bluuebunny/crossref_metadata_2025_split huggingface dataset:
Banana streak virus Identified for the First Time in Peru in Cavendish Banana (Musa AAA)
Authors: Pasberg-Gauhl C. , Lockhart B. E. L. , Castro-Mendivil Dibos F. , Rojas Llanque J. C. 
Published: June 2007

In October of 2005, a field survey was done in the province of Piura in northern Peru to determine the cause of a disease known locally as “mosaico” that was affecting organic Cavendish banana (Musa AAA) grown for the export market. Disease symptoms consisted of pronounced chlorotic and necrotic lesions on leaves of affected plants. Twenty-four farms were visited, and at each location, 10 randomly selected plants at flowering stage were evaluated for disease incidence and severity. Plants showing virus-like symptoms were observed in 18 of the 24 locations (75%). Fifty-two banana leaf samples, 27 from plants showing virus-like symptoms and 25 from asymptomatic plants, were tested for the presence of Banana streak virus (BSV), Cucumber mosaic virus (CMV), and Banana mild mosaic virus (BanMMV) by immunosorbent electron microscopy (ISEM) using partially purified leaf tissue extracts (2).The same extracts were also tested by immunocapture PCR (IC-PCR) for presence of BSV and specific BSV isolates (BSV-OL, BSV-GF, BSV-IM, and BSV-CAV) using badnavirus-specific degenerate primers and BSV isolate-specific primers, respectively (1). Seventeen of 27 leaf samples showing virus-like symptoms (63%) tested positive for BSV by ISEM and IC-PCR using badnavirus, but not isolate-specific, primers. The symptoms on the 10 samples that tested negative were not typical of BSV infection. One asymptomatic leaf sample (4%) also tested positive for BSV. To validate the PCR results, the nucleotide sequence of the amplicon from a plant showing the most prevalent foliar symptom type was determined. This sequence (GenBank Accession No. DQ674317) had ≤86% homology to the corresponding ORF III polyprotein region of BSV and other badnaviruses. Neither CMV nor BanMMV was detected in any of the 52 samples tested. From these results, it was concluded that “mosaico” disease of organic Cavendish bananas in northern Peru is associated frequently with BSV infection and that there is a high incidence of BSV infection in this area. To our knowledge, this is the first report of BSV occurrence in Peru. It was both surprising and interesting that neither BSV-OL nor BSV-GF, the two BSV isolates found most commonly in banana (Musa AAA) and plantain (Musa AAB) in South and Central America (B. E. L. Lockhart, unpublished), was detected in Cavendish banana in northern Peru. Failure to detect BSV-OL and BSV-GF suggests that field infection may be due to vertical transmission by clonal propagation rather than to horizontal transmission from local plantain and that control of “mosaico” disease could therefore be achieved by use of virus-free planting material. References: (1) A. D. W. Geering et al. Phytopathology 90:921, 2000. (2) B. E. L. Lockhart et al. Phytopathology 82:921, 1992.
Identification of Tomato yellow leaf curl virus and Tomato mottle virus in Two Counties in Alabama
Authors: Akad F. , Jacobi J. C. , Polston J. E. 
Published: June 2007

During July 2005, approximately 23% of tomato plants (Solanum lycopersicum L. ‘Sebring’) in a commercial field in St. Clair County, Alabama showed symptoms of stunting, leaf deformation, mottling, and reduced leaf size, which resembled symptoms of Tomato yellow leaf curl virus (TYLCV). A high population of whiteflies (Bemisia tabaci) was observed in this field, and as the season progressed, 100% of the plants became symptomatic. During October 2006, similar symptoms in tomato were observed at low incidences (less than 10%) in a commercial greenhouse in Jefferson County. Two samples from St. Clair County and six from Jefferson County were collected and tested for the presence of a begomovirus by PCR using three pairs of primers, PAR1c496 and PAL1v1978, a degenerate primer pair designed to amplify regions of the begomovirus A component, PBL1v2040 and PCRc154, a degenerate primer pair that amplifies a hypervariable region of the begomovirus B component (3), and C473 and PTYC1v2406, which are specific to TYLCV (1,2). Primer pair PAR1c496 and PAL1v1978 produced two amplicons (1,360 and 1,159 bp) in all samples tested, which suggests the presence of a monopartite and bipartite begomovirus. Primer pair pBL1v2040 and PCRc154 produced a 678-bp amplicon that would be consistent with the presence of a bipartite begomovirus. Primer pair C473 and PTYC1v2406 produced an 850-bp amplicon that would be consistent with the presence of TYLCV. Sequence analysis revealed that the 1,360-bp amplicon had 98% sequence identity to isolates of TYLCV from Cuba (GenBank Accession No. AJ223505), the Dominican Republic (GenBank Accession No. (AF04715), Florida (GenBank Accession Nos. AF260331 and AY530931), Egypt (GenBank Accession No. AY594174), and Almeria (GenBank Accession No. AJ489258). The 1,159-bp amplicon had a 97 to 99% sequence identity to the A component of Tomato mottle virus (ToMoV) Florida (GenBank Accession Nos. L14460, EF028241, and M90495) and Puerto Rico (GenBank Accession No. AY965900). Each of the eight tomato samples were shown to be infected with TYLCV and ToMoV. Symptoms of plants infected with both viruses resembled those of TYLCV because the milder symptoms of ToMoV are masked in the field by the more severe symptoms of TYLCV. To our knowledge, this is the first report of ToMoV and TYLCV in the state of Alabama. Reference: (1) M. Ghanim et al. Virology 240:295, 1998. (2) M. K. Nakhla et al. Phytopathol. Mediterr. 32:163, 1993. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993.
Occurrence and Molecular Characterization of Squash leaf curl Phillipines virus in Taiwan
Authors: Tsai W. S. , Shih S. L. , Green S. K. , Jan F.-J. 
Published: June 2007

