A5067222284- Plant Pathogens and Resistance
- Plant Pathogens and Fungal Diseases
- Yeasts and Rust Fungi Studies
- Seedling growth and survival studies
- Botany and Plant Ecology Studies
- Forest Insect Ecology and Management
- Plant Disease Resistance and Genetics
- Turfgrass Adaptation and Management
- Fire effects on ecosystems
- Forest ecology and management
- Ecology and Vegetation Dynamics Studies
- Tree-ring climate responses
- Plant responses to elevated CO2
- Plant responses to water stress
- Plant Parasitism and Resistance
- Plant Ecology and Soil Science
- Legume Nitrogen Fixing Symbiosis
- Forest Ecology and Biodiversity Studies
- Soybean genetics and cultivation
- Plant Surface Properties and Treatments
- Rangeland and Wildlife Management
- Indoor Air Quality and Microbial Exposure
- Plant-Microbe Interactions and Immunity
- Tannin, Tannase and Anticancer Activities
- Phytochemicals and Antioxidant Activities
Sphere Institute
2015-2025
US Forest Service
2013
University of California, Davis
1991-2007
University of California, Riverside
1978-1982
Aneuploidy can result in significant phenotypic changes, which sometimes be selectively advantageous. For example, aneuploidy confers resistance to antifungal drugs human pathogenic fungi. has also been observed invasive fungal and oomycete plant pathogens the field. Environments conducive generation of aneuploids, underlying genetic mechanisms, contribution invasiveness are underexplored. We studied diversification associated genome changes Phytophthora ramorum, a highly destructive...
Phytophthora is a long-established, well known and globally important genus of plant pathogens. Phylogenetic evidence has shown that the biologically distinct, obligate biotrophic downy mildews evolved from at least twice. Since, cladistically, this renders ‘paraphyletic’, it been proposed evolutionary clades be split into multiple genera (Runge et al. 2011; Crous 2021; Thines 2023; 2024). In letter, we review arguments for retention generic name with broad circumscription made by Brasier...
Abstract Forest pathogens are important drivers of tree mortality across the globe, but it is exceptionally challenging to gather and build unbiased quantitative models their impacts. Here we harness rare data set matching spatial scale pathogen invasion, host, disease heterogeneity estimate infection for four most susceptible host species Phytophthora ramorum , an invasive that drives biological cause in a broad geographic region coastal California southwest Oregon. As 2012, current field...
The tanoak (Lithocarpus densiflorus) acorn was a staple food in the Native American diet and is still used traditional dishes. Acorns from genus Quercus have been shown to contain large range of hydrolyzable tannins. However, neither nor condensed tannins characterized acorns. aim this study identify full extracts acorns using liquid chromatography/electrospray ionization-mass spectrometry/mass spectrometry. Condensed were identified as B type oligomers (epi)-catechin (procyanidins) with...
Over the past several years, plantings of California native plant nursery stock in restoration areas have become recognized as a pathway for invasive species introductions, particular Phytophthora pathogens, including first U.S. detections (Phytophthora tentaculata, quercina), new taxa, hybrid species, and dozens other soilborne species. Restoration may be conducted high-value limited habitats to sustain or re-establish rare populations. Once established, pathogens infest site are very...
<i>Phytophthora tentaculata</i> Kröber & Marwitz (Pythiaceae) has been detected in several native plant nurseries 4 California counties and restoration sites on orange sticky monkey flower (<i>Diplacus aurantiacus</i> (W. Curtis) Jeps. subsp. <i>aurantiacus</i> [Scrophulariaceae]), toyon (<i>Heteromeles arbutifolia</i> (Lindl.) M. Roem. [Rosaceae]), coffeeberry (<i>Frangula californica</i> (Eschsch.) A. Gray [Rhamnaceae]), sage (S<i>alvia</i> spp. L. [Lamiaceae]). These findings are the...
Exposure of tomato plants (Lycopersicon esculentum Mill.) to salinity stress either before or after inoculation with Phytophthora parasitica increased root and crown rot severity relative nonstressed controls. The synergy between P. parasitic was most pronounced on young (prebloom) least older (postbloom) plants. Salt stressed, inoculated had significantly reduced top weight, more necrosis, greater incidence mortality. Increased disease occurred even though experiments showed zoospore...
