bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Beech Bark Disease in Michigan
Authors: O'Brien J. G. , Ostry M. E. , Mielke M. E. , Mech R. , Heyd R. L. , McCullough D. G. 
Published: May 2007

Beech bark disease of American beech (Fagus grandifolia) is caused by the interaction of an introduced scale insect (Cryptococcus fagisuga) and the native fungus Nectria galligena, or N. coccinea var. faginata, which is thought to be introduced. Infestations of the insect precede development of the disease, and N. galligena is often found before N. coccinea var. faginata. Previously published records indicate that the beech scale extends as far west as eastern Ohio (2) and southern Ontario (Sajan, personal communication). The scale is now well established in several locations in both the Upper Peninsula (UP) and Lower Peninsula (LP) of Michigan. The scale insect has been found in beech stands throughout three counties (Oceana, Mason, and Muskegon) along the Lake Michigan shore in the LP, extending for at least 100 km from north to south, and occurring up to about 80 km inland. In the eastern UP, beech scale has been found in four counties (Alger, Chippewa, Luce, and Schoolcraft). The heaviest beech scale infestations are distributed around Ludington State Park in the west central LP and the Bass Lake Forest Campground in the eastern UP. The extent of the insect infestation suggests that it has been present in Michigan for many years, with anecdotal accounts placing the first observations of beech scale at Ludington State Park around 1990. These infection centers are distant from previously known beech scale infestations and are located in heavily used recreation areas, suggesting that the insect may have been transported by human activity. Perithecia of N. coccinea var. faginata were found in Ludington State Park in the LP at N 44° 1.951', W 86° 29.956' and perithecia of N. galligena were found at the Bass Lake site in the UP, at N 46° 27.748', W 85° 42.478'. The identity of the fungi collected from each location was confirmed by measurements of perithecium and ascospore morphology (1). Perithecia at both sites were scarce and difficult to find. Surveys planned for the summer and fall of 2001 will further delimit the occurrence and distribution of the pathogens involved in the disease in Michigan. To our knowledge, this is the first report of the beech scale and beech bark disease in Michigan, with N. galligena and N. coccinea var. faginata identified as the pathogens. References: (1) H. V. T. Cotter and R. O. Blanchard. Plant Dis. 65:332–334, 1981. (2) M. E. Mielke et al. Plant Dis. 69:905, 1985.
First Report of Powdery Mildew of Kenaf Caused by Leveillula taurica in South Africa
Authors: Swart W. J. , Terblanche J. 
Published: May 2007

Kenaf (Hibiscus cannabinus L.) is a fast-growing, bamboo-like annual plant belonging to the Malvaceae. The stem, which ranges from 1.5 to 4 m, presents a source of high-quality cellulose fibers. The plant is being investigated in South Africa with a view to commercial production. In April 2001, at least 50% of 4- to 5-month-old kenaf plants grown from seed in trials near Rustenburg, Northwest Province, South Africa, were observed as having powdery mildew. Signs included extensive growth of white, superficial mycelium and emergent conidiophores on the abaxial leaf surface, followed by partial defoliation. On older leaves, the abaxial leaf surface was completely covered by powdery mildew, and chlorotic and necrotic patches were clearly visible on the adaxial surface. Symptoms were observed on all five planted cultivars (Everglades 41, Cuba 108, El Salvador, SF459, and Tainung 2), and no difference in disease severity was noted among cultivars. Leveillula taurica (Lév.) Arnaud (anamorph Oidiopsis taurica [Lév.] Salmon) was subsequently identified by the presence of endophytic mycelia, often branched conidiophores, and dimorphic conidia borne singly or in short chains (1). In 100 measurements of each type, pyriform conidia averaged 69 ± 5 × 18 ± 2 μm and cylindrical conidia averaged 62 ± 6 × 16 ± 2 μm. The teleomorph was not observed. The source of L. taurica for this reported outbreak is unknown, and powdery mildew was not observed in a field of mature cotton (Gossypium hirsutum L.) growing within 10 m of the kenaf plot. L. taurica was reported on kenaf in Texas in 1992 (2) and in Italy in 1995 (3). The pathogen can cause significant losses in seed yield and reduce seed quality in susceptible kenaf cultivars. Although L. taurica has been reported from Hibiscus sabdariffa in Egypt (4), to our knowledge this is the first report of the pathogen occurring on kenaf in Africa. References: (1) H. J. Boesewinkel. Bot Rev. 46:167, 1980. (2) C. G. Cook and J. L. Riggs. Plant Dis. 79:968, 1995. (3) S. Frisullo et al. Inf. Fitopatol. 45:37–41, 1995. (4) M. Khairy, et al. Phytopathol. Medit. 10:269–271, 1971.
