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1.
Mol Phylogenet Evol ; 115: 140-160, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28757445

RESUMEN

This study investigated host-specificity and phylogenetic relationships in Australian galling flies, Fergusonina Malloch (Diptera: Fergusoninidae), in order to assess diversity and explore the evolutionary history of host plant affiliation and gall morphology. A DNA barcoding approach using COI data from 203 Fergusonina specimens from 5gall types on 56 host plant species indicated 85 presumptive fly species. These exhibited a high degree of host specificity; of the 40 species with multiple representatives, each fed only on a single host genus, 29 (72.5%) were strictly monophagous, and 11 (27.5%) were reared from multiple closely related hosts. COI variation within species was not correlated with either sample size or geographic distance. However variation was greater within oligophagous species, consistent with expectations of the initial stages of host-associated divergence during speciation. Phylogenetic analysis using both nuclear and mitochondrial genes revealed host genus-restricted clades but also clear evidence of multiple colonizations of both host plant genus and host species. With the exception of unilocular peagalls, evolution of gall type was somewhat constrained, but to a lesser degree than host plant association. Unilocular peagalls arose more often than any other gall type, were primarily located at the tips of the phylogeny, and did not form clades comprising more than a few species. For ecological reasons, species of this gall type are predicted to harbor substantially less genetic variation than others, possibly reducing evolutionary flexibility resulting in reduced diversification in unilocular gallers.


Asunto(s)
Dípteros/clasificación , Tumores de Planta/clasificación , Animales , Australia , Evolución Biológica , Dípteros/genética , Complejo IV de Transporte de Electrones/clasificación , Complejo IV de Transporte de Electrones/genética , Variación Genética , Especificidad del Huésped , Interacciones Huésped-Parásitos/fisiología , Myrtaceae/anatomía & histología , Myrtaceae/metabolismo , Filogenia
2.
Plant Dis ; 98(6): 851, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30708663

RESUMEN

In the summer of 2012, an outbreak of a newly discovered root and basal stalk rot of wild rice (Zizania palustris L.) cv. Franklin was observed in a 16-ha field in Big Valley, Lassen County, California (GPS coordinates 41°08'41.93″ N 121°10'07.49″ W). Infected plants exhibiting rot and dieback of roots and stalks were in various stages of decline, including death. Symptomatic stem and root tissues from affected plants were surface disinfected in 1% NaOCl for 90 s and placed on PARP agar plates, which were then incubated at 25°C in the dark for 1 week. Hyphal tips were used to start and maintain the organism in pure cultures. Isolates were transferred into petri plates with water and sterilized blades of turfgrass for the production of hyphae and reproductive structures. Isolates had coenocytic hyphae and produced zoospores 20 to 30 µm in diameter outside of sporangia (75 to 160 × 46 to 110 µm) from a naked mass of protoplasm, unlike from a vesicle, which is characteristic of Pythium spp. (2). Based on these morphological features, the isolate was tentatively identified as a Pythiogeton sp. Total genomic DNA was extracted from mycelia using the DNeasy Plant Mini Kit (Qiagen Inc., Valencia, CA). The internal transcribed spacers (ITS) 1 and 2 flanking the 5.8S rRNA regions were amplified by PCR and sequenced using universal ITS5 and ITS4 primers. A BLAST search of the 855-bp sequences revealed 98% similarity with a sequence of P. ramosum isolate Pg-164 (GenBank Accession No. JQ610190.1). The 21 nucleotide differences suggest that the isolate from wild rice may be an unreported species. The sequences were submitted to GenBank (KF719169). To fulfill Koch's postulates and confirm pathogenicity, 100 wild rice seeds were surface disinfected in 1% NaOCl for 90 s and placed in a 500 ml sterile pot with 250 g of autoclaved sand. Three 5 mm-diameter disks from the margin of a 7-day-old culture growing on PARP were placed in each of five pots. As a control, three 5 mm-diameter disks from a non-inoculated PARP plate were placed in five different pots, and five pots with autoclaved sand were not inoculated. All pots were kept in a randomized complete block design at 25°C for 14 days under a 14-h photoperiod. The pathogenicity test was repeated three times. After 14 days, the inoculated plants in all tests developed root and basal stalk rot, consistent with the symptoms observed on diseased wild rice in the field. The Pythiogeton sp. was consistently re-isolated on PARP from symptomatic plants but not from control plants. The non-inoculated wild rice plants remained asymptomatic. DNA sequences of the ITS region of the re-isolated Pythiogeton sp. revealed 100% identity with the isolate from the field. There have been reports of P. zeae on corn in Korea and P. zizaniae on water bamboo in Taiwan (1,2,3). This is the first report of a Pythiogeton sp. on wild rice. References: (1) P. J. Ann et al. Mycologia 98:116, 2006. (2) J. Huang et al. Mycoscience 54:130, 2013. (3) H. J. Jee et al. Mycologia 92:522, 2000.

