A5063153086- Plant Pathogens and Resistance
- Plant Pathogens and Fungal Diseases
- Yeasts and Rust Fungi Studies
- Plant Disease Resistance and Genetics
- Mycorrhizal Fungi and Plant Interactions
- Horticultural and Viticultural Research
- Fermentation and Sensory Analysis
- Botany and Plant Ecology Studies
- Turfgrass Adaptation and Management
- Seedling growth and survival studies
- Rangeland and Wildlife Management
- Insect behavior and control techniques
- Forest Insect Ecology and Management
- Plant Pathogenic Bacteria Studies
- Plant-Microbe Interactions and Immunity
- Entomopathogenic Microorganisms in Pest Control
- Fire effects on ecosystems
University of California, Davis
2016-2025
Beltsville Agricultural Research Center
2024-2025
Agricultural Research Service
2024-2025
United States Department of Agriculture
2025
Washington State University
2012-2021
University of Maryland, College Park
2016
Many members of the
Phylogenetic relationships between thirteen species of downy mildew and 103 Phytophthora (plant-pathogenic oomycetes) were investigated with two nuclear four mitochondrial loci, using several likelihood-based approaches. Three taxa all excluded from the previously recognized subgeneric clades Phytophthora, though strongly supported within paraphyletic genus. Downy mildews appear to be polyphyletic, graminicolous (GDM), brassicolous (BDM) colored conidia (DMCC) forming a clade unplaced taxon...
Phytophthora pseudosyringae is a self-fertile pathogen of woody plants, particularly associated with tree species from the genera Fagus, Notholithocarpus, Nothofagus and Quercus, which found across Europe in parts North America Chile. It can behave as soil infecting roots stem collar region, well an aerial leaves, twigs barks, causing particular damage United Kingdom western America. The population structure, migration potential outcrossing worldwide collection isolates were investigated...
Evidence of unintended introductions Phytophthora species into native habitats has become increasingly prevalent in California. If not managed adequately, can devastating agricultural and forest plant pathogens. Additionally, California’s natural areas, characterized by a Mediterranean climate dominated chaparral (evergreen, drought-tolerant shrubs) oak woodlands, lack sufficient baseline knowledge on biology ecology, hindering effective management efforts. From 2018 to 2021, soil samples...
The production of ornamental plants in Mexico represents a job-generating activity that has grown recent years; however, it is adversely affected by phytosanitary issues, notably those induced Phytophthora. Studies Phytophthora nurseries are scarce Mexico. aim this study was to identify species from selected plant as potential new hosts. Samples 13 genera diseased tissue and soil were collected eight during 2009–2010. Based on morphology sequences ITS rDNA, the 19 isolates obtained...
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...
Yeasts were isolated from grapes collected a research vineyard at the WSU-IAREC, located Prosser, WA. Species determination was based on cultural features, microscopic morphology, physiological tests and analysis of ITS D1/D2 rDNA sequence data. Fifty-three species found distributed among five fungal subphyla, greater number than expected similar published studies. Within Saccharomycotina, 13 in genera Candida, Hanseniaspora, Metschnikowia, Meyerozyma, Pichia, Wickerhamomyces Yamadazyma...
Pistachio is one of the most widely cultivated nut crops in California, with approximately 115,000 ha bearing pistachio trees. In recent years, several orchards were identified, declining trees leading to substantial tree losses. Symptoms included poor vigor, yellowing and wilting leaves, crown rot, profuse gumming on lower portion trunks. Thirty-seven Phytophthora-like isolates obtained from rot tissues rootstock grafted characterized by means multilocus phylogeny comprising internal...
A collection of 30 Phytophthora cactorum and 12 P. pseudotsugae (subclade 1a) strains isolated from several recent surveys across California was phylogenetically compared to a worldwide 112 conspecific using sequences three barcoding loci. The baited soil water wide variety forested ecosystems with geographic range more than 1000 km. Two cosmopolitan lineages were identified within the widespread cactorum, one being mainly associated strawberry production other closely apple orchards, oaks...