First Report of Ceratocystis Wilt of Acacia mearnsii in Uganda
Authors: Roux J. , Wingfield M. J. , Byabashaija D. Mujuni 
Published: May 2007

Ceratocystis albofundus, the cause of Ceratocystis wilt of Acacia mearnsii, is known only from South Africa. The only known hosts of this fungus are A. mearnsii, Acacia decurrens, and two species of Protea (1). This pathogen causes stem cankers, xylem discoloration, wilt, and the death of susceptible A. mearnsii trees in South Africa, leading to considerable losses to the forestry industry (1). During a recent survey of forest plantation diseases in Uganda, A. mearnsii trees with “streaked” discoloration of the xylem, typical of Ceratocystis infection, were found in southwestern Uganda. These trees had been damaged mechanically by the harvesting of side branches and/or stems for firewood and construction. Xylem discoloration was spreading through the trees from these wounds. Trees showed typical stem cankers and gummosis, which is associated with C. albofundus infection, as well as foliage wilting. Isolations from infected trees yielded a fungus that was similar morphologically to C. albofundus, with typical hat-shaped ascospores and light-colored perithecial bases (2). Sequencing of the internal transcribed spacer region of the ribosomal RNA operon of Ugandan isolates (CMW5329, CMW5964, GenBank accession no. AF388947) confirmed their identification, grouping them with C. albofundus and separating them from all other Ceratocystis species. This is the first report of C. albofundus from a country other than South Africa. C. albofundus is an important pathogen, and strategies to reduce losses need to be established in Uganda because the aggressiveness of C. albofundus to A. mearnsii has been shown in inoculation experiments (1). References: (1) Morris et al. Plant Pathol. 42:814, 1993. (2) Wingfield et al. Syst. Appl. Microbiol. 19:191, 1996.
First Report of Botrytis cinerea on Kenaf in South Africa
Authors: Swart W. J. , Tesfaendrias M. T. , Terblanche J. 
Published: May 2007

Kenaf (Hibiscus cannabinus L.) (Malvaceae) is a source of high-quality cellulose fibers and is being investigated in South Africa with a view to commercial production. In April 2001, 20 to 30% of 5-month-old kenaf plants grown from seed in experimental plots near Rustenburg, Northwest Province, South Africa, were affected by gray mold caused by Botrytis cinerea Pers.:Fr. Infected plants displayed brown necrotic areas that girdled the stem, resulting in wilting and lodging in at least 50% of observed cases. Symptoms included extensive growth of mycelia and gray conidia on stem lesions. Microscopic examination revealed hyaline, one-celled conidia and conidiophores conforming to the description of B. cinerea. Plating of diseased stem tissue on malt extract agar (MEA) consistently yielded B. cinerea. Koch's postulates were satisfied by applying toothpick tips (5 mm) colonized by B. cinerea on MEA to the stems of 10 120-day-old greenhouse-grown plants of each of five kenaf cultivars. A colonized toothpick tip was placed on the stem of each of five plants per cultivar at a point ≍15 cm above soil level. Another five plants of each cultivar were wounded once using a sharp dissecting needle, and a colonized toothpick tip was placed on top of each wound. Corresponding control treatments consisted of five additional plants per cultivar, each wounded and mock-inoculated with sterile toothpick tips. Inoculation points were wrapped in Parafilm. The experiment was conducted twice. Developing lesions were measured after 7 days. Mean lesion lengths for the two treatments, nonwounded and wounded, on the five cultivars were, respectively: 32.4 and 35.2 mm for Everglades 41; 14.9 and 53.8 mm for Cuba 108; 39.5 and 55.8 mm for El Salvador; 19.0 and 44.3 mm for SF459; and 12.4 and 43.9 mm for Tainung 2. The Newman-Keuls multiple comparison test revealed no significant difference (P < 0.05) in means among cultivars for the wounded treatment. For the nonwounded treatment, Everglades 41 and El Salvador were significantly more susceptible (P < 0.05) than the three remaining cultivars. No lesions developed on control treatments. The fungus was reisolated on MEA from all artificially inoculated plants. The pathogen is reported to cause serious losses in yield and fiber quality of kenaf in Spain (1). This is the first report of B. cinerea on kenaf in South Africa, and its potential impact on kenaf production in this country should be taken seriously. Reference: (1) A. De Cal and P. Melgarejo. Plant Dis. 76:539, 1992.
