bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Record of Xiphinema pacificum from a Peach Orchard in Georgia
Authors: Nyczepir A. P. , Lamberti F. 
Published: May 2007

In April 2000, a Xiphinema sp. was found in a peach (Prunus persica (L.) Batsch) orchard during a longidorid nematode survey in Concord, GA. The nematode was recovered from the rhizosphere of healthy and dying peach trees established on Lovell rootstock. Following a comparative microscope study, the species was identified as X. pacificum Ebsary, Vrain, & Graham, a putative species of the X. americanum group (2). All morphometric measurements coincided with the original description (1). In North America, this group of nematodes are natural vectors of four economically important nepoviruses that are responsible for causing substantial damage to a wide variety of crops. In spring 1999, tree death from bacterial canker (Pseudomonas syringae pv. syringae) occurred within this then 2-year-old orchard. Samples showed that populations of X. pacificum and Pratylenchus sp. were greater under dying trees (34 and 143/100 cm3 of soil) than under healthy trees (19 and 30/100 cm3 of soil), respectively. Samples taken during the 2000 survey contained 10 X. pacificum per 100 cm3 soil under apparently healthy trees. This nematode was originally described from British Columbia, Canada, where it seemed to be restricted in its distribution to vineyards in the south Okanagan Valley. To our knowledge, this is the first report of X. pacificum in the United States. References: (1) B. A. Ebsary et al. Can. J. Zool. 67:801, 1989. (2) F. Lamberti et al. Russian J. Nematol. 8:65, 2000.
First Report of Phoradendron macrophyllum on Populus tremuloides
Authors: Gilbertson R. , Mathiasen R. 
Published: May 2007

Phoradendron macrophyllum (Engelm.) Cockerell (Viscaceae) is a common mistletoe found on at least 60 hardwood tree species, including several species of cottonwood (Populus spp.) (1), and is distributed from northern Mexico through Arizona and New Mexico into central California (1). R. Gilbertson recently received a specimen of what appeared to be P. macrophyllum parasitizing a planted aspen (Populus tremuloides Michx.) on the Wear Ranch near Fort Grant, Graham County, AZ (T. 11 S., R. 21 E., Section 11). A large swelling on a branch bearing a few small mistletoe plants measuring less than 5 cm high indicated the infection. Comparison of the mistletoe leaf trichomes with those of P. macrophyllum (trichomes with two branches from a common base) and P. coryae Trel. (trichomes stellate with secondary and tertiary branching) indicated that the specimen was definitely P. macrophyllum (2). To our knowledge, this is the first report of P. macrophyllum, or any other mistletoe, on aspen. References: (1) R. Scharpf and F. Hawksworth. USDA For. Serv. Pest Leafl. 147, 1974. (2) D. Wiens. Brittonia 16:11, 1964.
First Report of Daylily Rust in the United States
Authors: Williams-Woodward J. L. , Hennen J. F. , Parda K. W. , Fowler J. M. 
Published: May 2007

In August 2000, rust symptoms were observed on the leaves of daylily plants (Hemerocallis sp. cv. Pardon Me) at a nursery in Dearing, GA. Based on urediniospore characters, the pathogen was tentatively identified as Puccinia hemerocallidis Thuem. Urediniospores were globose to ellipsoid and measured 19 to 30 × 17 to 22 μm (average size of 22 × 19 μm), corresponding to the previously reported description from Japan (1). Teliospores were absent from the sample but were found on daylily plants (cv. Star Struck) with symptoms similar to cv. Pardon Me from the same nursery in Dearing beginning in October 2000. However, the teliospores differed from those in the published description in that many one-celled teliospores (i.e., mesospores), measuring 32 to 43 × 14 to 19 μm (average size of 38 × 16 μm), were produced in addition to two-celled teliospores, which measured 41 to 53 × 16 to 21 μm (average size of 46 × 18 μm). Similar mesospores were present in a slide from an isotype specimen of P. hemerocallidis (US 72719) housed in the U.S. National Fungus Collection (Beltsville, MD). Daylily plants (cv. Pardon Me) were reinoculated with urediniospores by shaking infected plants over uninfected plants and exposing plants to 100% relative humidity for 24 h. Initial symptoms of small, discrete, yellow spots and streaks on the upper surfaces of leaves developed within 3 to 7 days, and uredia with urediniospores were evident at 7 to 14 days after inoculation. Daylily rust is native to Asia and may have been introduced into Georgia on plant materials sent from Central America. The original source of daylily rust is unclear because Central American producers also purchase and import plants from the United States for propagation and then sell divisions back to U.S. growers. Daylily rust is a disease of major concern for both daylily producers and gardeners. References: (1) N. Hiratsuka, et al. The Rust Flora of Japan. Tsukuba Shuppankai, Ibaraki, Japan, 1992.
First Report of Shoot Blight of Grapevine Caused by Sclerotinia sclerotiorum in Chile
Authors: Latorre B. A. , Guerrero M. J. 
Published: May 2007