Anthracnose caused by Colletotrichum species is one of the most frequent and damaging fungal diseases affecting avocado fruits (Persea americana Mill.) worldwide. In Chile, disease incidence has increased over last decades due to establishment commercial groves in more humid areas. Since 2018, unusual symptoms anthracnose have been observed on Hass fruits, with lesions developing a white gray sporulation. Morphological features multi-locus phylogenetic analyses using six DNA barcodes (act,...
Brown spot, caused by Cladosporium spp., is becoming a problematic postharvest disease of late season table grape (Vitis vinifera) in the California central valley, and management hindered knowledge gaps etiology epidemiology. spot herein described as pre- dry rot typified an external brown to black or mycelium which encases placenta. Isolates herbarum C. cladosporioides species complexes were recovered from 85 5% brown-spot affected berries, respectively. Five isolates complex, representing...
Geotrichum candidum was isolated from fruit of tomato ( Solanum lycopersicum ) in Washington state. Cultural and morphological features, rDNA sequence data, are reported. Koch's postulates were completed on fruit. This is the first report this fungus causing disease
Curvibasidium rogersii sp. nov. (Microbotryomycetes, Basidiomycota) is described on the basis of a strain (NRRL Y-48849) isolated from wine grapes ( Vitis vinifera ) in Washington state (USA). The taxonomic position was determined through analysis ITS region and D1/D2 domains LSU rRNA gene. Physiological morphological data also are presented. A basidial not observed.
Salal (Gaultheria shallon), Oregon grape (Berberis aquifolium), and red huckleberry (Vaccinium parvifolium) are common shrubs in the understory of northwestern forests ecologically, culturally, economically important to region. They also sold nurseries for use ornamental landscapes ecological restoration. These plant species were symptomatic Phytophthora nursery surveys Washington State between 2011 2015. Symptoms observed on these three hosts resembled those foliar infection other woody...
A pathogen causing disease on yellow nutsedge (Cyperus esculentus) growing in and near irrigated areas of onion seed bulb fields Idaho Oregon during July August, 1996 was morphologically molecularly characterized. Plant symptoms included necrotic spots, blotches blighting leaves, stems (culms) bracts. Symptomatic tissue contained glistening, white masses mycelium oval, semi-papillate sporangia emerging from stomata sporangiophores. Later, subspherical oogonia with smooth oospores were found...
More than 55% of U.S. lettuce (Lactuca sativa L.) production is in California, with Monterey Co. being the largest producer. Stunted mature romaine ‘Valencia’ and ‘Stomper’ iceberg ‘Frazier’ lettuces wilted outer leaves were collected from five commercial fields spring 2023 2024. Brown internal stem crown lesions progressed into sunken cavities plant collapse. Incidence was approximately 5 to 75%. Margins discolored tissue surface sterilized plated on PARP-CMA (Jeffers Martin 1986) colonies...
In April 2014, Phytophthora ramorum (Werres, De Cock & Man in't Veld) was recovered from symptomatic foliage of cherry laurel (Prunus laurocerasus) at an ornamental plant nursery in Washington State. Cherry laurel, also known as English is widely propagated WA because it commonly used landscaping. It invasive forests near the urban/wildland interface western US and Europe (Rusterholz et al. 2018). Given its popularity species, potential this host to spread P. regulatory concern due possible...
Phytophthora ramorum (Werres, De Cock & Man in't Veld) was recovered from symptomatic foliage of periwinkle at a botanical garden in WA March 2015. Symptoms were tan colored lesions with dark brown margin visible on both surfaces the leaf and found wounds or around margins. Periwinkle is native to Europe commonly used for ground cover ornamental landscapes. It known be invasive US forests near urban/wildland interface. Potential spread P. into regulatory concern, as well long distance other...