bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occurrence of Pestalotiopsis uvicola Causing Leaf Spots and Stem Blight on Bay Laurel (Laurus nobilis) in Sicily
Authors: Vitale A. , Polizzi G. 
Published: May 2007

In the spring of 2004, during a disease survey in three nurseries of eastern Sicily, a new leaf and stem problem was observed on 20 to 40% of young (2- to 6-month-old) container-grown bay laurel (Laurus nobilis L.). Affected plants exhibited sporadic water-soaked leaf spots on leaf edges that subsequently enlarged and turned into necrotic lesions. These spots were always bordered by a dark brownish margin. Frequently, these necrotic lesions expanded into stems causing blight of young shoots. No symptoms were observed on 2- to 3-year-old plants. Small portions (1 to 2 cm) of symptomatic tissue were surface disinfested for 30 s in 1% NaOCl, rinsed in sterile distilled water, placed on potato dextrose agar (PDA), and incubated at 22 ± 2°C. A fungus consistently isolated from affected tissues was identified as Pestalotiopsis uvicola (Speg.) Bissett based on morphological characters (1). Acervular conidiomata (as much as 250 μm in diameter) appeared in cultures on PDA at 24 ± 2°C over a period of 13 days. All isolates had 4-septate fusiform to narrow ellipsoid conidia with 2 to 4 apical appendages, often aggregated, and averaging 8 μm long. Conidia ranged from 20 to 25 μm long and 6 to 7 μm wide. Basal appendage was single, attenuated, and as much as 3 μm long. Three isolates of P. uvicola were selected for pathogenicity tests. Leaves and stems of 6-week-old seedlings of bay laurel were lightly wounded with a hypodermic needle, and a PDA mycelial plug (5 mm in diameter) was placed on the surface of wounded tissues. Sterile agar plugs were placed on control plants. This method was used to inoculate 6 plants for each isolate. All plants were incubated at 95 to 100% relative humidity and 25 ± 1°C. After 7 days, leaf spots and necrotic lesions on the stem similar to those observed in nurseries were observed. Control plants remained symptomless. Koch's postulates were fulfilled by reisolation of the fungus from affected tissues. Although found in only a few nurseries, the infections could be a threat to an important production area of bay laurel in Sicily. To our knowledge, this is the first report of P. uvicola on bay laurel in the world. Reference: (1) T. R. Nag Raj. Mycotaxon 26:211, 1986.
Occurrence of the Perfect Stage of Powdery Mildew of Sugar Beets in Southern Montana in 2003
Authors: Jacobsen B. , Johnston M. R. , Weltzien H. C. 
Published: May 2007

Wide spread powdery mildew infections on sugar beets were observed at the Southern Agricultural Experiment Station in Huntley, MT during September, 2003. Throughout the area, lower leaves were frequently heavily covered by the vegetative stage of the fungus with plants at the edge of the field having clearly visible abundant mature (black) and immature (brown) globose ascocarps on the leaf surfaces and stems. The fruiting structures had mostly branched appendages and were imbedded in the superficial mycelium. Their diameter ranged from 70 to 100 μm. Each ascocarp contained five to eight asci with one to four ascospores (mostly three) per ascus. Elliptical ascospores were hyaline and measured 20 to 25 μm long and 12 to 20 μm wide. On the basis of the descriptions given for isolates from Idaho and Colorado (1) and the usage of Erysiphe polygoni DC for powdery mildew on sugar beet in the United States, this isolate may be classified as E. polygoni DC. However, measurements taken show that ascocarps, asci, and ascospores also fall within the range of E. betae (Vanha) Weltz. as described by Weltzien (2). We strongly suggest that these species be compared by using rDNA analysis of the ITS region to determine whether they are separate species. If survival of the ascocarps and the viability and pathogenicity of the ascospores can be confirmed, epidemics of sugar beet powdery mildew could be understood as local and regional events that are not dependant on long distance dispersal of conidiospores. The occurrence of the perfect stage also could lead to the more frequent appearance of new races through genetic recombination. References: (1) J. J Gallian and L. E. Hanson. Plant Dis. 87:200, 2003. (2) H. C. Weltzien. Phytopathol. Z. 47:123, 1963.
First Report of Powdery Mildew Caused by Podosphaera aphanis var. aphanis on Potentilla fruticosa in Italy
Authors: Garibaldi A. , Bertetti D. , Gullino M. L. 
Published: May 2007