3.
Plant Dis ; 98(7): 1018, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30708902

RESUMEN

Seashore paspalum (Paspalum vaginatum Swartz) is a warm-season perennial turfgrass commonly used for golf courses that are grown in saline environments or using saline water for irrigation. However, seashore paspalum is also grown in non-saline conditions due to its low fertilizer and water requirements (2). In Barbados, on a newly constructed golf course, seashore paspalum 'Sea Isle Supreme' sprigs were imported from Georgia (United States) and were planted over 2006 and 2007 on greens, tees, fairways, and rough. Golf greens were constructed following the United States Golf Association Green Section (Far Hills, NJ) putting green guidelines. Tees and fairways were constructed using native soil. Two years after the grow-in, the putting greens began to exhibit irregular chlorotic patches, followed by gradual thinning and decline of turfgrass stand density in those areas. Additionally, turfgrass roots sampled from those symptomatic patches appeared to be abbreviated compared to non-symptomatic areas of the greens. A survey was conducted in May 2013 to determine if plant-parasitic nematodes were present coinciding with the observed symptoms, which were similar to those described in a previous report (3). Consequently, two samples were collected from each green with a total of four greens sampled. Each sample consisted of 20 soil cores (15 cm depth × 1.2 cm in diameter) from either areas of the greens showing symptoms or from non-symptomatic areas. Nematodes were extracted from 100 cm3 soil samples using a modified centrifugal-sugar flotation technique (4). No plant parasitic nematodes were present in any of the samples from the non-symptomatic areas. Three genera of plant parasitic nematodes were found in all the samples from the symptomatic areas: Helicotylenchus. Mesocriconema, and Pratylenchus. Nematode populations of these genera averaged 30, 60, and 200 nematodes per 100 cm3, respectively. Populations of the genera Helicotylenchus and Mesocriconema were below the action threshold levels for seashore paspalum used by the University of Florida Nematode Assay Laboratory (1). Currently, no threshold exists for Pratylenchus for seashore paspalum. Conversely, the genera Helicotylenchus. Mesocriconema, and Pratylenchus were found associated with the irregular chlorotic patches but not with the non-symptomatic areas. To our knowledge, this is the first report of plant parasitic nematodes associated with seashore paspalum maintained as putting greens in Barbados. References: (1) W. T. Crow. Nematode management for golf courses in Florida. EDIS. Accessed 31 July 2013 from: http://edis.ifas.ufl.edu/in124 , 2001. (2) R. R. Duncan and R. N. Carrow. Seashore Paspalum: The Environmental Turfgrass. John Wiley & Sons, Inc., Hoboken, New Jersey, 2000. (3) A. C. Hixson and W. T. Crow. Plant Dis. 88:680, 2004. (4) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964.

4.
Plant Dis ; 96(12): 1805-1817, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30727261

RESUMEN

The importance of fungicide seed treatments on cotton was examined using a series of standardized fungicide trials from 1993 to 2004. Fungicide seed treatments increased stands over those from seed not treated with fungicides in 119 of 211 trials. Metalaxyl increased stands compared to nontreated seed in 40 of 119 trials having significant fungicide responses, demonstrating the importance of Pythium spp. on stand establishment. Similarly, PCNB seed treatment increased stands compared to nontreated seed for 44 of 119 trials with a significant response, indicating the importance of Rhizoctonia solani in stand losses. Benefits from the use of newer seed treatment chemistries, azoxystrobin and triazoles, were demonstrated by comparison with a historic standard seed treatment, carboxin + PCNB + metalaxyl. Little to no stand improvement was found when minimal soil temperatures averaged 25°C the first 3 days after planting. Stand losses due to seedling pathogens increased dramatically as minimal soil temperatures decreased to 12°C and rainfall increased. The importance of Pythium increased dramatically as minimal soil temperature decreased and rainfall increased, while the importance of R. solani was not affected greatly by planting environment. These multi-year data support the widespread use of seed treatment fungicides for the control of the seedling disease complex on cotton.

