Sporulation potential of Phytophthora ramorum differs among common California plant species in the Big Sur region

Plant Disease ◽  
2020 ◽  
Author(s):  
Lisa Micaela Rosenthal ◽  
Sebastian N. Fajardo ◽  
David Rizzo
Keyword(s):  
Plant Species ◽  
Disease Risk ◽  
Field Studies ◽  
Lesion Size ◽  
Phytophthora Ramorum ◽  
Host Community ◽  
Additional Species ◽  
Transmission Potential ◽  
Big Sur ◽  
The Difference

Sudden oak death (SOD), caused by the generalist pathogen Phytophthora ramorum, has profoundly impacted California coastal ecosystems. SOD has largely been treated as a two-host system, with Umbellularia californica as the most transmissive host, Notholithocarpus densiflorus less so, and remaining species as epidemiologically unimportant. However, this understanding of transmission potential primarily stems from observational field studies rather than direct measurements on the diverse assemblage of plant species. Here, we formally quantify the sporulation potential of common plant species inhabiting SOD-endemic ecosystems on the California coast in the Big Sur region. This study allows us to better understand the pathogen’s basic biology, trajectory of SOD in a changing environment, and how the entire host community contributes to disease risk. Leaves were inoculated in a controlled laboratory environment and assessed for production of sporangia and chlamydospores, the infectious and resistant propagules, respectively. P. ramorum was capable of infecting every species in our study and almost all species produced spores to some extent. Sporangia production was greatest in N. densiflorus and U. californica and the difference was insignificant. Even though other species produced much less, quantities were non-zero. Thus, additional species may play a previously unrecognized role in local transmission. Chlamydospore production was highest in Acer macrophyllum and Ceanothus oliganthus, raising questions about the role they play in pathogen persistence. Lesion size did not consistently correlate with the production of either sporangia or chlamydospores. Overall, we achieved an empirical foundation to better understand how community composition affects transmission of P. ramorum.

Weed Control with Reduced Rates of Chlorimuron Plus Metribuzin and Imazethapyr in No-Till Narrow-Row Soybean (Glycine max)

1998 ◽  
Vol 12 (1) ◽  
pp. 32-36 ◽  
Author(s):  
William G. Johnson ◽  
Jeffrey S. Dilbeck ◽  
Michael S. Defelice ◽  
J. Andrew Kendig
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Field Studies ◽  
Weed Suppression ◽  
Crop Response ◽  
Soybean Production ◽  
No Till ◽  
Giant Foxtail ◽  
The Difference ◽  
Narrow Row

Field studies were conducted at three locations in 1993 and 1994 to evaluate weed control and crop response to combinations of glyphosate, metolachlor, 0.5 X and 1 X label rates of chlorimuron plus metribuzin applied prior to planting (PP), and 0.5 X and 1 X label rates of imazethapyr applied early postemergence (EPOST) or postemergence (POST) in no-till narrow-row soybean production. Giant foxtail densities were reduced with sequential PP followed by (fb) EPOST or POST treatments. Large crabgrass was reduced equivalently with all herbicide combinations involving chlorimuron plus metribuzin PP fb imazethapyr. Common cocklebur control was variable but was usually greater with treatments that included imazethapyr. Ivyleaf morningglory densities were not reduced with any herbicide combinations. Sequential PP fb EPOST or POST treatments tended to provide slightly better weed suppression than PP-only treatments, but the difference was rarely significant. Soybean yields with treatments utilizing 0.5 X rates were usually equal to 1 X rates.

scholarly journals Impact of the experimental removal of lizards on Lyme disease risk

2011 ◽  
Vol 278 (1720) ◽  
pp. 2970-2978 ◽  
Author(s):  
Andrea Swei ◽  
Richard S. Ostfeld ◽  
Robert S. Lane ◽  
Cheryl J. Briggs
Keyword(s):  
Lyme Disease ◽  
Disease Ecology ◽  
Disease Risk ◽  
Large Fraction ◽  
Host Community ◽  
Deer Mice ◽  
Infection Prevalence ◽  
Alternate Host ◽  
Experimental Removal ◽  
Tick Infection

The distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. Lizards (such as the western fence lizard; Sceloporus occidentalis ) play a unique role in Lyme disease ecology in the far-western United States. Lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks ( Ixodes pacificus —the vector for Lyme disease in that region) but are not competent reservoirs for the pathogen, Borrelia burgdorferi . Prior studies have suggested that the net effect of lizards is to reduce risk of human exposure to Lyme disease, a hypothesis that we tested experimentally. Following experimental removal of lizards, we documented incomplete host switching by larval ticks (5.19%) from lizards to other hosts. Larval tick burdens increased on woodrats, a competent reservoir, but not on deer mice, a less competent pathogen reservoir. However, most larvae failed to find an alternate host. This resulted in significantly lower densities of nymphal ticks the following year. Unexpectedly, the removal of reservoir-incompetent lizards did not cause an increase in nymphal tick infection prevalence. The net result of lizard removal was a decrease in the density of infected nymphal ticks, and therefore a decreased risk to humans of Lyme disease. Our results indicate that an incompetent reservoir for a pathogen may, in fact, increase disease risk through the maintenance of higher vector density and therefore, higher density of infected vectors.

Range extensions of grassland species in southern interior British Columbia

1985 ◽  
Vol 63 (12) ◽  
pp. 2240-2242
Author(s):  
Brian M. Wikeem ◽  
Reg F. Newman
Keyword(s):  
British Columbia ◽  
Plant Species ◽  
Field Studies ◽  
Grassland Species

Field studies and herbarium searches during 1983 and 1984 have revealed range extensions of three grassland plant species in the southern interior of British Columbia. These species include Allium geyeri Wats. var. tenerum Jones, Gaura coccinea (Nutt.) Pursh, and Sidalcea oregana (Nutt.) Gray ssp. oregana var. procera C. L. Hitchc. All three taxa were previously unknown to the Kamloops area and Sidalcea oregana is new to the province and Canada.

Performance of Abbreviated Protocols Versus Unenhanced MRI in Detecting Occult Breast Lesions of Mammography in Patients with Dense Breasts

2021 ◽  
Author(s):  
Suhong Zhao ◽  
Peipei Chen ◽  
Guangrui Shao ◽  
Baijie Li ◽  
Huikun Zhang ◽  
...  
Keyword(s):  
Reading Time ◽  
Area Under The Curve ◽  
Lesion Size ◽  
Lower Sensitivity ◽  
Chi Square ◽  
Dense Breast Tissue ◽  
Negative Findings ◽  
Chi Square Test ◽  
The Difference ◽  
Sensitivity Specificity

Abstract Objective: To assess the diagnostic ability of abbreviated protocols of MRI (AP-MRI) compared with unenhanced MRI (UE-MRI) in mammographically occult cancers in patients with dense breast tissue.Materials and Methods: The retrospective analysis consisted of 102 patients without positive findings on mammography who received preoperative MRI full diagnostic protocols (FDP) between January 2015 and December 2018. Two breast radiologists read the UE, AP, and FDP. The interpretation times were recorded. The comparisons of the sensitivity, specificity and area under the curve of each MRI protocol, and the sensitivity of these protocols in each subgroup of different size tumors used the Chi-square test. The paired sample t-test was used for evaluating the difference of reading time of the three protocols.Results: Among 102 women, there were 68 cancers and two benign lesions in 64 patients and 38 patients had benign or negative findings. Both readers found the sensitivity and specificity of AP and UE-MRI were similar (p>0.05), whereas compared with FDP, UE had lower sensitivity (Reader 1/Reader 2: p=0.023, 0.004). For different lesion size groups, one of the readers found that AP and FDP had higher sensitivities than UE-MRI for detecting the lesions ≤10 mm in diameter (p=0.041, p=0.023). Compared with FDP, the average reading time of UE-MRI and AP was remarkably reduced (p < 0.001).Conclusion: AP-MRI had more advantages than UE-MRI to detect mammographically occult cancers, especially for breast tumors ≤10 mm in diameter.

scholarly journals Alteration of plant species assemblages can decrease the transmission potential of malaria mosquitoes