Potentilla fruticosa L. (bush cinquefoil), belonging to the family Rosaceae, is an ornamental plant used in parks and gardens. During the spring and summer of 2005, severe outbreaks of a previously unknown powdery mildew were observed in several private gardens located near Biella (northern Italy). The adaxial and abaxial surfaces of leaves as well as the stems were covered with white mycelium. Buds and flowers also were affected. As disease progressed, infected leaves turned yellow and dehisced. Conidia formed in chains and were hyaline, ovoid, and measured 24.0 to 36.0 × 15.8 to 24.0 μm (average 30.1 × 20.0 μm). Fibrosin bodies were present. Chasmothecia were numerous, sphaerical, amber colored, and diameters ranged from 84.0 to 98.4 μm (average 90.4 μm). Each chasmothecium contained one ascus with eight ascospores. Ascospores measured 26.5 to 27.2 × 13.2 to 15.6 μm (average 26.8 × 14.0 μm). On the basis of its morphology, the causal agent was determined to be Podosphaera aphanis (Wallr.) U. Braun & S. Takamatsu var. aphanis U. Braun (1). Pathogenicity was confirmed through inoculations by gently pressing diseased leaves onto leaves of healthy P. fruticosa plants. Three plants were inoculated. Three noninoculated plants served as a control. Plants were maintained at temperatures ranging from 12 to 23°C. Ten days after inoculation, typical symptoms of powdery mildew developed on inoculated plants. Noninoculated plants did not show symptoms. The pathogenicity test was carried out twice. To our knowledge, this is the first report of powdery mildew on P. fruticosa in Italy. Erysiphe polygoni D.C. and Sphaerotheca macularis (Wallr.:Fr.) Lind were observed in the United States on P. fruticosa (2), while in Japan, the presence of S. aphanis var aphanis was reported (3). Voucher specimens are available at the AGROINNOVA Collection, University of Torino. References: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000 (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St Paul, MN, 1989. (3) S. Tanda et al. J. Agric. Sci. 39:258, 1995.
First Report of Tomato severe rugose virus in Chili Pepper in Brazil
Authors: Bezerra-Agasie I. C. , Ferreira G. B. , de Ávila A. C. , Inoue-Nagata A. K. 
Published: May 2007

Three definitive and three tentative begomovirus species have been reported in tomato fields in Brazil according to a recent review (1). Extensive surveys have been conducted since the 1990s in solanaceous weeds and other crops planted close to tomato fields, but no tomato-infecting geminiviruses have been reported on those crops. During November 2003, leaves of one chili pepper plant “dedo-de-moça” (Capsicum baccatum var. pendulum) showing symptoms of yellow mosaic and leaf distortion were collected in Petrolina de Goiás (Goiás State). Serological analyses were carried out with polyclonal antisera produced in our laboratory against the following viruses: Potato virus Y (PVY), Pepper yellow mosaic virus (PepYMV), Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV), and Chrysanthemum stem necrosis virus (CSNV). Serological data showed that the plant was not infected with any of these viruses. A begomovirus-specific DNA-A fragment of 1.3 kb was amplified by polymerase chain reaction (PCR) from the analyzed plant. The fragment shared 98% identity to the partial coat protein coding region (CP), 94% to the intergenic region (IR), and 95% to the partial AC1 coding region of Tomato severe rugose virus (ToSRV) (GenBank Accession No. AY029750). Total DNA from the original infected plant was used to biolistically inoculate healthy plants of C. annuum and C. baccatum var. pendulum. Four resulting symptomatic plants, two from C. annuum and two from C. baccatum, were tested using PCR for begomovirus, and the nucleotide sequence of the amplified fragment confirmed they were infected with ToSRV. Whitefly inoculation of C. annuum, C. baccatum, and tomato was also performed, and all plants expressing symptoms were confirmed to be infected with ToSRV by sequencing a begomovirus-specific amplified fragment. Cloning of the complete DNA-A was achieved by using TempliPhi (Amersham Biosciences, Piscataway, NJ) amplification and digestion with a single cutting restriction endonuclease (2). Sequencing of several clones showed that the complete DNA-A (GenBank Accession No. DQ207749) was 97% identical to ToSRV, confirming the results of the previous PCR analysis. The deduced amino acid sequences showed identities of 97% to the CP, 95% to AC1, 96% to AC2, 96% to AC3, and 88% to AC4 of ToSRV. Although begomoviruses have not yet been causing any significant losses in chili pepper in Brazil, they may be of potential importance. Moreover, chili pepper, a plant commonly found in gardens throughout the country, may serve as an alternate host in tomato-producing areas. To our knowledge, this is the first report of a begomovirus infecting chili pepper in Brazil. References: (1) C. M. Fauquet et al. Arch. Virol. 148:405, 2003. (2). A. K. Inoue-Nagata et al. J Virol Methods 116:209, 2004.
First Report of Brown Rot Caused by Monilinia fructicola on Imported Peach in Hungary
Authors: Petróczy M. , Palkovics L. 
Published: May 2007