Whitefly-transmitted, cucurbit-infecting begomoviruses (genus Begomovirus, family Geminiviridae) have been detected on cucurbit crops in Bangladesh, China, Egypt, Israel, Malaysia, Mexico, the Philippines, Thailand, United States, and Vietnam. Pumpkin plants showing leaf curling, blistering, and yellowing symptoms were observed in the AVRDC fields (Tainan, Taiwan) during 2001 and in nearby farmers' fields during 2005. Two samples from symptomatic plants were collected in 2001 and six collected in 2005. Viral DNAs were extracted (2), and the PCR, with previously described primers, was used to detect the presence of begomoviral DNA-A (4), DNA-B (3), and associated satellite DNA (1). Begomoviral DNA-A was detected in one of the 2001 samples and in all 2005 samples. The PCR-amplified 1.5 kb viral DNA-A from one positive sample each from the 2001 and 2005 collections was cloned and sequenced. On the basis of the 1.5-kb DNA-A sequences, specific primers were designed to completely sequence the DNA-A component. The overlap between fragments obtained using primer walking ranged from 43 to 119 bp with 100% nt identities. The complete DNA-A sequences were determined for the two isolates as 2,734 bp (2001) (GenBank Accession No. DQ866135) and 2,733 bp (2005) (GenBank Accession No. EF199774). Sequence comparisons and analyses were performed using the DNAMAN Sequence Analysis Software (Lynnon Corporation, Vaudreuil, Quebec, Canada). The DNA-A of the begomovirus isolates each contained the conserved nanosequence-TAATATTAC and six open reading frames, including two in the virus sense and four in the complementary sense. On the basis of a 99% shared nucleotide sequence identity, they are considered isolates of the same species. BLASTn analysis and a comparison of the sequence with others available in the GenBank database ( http://www.ncbi.nlm.nih.gov ) indicated that the Taiwan virus shared its highest nt identity (more than 95%) with the Squash leaf curl Philippines virus (GenBank Accession No. AB085793). Virus-associated satellite DNA was not found in any of the samples. DNA-B was found in both samples, providing further evidence that the virus was the same as the bipartite Squash leaf curl Philippines virus. To our knowledge, this is the first report of Squash leaf curl Philippines virus in Taiwan. References: (1) R. W. Briddon et al. Virology 312:106, 2003. (2) R. L. Gilbertson et al. J. Gen. Virol. 72:2843, 1991. (3) S. K. Green et al. Plant Dis. 85:1286, 2001. (4) M. R. Rojas et al. Plant Dis. 77:340, 1993.
First Report of the Root-Knot Nematode Meloidogyne minor on Turfgrass in Belgium
Authors: Viaene N. , Wiseborn D. B. , Karssen G. 
Published: June 2007