Occurrence of Pink Patch of Perennial Ryegrass Caused by Limonomyces roseipellis in Italy
Authors: Maccaroni M. , Corazza L. , Buonaurio R. , Cappelli C. 
Published: May 2007

In March 1999, an unusual pink gelatinous mycelium was observed on several cultivars of perennial ryegrass (Lolium perenne L.) turf grown in experimental plots in Saint Andrea d'Agliano, Perugia (central Italy). Approximately 50% of the turf area showed symptoms on susceptible varieties. The same symptoms, although with lower severity, were observed during the following year in two experimental fields in northern Italy. The presence of mycelium on infected leaf blades was extensive during periods of high relative humidity and high temperature. The disease decreased progressively when weather conditions became dry and cold. A fungus, characterized by pink colonies, was consistently isolated from leaves of affected plants on potato dextrose agar (pH 5.5). On the basis of the presence of clamp connections and binucleate hyphal cells, the fungus was identified as Limonomyces roseipellis Stalpers & Loerakker, the causal agent of pink patch of turfgrass (1,3). For the pathogenicity test, one isolate of L. roseipellis was grown on maize flour and sand medium (2) at 22 ± 2°C for 14 days. Inoculum (20 g) was added to a sterile mixture of sand and peat moss (1:1; 640 g). Two hundred seeds of L. perenne (cv. Amadeus) were sown in boxes containing infested or noninfested soil as a control. Boxes were kept in a greenhouse at 22 ± 2°C, 80% relative humidity, and 14 h of sunlight per day. Four to five weeks after sowing, typical lesions resembling natural symptoms were observed only on plants grown in inoculum-infested soil, and L. roseipellis was consistently reisolated from diseased plants. Pink patch is probably underestimated in turf since the symptoms are less severe compared with red thread caused by Laetisaria fuciformis (McAlpine) Burdsall, and the development of mycelium of Limonomyces roseipellis is slower. References: (1) J. D. Kaplan and N. Jackson. Plant Dis. 67:159, 1983. (2) Y. L. Nene et al. ICRISAT Inf. Bull. 10:1, 1981. (3) J. A. Stalpers and W. M. Loerakker. Can. J. Bot. 60:529, 1982.
First Report of a Group 16SrI, Subgroup B, Phytoplasma in Diseased Epilobium hirsutum in the Region of Tallin, Estonia
Authors: Alminaite A. , Davis R. E. , Valiunas D. , Jomantiene R. 