Non-native diseases of dominant tree species have diminished North American forest biodiversity, structure, and ecosystem function over the last 150 years. Since mid-1990s, coastal California forests suffered extensive decline endemic overstory tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon S. H. Oh (Fagaceae), following emergence exotic pathogen Phythophthora ramorum resulting disease sudden oak death. There are two central challenges to protecting tanoak: 1) P. has...
The genetic structure of a sample isolates the oomycete plant pathogen Phytophthora cinnamomi from natural and agricultural outbreaks long-distance movement individual genotypes were studied using four microsatellite markers to genotype 159 Californian, Mexican, worldwide origins. Allelic profiles identified 75 multilocus genotypes. A STRUCTURE analysis placed them in three groups characterized by different geographic host ranges, genic genotypic diversity, reproductive modes. When...
Blue oak woodlands in California have been a focus of conservation concern for many years. Numerous studies found that existing seedling and sapling numbers are inadequate to sustain current populations, recent work has suggested blue might be particularly vulnerable warming climate. recently experienced drought historically unprecedented severity, resulting the mortality tens millions trees, including an apparent spike communities. Here we present results survey tree composition Sequoia...
The relationship between quantity of epicuticular wax and plant sensitivity to hydrogen chloride (HCl) gas was investigated using 8-, 12-, 16-day-old Phaseolus vulgaris L. plants exposed for 20 min 27.6 ± 3.9 mg HCl∙m −3 . Twelve-day-old were more sensitive than 8- or possessed the lowest mean surface quantity. Multiple regression analysis showed that negatively linearly related percent leaves glazed. Necrotic injury also correlated with quantity, but a lesser degree glazing. Chamber...
Author(s): Swiecki, Tedmund J; Quinn, Matt; Sims, Laura; Bernhardt, Elizabeth; Oliver, Lauralea; Popenuk, Tina; Barbelotto, Matteo M | Abstract: Multiple species of Phytophthora have been identified in production facilities plants used reforestation and restoration projects. There's a risk that infected plant stock will lead to Phytophthoraspecies establishing spreading habitats that, having never experienced their presence, may be highly susceptible infection. Eradication these pathogens,...
Rooted cuttings of Chrysanthemum morifolium 'Paragon' grown in nutrient solution were given a 24-h pulse exposure to salinity by amending the with 200 mequiv. NaCl/L. The then returned nonsalinized solution; one half inoculated motile zoospores Phytophthora cryptogea Pethybr. & Laff, and other maintained as non-inoculated controls. Nonstressed also P. cryptogea, roots from all treatments sampled at various intervals thereafter for light electron microscopy. Penetration nonstressed was...
Ione manzanita (Arctostaphylos myrtifolia) is a rare, endemic, evergreen shrub restricted to formation soils (infertile, acidic, sedimentary oxisols) in the foothills of Sierra Nevada. The widely distributed A. viscida (whiteleaf manzanita) intermixes with myrtifolia at margins soils. In 2002, we observed extensive mortality within two mixed stands and near Ione, CA. At one site, nearly all plants both species 0.25-ha area had died recently. second most on several hectares least 5 years...
Widespread Phytophthora infections have been discovered in nursery stock used California restoration plantings. In response, Nursery Best Management Practices (NPBMPs) designed to exclude from plants were developed address the need for clean planting projects. A pilot program implement systematic use of NPBMPs, Accreditation Improve Restoration (AIR), was and started 2018. As 2020, 13 northern nurseries evaluated, five met all requirements. 564 tests conducted over 4 years with a sensitive...
In 2014, Phytophthora root rot was identified as a serious problem in nursery plants grown for habitat restoration California. To support efforts to produce stock free of species, we developed standardized leachate baiting method that can be conducted by staff. Each plant an array up 42 container-grown is irrigated six times at 15-min intervals with water volume. Irrigation collected specialized vessel containing green (unripe) pear bait. Test sensitivity assessed using arrays...