The root-knot nematode, Meloidogyne minor, was described during 2004 after it was found on potato roots in a field in the Netherlands and in golf courses in England, Wales, and Ireland (2). Since it is associated with yellow patch disease in turf grass and causes deformation of potato tubers (2), it is important to know whether this organism is already widespread in these and neighboring countries. In addition, it has a relatively wide host range (2,4). A small survey conducted in Belgium was comprised of 10 golf courses geographically spread over the country. In each location, 3 to 9 samples were taken (one per green) consisting of 30 to 40 cores (1.5 × 20 cm deep). Nematodes were extracted from a 200-g subsample (containing roots) from each sample using zonal centrifugation (1). All Meloidogyne spp. were mounted on semipermanent slides and identified morphologically. M. minor was discovered in 3 of 6 samples taken in April 2006 from a golf course in Hasselt (northeastern Belgium). Between 41 and 50 M. minor per 100 g of soil were found together with M. naasi (7 to 20 individuals per 100 g of soil). Occurrence of M. minor together with other Meloidogyne species has been reported in natural and cultivated sites (2,4). Moreover, spores of Pasteuria spp. were clearly visible on 42% of the observed second-stage juveniles of M. minor, but not on those of M. naasi. The infected juveniles had between 2 and 15 spores attached to their cuticles. Additional juveniles were extracted from the soil samples and used for molecular identification by real-time PCR (2), which confirmed the presence of M. minor. There were no symptoms on the grass, consisting of a mixture of Agrostis stolonifera (10%), Festuca rubra (30%), and Poa annua (60%). Grass was sown in Rhine sand and heath land compost used for the construction of the greens in Hasselt. It could be that these soil amendments were infested with M. minor or that M. minor was introduced by other means, e.g., shoes, maintenance machinery, or golf equipment. On the other hand, the detection of M. minor in this small survey indicates that the species may be prevalent in golf courses in the region. The nematode has been found in several golf courses and sport fields in the United Kingdom and the Netherlands, including a golf course at Breda (close to the Belgian border) (3). The survey will be expanded to include grasslands and dune areas, the presumed natural habitat of M. minor. References: (1) G. A. Hendrickx. Nematologica 41:308, 1995. (2) G. Karssen et al. Nematology 6:59, 2004. (3) W. Lammers et al. Meloidogyne minor. Pest Risk Assessment. Online publication, www.minlnv.nl/pd - Schadelijke organismen, 2006. (4) S. J. Turner and C. C. Fleming. Comm. Appl. Biol. Sci. Ghent University 70:885, 2005.
First Report of Haplotype I-b of Phytophthora infestans in Central Mexico
Authors: Garay-Serrano E. , Fernández-Pavía S. P. , Rodríguez-Alvarado G. , Flier W. G. , Lozoya-Saldaña H. , Rojas-Martínez R. I. , Goss E. M. , Grünwald N. J. 
Published: June 2007

Central Mexico is considered a center of genetic diversity for Phytophthora infestans on the basis of a range of genotypic and phenotypic characteristics (3). Surprisingly, while mitochondrial DNA (mtDNA) haplotypes I-a, II-a, and II-b have been reported from central Mexico, haplotype I-b has not been found in central Mexico (1). Therefore, a more extensive search for haplotypes was conducted in areas where sexual reproduction occurs. During the summer of 2003, leaflets of cvs. Rosita and Tollocan with a single lesion of late blight were collected in the area of Villarreal, located in Terrenate County in Tlaxcala, Mexico (170 km northeast of Mexico City). Fourteen P. infestans isolates were characterized for mtDNA haplotype, isozyme genotype (glucose 6- phosphate isomerase [Gpi] and peptidase [Pep]), and mating type. Isolation, mating type, and isozyme genotype were characterized following reported protocols (1,4). MtDNA haplotype was determined by amplifying and digesting the P2 and P4 regions and comparing amplicons to those of reference strains of known haplotype (1,2). Twelve isolates were mtDNA haplotype I-a and two were I-b. While the mtDNA I-b has been associated with the US-1 lineage (mating type: A1, Gpi: 86/100, Pep: 92/100), the genotypes for the Mexican isolates were A2, 86/100 Gpi, 100/100 Pep from cv. Rosita and A2, 86/100 Gpi, 92/100 Pep from cv. Tollocan. To our knowledge, this is the first report of the I-b mtDNA haplotype of P. infestans from central Mexico and it is now clear that all four haplotypes exist in Mexico. This finding therefore, stresses the importance of including a representative regional sampling of Mexican and Andean isolates in studies inferring the origin of this species. References: (1) W. G. Flier et al. Phytopathology 93:382, 2003. (2) G. W. Griffith and D. S. Shaw. Appl. Environ. Microbiol. 64:4007, 1998. (3) N. J. Grünwald and W. G. Flier. Ann. Rev. Phytopathol. 43:171, 2005. (4) N. J. Grünwald et al. Phytopathology 91:882, 2001.
Occurrence of Blight Caused by Sclerotium rolfsii on Lolium perenne in Argentina
Authors: Goldring L. , Lacasa M. , Wright E. R. , Pérez B. A. , Rivera M. C. 
Published: June 2007