Brown rot caused by Monilinia fructicola is one of the most important diseases of peach. The pathogen is included in the EPPO A2 list of quarantine organisms for Europe (2). M. laxa and M. fructigena are common in Hungary, but M. fructicola has never been reported in orchards, in trade, or in markets. In early October 2005, brown rot was observed on imported peaches from Italy and Spain at a vegetable market and some supermarkets in Budapest. The variety of peach was identified as ‘Michellini’ by colleagues in the Department of Pomology of Corvinus University. The pathogen was identified as M. fructicola on the basis of morphological and molecular characteristics. Symptoms began with a small, circular brown spot, and the rot spread rapidly. At the same time, numerous small, grayish stromata developed. Finally, the whole surface of the fruit was covered with conidial tufts. The conidia were one-celled, lemon-shaped, hyaline, 15.7 × 10.3 μm, and produced in branched monilioid chains. Conidia from infected fruit were transferred to potato dextrose agar. Fungal mycelium grew at a linear rate of 10.7 mm per 24 h at 22°C in the dark. The color of the colony was grayish, and the sporulation showing concentric rings was abundant (sporulation is sparse in M. laxa or M. fructigena). The colony was not rosetted and the margin was not lobed, in contrast with M. laxa. Pathogenicity was tested by inoculating surface-sterilized, mature peach fruits with conidia. Inoculated and control fruits were placed in a sterilized glass container at room temperature. After 5 days of incubation, typical brown rot symptoms developed on inoculated fruits while control fruits remained healthy. M. fructicola was reisolated from the inoculated fruits. PCR was used to identify the fungus (1). Species-specific internal transcribed spacer (ITS) primers for M. fructicola, M. laxa, and M. fructigena were used to amplify the DNA of isolates. Three type-cultures were used as the positive control. Following the removal of the mycelia from the agar, total DNA was extracted using a cetyltrimethylammoniumbromide extraction. The nucleic acid-containing pellet was resuspended in RNase containing Tris-EDTA buffer. DNA quality was assessed by gel electrophoresis on 1% agarose gel stained with ethidium bromide. The molecular genetic identification method confirmed the results of morphological identification. To our knowledge, this is the first report of M. fructicola on peaches in Hungary or in eastern Europe. References: (1) R. Ioos and P. Frey. Eur. J. Plant Pathol. 106:373, 2000. (2) OEPP/EPPO. List of A2pests regulated as quarantine pests in the EPPO region. Version 2005-09. Online publication, 2005.
First Report of Tomato spotted wilt virus in Leek (Allium porrum) in the United States
Authors: Nischwitz C. , Mullis S. W. , Gitaitis R. D. , Csinos A. S. , Olson S. M. 
Published: May 2007

Tomato spotted wilt virus (TSWV) is a member of the family Bunyaviridae. It has many important crop hosts including tomato, pepper, tobacco, peanut, and onion. In Georgia, Vidalia onions (Allium cepa), a close relative of leek, can be infected by TSWV and Iris yellow spot virus (IYSV), which is another thrips-vectored tospovirus (2). For this reason, samples of leek transplants with virus-like symptoms in one field at the border of Georgia and Florida were tested for the presence of TSWV and IYSV. The transplants had been grown from seed in a greenhouse at the same location. The sampled plants exhibited extended bleaching of leaf tips and necrotic lesions. These symptoms were also seen on onion plants infected with TSWV and IYSV. The only natural infections of leek with IYSV have been reported thus far only from Reunion Island (4) and Slovenia (1), but to our knowledge, TSWV has not been reported as a pathogen of leek. Green tissue near the necrotic lesions and bleached tips of one symptomatic leaf per plant was sampled and analyzed using a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) (Agdia, Inc., Elkhart, IN). Of 90 plants tested, eight were positive for TSWV and none were positive for IYSV. Leek samples testing positive using ELISA were blotted onto FTA cards (Whatman Inc., Brentford, UK) to bind viral RNA for preservation and then processed according to the manufacturer's protocol. Punch-outs from the FTA cards were used for reverse transcription polymerase chain reaction (RT-PCR) with the TSWV-specific forward primer (5′-TTAAGCAAGTTCTGTGAG-3′) and reverse primer (5′-ATGTCTAAGGTTAAGCTC-3′) (3) to confirm the identity of TSWV. The primers are specific to the viral nucleocapsid gene. An amplicon of the expected size (774 bp) was produced from TSWV ELISA-positive leek plants, but not from healthy controls. TSWV has been found in many plants worldwide, but to our knowledge this is the first report of TSWV infecting leek. The effect that TSWV has on leek production is currently unknown. References: (1) D. A. Benson et al. Nucleic Acids Res. 1:32 (Database issue):D23-6, 2004. (2) S. W. Mullis et al. Plant Dis. 88:1285, 2004. (3) H. R. Pappu et al. Tob. Sci. 40:74, 1996. (4) I. Robène-Soustrade et al. Online publication. New Dis. Rep. 11, 2005.
First Report of Tomato apical stunt viroid in Tomato in Tunisia
Authors: Verhoeven J. Th. J. , Jansen C. C. C. , Roenhorst J. W. 
Published: May 2007

