bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Report of Cylindrocarpon destructans as a Root Pathogen of Mediterranean Quercus Species in Spain
Authors: Sánchez M. E. , Lora F. , Trapero A. 
Published: May 2007

Cylindrocarpon spp. have been described as producing root rot in Quercus spp. in forest nurseries, mostly when the host plants were weakened (1). To our knowledge, this is the first description of root rot of Mediterranean Quercus (Q. ilex, Q. suber, and Q. faginea) seedlings caused by C. destructans. In spring 2000, heavy mortality of Quercus seedlings was recorded in a nursery in southeastern Spain. The affected plants were 9 months old and growing in the open air in fertilized peat. Symptoms consisted of browning and wilting of leaves, with extensive necrosis of feeder roots. C. destructans (macroconidia averaging 36 × 6 μm, 1 to 3 septate; microconidia 10 × 3 μm; chlamydospores rough, single, or in chains, averaging 9 μm in diameter) was consistently isolated from the necrotic rootlets. Pathogenicity of one isolate from Q. faginea and of a mixture of isolates from the three affected Quercus spp. was determined. Fungal isolates were grown on potato dextrose agar plates for 1 month to allow chlamydospore production, and the inocula were prepared by mixing the contents of three colonized plates with 125 ml of sterile water. Six replicates of 12-month-old Q. ilex and Q. suber seedlings were inoculated by mixing the inoculum from the three plates with the potting medium prior to planting the seedling. All inoculated and control plants (only water added) were grown in a sand-lime-peat soil mixture under greenhouse conditions and watered as needed. After 5 weeks, all the inoculated plants showed extensive root necrosis accompanied by crown symptoms and rapid plant death. No symptoms were evident in control plants, and they produced new rootlets. No significant difference in pathogenicity was noted between the single isolate compared with the mixture of isolates, and the Quercus species did not significantly differ in susceptibility to root rot. C. destructans was easily recovered from necrotic roots. Reference: (1) D. Brayford. Cylindrocarpon. Pages 103–106 In: Methods for Research on Soilborne Phytopathogenic Fungi. American Phytopathological Society, St. Paul, MN, 1992.
Occurrence of Severe Outbreaks of Leaf Mold Caused by Fulvia fulva in Greenhouse Tomatoes in Chile
Authors: Latorre B. A. , Besoain X. 
Published: May 2007

Severe outbreaks of leaf mold, affecting as much as 100% of the plants, have occurred in greenhouse tomatoes (Lycopersicon esculentum Mill.) in the V Region in the central zone of Chile (32°50′ to 33°10′ latitude south) during the past 2 years. Symptoms consisted of yellow spherical to elongated leaf spots, first noticeable on the upper surface of older leaves, followed by leaf necrosis and defoliation. Invariably, an olive green-to-gray leaf mold developed on the under surface of the spots. No symptoms were observed on fruits and rarely occurred on petioles and stems. Isolation on acidified potato dextrose agar (APDA) consistently yielded dark green colonies of a very slow growing fungus that was identified as Fulvia fulva (Cooke) Cif. (=Cladosporium fulvum Cooke) (1). Identification was based on the presence of a dark septate mycelium, ovoid to ellipsoid conidia, usually one or two cells, pale or slightly yellow, 11 × 40 μm long, and the presence of mostly unbranched conidiophores that were broader at the tip. Conidia were produced in short chains, and a very distinctive hilum was always observed (1,3). Thin sections of leaf lesions revealed the presence of inter- and intracellular mycelia that protruded through the stomata forming a small stroma in the stomatal cavity from which the conidiophores were produced. Leaf inoculations of tomato cvs. Fortaleza and Cal-Ace with a mixture of mycelia and conidia from isolates Fv1 and Fv2 on APDA (approximately 106 propagules per ml) and with three different samples of conidia (106 conidia per ml) obtained directly from actively growing lesions resulted in the development of pale to dark yellow spots after 12 to 15 days of incubation under greenhouse conditions (temperatures ranging from 9 to 30°C). Leaf spots developed mainly on inoculated leaflets, but occasionally symptoms were obtained on other leaflets on the same leaf. Reisolations made from samples of artificially inoculated leaves always yielded F. fulvia on APDA. Therefore, it was concluded that F. fulvia was the cause of the severe outbreaks of tomato leaf mold found in central Chile. Previously, it has been reported in northern Chile (I Region approximately 2,000 km away) (2). To our knowledge, this is the first confirmed report of leaf mold on greenhouse tomato in central Chile. References: (1) P. Holliday and J. L. Mulder. Fulvia fulva. No. 487 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1976. (2) F. Mujica and C. Vergara. Flora Fungosa Chilena. 2nd ed. Universidad de Chile, Facultad de Agronomía, Santiago, Chile, 1980. (3) A. F. Sherf and A. A. Macnab. Vegetable Diseases and Their Control, 2nd ed. John Wiley and Sons, New York, 1986.
First Report of Basal Stem Rot Caused by Pythium Group G on Kenaf in South Africa
Authors: Swart W. J. , Tesfaendrias M. T. , Botha W. 
Published: May 2007

