum var. sojae, and Phomopsis longicolla. References: (1) J. A. McGee and D. C. Biddle. Plant Dis. 71:620, 1987. (2) A. W. Zhang et al. Phytopathology 88:1306, 1998.
First Report of Frankliniella fusca as a Vector of Impatiens necrotic spot tospovirus
Authors: Naidu R. A. , Deom C. M. , Sherwood J. L. 
Published: May 2007

Of more than a dozen members of the genus Tospovirus, Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV) are among the most damaging viruses found in North America (3). TSWV is a major problem in vegetable and field crops, whereas INSV is commonly encountered in the floriculture and nursery industries. TSWV is transmitted by several thrips species, of which the western flower thrips (WFT, Frankliniella occidentalis Pergande) is the most predominant vector. INSV has been reported to be transmitted only by WFT (1). To determine if tobacco thrips (TT, F. fusca Hinds) can transmit INSV, a virus-free culture of TT was reared on detached peanut cv. Florunner leaves in 0.5-liter polypropylene cups with closed lids at 25 ± 2°C with constant light. Fresh peanut leaves were exchanged every 2 to 3 days to maintain the thrips colony. For transmission studies, adult thrips were confined on peanut leaves for 24 h for oviposition and then the peanut leaves, sans adults thrips, were transferred to a new cup. Leaves were examined daily for larval emergence, and similarly aged first instar larvae (<12 h old) were given an acquisition access period of 24 to 48 h on INSV-infected detached leaves of Emilia sonchifolia. The larvae were subsequently transferred to healthy peanut leaves and reared until adult emergence. Groups of 10 adults per plant were given a 48-h inoculation access period on 10-day-old healthy E. sonchifolia seedlings. Thrips were subsequently killed, and the plants were maintained in a growth chamber at 28 ± 2°C, and with a 16/8 light/dark photoperiod. Transmission studies were repeated 10 times with different sources of infected plants and different batches of larvae following acquisition access periods. Seven to ten days after inoculation, plants developed symptoms consisting of chlorotic spots, mosaic, and mottling. The presence of INSV in these symptomatic plants was confirmed by ELISA using INSV ImmunoStrip Test (Agdia, Inc., Elkhart, IN) and by reverse transcription-polymerase chain reaction assay with primers specific to the INSV-NSs gene. Our results demonstrate that TT can serve as a vector of INSV. INSV has been reported in peanut in the southeastern United States (2). WFT and TT transmit TSWV in peanuts, with the latter being the predominant vector species in Georgia and other parts of the region. TT transmission of INSV is of concern because of the increased incidence in recent years of INSV in peanuts and the potential for synergistic or gene exchange between TSWV and INSV, since mixed infections with both viruses have been observed (4). References: (1) M. L. Daughtrey et al. Plant Dis. 81:1220, 1997. (2) S. S. Pappu et al. Plant Dis. 83:966, 1999. (3). J. L. Sherwood et al. Pages 1034–1040 in: Encyclopedia of Plant Pathology. C. Maloy and T. D. Murray, eds. John Wiley and Sons, Inc., New York, 2001. (4) L. Wells et al. Phytopathology (Abstr.) 94:S94, 2001.