bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Exobasidium Disease of Fruit and Leaves of Highbush Blueberry
Authors: Cline W. O. 
Published: May 2007

Fruit of highbush blueberries (Vaccinum corymbosum L.) in southeastern North Carolina have been observed to suffer from sporadic outbreaks of distinct green spots on ripe fruit. Though edible, affected fruit are unsightly in market containers of fresh berries. In 1997, this disorder affected over 25% of the berries from a 5.7-ha field of the cv. Wolcott, rendering all fruit from this field unsaleable. In May 1998, the symptom was again observed in a planting of cv. Croatan. Samples were collected on the packing line from hand-harvested fruit and from the field. Sharply delineated green spots were observed on otherwise normal ripe fruit. The spots were 2 to 10 mm in diameter, circular or rarely irregular, not sunken or protruding, and often tinged with red. Affected tissues in ripe fruit extended 2 to 3 mm into the berry and were the texture and color of green, unripe fruit. Sparse white fungal growth was visible on the surface of some affected areas. In the field, spots were observed on fruit and leaves. Incidence was estimated at 5 and 1%, respectively. Spots on affected leaves were circular, 4 to 7 mm in diameter, light green, slightly thickened, and smooth on the upper surface; the underside was covered with dense white fungal growth. Microscopic examination of thinly sectioned berry and leaf tissue in water mounts revealed round basidia bearing 2 to 6 (most often 4) basidiospores (4.0 to 5.2 × 13 to 15 μm). Spores were consistent with descriptions of Exobasidium vaccinii (Fuckel) Woronin (1), being musiform to fusiform, slightly curved, and hyaline with a conspicuous hylar appendage, some with transverse septa. This is the first report of blueberry fruit infection by an Exobasidium species. Reference: (1) F. L. Caruso and D. C. Ramsdell, eds. 1995. Compendium of Blueberry and Cranberry Diseases. American Phytopathological Society, St. Paul, MN.
Gliricidia Little Leaf Disease in Costa Rica
Authors: Kenyon L. , Harrison N. A. , Richardson P. A. 
Published: May 2007

Gliricidia sepium is a multipurpose, legume tree species native to Central America and Mexico with wide social and economic importance. Gliricidia little leaf disease (GLLD) is associated with infection by a phytoplasma and is manifested by one or more symptoms, including leaflet yellowing, leaflet size reduction, shortened internodes, and shoot proliferation, often leading to branch die-back or death of young trees. Trees with symptoms were seen in fences and natural stands in the Nicoya Peninsular and on road sides west of San Jose, Costa Rica. Shoot samples were collected from eight symptom-bearing trees in different locations and from two healthy-looking trees in the southeast where no GLLD symptoms were observed. DNA from each sample was used as template in polymerase chain reaction (PCR) with universal phytoplasma rRNA gene primers P1 and P7 (1). DNA from a GLLD-infected tree from Honduras, and a pigeon pea witches'-broom infected Cajanus cajan from Florida, served as positive controls, while DNA from healthy G. sepium and C. cajan seedlings were used as negative controls. A 1.8-kb PCR product, indicative of presence of phytoplasma DNA, was amplified from all symptom-bearing tree samples and positive control DNAs, but not from DNA from the apparently healthy trees or seedlings. Restriction fragment length pattern analysis of PCR products with a range of endonucleases showed no difference between the Honduran and Costa Rican phytoplasma isolates. The distribution and symptom types observed in Costa Rica suggest that GLLD has recently arrived from Nicaragua and is spreading southeast. Reference: (1) L. Kenyon et al. Plant Pathol. 47:671, 1998.
First Report of Bipolaris sorghicola on Johnsongrass in Argentina
Authors: Acciaresi H. , Mónaco C. 
Published: May 2007