A perennial ryegrass (Lolium perenne L.) lawn located at Castelar (Buenos Aires Province) showed disease symptoms during the summer of 2003. Chlorotic patches as much as 15 cm in diameter appeared on the lawn. Later, dead plants with white mycelia developing on the crown and surrounding soil occurred at the periphery of the rings. Plants showed leaf chlorosis and crown and root rot. No sclerotia developed on plant organs. Diseased plants were collected, washed with running tap water for 4 h, and disinfested in 5% NaOCl for 2 min. Pieces, 3 to 5 mm long from symptomatic leaves, crowns, and roots, were incubated on 2% potato dextrose agar (PDA) at 22 to 25°C with a 12-h light/dark cycle. Mycelia growing on the soil surface was transferred to PDA and incubated under the same conditions. After 3 to 4 days, white, conspicuous mycelia that produced sclerotia grew from diseased tissue pieces and soil mycelial samples. Sclerotia were nearly spherical, 1 to 2 mm in diameter, white but turning brown with age, and produced in large numbers over the entire colony surface. Primary hyphae showed clamp connections at the septa. A pathogenicity test was performed with 20 1-month-old plants of L. perenne grown in a 1:1 (v/v) mixture of sand and soil contained in 24- × 17- × 4-cm plastic trays. Seven-day-old fungal cultures grown on PDA were cut into 1- cm2 pieces and placed among the plants on the substrate. Each tray was inoculated with seven inoculum pieces. Five trays of plants were inoculated with the fungus, and plants in five trays that served as controls had only sterile pieces of PDA placed on the substrate. All plants were maintained at 25°C and watered frequently. First symptoms, consisting of chlorosis, were observed 4 days after inoculation. Of the plants, 34, 59, 60, 65, and 70% developed symptoms 6, 9, 14, 17, and 21 days after inoculation, respectively. Control plants remained healthy. The fungus was reisolated from diseased plants and identified as Sclerotium rolfsii Sacc. (teleomorph Athelia rolfsii (Curzi) C.C. Tu & Kimbr.) on the basis of morphological and cultural characteristics (3,4). The disease has been observed causing stalk rot on perennial ryegrass in the United States (1) and Australia (2). To our knowledge, this is the first report of S. rolfsii causing disease on L. perenne in Argentina. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society. St. Paul, MN. 1989. (2) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2007. (3) J. E. M. Mordue. No. 410 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, UK, 1974. (4) Z. K. Punja and A. Damiani. Mycologia 88:694, 1996.
First Report of Powdery Mildew on Tomato Caused by Oidium neolycopersici in Venezuela
Authors: Montilla J. O. , González M. S. , Renaud D. 
Published: June 2007

During 2004 and 2005, a powdery mildew was observed in tomato (Lycopersicon esculentum Mill. cv. Rio Grande) fields in several states in Venezuela. Symptoms included development of patches of dense white mycelium, predominantly on the upper leaf surface. Leaves in the middle and lower canopies were the most affected. Similar symptoms sometimes were observed on stems. The foliage of infected plants turned yellow and showed necrosis followed by desiccation and rapid defoliation. Microscopic examination revealed the presence of typical structures of the Oidium genus. Hyphae were hyaline and septate. Conidiophores were unbranched, erect, measured 51 to 108 (80) μm, and consisted of 3 or 4 cells. Conidia were hyaline, ellipsoidal to ovoidal, and measured 16 to 43 (30) × 12 to 22 (16) μm. Conidia were produced singly, without fibrosin bodies. Conidial polar germination was common. Appressoria were lobed. The sexual stage was not found. The fungus was identified as Oidium neolycopersici, recently recognized as a distinct species (1,2). Conidia from infected tomato leaves were shaken onto leaves of 10 plants of L. esculentum and L. pimpinellifolium (Jusl.) Mill. and five plants of a weed (Physalis peruviana L.). Noninoculated plants served as a control. Symptoms that developed on all inoculated plants were similar to those of plants naturally infected. Within 7 to 8 days, symptoms in L. esculentum consisted of small colonies that quickly covered large portions of foliar tissue. L. pimpinellifolium showed small and localized symptoms after 10 days and P. peruviana showed symptoms after 15 days. To our knowledge, this is the first report of O. neolycopersici in Venezuela. References: (1) H. Jones et al. Mol. Plant Pathol. 2:303, 2001. (2) L. Kiss et al. Mycol. Res. 105:684, 2001.
Effect of benzotriazole derivatives on the corrosion of steel in simulated concrete pore solutions
Authors: Sheban Mashal , Abu‐Dalo Muna , Ababneh Ayman , Andreescu Silvana 
Published: June 2007