5.
Int J Syst Evol Microbiol ; 61(Pt 9): 2073-2080, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20870891

RESUMEN

A novel bacterium of the genus Pasteuria was discovered parasitizing bacterivorous nematodes of the genus Bursilla, in selected bermudagrass (Cynodon) field plots in Davie, FL, USA. Soil containing this bacterium was sampled and supplied with bi-weekly inoculations of cultured species of the genus Bursilla in order to build and maintain a source of endospores for continuous in vivo conservation of the bacteria for further study and characterization. 16S rRNA gene sequence similarities supported its congeneric ranking with other members of the genus Pasteuria that have been identified from nematodes and cladocerans. There were, however, no clear sister candidates for this organism, which supported the evidence of endospore ultrastructure and host-range studies, suggesting it belonged to a novel taxon. Because members of the genus Pasteuria cannot yet be isolated, definitive type strains could not be maintained; therefore, the name 'Candidatus Pasteuria aldrichii' is proposed for this organism.


Asunto(s)
Pasteuria/clasificación , Pasteuria/aislamiento & purificación , Rhabditoidea/microbiología , Microbiología del Suelo , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , Catalasa/metabolismo , Pared Celular/química , China , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácido Diaminopimélico/análisis , Ácidos Grasos/análisis , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Oxidorreductasas/metabolismo , Pasteuria/patogenicidad , Pasteuria/fisiología , Peptidoglicano/química , Fosfolípidos/análisis , Filogenia , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Cloruro de Sodio/metabolismo , Esporas Bacterianas/citología , Temperatura , Árboles
6.
Plant Dis ; 95(10): 1308-1310, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30731688

RESUMEN

Water-displacement and WinRHIZO root-scanning methods were compared for efficacy of root damage assessment. Results from both methods were similar and a highly significant relationship was found between the two methods in trial one (r2 = 0.9968, P < 0.0001) and trial two (r2 = 0.9988, P < 0.0001). Both protocols provide consistent root volume measurements; however, water displacement is preferred as an economical method if a quick evaluation of a large amount of roots is essential. For a more detailed root morphological and architectural analysis, WinRHIZO root scanning provides additional information about several root parameters that cannot be measured by simple water displacement.

7.
Mol Ecol ; 19 Suppl 1: 4-20, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20331766

RESUMEN

Biodiversity assessment is the key to understanding the relationship between biodiversity and ecosystem functioning, but there is a well-acknowledged biodiversity identification gap related to eukaryotic meiofaunal organisms. Meiofaunal identification is confounded by the small size of taxa, morphological convergence and intraspecific variation. However, the most important restricting factor in meiofaunal ecological research is the mismatch between diversity and the number of taxonomists that are able to simultaneously identify and catalogue meiofaunal diversity. Accordingly, a molecular operational taxonomic unit (MOTU)-based approach has been advocated for en mass meiofaunal biodiversity assessment, but it has been restricted by the lack of throughput afforded by chain termination sequencing. Contemporary pyrosequencing offers a solution to this problem in the form of environmental metagenetic analyses, but this represents a novel field of biodiversity assessment. Here, we provide an overview of meiofaunal metagenetic analyses, ranging from sample preservation and DNA extraction to PCR, sequencing and the bioinformatic interrogation of multiple, independent samples using 454 Roche sequencing platforms. We report two examples of environmental metagenetic nuclear small subunit 18S (nSSU) analyses of marine and tropical rainforest habitats and provide critical appraisals of the level of putative recombinant DNA molecules (chimeras) in metagenetic data sets. Following stringent quality control measures, environmental metagenetic analyses achieve MOTU formation across the eukaryote domain of life at a fraction of the time and cost of traditional approaches. The effectiveness of Roche 454 sequencing brings substantial advantages to studies aiming to elucidate the molecular genetic richness of not only meiofaunal, but also all complex eukaryotic communities.