Target leaf spot was found on johnsongrass (Sorghum halepense (L.) Pers.) in La Plata, Argentina (34°54′S, 58°30′W). Up to 80% disease severity was observed in adult plants. In most diseased plants, spots were well defined, delimited by leaf veins, and elongated. Individual lesions ranged in size from small spots (2 to 3 mm) to large lesions (10 to 15 mm). Lesions sometimes coalesced to produce extensive areas of necrosis. Isolates identified as Bipolaris sorghicola (Lefebre & Scherwin) Alcorn (1) grew slowly on potato dextrose agar medium, producing a compact dark brown mycelium. Conidia were 40 to 80 μm long, slightly curved and golden brown, with three to seven pseudosepta. Although germination of conidia was mainly bipolar, lateral germination sometimes was observed. Twenty monoconidial isolates were inoculated at 105 conidia per cm3 on johnsongrass at the 4-leaf stage to confirm the pathogenicity of B. sorghicola. After inoculation, plants were placed in a high-humidity chamber for 24 h; thereafter, they were kept at 25°C day and 18°C night temperatures. Typical lesions developed after 10 days. The pathogen was reisolated from lesions after 15 days. Johnsongrass is one of the most noxious weeds in the world. Due to its potential as a biocontrol agent, further studies are needed to determine the effect of B. sorghicola on johnsongrass. Reference: (1) J. L. Alcorn. Mycotaxon 27:1, 1983.
First Report of Soilborne Rye Mosaic Virus in Rye in Denmark
Authors: Nielsen S. L. , Nicolaisen M. , Koenig R. , Huth W. 
Published: May 2007

Soilborne wheat mosaic furovirus (SBWMV)-like particles were detected in rye (Secale cereale) grown in sandy soil in West Zealand during spring 1999. Infected plants showed yellow leaf mosaic and light stunting. Electron microscopy of negatively stained crude sap preparations revealed rigid rod-shaped particles with two average lengths, 296 and 162 nm; average diameter was 23 nm. Sap-inoculation to Chenopodium quinoa and C. amaranticolor produced local leaf lesions when grown at 17°C but none when grown at 22 to 25°C. All the features agree with the description of SBWMV (1). Immunosorbent electronmicroscopy with polyclonal antiserum produced by W. Huth to furovirus-like particles isolated from rye in Germany gave a distinct decoration to particles. Light microscopy of roots cleared with 10% KOH and stained with a 0.5% solution of trypan blue in lactoglycerol revealed resting spores with a morphology and size similar to Polymyxa graminis, a furovirus vector. This is the first record of a furovirus on cereals in Denmark. The complete nucleotide sequence of the isolate was analyzed and compared with data on isolates from wheat. Sequence identity was only 74%. Therefore, the isolate was designated as soilborne rye mosaic virus. SBRMV has been recorded previously in rye and triticale in several regions of Germany (2). References: (1) M. K. Brakke. 1971. CMI/AAB Descr. Plant Viruses No. 77. (2) W. Huth. Nachrichtenbl. Dtsch. Pflanzenschutzdienstes 50:163, 1998.
Powdery Mildew Caused by an Oidium sp. on Twenty-One Annual Medicago spp. in California
Authors: Graves W. L. , Stuteville D. L. , Johnson R. C. , Greene S. L. 
Published: May 2007

Powdery mildew was observed in plots of USDA Plant Introduction accessions of medic plants grown for seed increase at Riverside, CA, from 1995 to 1998. White, diffuse to dense, amphigenous mycelia bearing Oidium conidia appeared on shoots in April each year and remained active until the last plants matured in June. Invaded leaflets became necrotic and dropped prematurely, sometimes leaving a green petiole. However, mildew incidence was low in most plots, and symptomless plants occurred in all species. Conidia were ellipsoid-cylindrical and measured 15 to17 × 39 to 47 µm. A sexual state of the fungus was not observed. Morphological characteristics of the anamorph matched those of Erysiphe pisi (1). In growth chambers, conidia from medic plants caused severe mildew of garden pea (Pisum sativum L. ‘Early Perfection’). Powdery mildew occurred in plots of Medicago ciliaris, M. constricta, M. coronata, M. disciformis, M. doliata, M. granadensis, M. intertexta, M. italica, M. lesinsii, M. littoralis, M. lupulina, M. minima, M. murex, M. noeana, M. orbicularis, M. rigidula, M. rotata, M. rugosa, M. scutellata, M. truncatula, and M. turbinata. We believe this is the first report of naturally occurring powdery mildew on these species in the United States. Reference: (1) H. J. Boesewinkel. Bot. Rev. 46:167, 1980.
First Report of East African Cassava Mosaic Begomovirus in Nigeria
Authors: Ogbe F. O. , Atiri G. I. , Robinson D. , Winter S. , Dixon A. G. O. , Quin F. M. , Thottappilly G. 
Published: May 2007