Kenaf (Hibiscus cannabinus L. Malvaceae) presents a source of high-quality cellulose fibers and is being investigated in South Africa for commercial production. In March 2001, 12 5-month-old kenaf plants grown from seed in experimental plots near Bloemfontein, South Africa, displayed large, black, sunken lesions (10 to 20 cm long) at the base of the stem, and severe root rot. A study was undertaken to characterize the pathogen, and to determine the relative susceptibilities of five kenaf genotypes being considered for commercial cultivation. Isolations from diseased tissue on malt extract agar consistently yielded a fungus identified as Pythium group G (1). Four-month-old kenaf plants were artificially inoculated in the field by inserting wooden toothpick tips colonized by the pathogen approximately 25 cm above soil level into the stems of 10 plants of each of five genotypes. Inoculation points were wrapped using Parafilm. The fungus was highly virulent to all five kenaf genotypes in two experiments, with mean cambial lesion lengths of 117, 119, 120, 122, and 139 mm at 7 days after inoculation for Tainung-2, Cuba 108, SF-459, El Salvador, and Everglades 41, respectively. Lesions ranged from 44 to 164 mm, with an overall mean of 124 mm for all five genotypes. No lesions developed in control plants. Although Everglades had the longest lesions, there were no significant differences (P < 0.05) among genotypes. Koch's postulates were completed by reisolating the fungus from all inoculated plants. To our knowledge, there are no published reports of Pythium group G causing stem or root rot of kenaf. References: (1) M. W. Dick. Keys to Pythium. University of Reading Press, Reading, UK, 1990.
First Report of the Root-Knot Nematode Meloidogyne kralli in Switzerland
Authors: Karssen G. , Grunder J. 
Published: May 2007

The root-knot nematode Meloidogyne kralli Jepson was originally described from Carex acuta L. near the Elva River in Estonia (3). This species, which was rarely detected in Russia, Poland, and the UK, was observed on Cyperaceae hosts in very wet, sandy, peat, and silt soils (1). Although marked as a rare and unusual root-knot nematode, a wider European distribution was hypothesized, particularly for natural habitats where Cyperaceae are common (4). In October 2001, we finished the first root-knot nematode survey in Switzerland, which included a protected peat-moss area named Hüttensee near Wädenswil at 660 m altitude. Small smooth galls were observed on the roots of different Carex species. These galls contained several hatched second-stage juveniles, partly swollen juveniles, and a few swollen adult females with small egg masses. No protruding egg masses were observed outside the galls and no males were observed inside. Second-stage juveniles together with males also were isolated from adhering soil. The identification of these nematodes as M. kralli was based on female and second-stage juvenile morphology, and female malate dehydrogenase and esterase isozyme phenotypes (2,4). M. kralli is the only root-knot nematode known to parasitize Cyperaceae hosts, although this nematode has other monocotyledonous hosts, such as Hordeum vulgare L. (1). To our knowledge this is the first published report of M. kralli from the Alps. References: (1) M. W. Brzeski. Nematodes of Tylenchina in Poland and Temperate Europe. Page 242 in: Muzeum i Instytut Zoologii PAN, Warszawa, Poland, 1998. (2) P. R. Esbenshade and A. C. Triantaphyllou. J. Nematol. 17:6, 1985. (3) S. Jepson. Rev. Nematol. 6:239, 1983. (4) G. Karssen and T. van Hoenselaar. Nematologica 44:713, 1998.
First Report of Powdery Mildew on Euryops pectinatus in Italy
Authors: Garibaldi A. , Minuto A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Euryops pectinatus is grown in Italy for landscape use in parks and gardens. In 2001, severe outbreaks of a previously unknown powdery mildew were observed in commercial farms located in Albenga (northern Italy). All green parts (leaves, stems, and petioles) became covered with a white mycelium. Infections were particularly severe on the upper leaf surface. With progress of the disease, infected leaves turned yellow and died. The presence of powdery mildew infections on leaves and stems only rarely was linked to growth reduction. Conidia were hyaline, cylindric to slightly doliform, did not show fibrosin bodies, borne in chains, and measured 24 to 41 × 12 to 20 μm. Cleistothecia were not observed. The pathogen was identified as Oidium sp. subgen. Fibroidium (1). Pathogenicity was confirmed by gently pressing diseased leaves on leaves of healthy E. pectinatus plants. Inoculated plants were maintained in a growth chamber at 20 to 24°C. After 12 to 14 days, powdery mildew symptoms developed. A similar disease of E. pectinatus was observed in 1999 in California and identified as being caused by Podosphaera (Sphaerotheca) fusca (2). It is possible that the powdery mildew observed in Italy belongs to the same species, also considering that recently the two genera, Podosphaera and Sphaerotheca, have been unified in the genus Podosphaera (1). References: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (2) G. S. Saenz et al. Plant Dis. 84:1048, 2000.
First Report of Phoma exigua on Centaurea solstitialis (Asteraceae) in Russia
Authors: Widmer T. , Castlebury L. , Rossman A. 
Published: May 2007

