A5076588895- Plant Pathogens and Resistance
- Plant Pathogens and Fungal Diseases
- Yeasts and Rust Fungi Studies
- Plant Disease Resistance and Genetics
- Plant Disease Management Techniques
- Plant-Microbe Interactions and Immunity
- Nematode management and characterization studies
- Mycorrhizal Fungi and Plant Interactions
- Fungal Plant Pathogen Control
- Powdery Mildew Fungal Diseases
- Berry genetics and cultivation research
- Plant and Fungal Interactions Research
- Horticultural and Viticultural Research
- Botany and Plant Ecology Studies
- Genomics and Phylogenetic Studies
- Fungal Biology and Applications
- Forest Insect Ecology and Management
- Plant Parasitism and Resistance
- Composting and Vermicomposting Techniques
- Plant pathogens and resistance mechanisms
- Turfgrass Adaptation and Management
- Plant Virus Research Studies
- Public Health and Environmental Issues
- Mycotoxins in Agriculture and Food
- Agricultural and Food Sciences
Driscoll Children's Hospital
2019-2025
California Polytechnic State University
2015-2023
University of California, Riverside
2018
Cal Poly Corporation
2016
North Carolina State University
2006-2014
University of California, Berkeley
2004-2009
Lawrence Berkeley National Laboratory
2006
Wageningen University & Research
2006
Oregon State University
2000-2002
Pennsylvania State University
2000-2002
Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and sudden oak death ramorum. Oömycetes such as these species share kingdom Stramenopila with photosynthetic algae diatoms, presence of many genes probable phototroph origin supports a ancestry stramenopiles. Comparison two species' genomes reveals rapid expansion diversification protein families associated plant infection hydrolases, ABC transporters, toxins, proteinase inhibitors, and, in particular,...
With the increased attention given to genus Phytophthora in last decade response ecological and economic impact of several invasive species (such as P. ramorum, kernoviae, alni), there has been a significant increase number described species. In part, this is due extensive surveys historically underexplored ecosystems (e.g., forest stream ecosystems) undertaken determine spread involvement decline worldwide oak decline). The past seen an approximate doubling within Phytophthora, will likely...
Microbial-root associations are important to help plants cope with abiotic and biotic stressors. Managing these interactions offers an opportunity for improving the efficiency sustainability of agricultural production. By characterizing bacterial archaeal community (via 16S rRNA sequencing) associated bulk rhizosphere soil sixteen strawberry cultivars in two controlled field studies, we explored relationships between microbiome plant resistance soil-borne fungal pathogens (Verticillium...
Abstract Analysis of 12 polymorphic simple sequence repeats identified in the genome Phytophthora ramorum , causal agent ‘sudden oak death’, revealed genotypic diversity to be significantly higher nurseries (91% total) than forests (18% total). Our analysis only two closely related genotypes US forests, while genetic structure populations from European was intermediate complexity, including multiple, genotypes. Multilocus determined reproduce clonally and are likely descendants a single...
Isolates of Phytophthora infestans (n = 178) were collected in 2002 to 2009 from the eastern United States, Midwestern and Canada. Multilocus genotypes defined using allozyme genotyping, DNA fingerprinting with RG-57 probe. Several previously described three new mulitilocus detected. The US-8 genotype was found commonly on commercial potato crops but not tomato. US-20 tomato North Carolina through 2007 Florida 2005. US-21 2005 2006 2007. US-22 detected Tennessee New York became widespread...
Summary Powdery mildew is an economically important disease caused by c . 1000 different fungal species. Erysiphe vaccinii emerging powdery species that impacting the blueberry industry. Once confined to North America, E. now spreading rapidly across major blueberry‐growing regions, including China, Morocco, Mexico, and USA, threatening millions in losses. This study documents its recent global spread analyzing both herbarium specimens, some over 150‐yr‐old, fresh samples collected...
The finding of Phytophthora ramorum — the pathogen that causes sudden oak death in four California native trees on rhododendron Europe led us to hypothesize its host range California's natural forests was much greater than previously suspected. In addition affected species, we have now identified an additional 13 species from 10 plant families act as hosts for P. California. Our data indicates nearly all state's main tree mixed-evergreen and redwood-tanoak including coniferous timber coast...
In September and October 2011, a new disease was observed on Buxus spp. in North Carolina Connecticut, respectively. Carolina, over 10,000 containerized sempervirens (American boxwood) were affected at one location. A few weeks later, the found Connecticut entire plantings of B. ‘Suffruticosa’ (English two residential properties, shortly thereafter 150,000 plants production nurseries. Initial foliar symptoms appeared as light to dark brown spots, often with borders. Spots enlarged coalesced,...
Field experiments were conducted in silty-clay loam Corvallis, OR during the summers of 1995 and 1996 to study effects green manure cover crops (Sudan grass, rape, barley), soil solarization, fumigation, combinations those treatments on population densities pathogens Verticillium dahliae, Phytophthora cinnamomi, Pratylenchus penetrans, Agrobacterium rhizogenes. Nylon mesh bags containing infested with V. dahliae cinnamomiwere buried 5, 10, 20, 30 cm deep. Soil solarization was performed over...