Cassava (Manihot esculenta Crantz) is an important food crop in sub-Saharan Africa. One of the major production constraints is cassava mosaic disease caused by African cassava mosaic (ACMV) and East African cassava mosaic (EACMV) begomoviruses. ACMV is widespread in its distribution, occurring throughout West and Central Africa and in some eastern and southern African countries. In contrast, EACMV has been reported to occur mainly in more easterly areas, particularly in coastal Kenya and Tanzania, Malawi, and Madagascar. In 1997, a survey was conducted in Nigeria to determine the distribution of ACMV and its strains. Samples from 225 cassava plants showing mosaic symptoms were tested with ACMV monoclonal antibodies (MAbs) in triple antibody sandwich enzyme-linked immunosorbent assay (1). Three samples reacted strongly with MAbs that could detect both ACMV and EACMV. One of them did not react with ACMV-specific MAbs while the other two reacted weakly with such MAbs. With polymerase chain reaction (2), the presence of EACMV and a mixture of EACMV and ACMV in the respective samples was confirmed. These samples were collected from two villages: Ogbena in Kwara State and Akamkpa in Cross River State. Co-infection of some cassava varieties with ACMV and EACMV leads to severe symptoms. More importantly, a strain of mosaic geminivirus known as Uganda variant arose from recombination between the two viruses (2). This report provides evidence for the presence of EACMV in West Africa. References: (1) J. E. Thomas et al. J. Gen. Virol. 67:2739, 1986. (2) X. Zhou et al. J. Gen. Virol. 78:2101, 1997.
Occurrence of Smut Caused by a Ustilago sp. on Dry-Beans
Authors: Costa J. L. da S. , de Oliveira V. C. 
Published: May 2007

In September 1997, after the tropical winter season and following a long warm (28 to 33°C) and rainy (27 mm) period, smut symptoms were observed on two dry-bean (Phaseolus vulgaris) fields in Brazil. Brownish to blackish powdery masses of spores were observed on stems, pods, and roof green and senescent plants. No galls were observed. Hyphae in infected tissue were intercellular; no clamp connections were observed. Typical globose teliospores were observed that measured 7 to 11 μm. Spores were uninucleate or binucleate; predominantly brownish with flattened poles and equatorial band; the exospore wall was thick and surface ornamented (echinulate-type). Teliospores incubated in water drops generated transversely septate promycelia, unbranched, producing terminal and lateral basidiospores. The fungus did not grow well on potato dextrose agar (PDA) medium, generating yeastlike colonies. To confirm pathogenicity of a Ustilago sp., spores collected from field-infected plants were inoculated on 8- and 20-day old seedlings of dry-bean cultivars Rosinha and Perola. Spore suspensions of 105 teliospores were sprayed all over the plants. After inoculation, plants were kept in a moist chamber (relative humidity [RH] 100%) for 2 days. At the third day, inoculated plants were covered with clear polyethylene bags and transferred to the greenhouse (RH 50%, temperature 25 ± 2°C). Noninoculated controls were included for comparisons. Within 2 weeks, all inoculated plants reproduced field symptoms of darkened tissues covered by profuse sori containing teliospores and basidiospores. Eight-day-old plants died 2 weeks after inoculation. Noninoculated plants did not develop any symptoms. Teliospores obtained from dead plants were identical to those used for inoculation, thus completing Koch's postulates. Fischer (1), and later Fischer and Shaw (2), proposed a species concept for Ustilago based on morphology (primarily of the teliospore), symptomatology, and host specialization at the host-family level. Although the teliospores found on dry-beans, in Brazil, are much like those of Ustilago maydis, the fungus did not cause galls on plants, was able to infect roots and kill seedlings. and is very well adapted to a legume plant. Cross inoculation tests indicated that spores from dry-beans cannot cause disease symptoms on maize. We therefore regard the bean smut as a new species. We are not aware of any other Ustilago sp. being reported on a legume host. References: (1) G. W. Fischer. 1953. Manual of the North America Smut Fungi. (2) G. W. Fischer and C. G. Shaw. Phytopathology 43:181, 1953.
Occurrence of Dactylaria higginsii on Purple Nutsedge in Florida
Authors: Kadir J. B. , Charudattan R. 
Published: May 2007