Phoma exigua Desm. (teleomorph Didymella exigua (Niessl) Sacc.) was isolated from wilted Centaurea solstitialis L. (yellow starthistle) plants displaying necrosis of the crown that were found near Krasnodar, Russia. The fungus was identified using morphological and cultural characteristics (1,2) and confirmed by sequencing the complete internal transcribed spacer region of the nuclear rDNA (GenBank Accession No. AY089978). P. exigua is a relatively common soilborne fungus that is weakly pathogenic on a diverse range of primarily dicotyledonous plants throughout the world (1). To our knowledge, it has never been reported previously on members of the genus Centaurea. Yellow starthistle is native to eastern Europe and the Mediterranean Region, and is now a noxious weed in North America for which P. exigua is being investigated as a potential biological control agent. Repeated pathogenicity studies (N = 30) resulted in a mortality of 80 and 93% within 7 days when 1-week-old seedlings were transplanted in soil infested with P. exigua-colonized wheat seed at rates of 6.7 and 10% (vol/vol), respectively. Symptoms of the seedlings included necrosis of the stem and wilting of the seedling. Pycnidia were observed in the roots of dead seedlings. The isolate of P. exigua has been deposited as a dried specimen at the U.S. National Fungus Collections, Beltsville, MD (BPI 841766) and as a living culture at the CBS collection in Utrecht, Netherlands (CBS 110211). References: (1) G. Morgan-Jones and K. B. Burch. Mycotaxon 32:477, 1988. (2) H. A. Van Der Aa et al. Persoonia 17:435, 2000.
First Report of Strawberry Anthracnose (Colletotrichum acutatum) in Strawberry Fields in New York
Authors: Turechek W. W. , Heidenreich C. , Pritts M. P. 
Published: May 2007

Strawberry plants with red to black, sunken, fusoid lesions on runners and leaf petioles were found in several first-year plantings in grower's fields in western New York in 2000. Affected cultivars included Honeoye, Jewel, and Primetime. Sections of petiole were excised from lesion margins and plated on potato dextrose agar (PDA) amended with chloramphenicol, streptomycin sulfate, and tetracycline hydrochloride at 100 μg/ml. The fungus, Colletotrichum acutatum (J.H. Simmonds), was consistently isolated and identified based on conidia morphology and its growth rate in culture relative to reference cultures of C. acutatum, C. gloeosporoides, and C. fragariae (1,2). The average size of conidia produced on PDA was 15.2 × 5 μm. For each of six isolates, three plants each of six-week-old Honeoye and Kent were spray inoculated with a conidial suspension (106 conidia per ml), and petioles, leaves, and crowns were stabbed with a sterile pin following inoculation. After 14 days at 20 to 25°C, petioles and leaves on all inoculated plants developed lesions consistent with those seen in the field. The fungus was readily reisolated from leaf and petiole lesions. Subsequent inoculations on detached fruit under the same conditions yielded circular, sunken, dry lesions that produced a salmon-colored, slimy, spore mass typical of C. acutatum. This is the second report of strawberry anthracnose in the northeastern United States (3) and to our knowledge, the first report in New York. References: (1) J. A. García Muñoz et al. Mycologia 92:288, 2000. (2) P. S. Gunnel and W. D. Gubler. Mycologia 84:157, 1992. (3) J. A. LaMondia. Plant Dis. 75:1286, 1991.
Molecular Characterization of Tobacco leaf rugose virus, a New Begomovirus Infecting Tobacco in Cuba
Authors: Domínguez M. , Ramos P. L. , Echemendía A. L. , Peral R. , Crespo J. , Andino V. , Pujol M. , Borroto C. 
Published: May 2007