Asunto(s)
Biodiversidad , Metagenómica/métodos , Filogenia , Análisis de Secuencia de ADN/métodos , Animales , Biología Computacional , ADN/aislamiento & purificación , Ecosistema , Evolución Molecular , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 18S/genética , Subunidades Ribosómicas Pequeñas de Eucariotas
8.
Phytopathology ; 100(11): 1222-30, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20698756

RESUMEN

Verticillium dahliae is a soilborne fungal pathogen that causes vascular wilt in a variety of economically important crops worldwide. There are two races of V. dahliae that infect tomato and lettuce. Although race-1-specific resistance has been identified in both tomato and lettuce, no resistant sources are available for race 2. Molecular analyses were employed to characterize the genetic variability and race structure of 101 isolates of V. dahliae from a variety of hosts, mainly from central and coastal California, and 10 isolates exotic to this area. Analyses of the 16 simple sequence repeat (SSR) markers illustrated that tomato subpopulations from central California were distinct relative to the marigold subpopulations. In contrast, cotton and olive isolates showed admixture with tomato isolates. Analyses of both the ribosomal DNA intergenic spacer regions and SSR markers revealed high genetic variability among isolates but were unable to delineate races of V. dahliae. However, a polymerase chain reaction (PCR) assay was applied to amplify a race-1-specific amplicon from the isolates in many hosts from different geographic areas, and was coupled with virulence assays for validation of the data. Results of the PCR assay showed 100% concordance with the virulence assay to differentiate race 1 from race 2 of 48 isolates from tomato. The results indicate that the PCR assay can be applied to differentiate the two races to support our related aim of breeding host resistance, and further reveal insights into the distribution of races in tomato and lettuce cropping systems in California.


Asunto(s)
Variación Genética , Reacción en Cadena de la Polimerasa , Verticillium/genética , California , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Filogeografía
9.
Plant Dis ; 94(2): 276, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30754278

RESUMEN

In August of 2009, powdery mildew was observed on peppermint (Mentha piperita L.) in several commercial fields in the Fall River Valley of eastern Shasta County, California. Plant growth was apparently reduced by the disease, but its impact on yield was unknown. White fungal growth was restricted to the adaxial surfaces, where colonies were thin and effused. Heavily infected leaves developed a reddish tint as growth prematurely ceased. Doliform conidia ([26.6-] 29.2 [-31.7] × [13.2-] 15.6 [-16.8] µm) were produced in chains of approximately six conidia. Foot cells were cylindrical ([41.3-] 55.2 [-75.0] × [11.2-] 12.0 [-12.8] µm). Immature chasmothecia were yellowish brown and approximately 100.0 µm in diameter with flexuous, mycelium-like appendages up to 200 µm long. All these features were consistent with those of Golovinomyces biocellatus. Asci were not observed. To confirm the identity of the fungus, nuclear rDNA internal transcribed spacer (ITS) regions were amplified by PCR with universal primers ITS4 and ITS5. The sequence (537 bp) was an exact match for several submissions of G. biocellatus in GenBank (e.g., Accession No. EU035602, a sequence of the fungus from mint in Australia [1]). Pathogenicity was confirmed by brushing spores from naturally infected leaves onto three rooted cuttings of M. piperita 'Black Mitchum'. After the plants were covered with a plastic bag for 36 h to maintain high humidity, they were kept on a greenhouse bench at 23 to 28°C. Three noninoculated plants, which served as controls, were placed in another greenhouse in similar conditions. The experiment was repeated once. All inoculated plants developed signs of powdery mildew within 7 days of inoculation whereas noninoculated plants remained disease free. The fungus on inoculated leaves was morphologically indistinguishable from the one used to inoculate the plants. To our knowledge, this is the first report of G. biocellatus on peppermint in California. References: (1) J. R. Liberato and J. H. Cunnington. Australas, Plant Dis. Notes 2:38, 2007.