In May 2005, the Plant Protection Service in the Netherlands received two tomato (Lycopersicon esculentum) plant specimens for diagnosis from a protected crop production facility of 2.5 ha near Kebili in Tunisia. Growth of the plants was reduced and leaves were chlorotic and brittle. Ripening of the fruits was delayed and their storage life was reduced from 3 weeks to 1 week. The grower reported that initially only 5% of plants showed symptoms; however, the number of symptomatic plants increased quickly to 100% as a result of increasing temperatures in the production facility. Test plant species Chenopodium quinoa, Datura stramonium, Nicotiana glutinosa, N. hesperis-67A, N. occidentalis-P1, and L. esculentum ‘Money-maker’ were mechanically inoculated with sap from the affected plants. Symptoms including chlorosis and stunting were observed only on L. esculentum. Reverse transcriptase-polymerase chain reaction (RT-PCR) with universal pospiviroid primers Pospi1-RE/FW (2) yielded amplicons of the expected size (196 bp) for each of the two samples. One of these amplicons was sequenced and showed the highest identity to the four isolates of Tomato apical stunt viroid (TASVd) in the NCBI Gen-Bank. Subsequently, the complete sequence of the Tunisian isolate (Gen-Bank Accession No. DQ144506) was determined by sequencing the am-plicon obtained after RT-PCR using primers developed for the detection of Citrus exocortis viroid (CEVd) (1). The isolate consisted of 363 nucleotides and showed the highest sequence identity (96.7%) to tomato isolates of TASVd from Indonesia and Israel (GenBank Accession Nos. X06390 and AY062121, respectively), 92.6% to a tomato isolate from the Ivory Coast (GenBank Accession No. K00818), and 87.7% to an isolate from Solanum pseudocapsicum (GenBank Accession No. X95293). The next highest sequence identity was 81.5% to an isolate of CEVd (GenBank Accession No. X53716). On the basis of these results, the viroid was identified as TASVd. To our knowledge, this is the first report of TASVd in Tunisia. Reference: (1) N. Önelge. Turkish J. Agric. For. 21:419, 1997. (2) J. Th. J. Verhoeven et al. Eur. J. Plant Pathol. 110:823, 2004.
First Report of Rice yellow mottle virus in Rice in Uganda
Authors: Pinel-Galzi A. , Fargette D. , Hull R. 
Published: May 2007

Rice yellow mottle virus (RYMV) of the genus Sobemovirus is a major biotic constraint to rice production in Africa. First reported in Kenya in 1966, RYMV was later found in most countries in Africa where rice (Oryza sativa) is grown (2). During July 2000, plants with leaf yellowing and mottling symptoms were observed in Uganda in a subsistence rice field northeast of Lake Victoria, close to the Nile River. RYMV was detected by using enzyme-linked immunosorbent assay with polyclonal RYMV antisera (1) in the four samples collected. Discriminant monoclonal antibodies revealed that the samples contained RYMV serotype 4, a serotype found in eastern Africa (Madagascar, Kenya, and Tanzania) (2). The 720-nt long coat protein gene of two isolates was amplified by reverse transcriptase-polymerase chain reaction and sequenced (1). The two Ugandan isolates had 99% nt sequence identity (EMBL Accession Nos. AM114523 and AM114524). They belonged to a monophyletic group (97% nt identity) containing isolates from eastern Kenya and northern Tanzania (close to the Lake Victoria). These form a sister group (93% identity) of isolates from Lake Malawi Region in western Tanzania and are more distantly related (88% identity) to the basal strains from eastern Tanzania (2). Isolation of the Lake Victoria Region from the rest of the Tanzania by distance, physical barriers, and patchy rice cultivation explains the specificity of the strain. Year-round growth of wild and cultivated rice around the lake ensures host continuity in time and space that facilitates spread that accounts for the homogeneity of the isolates of this area. Knowledge of the presence of RYMV in Uganda is important since rice cultivation is intensified in this country and is planned in neighboring southern Sudan. References: (1) A. Pinel et al. Arch. Virol. 145:1621, 2000. (2) O. Traoré et al. Mol. Ecol. 14:2097, 2005.
First Report of Puccinia sorghi on Maize in Oman
Authors: Deadman M. L. , Al Sa'di A. , Al Maqbali Y. , Livingston S. , Aime M. C. 
Published: May 2007