Tobacco (Nicotiana tabacum L.) is the main raw material for the cigar industry and one of the most important crops in Cuba comprising 49,654 ha. During the past 20 years, foliar rugosity and stunting symptoms have been observed in several tobacco producing areas. These symptoms were correlated with the presence of typical geminivirus nuclear inclusions and the transmission of the causal agent by whiteflies (Bemisia tabaci Genn) (1). To identify the suspect geminivirus, diseased leaf samples were collected in Havana province in 2000 and 2001. Sap extracts or leaf pieces were used to inoculate healthy tomato and tobacco plants by mechanical and graft inoculation procedures. Characteristic symptoms were reproduced in tobacco plants only by grafting (8 to 10 plants). DNA extracts from symptomatic plants were analyzed by Southern blot and polymerase chain reaction. The presence of a bipartite begomovirus was supported by the observation of hybridization signals (1.6 kb to 3 kb) at low stringency to probes derived from DNA-A and DNA-B of Taino tomato mottle virus. Furthermore, typical begomovirus amplicons of approximately 1.4 kb and 1.2 kb were amplified using the primer sets PAL1v1978-PAR1c715 and PAL1c1960-PAR1v722 (2), respectively. Amplicons were cloned, and their nucleotide sequences (nt) obtained from two clones each. Sequence for component A was assembled, and some fragments were compared with those for other begomoviruses using CLUSTAL W. For the CP gene (756 nt) (GenBank Accession No. AJ488768), the comparison revealed the highest percentages of nt identity with Sida golden mosaic virus from Florida (SiGMV-F, GenBank Accession No. AF049336) (86%), Tomato mottle virus (GenBank Accession No. L14460) (83.5%), and the yellow vein strain of Sida golden mosaic virus from Honduras (GenBank Accession No. Y11099) (83.3%). In addition, the percentages of nt identity obtained using the core region (a 540-nt fragment located between positions 147 and 687) of the CP gene from the tobacco virus were calculated. The best scores were as follows: SiGMV-F, 87.8%; Jatropha mosaic virus (JMV) from Puerto Rico (GenBank Accession No. AF058025), 86.9%; and Tomato rugose mosaic virus (GenBank Accession No. AF291705), 86.3%. Finally, comparisons of the common region (CR, 144 nt) revealed the highest values with JMV from Jamaica (JMV-JM) DNA-A and DNA-B (GenBank Accession Nos. AF324410 and AF324411; 89% and 91.1%, respectively). Interestingly, the CR analysis revealed the presence of the Ori-associated iterative motif GGGGT, which is the same in the CR of JMV-JM. Although the data suggest that the tobacco begomovirus is related to the JMV-JM isolate, it is a new species, and the name of Tobacco leaf rugose virus (TbLRV) is proposed. References: (1) S. Quintero and J. Santiesteban, Agrotec. Cuba 11(1), 1979. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993.
First Report of an Isolate of Pelargonium zonate spot virus in Commercial Glasshouse Tomato Crops in Southeastern France
Authors: Gebre-Selassie K. , Delecolle B. , Gognalons P. , Dufour O. , Gros C. , Cotillon A. C. , Parrella G. , Marchoux G. 
Published: May 2007