10.
Mol Ecol ; 18(5): 985-96, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19207247

RESUMEN

Comparisons of nematode communities among ecosystems have indicated that, unlike many organisms, nematode communities have less diversity in the tropics than in temperate ecosystems. There are, however, few studies of tropical nematode diversity on which to base conclusions of global patterns of diversity. This study reports an attempt to estimate nematode diversity in the lowland tropical rainforest of La Selva Biological Research Station in Costa Rica. We suggest one reason that previous estimates of tropical nematode diversity were low is because habitats above the mineral soil are seldom sampled. As much as 62% of the overall genetic diversity, measured by an 18S ribosomal barcode, existed in litter and understorey habitats and not in soil. A maximum-likelihood tree of barcodes from 360 individual nematodes indicated most major terrestrial nematode lineages were represented in the samples. Estimated 'species' richness ranged from 464 to 502 within the four 40 x 40 m plots. Directed sampling of insects and their associated nematodes produced a second set of barcodes that were not recovered by habitat sampling, yet may constitute a major class of tropical nematode diversity. While the generation of novel nematode barcodes proved relatively easy, their identity remains obscure due to deficiencies in existing taxonomic databases. Specimens of Criconematina, a monophyletic group of soil-dwelling plant-parasitic nematodes were examined in detail to assess the steps necessary for associating barcodes with nominal species. Our results highlight the difficulties associated with studying poorly understood organisms in an understudied ecosystem using a destructive (i.e. barcode) sampling method.


Asunto(s)
Biodiversidad , Nematodos/clasificación , Lluvia , Árboles , Clima Tropical , Animales , Costa Rica , Isópteros/parasitología , Funciones de Verosimilitud , Datos de Secuencia Molecular , Parásitos/clasificación , Plantas/parasitología , Dinámica Poblacional , Suelo/parasitología
11.
Science ; 215(4534): 852-5, 1982 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-17747850

RESUMEN

Personal computers priced for the consumer market have a wide range of applications and variable memory, computational, and display capabilities. The genesis of individual computing devices, some of their applications, and the market for personal computers are discussed in this article.

12.
Science ; 213(4508): 618-22, 1981 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-17847458

RESUMEN

The Strategic Petroleum Reserve is intended to reduce the vulnerability of the United States to interruptions in the oil supply from foreign sources. Storage for 248 million barrels of crude oil in salt caverns and mines, with equipment for pumping and distribution, was constructed and operationally tested in a 4-year period. Its present inventory is the largest known crude oil reserve in the world. Facilities for expanding the reserve's capacity by another 290 million barrels are being developed by solution-mining in salt domes.

13.
Tob Control ; 18(2): 156-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19208667

RESUMEN

BACKGROUND: Although research indicates that second-hand smoke (SHS) harms both human and animal health, data on the percentage of pet owners who smoke or allow smoking in their homes are not readily available. OBJECTIVE: To investigate pet owners' smoking behaviour and policies on smoking in their homes, and the potential for educational interventions to motivate change in pet owners' smoking behaviour. METHODS: A web-based survey was used with 3293 adult pet owners. The main outcome measures were smoking behaviour of pet owners and their cohabitants; policies on smoking in pet owners' homes; and impact of information about the dangers of pet exposure to SHS on pet owners' smoking intentions. RESULTS: Of respondents, 21% were current smokers and 27% of participants lived with at least one smoker. Pet owners who smoke reported that information on the dangers of pet exposure to SHS would motivate them to try to quit smoking (28.4%) and ask the people with whom they live to quit smoking (8.7%) or not to smoke indoors (14.2%). Moreover, non-smoking pet owners who live with smokers said that they would ask the people with whom they live to quit (16.4%) or not smoke indoors (24.2%) if given this information. About 40% of current smokers and 24% of non-smokers living with smokers indicated that they would be interested in receiving information on smoking, quitting, or SHS. CONCLUSIONS: Educational campaigns informing pet owners of the risks of SHS exposure for pets could motivate some owners to quit smoking. It could also motivate these owners and non-smoking owners who cohabit with smokers make their homes smoke-free.


Asunto(s)
Animales Domésticos , Conocimientos, Actitudes y Práctica en Salud , Cese del Hábito de Fumar/métodos , Prevención del Hábito de Fumar , Contaminación por Humo de Tabaco/efectos adversos , Adolescente , Adulto , Anciano , Contaminación del Aire Interior/efectos adversos , Animales , Femenino , Educación en Salud , Humanos , Masculino , Michigan , Persona de Mediana Edad , Motivación , Fumar/psicología , Cese del Hábito de Fumar/psicología , Adulto Joven
14.
Plant Dis ; 93(6): 674, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30764418