Grapevine (Vitis vinifera L.), cv. Red Globe, in Northern Chile was found with symptoms of shoot blight early in the spring. Symptoms consisted of elongated cankered lesions surrounded by water-soaked tissues that developed mainly at the base of new shoots. The distal part of the shoots withered. Symptoms were similar to the shoot blight caused by Botrytis cinerea Pers. early in the spring, except that superficial gray sporulation was always absent. Isolation on acidified potato dextrose agar (APDA) consistently yielded a fungus that produced white mycelium and black spherical to elongated sclerotia (2 to 10 mm in diameter); the fungus was identified as Sclerotinia sclerotiorum (Lib.) de Bary (2). New shoots were inoculated by inserting a 4-mm plug of mycelium from actively growing cultures on APDA into a cut made at the base of each of five shoots per cultivar with a sterile scalpel. Inoculated wounds were sealed with Parafilm tape to avoid rapid dehydration. Inoculated plants and an equal number of wounded but not inoculated plants of each cultivar were left as controls and maintained in a screenhouse. Inoculations of grapevine cvs. Thompson Seedless, Flame Seedless, Red Globe, Ribier, and Chardonnay with S. sclerotiorum isolates SC-1, SC-2, and SC-3 and B. cinerea (isolate BC1-3 from grapevine) resulted after 7 days of incubation in canker lesions that were similar to those observed in the field. Cankers caused by S. sclerotiorum varied significantly (P < 0.05) in length from 13.3 to 28.7 mm on ‘Red Globe’, 5.3 to 20.7 mm on ‘Thompson Seedless’, 4.0 to 17.7 mm on ‘Flame Seedless’, 2.0 to 11.3 mm on ‘Ribier’, and 0.0 to 7.6 mm on ‘Chardonnay’. Mature berries of ‘Flame Seedless’ table grapes were surface-disinfected with 1% NaOCl for 1 min, punctured with a sterile needle, and inoculated with a mycelium plug. All S. sclerotiorum isolates and the B. cinerea isolate were pathogenic on mature berries, which developed a soft rot and superficial mycelium after 5 days of incubation at 25°C in humid chambers. Reisolations from diseased shoots and rotten berries were successfully performed on APDA. We concluded that S. sclerotiorum and B. cinerea could cause canker lesions on new shoots early in the spring. S. sclerotiorum has been previously associated with soft rotting of mature berries of grapes worldwide (1), but to our knowledge, this is the first confirmed report demonstrating that S. sclerotiorum can cause shoot blight. Considering that grapevines are cultivated on 2-m-high trellises in Chile, we speculate that wind disseminated ascospores may infect shoots. However, ascocarps have not yet been found in vineyards in Chile. References: (1) W. B. Hewitt. Berry rots and raisin molds. Pages 26–28 in: Compendium of Grape Diseases. R. C. Pearson and A. C. Goheen, eds. The American Phytopathological Society, St. Paul, MN, 1994. (2) L. Kohn. Phytopathology 69:881, 1979.
A New Bacterial Leaf Spot Disease of Broccolini, Caused by Pseudomonas syringae pathovar maculicola, in California
Authors: Cintas N. A. , Bull C. T. , Koike S. T. , Bouzar H. 
Published: May 2007