In September 1994, a population of severely diseased purple nutsedge (Cyperus rotundus L.) was found in Gainesville, FL. The symptoms were characterized by necrotic leaf spots, blotches, and foliar blighting. A fungal isolate was consistently recovered from symptomatic leaves and grown in pure culture. Based on the characteristics of conidia (28.6 × 6.6 μm) and conidiophores (45.2 × 7.0 μm at the broadest base), the fungus was identified as Dactylaria higginsii (Luttrell) M.B. Ellis. This fungus was first described as Piricularia [sic] higginsii from Georgia (4) and later redescribed as D. higginsii (2). A Pyricularia sp. and P. grisea (Cooke) Sacc. have been recorded on C. alternifolius L., C. papyrus L., and other Cyperus spp. from Florida, but species of Pyricularia or Dactylaria have not been reported from this state on purple nutsedge (1). Proof of pathogenicity (Koch's postulates) was established in repeated trials in a greenhouse; the disease symptoms were reproduced, and the fungus was reisolated from inoculated plants and confirmed to be the same organism used for inoculations. Four- to six-leaf-stage purple nutsedge and yellow nutsedge (C. esculentus L.) plants were sprayed with a suspension of 1 × 106 conidia per ml amended with 0.02% Silwet L-77 (vol/vol). Control plants were sprayed with 0.02% Silwet L-77 only. Small, water-soaked lesions developed 4 days after inoculation. The lesions coalesced into larger necrotic blotches with grayish centers 8 days after inoculation. Most of the inoculated foliage was blighted within 15 days after inoculation. The disease did not kill nutsedge bulbs or tubers, but reduced shoot and tuber yields. None of the control plants developed any symptoms. The ability of D. higginsii to cause severe disease and reduce the yields of vegetative organs indicates that it has potential as a biological control agent for purple nutsedge and yellow nutsedge, two of the world's worst weeds. This is the first record of occurrence of D. higginsii outside of its original distribution in Georgia (3). References: (1) S. A. Alfieri, Jr., et al. 1994. Diseases and Disorders of Plants in Florida. Bull. No. 14. Division of Plant Industry, Gainesville, FL. (2) M. B. Ellis. 1976. More Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England. (3) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN. (4) E. S. Luttrell. Mycologia 46:810, 1954.
First Report of Soybean Dwarf Virus Infecting Lentil and Beet Western Yellows Virus Infecting Lentil and Chickpea Crops in Ethiopia
Authors: Tadesse N. , Ali K. , Gorfu D. , Abraham A. , Lencho A. , Ayalew M. , Yusuf A. , Makkouk K. M. , Kumari S. G. 
Published: May 2007

A survey conducted during November 14–23, 1998, to identify viruses infecting chickpea (Cicer arietinum) and lentil (Lens culinaris) crops in the Shewa province of Ethiopia covered 33 chickpea and 32 lentil fields randomly selected. Identity of the viruses present and virus incidence were determined on the basis of laboratory testing of 100 to 200 randomly collected samples in addition to 15 to 20 symptomatic samples from each field. A total of 5,427 lentil and 3,836 chickpea samples were collected and tested for the presence of 12 different viruses by tissue blot immunoassay (1) at the Plant Pathology Laboratory in Debre Zeit Agriculture Research Center, Ethiopia. All antisera were virus specific, including those for beet western yellows virus (BWYV; ATCC PVAS-647) and soybean dwarf virus (SbDV; ATCC PVAS-650). More than 21% of the samples from 5 chickpea fields were infected; the most common virus was BWYV. Also, at least 21% of the samples from 11 lentil fields were virus positive; the most widespread virus was PSbMV. Highest rates of infection: of lentil in a single field, PSbMV in 58.5% of the samples; in a chickpea field, 41.3% of the samples positive for BWYV. Other viruses such as faba bean necrotic yellows nanovirus (FBNYV) and broad bean wilt fabavirus in chickpea and FBNYV, broad bean stain comovirus, bean yellow mosaic potyvirus, and cucumber mosaic cucumovirus in lentil were detected at very low incidence. Reference: (1) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994
First Report of Clover Yellow Edge Phytoplasma in Corylus (Hazelnut)
Authors: Jomantiene R. , Postman J. D. , Montano H. G. , Maas J. L. , Davis R. E. , Johnson K. B. 
Published: May 2007