RESUMEN

The disease caused by thrips-transmitted Iris yellow spot virus (IYSV; genus Tospovirus, family Bunyaviridae) has become a major constraint to bulb and seed onion crops in several parts of the country and the world (1,3). As part of an ongoing survey for IYSV incidence in onion in the western United States, commercial fields in Lyon County, Nevada and several commercial fields in the northern Californian counties of Colusa, San Benito, Sutter, and Yolo were surveyed during the summer of 2008. Symptomatic plants were found widespread in northern California, especially in seed-production fields. In Lyon County, NV, symptoms were observed only on volunteer onions in one commercial field. Symptoms on leaves and scapes included characteristic diamond-shaped lesions with or without green islands. Four samples from Nevada and fourteen from northern California were tested by double-antibody sandwich (DAS)-ELISA using a commercially available kit (Agdia Inc., Elkhart, IN). All tested samples were found positive in ELISA. IYSV infection was verified by reverse transcription (RT)-PCR. Total nucleic acids were prepared from symptomatic tissue, and primers specific to the small (S) RNA of IYSV were used to amplify an approximate 1.2-kb region of the S-RNA. This region included the complete nucleoprotein (N) gene (2). The amplicons from one sample each from Nevada and northern California were sequenced (GenBank Accession Nos. FJ713699 and FJ713700, respectively). Sequence analysis showed that the amplicons contained a single open reading frame of 822 bp, coding for a 273-amino acid N protein, and the gene shared 96 to 98% identity with known IYSV N gene sequences. To our knowledge, this is the first report of IYSV in onion in Nevada. In California, outbreaks of IYSV had been reported earlier in Imperial Valley and Antelope Valley in southern California (4), and the disease has been increasing in incidence in bulb and seed crops in northern California, as well. California and Nevada are major onion-producing states in the United States and regular surveys to determine the incidence and impact on yield are needed to develop an integrated disease management program. References: (1) D. H. Gent et al. Plant Dis. 90:1468, 2006. (2) H. R. Pappu et al. Arch. Virol. 151:1015, 2006. (3) H. R. Pappu and M. E. Matheron. Online publication. doi:10.1094/PHP-2008-0711-01-BR. Plant Health Progress, 2008. (4) G. J. Poole et al. Online publication. doi:10.1094/PHP-2007-0508-01-BR. Plant Health Progress, 2007.

15.
Plant Dis ; 93(12): 1298-1304, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30759505

RESUMEN

Sixty-one isolates of Fusarium oxysporum f. sp. vasinfectum were collected from cotton plants (Gossypium spp.) with symptoms of Fusarium wilt to determine the composition of races present in the southeastern United States. Analysis of partial sequences of the translation elongation factor gene revealed four novel genotypes, as well as the presence of races 3 and 8 for the first time in the United States outside of California. The majority of isolates (16 of 27) sampled from Arkansas were novel genotypes. A subset of isolates representing the novel genotypes was compared with previously described races using sequences from translation elongation factor, phosphate permase, and ß-tubulin genes and their pathogenicity on a total of six Upland (Gossypium hirsutum) and Pima (G. barbadense) cotton cultivars. Two of the novel genotypes belonged to a clade containing races 1, 2, 4, 6, and 8 and two shared ancestry with race 3. All new genotypes were pathogenic to at least some of the cotton cultivars tested. The Pima cv. Phytogen 800 was relatively resistant to all genotypes of the pathogen. These results indicate that the population of F. oxysporum f. sp. vasinfectum in the southeastern United States is more diverse than previously recognized.