In 1998, a new disease was detected on 3-week-old commercial broccolini (Brassica oleracea L. var. botrytis × B. alboglabra) transplants in a Salinas Valley, Monterey County, CA greenhouse. Initial symptoms were small (2 to 4 mm diameter) circular to angular, water-soaked spots. As the disease progressed, spots remained relatively small, but turned tan to brown. When diseased tissues were macerated and streaked on King's medium B, a blue-green fluorescent pseudomonad was consistently isolated. Strains were levan positive, oxidase negative, and arginine dihydrolase negative. Strains did not rot potato slices, but induced a hypersensitive reaction on tobacco (Nicotiana tabacum L. ‘Turk’). Fatty acid methyl ester analysis (MIS-TSBA, version 4.10, MIDI Inc., Newark, DE) indicated that strains had a high similarity index (0.82 or higher) to Pseudomonas syringae, and GN (version 3.50, Biolog, Inc., Hayward, CA) profiles also identified strains as P. syringae. The bacterium associated with the disease, therefore, was identified as P. syringae van Hall. Pathogenicity was demonstrated by growing inoculum in nutrient broth shake cultures for 48 h, misting the broth cultures (1×106 CFU/ml) onto broccolini (cv. Aspabrock), and subjecting the plants to 48 h of high humidity. Control plants were misted with sterile nutrient broth. After 4 to 5 days in a greenhouse, leaf spot symptoms developed on all inoculated broccolini plants, and reisolated strains were characterized and found to be P. syringae. Control plants remained symptomless. The results of two sets of pathogenicity tests were the same. Repetitive sequence-based polymerase chain reaction using the BOXA1R primer resulted in identical banding patterns for the broccolini pathogen and for known isolates of P. syringae pv. maculicola from crucifers. In host range testing, P. syringae pv. maculicolawas pathogenic to broccolini plants. The broccolini isolates and P. syringae pv. maculicola isolates had the same pathogenicity results when crucifers and tomatoes were tested as hosts; broccoli and cauliflower (B. oleracea var. botrytis) were infected, and tomato results were variable. These tests suggest that the broccolini pathogen is the bacterial leaf spot pathogen, Pseudomonas syringae pv. maculicola, that occurs on broccoli and cauliflower transplants (1). To our knowledge, this is the first report of this pathogen causing a disease on commercially grown broccolini. Reference: (1) S. T. Koike et al. Plant Dis. 82:727, 1998.
First Report of Fusarium crookwellense Causing Tip Blight on Cones of Hop
Authors: Pethybridge S. J. , Hay F. S. , Wilson C. R. , Sherriff L. J. , Leggett G. W. 
Published: May 2007