During investigations into the cause of a stunt syndrome affecting cultivated European hazelnut trees (Corylus avellana L.) in Oregon, the clover yellow edge (CYE) phytoplasma was detected for the first time in this crop. The cause of hazelnut stunt syndrome (HSS) is unknown, but the disease has been transmitted by grafting and apparently has moved within orchards through root grafts (1). Severely affected trees persist for many years, but their nut production is greatly reduced. Previous attempts to detect viruses, bacteria, and other pathogens have been unsuccessful. HSS has been observed only in Oregon and already had been present for more than 10 years when it was first reported in 1970 (1). In June, 1999, leaf samples were collected from two affected and two apparently healthy (symptomless) hazelnut trees in a field plot at Oregon State University, Corvallis, and from a healthy greenhouse-grown tree. Leaf samples were sent to the USDA Beltsville, MD, laboratory, where they were assessed for phytoplasma infection, using nested polymerase chain reactions (PCRs). PCRs were primed by phytoplasma universal primer pairs P1/P7 and F2n/R2 (3) for amplification of phytoplasma 16S ribosomal (r) DNA (16S rRNA gene) sequences according to the procedures of Gunderson and Lee (2). Phytoplasma-characteristic 1.2-kbp DNA sequences were amplified from all field-tree samples. No DNA sequences were amplified from samples of the greenhouse-grown tree. Restriction fragment length polymorphism patterns of rDNA digested with AluI, KpnI, HhaI, HaeIII, HpaII, MseI, RsaI, and Sau3A1 endonucleases indicated that all diseased hazelnut trees as well as symptomless field trees were infected by a phytoplasma classified in group 16SrIII (peach X-disease group), subgroup B (III-B, type strain CYE phytoplasma). No phytoplasmas were detected in samples from the greenhouse-grown tree. Nucleotide sequences were determined for 16Sr DNA fragments amplified from the hazelnut CYE phytoplasma in nested PCRs primed with F2n/R2. The sequences were deposited in GenBank under Accession no. AF189288. Sequence similarity between 16Sr DNAs of the hazelnut CYE strain (CYE-Or) and the Canadian clover yellow edge strain (CYE-C, GenBank Accession no. AF175304) phytoplasma was 99.9%. Decline and yellows disorders of hazelnut in Germany and Italy have been associated with infections by apple proliferation, pear decline, and European stone fruit yellows phytoplasmas (4). These phytoplasmas are classified in 16Sr group X, the apple proliferation group of phytoplasmas. This is the first report of the CYE phytoplasma infecting Corylus. References: (1) H. R. Cameron. Plant Dis. Rep. 54:69, 1970. (2) D. E. Gunderson and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (3) R. Jomantiene et al. HortScience 33:1069, 1998. (4) C. Marcone et al. Plant Pathol. 45:857,1996.
Natural Infection of Alstroemeria brasiliensis with Lily Mottle Virus
Authors: Bouwen I. , van der Vlugt R. A. A. 
Published: May 2007

During a survey for a European Union-funded project on viruses of Alstroemeria, two A. brasiliensis plants were found expressing virus-like symptoms, including leaf chlorosis with deep-green oval spots and flower color breaking. In enzyme-linked immunosorbent assays (ELISA), no positive reaction was obtained with antisera to Alstroemeria mosaic, Alstroemeria carla, Cucumber mosaic, Freesia mosaic, or Tobacco rattle virus or potyvirus-specific monoclonal antibodies (Agdia, Elkhart, IN). ELISA reactions were positive with antisera to Lily mottle (LMoV) and Rembrandt tulip breaking viruses (1). In electron microscopy preparations of A. brasiliensis, potyvirus-like particles were observed. Using sap-inoculation, the virus was transferred to a range of host species. Chenopodium quinoa, Nicotiana occidentalis accession 37B, and N. occidentalis subsp. obliqua (P1) expressed local lesions; N. clevelandii expressed local and systemic mottle; and N. benthamiana expressed local lesions, systemic vein yellowing, and leaf crinkling. Isolated total RNA from infected N. benthamiana was used for initial cDNA synthesis and polymerase chain reaction amplification with a potyvirus-specific primer set (2). The amplicon (≈670 bp) was cloned and sequenced. The sequence showed 92% homology with the corresponding region of LMoV RNA (GenBank accession no. S44147). The results confirm the infection of A. brasiliensis with LMoV. This is the first report of natural infection of Alstroemeria by LMoV. References: (1) E. L. Dekker et al. J. Gen. Virol. 74:881, 1993. (2) R. A. A. van der Vlugt et al. Phytopathology 89:148, 1999.