Published: May 2007

Symptoms of phyllody of flowers and general plant yellowing indicating possible phytoplasma infection were observed in diseased plants of hairy willow-weed (Epilobium hirsutum L., family Onagraceae) growing in a meadow at Harku Village near Tallin, Estonia. DNA was extracted from diseased E. hirsutum using a Genomic DNA Purification Kit (Fermentas AB, Vilnius, Lithuania) and used as a template in nested polymerase chain reaction (PCR). Ribosomal (r) DNA was initially amplified in PCR primed by phytoplasma universal primer pair P1/P7 (4) and reamplified in PCR primed by nested primer pair 16SF2n/16SR2 (F2n/R2) (1) as previously described (2). Products of 1.8 kbp and 1.2 kbp were obtained in PCR primed P1/P7 and F2n/R2, respectively, from all four symptomatic plants examined. These data indicated that the diseased E. hirsutum plants were infected by a phytoplasma, termed epilobium phyllody (EpPh) phytoplasma. The 16S rDNA amplified in PCR primed by nested primer pair F2n/R2 was subjected to restriction fragment length polymorphism (RFLP) analysis using restriction endonucleases AluI, MseI, HpaI, HpaII, HhaI, RsaI, HinfI, and HaeIII (Fermentas AB). On the basis of the collective RFLP profiles, EpPh phytoplasma was classified in group 16SrI (aster yellows phytoplasma group), subgroup B (aster yellows phytoplasma subgroup), according to the phytoplasma classification scheme of Lee et al. (3). The 1.8-kbp rDNA product of P1/P7-primed PCR, which included 16S rDNA, 16S-23S intergenic spacer region, and the 5′ -end of 23S rDNA, was cloned in Escherichia coli using the TOPO TA Cloning Kit (Invitrogen, Carlsbad, Ca) according to manufacturer's instructions and sequenced. The sequence was deposited in the GenBank database as Accession No. AY101386. This nucleotide sequence shared 99.8% sequence similarity with a comparable rDNA sequence (GenBank Accession No. AF322644) of aster yellows phytoplasma AY1, a known subgroup 16SrI-B strain. The EpPh phytoplasma sequence was highly similar (99.9%) to operons rrnA (GenBank Accession No. AY102274) and rrnB (GenBank Accession No. AY102273) from Valeriana yellows (ValY) phytoplasma infecting Valeriana officinalis plants in Lithuania. ValY phytoplasma was found to exhibit rRNA interoperon sequence heterogeneity (D. Valiunas, unpublished data). To our knowledge, this is the first report to reveal E. hirsutum as a host of phytoplasma and to demonstrate the occurrence of a plant pathogenic mollicute in the northern Baltic region. References: (1) D. E. Gundersen and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (2) R. Jomantiene et al. HortScience 33:1069, 1998. (3) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (4) B. Schneider et al. Phlogenetic classification of plant pathogenic mycoplasma-like organisms or phytoplasmas. Page 369 in: Molecular and Diagnostic Procedures in Mycoplasmology, Vol 1, R. Razin, and J. G. Tully eds. Academic Press, San Diego, 1995.
First Report of False Smut of Corn (Zea mays) in the Mississippi Delta
Authors: Abbas H. K. , Sciumbato G. , Keeling B. 
Published: May 2007

False smut, caused by Ustilaginoidea virens, occurs on rice, corn, and other Gramineae, but is of little economic importance. False or green smut of corn resembles most closely false smut of rice (1). During surveys in 2000 at Mississippi State University, Delta Experiment Station, Stoneville, 32 (2.5%) of 1,280 commercial and inbred corn hybrids had false smut on the tassel. The percentage of plants infected with false smut ranged from 5 to 15% based on a sample of 20 corn plants from a single 4.9-m row plot. Galls (sclerotia), which are similar to ergot, replaced flowers on tassels of infected plants. Disease severity ranged from 2 to 50% infected flowers per inbred. Mature sclerotia were spherical, 6 to 17 mm in diameter, olive green to black, and velvety with white interiors. The fungus could not be isolated on potato dextrose agar. Only the tassels were infected, which resulted in little damage to the plant, except for a decrease in pollen production. Although the disease has been reported to infect other parts of the corn plant, the injury will likely be less on corn than rice. In 2001 and 2002, the disease was not observed. Disease incidence was more prevalent in 2000 because of hot, wet weather immediately after the crop was planted. The observation of the disease in one growing season suggests the pathogen may be common in the Mississippi Delta and the disease may occur under favorable environmental conditions and susceptible corn hybrids. Reference: (1) J. K. Pataky. False smut. Page 35 in: Compendium of Corn Diseases, 3rd ed. D. G. White, ed. American Phytopathological Society, St. Paul, MN, 1999.