Hop (Humulus lupulus L.) is grown primarily for the alpha and beta acids produced in the strobile (cone) and used for bittering beer. In late summer (March) 2001, necrotic lesions covering the tips of cones of cvs. Agate, Nugget, and Willamette at hop farms in Tasmania, Australia, were observed. The necrotic lesions encompassed the proximal tips and affected between 5 and 60% of the cone; however, all bracts in the whorl were always affected. Diseased cones were observed in all seven gardens included in the survey. The incidence of plants with cone tip blight in ‘Nugget’ ranged from 5 to 30% in three gardens, in ‘Agate’ ranged from 3 to 10% in three gardens, and in the only ‘Willamette’ garden 30% of cones were affected. Pieces of infected hop cones (N = 55) were surface-treated for 1 min in 2% sodium hypochlorite, placed on 2% water agar, and incubated at 22 ± 2°C. Fusarium crookwellense Burgess, Nelson, & Toussoun was isolated from 95% of the cones (1). F. crookwellense was identified on carnation leaf agar by L. Burgess, University of Sydney, Australia. Koch's postulates were fulfilled by inoculating detached mature hop cones of cvs. Nugget and Willamette (N = 20 for each cultivar) with an atomized conidial suspension (3.5 × 105 spores of a single F. crookwellense isolate per milliliter) until runoff and incubated at 20 ± 2°C in a sealed container on plastic mesh over tissue wetted with sterile distilled water. Symptoms first appeared 5 days after inoculation and were identical to those found in the field. No disease symptoms were observed on cones subjected only to sterile distilled water. The pathogen was reisolated from diseased tissue on inoculated cones, completing Koch's postulates. Similar disease symptoms on hop cones have been described in Oregon and were associated with infection by F. sambucinum and F. avenaceum (C. Ocamb, personal communication). To our knowledge, this is the first report of the infection of hop cones by F. crookwellense. Reference: (1) L. W. Burgess et al. Laboratory Manual for Fusarium Research, 3rd ed. University of Sydney, Australia, 1994.
Occurrence of Bacterial Leaf Spot of Escarole Caused by Pseudomonas cichorii in the Everglades Agricultural Area of Southern Florida
Authors: Pernezny K. , Raid R. N. 
Published: May 2007

In the fall of 1997, 1998, and 2000, a leaf spot disease of escarole (Cichorium endivia L.) was widespread among commercial plantings in the Everglades Agricultural Area (EAA), south and east of Lake Okeechobee, FL. Symptoms consisted of dry, dark gray-to-black lesions that expanded to ≈4 cm in diameter. Concentric rings were often observed in mature lesions. Growers and scouts in the area consistently identified this disease as Alternaria leaf spot, because the symptoms closely resembled Alternaria leaf spots seen on a number of other vegetables. Prolific bacterial streaming occurred when cut portions of lesions were observed microscopically. A fluorescent bacterium was consistently isolated when a sterile inoculation needle was pushed through lesions. Eight bacterial strains were isolated, restreaked to obtain pure cultures, and characterized. All strains were aerobic, gram-negative rods that were oxidase positive and arginine dihydrolase negative. Negative reactions were recorded for levan formation and rotting of potato slices. All strains utilized glucose, mannitol, and m-tartrate and were negative for sucrose, sorbitol, benzoate, d-arabinose, l-rhamnose, and cellobiose. Results for utilization of D-aspartate were variable. Based on these results, the causal agent of bacterial leaf spot of escarole was identified as Pseudomonas cichorii. Greenhouse-grown plants of escarole, cv. Full Heart, and Cos lettuce, cv. Tall Guzmaine, were mistinoculated with a suspension (107 CFU/ml) of each test strain from escarole and P. cichorii strain Pc28, originally isolated from celery (1). Plants were bagged for 3 days after inoculation. Symptoms characteristic of this disease were evident on escarole inoculated with all test strains and Pc28 6 days after inoculation. Pure cultures of P. cichorii were recovered from lesions on King's B medium. Three test strains produced mild leaf spot symptoms in Cos lettuce, but the symptoms were distinctly different from those associated with the common bacterial leaf spot of lettuce in Florida caused by Xanthomonas campestris pv. vitians (2). To our knowledge, this is the first report of P. cichorii causing this unusual target spot symptom on escarole in the EAA. References: (1) K. Pernezny et al. Plant Dis. 78:917, 1994. (2) K. Pernezny et al. Plant Dis. 79:359, 1995.
First Report of Tomato chlorosis virus in Italy
Authors: Accotto G. P. , Vaira A. M. , Vecchiati M. , Finetti Sialer M. M. , Gallitelli D. , Davino M. 
Published: May 2007