In summer 2000, symptoms similar to Pelargonium zonate spot virus (PZSV) were observed for the first time on tomato plants in southeastern France. The plants were from commercial glasshouse fresh-market crops. Symptoms observed were chlorotic mottling with bright yellow distinct rings on leaves and curved line patterns on stems. Fruit symptoms included chlorotic and necrotic spotting, marked concentric ring patterns, and distortions. Diagnosis was made from symptomatic leaves and fruits by mechanical inoculation on a set of host plants. Local chlorotic and necrotic lesions were observed on Chenopodium amaranticolor, C. quinoa, Cucumis sativus cv. Marketer, Cucumis melo cv. Vedrantais, Phaseolus vulgaris cv. Pinto, Vicia faba cv. D'Aguadulce, Vigna unguiculata cv. Black Eye, and systemic symptoms were observed on Capsicum annuum cvs. Yolo Wonder, Yolo Y, Florida VR2, and Criollo de Morelos 334, Datura stramonium, Lycopersicon esculentum cvs. Momor and Stevens, L. hirsutum (PI 134417 and PI 247087), Nicotiana benthamiana, N. clevelandii, N. tabacum cv. Xanthi nc, Ocimum basilicum cv. Latino, Petunia hybrida cv. Rose du ciel, and Physalis floridana. No reaction was observed on Pisum sativum cv. Douce Provence, Salvia splendens cv. Etna, or Zinnia elegans cv. Liliput. Symptoms on tomato of PZSV, Parietaria mottle virus (PMoV), and Tomato spotted wilt virus (TSWV) are similar, particularly those elicited in fruits. Therefore, the field samples were checked using double-antibody sandwich enzyme-linked immunosorbent assay against antisera of the type-strain of PZSV and tomato strain of PMoV and their homologous antigenes, which were supplied by D. Gallitelli and P. Roggero respectively, and our antiserum of TSWV. Electron microscopy of negatively stained preparations from leaves of tomato and D. stramonium showed that the sap contained very few paraspheric shaped particles, 26 to 29 nm in diameter. Three isolates collected from two different regions (Vaucluse and Bouches du Rhône) showed a very close serological relationship with the Italian type-strain of PZSV and tested negative against antisera of PMoV and TSWV. The French isolates were biologically different from the type-strain, but were similar to the Spanish strain of PZSV because they infected D. stramonium, N. benthamiana, O. basilicum, and V. unguiculata (2). Moreover, in transverse tissue sections, virions were not observed in the nucleus and tubular structures, unlike the Italian isolates, (1) but were present in the cytoplasm and particularly in the mesophyll cells. There are only a few records of the occurrence and distribution of PZSV in Mediterranean countries. References: (1) M. A Castellano and G. P Martelli. Phytopathol. Mediterr. 20:64, 1981. (2) M. Luis-Arteaga. Plant Dis. 84:807, 2000.
First Report of Sweet potato leaf curl virus in Peru
Authors: Fuentes S. , Salazar L. F. 
Published: May 2007

Leaf curling symptoms have been reported in sweet potato (Ipomoea batatas) plants infected with a geminivirus (1). Leaf curl disease appeared in Peru after the 1997 to 1998 El Niño, when the population and activity of whiteflies (Bemisia tabaci, B. argentifolii, and B. afer) increased. Approximately 6% of plants in farmers' commercial fields in San Ramón, Junín (September 2000) and Cañete, Lima (February 2001) showed typical leaf curling symptoms. Seventeen plants in total were collected from both places, and stem scions from those plants were graft-inoculated to I. setosa, which developed symptoms of leaf curling, interveinal chlorosis, and stunting. Total nucleic acid was obtained from infected sweet potato and I. setosa plants using cetyltrimethylammoniumbromide (CTAB) extraction, and primers PW285-3 (5′-CGT CGT TAG CAG TCT GCA GGC CTC CTC TAG-3′) and PW285-4 (5′ -AAC TGT AAA TAC GGA ACT GCA GTT CGA ATT-3′) for Sweet potato leaf curl virus (SPLCV), developed and provided by R. Valverde and C. Clark of Louisiana State University (2), were used to amplify SPLCV by polymerase chain reaction (PCR). Expected DNA fragments of ca. 900 bp (in all samples) and 2.4 kp (in some samples), characteristic of the subgenomic and genomic DNAs of SPLCV respectively, were obtained from symptomatic but not from symptomless (uninfected) plants. This 2.4-kb fragment was amplified in relatively small amounts compared to the 900-bp fragment. Presence of SPLCV was also confirmed by nucleic acid spot hybridization using a full-length clone of SPLCV-US. Fourteen of 17 plants infected with SPLCV were also infected with Sweet potato chlorotic stunt virus (determined by nitrocellulose membrane enzyme-linked immunosorbent assay serological test), which is also transmitted by whiteflies. These viruses now seem to be common in farmers' fields in San Ramón and Cañete. To our knowledge, this is the first report of SPLCV in Peru. References: (1) P. Lotrakul et al. Plant Dis. 82:1253, 1998. (2) P. Lotrakul and R. A. Valverde. Cloning of a DNA-A like genomic component of sweet potato leaf curl virus: nucleotide sequence and phylogenetic relationships. Molecular Plant Pathology On-Line ( http://www.bspp.org.uk/mppol/1999/0422lotrakul/paper.htm ), 1999.