First Report of Silybum marianum as a Host of Puccinia punctiformis
Authors: Berner D. K. , Paxson L. K. , Bruckart W. L. , Luster D. G. , McMahon M. , Michael J. L. 
Published: May 2007

Silybum marianum (L.) Gaertn. (milk thistle) is a problematic invasive weed in the western United States. The rust fungus, Puccinia punctiformis (F. Strauss) Rohl., is found throughout the world as a pathogen of Cirsium arvense (L.) Scop. (Canadian thistle). Recently, plants of S. marianum grown from surface-disinfested seeds in our quarantine greenhouse were parasitized by a rust. Apparently, an isolate of P. punctiformis collected from C. arvense in Turkey that was present in the greenhouse had spread to adjacent S. marianum plants and caused infection without applying any artificial dew period. Ribosomal internal transcribed spacer region sequences from fungal spore DNA isolated from the two hosts were identical. Initial signs on S. marianum were abundant, fragrant spermogonia on large leaves. These signs occur on secondary shoots of C. arvense and are indicative of systemic fungal infection (1). As the fungus infection developed on S. marianum, uredinia and urediniospores were produced. Sori on older leaves also produced teliospores. Urediniospores from infected leaves were harvested and sprayed uniformly on eight 17-day-old plants of S. marianum grown in isolation from P. punctiformis. The spore suspension consisted of 4 mg urediniospores suspended in 40 ml distilled water. Inoculated plants were incubated for 18 h in a dew chamber at 20°C in the dark and transferred to a greenhouse (20 to 25°C, 30 to 50% relative humidity, and natural light). After 13 days, uredia with urediniospores developed on four of the plants. Using the same procedure, inoculations were repeated on plants of S. marianum and S. eburneum Coss. & Durieu (the only other species described in the genus) with urediniospores of a domestic isolate of the fungus from C. arvense in Maryland. Of 51 inoculated plants of S. marianum, 23 became infected and produced uredinia. None of the 12 inoculated plants of S. eburneum showed symptoms of infection. In nature, C. arvense and S. marianum occupy different ecological areas. C. arvense is found predominately in humid temperate habitats, while S. marianum is found in habitats with a dry Mediterranean climate. Life cycles of each host are also different. C. arvense is a perennial that emerges in spring and dies back in winter, while S. marianum is a winter annual that emerges in fall and dies in late spring. Because of the differences in life cycles combined with the different geographical distribution, P. punctiformis from C. arvense may rarely encounter susceptible S. marianum plants in the field. Since fungal spores can be produced routinely on artificially inoculated plants, there might be potential to use P. punctiformis for biological control of S. marianum. To our knowledge, this is the first report of S. marianum as a host for P. punctiformis. Reference: (1) A. H. R. Buller. Puccinia sauveolens and its sexual process. Page 345 in: Researches on Fungi. Vol VII. The Sexual Process in the Uredinales, Toronto, Canada, 1950.
Natural Occurrence of Groundnut ringspot virus on Soybean in South Africa
Authors: Pietersen G. , Morris J. 