During winter 2000-2001, an unusual disease of tomato was observed in some greenhouses in Sardinia, Sicily, and Apulia, in southern Italy. Plants were chlorotic and reduced in size, expanded leaves showed interveinal yellowing, and older leaves developed interveinal reddish-bronze necrosis and downward rolling. The symptoms resembled those recently reported from Portugal (1) as induced by Tomato chlorosis virus (ToCV) (family Closteroviridae, genus Crinivirus), a whitefly-transmitted virus new to Europe. Symptomatic leaf tissues were extracted and analyzed by reverse transcription-polymerase chain reaction as described by Louro et al.(1). The 439-bp ToCV-specific DNA fragment was amplified in samples collected from 6 of 14 greenhouses in Sardinia, 2 of 5 greenhouses in Sicily, and 1 of 1 greenhouse in Apulia. The sequence of the fragment obtained from a Sicilian isolate (GenBank Accession No. AY048854) showed more than 99% identity to ToCV isolates (Accession Nos. AF024630 and AF234029) from the United States and Portugal, respectively. Infestations of Trialeurodes vaporariorum and Bemisia tabaci have been reported in autumn. To our knowledge, this is the first report of ToCV in Italy. Although we found the virus in three regions of the country, its distribution is likely to be wider, since the symptoms can be mistaken for those of a physiological disorder or of Tomato infectious chlorosis virus, another crinivirus infecting tomato. Reference: (1) Louro et al. Eur. J. Plant Pathol. 106:589, 2000.
First Report of Alfalfa Witches Broom Disease in Oman Caused by a Phytoplasma of the 16Sr II Group
Authors: Khan A. J. , Azam K. M. , Deadman M. L. , Al-Subhi A. M. , Jones P. 
Published: May 2007

Alfalfa (Medicago sativa L.) is a primary forage crop in the Sultanate of Oman. A new disease of alfalfa in Oman is characterized by proliferation of shoots and yellowing of leaves in 1- to 2-year-old plants and tillering of stems in 4- to 5-year-old plants. Annual losses due to this disease are estimated at more than US$ 23 million. Samples of healthy and infected alfalfa plants were collected from different regions. Total DNA was extracted according to Khadhair et al. (1), with minor modifications. Amplification of 16S rDNA was done using a nested polymerase chain reaction (PCR) approach with primers P1/P7 and R16F2n/R16R2. DNA from healthy leaves and sterile water was used as a negative control, while DNA from periwinkle infected with faba bean phyllody (16SrII-C), aster yellows (16SrI), tomato big bud (16SrII-D), sweet potato little leaf (16SrII-D), catharanthus phyllody (16SrVI), and sesame phyllody (16SrII-A) were used as positive controls and for restriction fragment length polymorphism (RFLP) comparisons. Nested 1.25-kb PCR products from infected plant samples were subjected to RFLP analysis with restriction endonucleases RsaI, AluI, HaeIII, HhaI, EcoRI, TaqI, Tru9I, and Sau3AI. The analysis showed that the alfalfa witches' broom phytoplasma (AWBP) belonged to the 16SrII group (peanut witches' broom) and that the AWBP was most similar to sweet potato little leaf (16SrII-D) but distinct from “Candidatus Phytoplasma aurantifolia,” the cause of lime witches' broom in Oman. Other phytoplasmas infecting alfalfa have been reported from Europe and North America (1,3), but they belong to the 16SrVI (clover phyllody) and 16SrI (aster yellows) groups. An alfalfa witches' broom reported from Italy (2) forms a separate grouping (4). To our knowledge, this is the first report of a phytoplasma from the peanut witches' broom group infecting alfalfa in the Sultanate of Oman. References: (1) A. H. Khadhair et al. Microbiol. Res. 152:259, 1997. (2) C. Marcone et al. J. Plant Pathol. 79:211, 1997. (3) R. D. Peters et al. Plant Dis. 83:488, 1999. (4) E. Seemuller et al. J. Plant Pathol. 80:3, 1998.
Disease of Floral Buds of Kiwifruit in Spain Caused by Pseudomonas syringae
Authors: González A. J. , Ávila M. 
Published: May 2007