Maize (Zea mays L.) is an important annual forage crop cultivated in the Sultanate of Oman, especially during the summer months. It is used for green fodder and grains and often intercropped in fruit orchards, especially under date palms. In April of 2005, leaf samples showing rust symptoms were collected from Samail, 100 km south of Muscat. Oval-shaped, red-brown pustules covered both sides of the leaves and yielded urediniospores typical of Puccinia sorghi Schwein. Urediniospores were roughly subglobose, measured 23 to 28 × 20 to 25 μm, echinulate, with three or four equitorial germ pores (2). Teliospores (38 to 42 × 16 to 19 μm) were observed, but few in numbers, most probably because of the time of year of collection. Pathogen identity was confirmed by nuclear ribosomal large subunit (28S) and internal transcribed spacer region 2 (ITS-2) DNA analysis (voucher sequence deposited in GenBank, Accession No. DQ345724, voucher specimen deposited in the U.S. National Fungus Collections, BPI 871134). P. sorghi has previously been reported from Yemen and Saudi Arabia (1) but not from Oman. Maize is grown throughout the year in Oman, and pathogen survival probably does not require the presence of the alternate host, nonetheless, Oxalis species are present and current research is attempting to locate and confirm the presence of the aecial stage in Oman. References: (1) CMI Distribution Maps of Plant Diseases. Map No. 279. Ed. 4. CABI, Wallingford, UK, 1978. (2) D. G. White, ed. Compendium of Corn Diseases. The American Phytopathological Society, St Paul, MN, 1999.
First Report of Powdery Mildew Caused by Leveillula clavata on Poinsettia (Euphorbia pulcherrima) in Italy
Authors: Garibaldi A. , Minuto A. , Gullino M. L. 
Published: May 2007

Euphorbia pulcherrima (poinsettia) is a winter-flowering plant grown primarily for Christmas sales. During the fall of 2005, severe outbreaks of a previously unknown powdery mildew were observed on cv. Gala in a commercial greenhouse located in Albenga (northern Italy). The abaxial surfaces of green leaves were irregularly covered with white mycelia and conidia, while the adaxial surfaces only showed slight chlorotic round lesions. As the disease progressed, mycelium turned from rose to reddish. Symptoms and signs were never observed on red bracts. Conidia were clavate (55 to 95 × 20 to 40 μm, average 70 × 23 μm) and borne singly on conidiophores that emerged through stomata. On the basis of host, morphological characteristics, and microscopic observations of the intercellular colonization of mesophyll cells, the pathogen was identified as a species of Oidiopsis. Although chasmothecia were not observed, the causal agent based on the literature is believed to be Leveillula clavata Nour (2). Pathogenicity was confirmed by inoculating young leaves of three 4-month-old E. pulcherrima plants, cv. Gala, with a conidial suspension (3 × 105 conidia/ml). Three noninoculated plants sprayed with deionized water served as control. After inoculation, plants were maintained in a growth chamber at 18°C with relative humidity ranging from 56 to 100%. After 20 days, powdery mildew symptoms were observed on leaves of inoculated plants. Noninoculated plants remained healthy. The pathogenicity test was carried out twice. To our knowledge, this is the first report of L. clavata on poinsettia in Italy and probably in Europe. It presently is restricted to a few commercial farms. L. clavata previously has been observed on poinsettia in Kenya (1,2). Voucher specimens are available at the AGROINNOVA Collection, University of Torino. References: (1) M. L. Daughtrey et al. Powdery Mildew Diseases. Pages 39–42 in: Compendium of Flowering Potted Plant Diseases. The American Phytopathological Society, St. Paul, MN, 1995. (2) M. A. Nour. Trans. Brit. Mycol. Soc. 40:477, 1957.