16.
Plant Dis ; 93(5): 546, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-30764155

RESUMEN

During the 2008 early-summer growing season, virus-like necrosis symptoms, most similar to those induced by Tobacco streak virus (TSV), were observed in leaves, stems, and petioles of processing tomato plants in the Central Valley of California. Symptoms were observed in numerous fields in Merced, San Joaquin, and Yolo counties, though the incidence of the disease in most fields was not high (not more than 5% but over 20% in some areas). Antibody-based tests of representative samples of the disease for infection with Tomato spotted wilt virus, TSV, and Tomato apex necrosis virus, which cause similar symptoms, were negative. A putative virus-like agent was sap- and graft-transmitted to tomato plants and induced necrotic spots in leaves and stem and petiole necrosis symptoms that were similar to those observed in the field. Eventually, these plants recovered from these symptoms. In sap-transmission experiments, the virus-like agent induced systemic symptoms in Chenopodium quinoa and C. amaranticolor (stunted growth and leaf curl and necrosis), Nicotiana benthamiana (necrotic leaf and stem lesions), N. tabacum cvs. Havana and Turkish (stunted growth and necrotic etching and ringspots followed by recovery for cv. Havana but not for cv. Turkish), and Datura stramonium (mild mottle and ringspots in newly emerged leaves followed by recovery); no symptoms were observed in inoculated common bean (cv. Topcrop), pumpkin (cv. Small Sugar), pepper, and N. glutinosa plants. Virus minipurification was performed with leaves from noninfected and infected D. stramonium plants, and polyacrylamide gel electrophoresis analyses revealed a protein band of ~29 kDa in infected but not noninfected plants. This protein was purified and subjected to liquid chromatography-mass/mass spectrometry analysis. Four peptides, obtained from the trypsin-digested protein, each had the highest match (score of 118) with the capsid protein (CP) of Parietaria mottle virus (PMoV), an ilarvirus that induces leaf and stem necrosis in tomatoes in Europe (1). Using sequences of PMoV and other ilarviruses, a single primer was designed from the 3' nontranslated region and paired with primers designed from conserved regions of ilarvirus RNAs 1, 2, and 3. In reverse transcription-PCR analyses, these primer pairs directed the amplification of the expected-sized fragments for ilarvirus RNAs 1, 2, and 3 from RNA extracts prepared from leaves with the unusual necrosis symptoms. Sequence analyses confirmed these were ilarvirus fragments. Partial RNA 1, 2, and 3 sequences were 81, 84, and 82% identical, respectively, with those of PMoV and 80, 77, and 69% identical, respectively, with those of TSV. The amino acid sequence of the CP gene (GenBank Accession No. FJ236810) was 86 and 61% identical to those of PMoV and TSV, respectively. Together, these results indicate the necrosis disease of tomato is caused by a new ilarvirus species, tentatively named Tomato necrotic spot virus, although further studies are needed to confirm this. The mode of transmission of this new ilarvirus to tomatoes in the field is unknown, but it may involve thrips feeding on infected pollen, a known method of transmission for TSV (2). References: (1) L. Galipienso et al. Plant Pathol. 54:29, 2005. (2) R. Sdoodee and D. S. Teakle. Plant Pathol. 36:377, 1987.

17.
Tob Control ; 17(3): 211-4, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18339800

RESUMEN

In 1983 and 1986, the International Advertising Association (IAA) published an original version and then a revision of a report entitled "Tobacco Advertising Bans and Consumption in 16 Countries," which were edited by J J Boddewyn, a marketing professor. The reports concluded that tobacco advertising bans have not been accompanied by any significant reduction in tobacco consumption. Opponents of tobacco advertising restrictions trumpeted the IAA reports in print materials, media communications and legislative hearings during the 1980s and beyond. A new analysis of tobacco industry documents and transcripts of tobacco litigation testimony reveals that British American Tobacco ghost-wrote the IAA reports and that the Tobacco Institute (the trade association then representing the major US cigarette manufacturers) helped to arrange for Boddewyn to present the findings to the US Congress and the media. Further research on tobacco industry documents and tobacco litigation transcripts should assess whether tobacco industry sources were responsible for ghost-writing other studies favourable to the industry.


Asunto(s)
Publicidad/legislación & jurisprudencia , Autoria , Industria del Tabaco/legislación & jurisprudencia , Humanos , Prevención del Hábito de Fumar
18.
J Vet Intern Med ; 22(1): 153-7, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18289303