In 1999 and 2000, decay of floral buds of Actinidia deliciosa was observed in plantations in the Principality of Asturias, Spain. Bud decay led to a decrease (up to 40%) in the production of kiwifruit. Floral buds with symptoms of browning and necrosis were collected from different areas (Villaviciosa, Grado, and Pravia) and processed for microbiological analysis. A fluorescent bacterium was recovered on King's B medium and identified as Pseudomonas syringae by the LOPAT scheme and Hugh-Leifson reaction (2). Other biochemical features included esculin and gelatin hydrolysis and acid production from mannitol, erythritol, sorbitol, and m-inositol, which are features associated with P. syringae (2). Three isolates from different samples were selected to test pathogenicity using Koch's postulates. Overnight broth cultures of each isolate (109 CFU/ml) were used to infect A. deliciosa in the trials by the following procedures: (i) atomization on branches and buds; (ii) bud injection (1 ml in each bud); and (iii) bud cutting with a scalpel dipped in the suspension. Branches and buds inoculated with sterile water were used as controls. The inoculated parts were enclosed in plastic bags for 48 h. Assays were repeated at least twice. Disease symptoms appeared 2 days later, initially as dark brown spots that developed into an extensive bud rot in all inoculated cases, while no symptoms occurred in controls. P. syringae was successfully recovered from infected samples but not from control samples. The data support the pathogenicity of P. syringae on A. deliciosa. Although P. syringae was previously reported in Italy as the causal agent of disease on floral buds of A. deliciosa (1), to our knowledge, this is the first report of infection of kiwifruit by this pathogen in Spain. References: (1) G. M. Balestra and L. Varvaro. J. Phytopathol. 145:375, 1997. (2) MAPA, Manual de laboratorio, MAPA, Madrid, Spain, 1991.
First Report of Tomato spotted wilt virus and Impatiens necrotic spot virus in Slovenia
Authors: Mavrič I. , Ravnikar M. 
Published: May 2007

In July 2000, concentric necrotic rings and patterns were observed on greenhouse-grown pepper (Capsicum anuum L. ‘Blondi’). Symptoms were present only on lower leaves, not on young leaves or fruits. Typical tospovirus particles using electron microscopy were observed in leaf-dip preparations of symptomatic leaves. Impatiens necrotic spot virus (INSV) was detected in symptomatic but not in asymptomatic tissues using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with polyclonal antiserum (Loewe Biochemica, Sauerlach, Germany). Nicotiana benthamiana, N. rustica, and Petunia sp. were mechanically inoculated with sap of symptomatic leaves. Local and systemic symptoms were observed only on N. benthamiana. Tomato spotted wilt virus (TSWV) infections were later confirmed in some pepper and tomato plants with distinct systemic symptoms and in greenhouse-grown chrysanthemums, calla lilies, cyclamen and spatiphylum using DAS-ELISA with polyclonal antiserum. Severe systemic symptoms were observed only on some chrysanthemum cultivars, where the infection rate of TSWV was between 80 and 100%. Such TSWV-infected plants were not marketable. Symptomless infections by the same virus were also found. At one location, calla lilies were heavily infected by TSWV, but only local symptoms on leaves were observed. INSV was also confirmed using DAS-ELISA on different chrysanthemum cultivars. Mixed infections of TSWV and INSV were detected using DAS-ELISA on calla lilies with local necrotic rings and patterns on leaves and on Impatiens walerana with systemic necrosis. A limited number of weeds from the vicinity of greenhouses containing symptomatic plants were tested for the presence of TSWV using DAS-ELISA, and only Artemisia vulgaris was infected. Both viruses, TSWV from chrysanthemum and INSV from pepper, were isolated on test plants, and their identity was confirmed using DAS-ELISA. For further verification of TSWV and INSV infection, immunocapture reverse-transcription polymerase chain reaction was performed using general tospovirus primers (1). Amplification products of the expected size were detected and sequenced. Comparison of nucleic acid sequences of amplification products with viral sequence databases confirmed the identities of both viruses. To our knowledge, this is the first report of TSWV and INSV infection in ornamental and vegetable plants in Slovenia. Reference: (1) R. J. Weekes et al. Acta Hortic. 431:159, 1996.