ABSTRACT The choice of detection method for phytopathogens can be critically important in determining the success or failure pest regulation systems. We present an assay Phytophthora ramorum that uses 5' fluorogenic exonuclease (TaqMan) chemistry to detect and quantify pathogen from diseased tissue, include a universal primer probe set internal positive control. This is sensitive, detecting as little 15 fg target DNA when used nested design 50 single round polymerase chain reaction. None 17...
Phytophthora spp. represent a serious threat to agricultural and ecological systems. Many novel have been reported in recent years, which is indicative of our limited understanding the ecology diversity nature. Systematic cataloging genotypic phenotypic information on isolates previously described species serves as baseline for identification, classification, risk assessment new isolates. The Database (PD) was established catalog such data web-accessible searchable format. To support...
Anthracnose crown rot of strawberry, caused by Colletotrichum acutatum, is an important disease affecting California nursery and fruit production. Preplant dip treatments transplants with fludioxonil-cyprodinil or azoxystrobin are industry standards for managing the have been used extensively. Following reports reduced efficacy in field, high levels quinone outside inhibitor (QoI) resistance were detected isolates pathogen. Resistance was associated G143A mutation cytochrome b gene, similar...
Plants recruit diverse microbial communities from the soil to their roots. Intermicrobial interactions and connectivity in root microbiome play essential roles plant health by promoting resistance soilborne pathogens. However, understanding of these under field conditions is still scarce. Using a strawberry crop model, we characterized prokaryotic fungal rhizosphere roots three cultivars grown displaying varying degrees pathogen Macrophomina phaseolina. We tested hypothesis that resistant...
Extension and research professionals worked with a focus group of 10 nursery owners managers across five-state region (Georgia, Kentucky, North Carolina, South Tennessee) in the southeastern United States to prioritize diverse pests production issues that are related container field production. A second meeting, focused on technology, was followed by survey asked growers potential inputs uses information technology features they most valued, for example, might be included within...
Phytophthora isolates associated with ornamental plants or recovered from irrigation water in six states the southeastern United States (Georgia, North Carolina, South Tennessee, Texas, and Virginia) were identified screened for sensitivity to mefenoxam. Isolates forest suburban streams Georgia Virginia included comparison. A new vitro assay, utilizing 48-well tissue culture plates, was used screen mefenoxam sensitivity; this assay allowed high throughput of less material than traditional...
Herbaceous ornamental plants exhibiting symptoms of Pythium root rot were collected from 26 greenhouses in 21 counties North Carolina (NC) 2010 to 2012. Plant ranged mild stunting severe wilting, rot, and death. Roots plated on selective media, 356 isolates recovered 34 host species. Selected identified by sequencing the internal transcribed spacer (ITS) rDNA gene region. Seventeen species identified, with P. aphanidermatum, irregulare, myriotylum comprising 75% 320 sequenced. Twelve had...
Phytophthora spp. are waterborne plant pathogens that commonly found in streams, rivers, and reclaimed irrigation water. Rhododendron Pieris trap plants at two commercial nurseries were irrigated with water naturally infested during the 2011 2012 growing seasons to assess frequency of disease. consistently recovered from samples every collection time but detected on only 2 384 seasons. Pathogenicity assays proved hydropathica taxon PgChlamydo, taxa nurseries, foliar Pieris; however, neither...
Sensitivity of Botrytis cinerea to seven fungicide chemical classes was determined for 888 isolates collected in 2016 from 47 California strawberry fields. Isolates were early season (minimum exposure) and late (maximum the same planting block each field. Resistance using a mycelial growth assay, variable frequencies resistance observed at both sampling times (early %, %): boscalid (12, 35), cyprodinil 46), fenhexamid (53, 91), fludioxonil (1, 4), fluopyram (2, 7), iprodione (25, 8),...
Root rot caused by Phytophthora fragariae var. and P. rubi are major concerns in strawberry raspberry production the Pacific Northwest. Of lesser importance is black root of strawberry, a complex fungi nematodes. Soil solarization was evaluated 1997 planting 1998 for: (i) enhancing plant health growth, (ii) reducing population densities root-destroying pathogens. Plots were solarized from mid-July to mid-September. Maximum mean soil temperatures plots recorded at 10 cm depth 48 33°C 46 29°C...
Black shank disease of tobacco, caused by the oomycete Phytophthora nicotianae, is a major threat to production in United States and tobacco-producing areas worldwide. In statewide survey North Carolina, rapid shift from race 0 1 was documented. Collected pathogen isolates were characterized phenotypically for mating type mefenoxam sensitivity, genotypically comparing sequences three cytoplasmic two nuclear regions. Both A1 A2 types found throughout state. When both recovered same field,...
The primary objectives of this study were to determine if a single-strand conformation polymorphism (SSCP) analysis can be used for rapid identification Phytophthora ramorum, an important quarantine plant pathogen worldwide, and further assess the potential SSCP technique as taxonomic tool genus Phytophthora.SSCP ribosomal DNA internal transcribed spacer 1 was characterized 12 isolates P. using recently reported protocol. patterns species then compared with those 18 closely related species....