Published: May 2007

Mechanically transmissible viruses were isolated from two soybean (Glycine max Merr.) plants from Rustenburg, Northwest Province and Greytown, KwaZulu-Natal, South Africa, respectively (2). Viruses were isolated by two serial local-lesion transmissions on Chenopodium quinoa. Ringspot symptoms on Nicotiana benthamiana suggested the presence of tospoviruses. This was supported by the detection of typical tospoviruslike particles in ultrathin sections of infected plants. Serological analysis of samples using various tospovirus antisera in a number of enzymelinked immunosorbent assay formats suggested the two isolates had epitopes in common with Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV), and Tomato chlorotic spot virus (TCSV). Nucleotide sequences were determined using reverse transcriptionpolymerase chain reaction (RT-PCR) for 857 bp of the nucleoprotein gene of the two isolates (GenBank Accession Nos. AF487516 and AF 487517). These revealed a 99% nucleotide identity with each other. Sequence comparison with cognate regions of TSWV (GenBank Accession No. D00645), GRSV-SA-05 (GenBank Accession No. S54327), and TCSV (GenBank Accession No. S54325) revealed that both isolates share 97% nucleotide sequence identity with GRSV (SA-05) from peanut also originally from South Africa (1). Both isolates are therefore considered GRSV. To our knowledge, this is the first report of the natural occurrence of GRSV on soybean worldwide. References: (1) A. C. de Avila et al. J. Gen. Virol. 74:153, 1993. (2) G. Pietersen et al. Afr. Plant Prot. 4:65, 1998.
Recent Outbreak of Soybean Stem Canker Caused by Diaporthe phaseolorum var. caulivora in the Main Soybean-Producing Region of Argentina
Authors: Pioli R. N. , Morandi E. N. , Luque A. , Gosparini C. O. 
Published: May 2007

The first report of soybean stem canker (SSC) caused by Diaporthe phaseolorum var. caulivora in South America was published in 2001, and was based on an isolate obtained in 1999 at Oliveros, Santa Fe (32°33′S, 60°51′W), Argentina (2). During the 2001 to 2002 growing season, isolates of D. phaseolorum var. caulivora were obtained from stems of field-grown soybeans (Glycine max L.) exhibiting SSC symptoms. Isolates were collected in three localities of the main soybean-producing region of Argentina: Marcos Juárez, Córdoba (32°66′S, 62°10′W); Salto, Buenos Aires (34°20′S, 60°33′W); and Diego de Alvear, Santa Fe (34°21′S, 62°10′W), and disease incidence in the fields was 10 to 60%, 5 to 15%, and 10 to 20%, respectively. The pathogen was isolated on potato glucose agar acidified with 0.2% lactic acid cultured in the dark at 25 ± 1°C. White colonies with compact and tufted mycelium were produced and turned yellow and light tan after 6 days. Appressed and fluffy mycelia were observed in old cultures. Stromata (2 mm diameter) were produced but pycnidia were not detected. After 20 days in culture at 25 ± 1°C under a 12-h light and 12-h dark regime, clustered perithecia developed on stem segments. For each isolate, 10 perithecia, 90 asci, and 30 bicellular, biguttulate ascospores were measured. Averages of asci length and width were 28.3 ± 2.3 and 5.9 ± 0.7 μm, respectively. Averages of ascospores mean length and width were 8.4 ± 0.6 and 2.5 ± 0.4 μm, respectively. These measures were similar to the measures obtained previously (2). Based on these features, the new isolates were classified as D. phaseolorum var. caulivora (Athow & Caldwell). Clustered perithecia, smaller asci and ascospores, and the development of fluffy mycelia with age were the main characteristics that distinguished D. phaseolorum var. caulivora from D. phaseolorum var. meridionalis (1). Pathogenicity trials were performed on cvs. Tracy M, Crockett, Hutchenson, and RA 702 in the greenhouse by placing a small amount of mycelium in soybean seedling hypocotyls wounds made with a scalpel. The pathogen was reisolated from stem portions of the symptomatic plants. Control plants remained healthy. The results reported here show that D. phaseolorum var. caulivora is widely disseminated in the main soybean-producing region of Argentina, where it coexists with D. phaseolorum var. meridionalis (2). The coexistence of both varieties indicates pathogen variability in the region is higher than previously recognized. References: (1) R. N. Pioli et al. Plant Dis. 83:1071, 1999. (2) R. N. Pioli et al. Plant Dis. 85:95, 2001.