RESUMEN

BACKGROUND: Lymphoma is the most common malignancy affecting cats. A protocol employing vincristine, l-asparaginase, cyclophosphamide, doxorubicin, and prednisone (VELCAP-S) is effective and well tolerated in dogs with lymphoma. A 24-week variation of this protocol (VELCAP-C) was developed for treatment of cats. HYPOTHESIS: That VELCAP-C will result in survival times for cats with lymphoma that are similar to those obtained when cats are treated with a protocol that includes fewer chemotherapy agents. ANIMALS: Sixty-one cats with lymphoma. METHODS: Retrospective study. Outcomes evaluated were response to VELCAP-C therapy, toxicosis, and survival time. The effect of signalment, staging, CBC, and serum chemistry profile and dosage on these outcomes was examined. RESULTS: Six cats (10%) completed the protocol with a median survival of 1189 days. Forty-three percent (23 of 61) of the cats achieved complete response (CR) with a median survival time of 62 days. Cats that required a dose reduction of any drug during induction were more likely to achieve CR. Weight loss and hepatomegaly at diagnosis were negatively associated with response to treatment. Increased lactate dehydrogenase (LDH) serum activity at the time of initial treatment correlated with decreased survival times. CONCLUSIONS AND CLINICAL IMPORTANCE: This multi agent protocol did not provide improved survival over historical data using protocols with fewer agents. Serum LDH activity levels might provide useful prognostic information for cats with lymphoma.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Enfermedades de los Gatos/tratamiento farmacológico , Linfoma/veterinaria , Animales , Asparaginasa/administración & dosificación , Asparaginasa/efectos adversos , Enfermedades de los Gatos/diagnóstico , Gatos , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Femenino , Linfoma/diagnóstico , Linfoma/tratamiento farmacológico , Masculino , Prednisona/administración & dosificación , Prednisona/efectos adversos , Inducción de Remisión , Estudios Retrospectivos , Vincristina/administración & dosificación , Vincristina/efectos adversos
19.
Plant Dis ; 92(5): 831, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-30769614

RESUMEN

In March 2007, mung bean (Vigna radiata) sprouts produced in an indoor sprouting facility in northern California developed brown lesions beginning 5 days after germination. Dark brown-to-reddish brown lesions with distinct margins developed on the stem, hypocotyl, and first true leaves of affected sprouts. Although all seed is routinely soaked in 20,000 mg Ca(OCl)2/liter of water for 15 min before germination, approximately 5 to 10% of the bean sprouts in several growing baskets (1.5 × 1.5 m) were affected and had to be discarded. Each basket contained approximately 1 t of sprouts. To isolate the causal organism, symptomatic stems were surface disinfested for 1 min in 0.5% NaOCl and incubated on acidified potato dextrose agar (PDA) at 25°C. Cultures were identified as Rhizoctonia solani on the basis of morphological features including right-angled branching of brown hyphae and the presence of sclerotia. PCR amplification of the internal transcribed spacer region was performed with primers RS1 and RS4 (2). Sequences were identical to R. solani AG4-HG-II in GenBank (Accession No. AF354074). To conduct pathogenicity tests, a 5-mm2-diameter disk from the margin of a culture of the fungus on PDA was placed in the center of 25 5-day-old germinated sprouts placed in a plastic box (15 × 10 × 5 cm) held at 25°C. Two isolates of R. solani cultured from different lots of sprouts were included in the assays. Controls received noncolonized agar. Treatments were replicated four times and each experiment was repeated three times. A moist paper towel was included in each box to maintain humidity. After 3 days, symptoms developed in the inoculated boxes but not in the noninoculated boxes. The fungus was reisolated from lesions, completing Koch's postulates. To our knowledge, this is the first report of R. solani on mung bean sprouts in a commercial sprouting facility. However, R. solani has been associated with root rot of mung bean plants in the field (1). References: (1) T. R. Anderson. Can. Plant Dis. Surv. 65:1, 1985. (2) C. Guillemaut et al. Can. J. Microbiol. 49:556, 2003.

20.
Plant Dis ; 91(5): 585-592, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-30780705

RESUMEN

Fusarium solani f. sp. eumartii, historically considered solely a pathogen of potato (Solanum tuberosum), was associated with tomato plants (Lycopersicon esculentum) exhibiting foot rot symptoms in California. The pathogenicity of California isolates of F. solani f. sp. eumartii from potato plants with Eumartii wilt symptoms and tomato plants with foot rot symptoms was determined on potato, tomato, pepper (Capsicum anuum), and eggplant (S. melongena). Isolates from both potato and tomato caused dry rot symptoms on potato tubers and root or collar rot on all four host species in the greenhouse. In field trials, isolates from both tomato and potato were pathogenic on tomato, potato, and pepper, confirming that the host range of F. solani f. sp. eumartii is not limited to potato. The phylogeny of isolates from potato and tomato was determined based on sequences of two DNA fragments: rDNA internal transcribed spacer regions and partial sequences of elongation factor 1-α. All of the California isolates of F. solani f. sp eumartii from tomato and potato formed a single monophyletic clade distinct from other formae speciales and mating populations of F. solani. The results of this study demonstrate that Eumartii wilt and tomato foot rot in California both are caused by F. solani f. sp. eumartii.

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