PurposeThe aim of this research was to develop corrosion protection systems for reinforced concrete structures under chloride attack. Benzotriazole (BTA) and BTA derivatives were used as corrosion protection materials for the steel.Design/methodology/approachThe effect of BTA and four other BTA derivatives on the corrosion resistance of steel in simulated concrete pore (SCP) solutions was studied. BTA derivatives were used as two separate protection systems: inhibition and pickling protection systems. The experiments were performed in SCP solutions which simulated concrete with and without severe chloride attacks. Electrochemical techniques, i.e. potentiodynamic polarization and electrochemical impedance, and Fourier transform infrared spectroscopy (FTIR) were used to assess the steel corrosion protection systems.FindingsThe potentiodynamic polarization studies showed an increase in the pitting potential for all protection systems tested. In addition, a large increase in the steel solution interfacial resistance was observed by electrochemical impedance studies (EIS) due to the formation of steel‐BTA derivatives complex on the surface. This film was formed on the steel surface with either mono‐or bi‐dentate bonds between the triazolic nitrogen ring and the steel surface as shown by the FTIR.Research limitations/implicationsBTA derivatives provided good protection for steel in SCP solutions, indicating their applicability in reinforced concrete structures. However, tests using reinforced concrete samples are required to study possible interactions between steel, BTA derivatives and concrete constitutes, e.g. sand, gravel, cement and chemical admixtures. These BTA‐based systems also should be studied under carbonation attack.Originality/valueBTA derivatives provided a good protection for steel in the SCP solutions, and this indicates the applicability to use them in reinforced concrete structures.
Choice of entry modes in sequential FDI in an emerging economy
Authors: Zhang Yi , Zhang Zigang , Liu Zhixue 
Published: June 2007

PurposeThis paper seeks to challenge the traditional wisdom that sheds light upon sequential entry modes in developed countries by exploring the dynamic entry mode choice in sequential foreign direct investment (FDI) in emerging economies.Design/methodology/approachA review of the literature on the entry mode choice is undertaken. Based on analysing two related theories consisting of the knowledge‐based theory of the firm and organizational learning theory, entry mode choices in sequential FDI in emerging economies are investigated using both an internationalisation process model and the capability‐developing perspective, and exclusive propositions are put forward accordingly. Then, these propositions are tested on the context of China with the methodology of paired‐samples t‐tests.FindingsBased on macro‐level longitudinal data in China from 1979 to 2005, the choice of entry mode in sequential FDI in emerging economies is inconsistent with the capability‐developing theory of the firm, but is consistent with the international process model.Practical implicationsThis study provides four practical implications. First, managers intending to invest abroad need to consider the cost and return of a specific entry mode. Second, knowledge about host markets has a more important effect on entry mode choice in emerging markets than MNCs' internal organizational capabilities. Third, MNCs adopt sequential investment in emerging economies, in which they adopt joint ventures in earlier entries and then shift to green‐field investment in later entries. Fourth, experiential learning, which consists of learning about host markets and local partners' skills, is emphasized in sequentially entering emerging markets.Originality/valueThis paper expands the research scope of previous studies that either explore a static choice of entry mode in foreign markets or only examine the entry mode choice in sequential FDI in developed countries. Taking into consideration the dynamic choice of entry modes, the paper studies sequential FDI in emerging economies, which throws light upon theoretical analysis of sequential FDI in China, and which has practical implications for foreign firms that are interested in China and planning to enter China's markets.
Activist investment: institutional investor monitoring of portfolio companies
Authors: Martin Roderick , Nisar Tahir M. 
Published: June 2007

PurposeThe purpose of the paper is to show what Asset managers undertake to operate in accordance with the Statement of Institutional Shareholders' Committee (ISC) whenever they engage with portfolio companies on behalf of their institutional investor clients. The Statement (2002) states that institutional shareholders have a responsibility to make considered use of their votes, and to enter into a dialogue with companies based on the mutual understanding of objectives.Design/methodology/approachA survey study of Asset managers was conducted to evaluate their adherence to the ISC Principles.FindingsThe findings in the paper show that fund managers routinely analyse information concerning those companies in which they invest, and have meetings with company managers. Managers are also involved in activities to promote standards of corporate governance and corporate accountability. It is also found that managers' experience in managing deal flows, funds' specialization and engagement specialists are the key drivers of adherence to the ISC Principles.Originality/valueThe paper highlights the importance of specific fund capabilities for monitoring and controlling portfolio companies.