2017 ◽  
Vol 55 (2) ◽  
pp. 841-851 ◽  
Author(s):  
Babak Ebrahimi ◽  
Bryan T. Jackson ◽  
Julie L. Guseman ◽  
Colin M. Przybylowicz ◽  
Christopher M. Stone ◽  
...  
Keyword(s):  
Plant Species ◽  
Species Assemblages ◽  
Transmission Potential ◽  
Malaria Mosquitoes

scholarly journals The Use of Native Halophytes in Landscape Design in The Central Anatolia, Turkey

2018 ◽  
Vol 6 (12) ◽  
pp. 1718
Author(s):  
Coşkun Sağlam ◽  
Serpil Önder
Keyword(s):  
Plant Species ◽  
Salt Marshes ◽  
Global Climate ◽  
Agricultural Practices ◽  
Field Studies ◽  
Research Area ◽  
Landscape Design ◽  
Central Anatolia ◽  
Barren Land ◽  
Halophytic Plant

In this study, the usability of some herbaceous halophytes grown naturally in salt marshes that dry most of the year in Central Anatolia Region were investigated in landscape design. Within the scope of the research, in the years of 2016 and 2017, seasonal field studies were carried out in saline habitats in the vicinity of Konya, Ankara, Aksaray and Nevşehir, and taken photographs and herbarium samples of halophytic plant species. The general botanical and ecological characteristics of the selected species are given and the values used in landscape design have been determined considering the aesthetic and functional properties. As a result of the field studies carried out during the vegetation periods, 59 halophytic plant species, belonging to 38 genera and 19 families that could be used in landscape design were identified. The most representative family was the Asteraceae with 11 species, followed by Plumbaginaceae (9 species) and Chenopodiaceae (8 species). The genus Limonium from Plumbaginaceae family is well represented with 8 species for landscape use. The endemism rate of halophytes used in landscape design is 42% (25 species) in the research area. The most common uses in landscape design are determined in roof gardens by 49 species, followed in ground conservation and erosion prevention by 31 species. Since these halophytic species, which are mostly succulent and endemic, are well adapted into both wet and dry areas. Their use in landscape design is of great importance for restoration of arid and barren land, which may increase as a result of global climate change, conservation of biodiversity as well as sustainable agricultural practices.

scholarly journals Integrating Spatiotemporal Epidemiology, Eco-Phylogenetics, and Distributional Ecology to Assess West Nile Disease Risk in Horses

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1811
Author(s):  
John M. Humphreys ◽  
Angela M. Pelzel-McCluskey ◽  
Lee W. Cohnstaedt ◽  
Bethany L. McGregor ◽  
Kathryn A. Hanley ◽  
...  
Keyword(s):  
Community Dynamics ◽  
Disease Risk ◽  
Bird Species ◽  
Integrated Approach ◽  
The United States ◽  
Host Community ◽  
Avian Host ◽  
West Nile ◽  
Phylogenetic Structure ◽  
Vaccination Programs

Mosquito-borne West Nile virus (WNV) is the causative agent of West Nile disease in humans, horses, and some bird species. Since the initial introduction of WNV to the United States (US), approximately 30,000 horses have been impacted by West Nile neurologic disease and hundreds of additional horses are infected each year. Research describing the drivers of West Nile disease in horses is greatly needed to better anticipate the spatial and temporal extent of disease risk, improve disease surveillance, and alleviate future economic impacts to the equine industry and private horse owners. To help meet this need, we integrated techniques from spatiotemporal epidemiology, eco-phylogenetics, and distributional ecology to assess West Nile disease risk in horses throughout the contiguous US. Our integrated approach considered horse abundance and virus exposure, vector and host distributions, and a variety of extrinsic climatic, socio-economic, and environmental risk factors. Birds are WNV reservoir hosts, and therefore we quantified avian host community dynamics across the continental US to show intra-annual variability in host phylogenetic structure and demonstrate host phylodiversity as a mechanism for virus amplification in time and virus dilution in space. We identified drought as a potential amplifier of virus transmission and demonstrated the importance of accounting for spatial non-stationarity when quantifying interaction between disease risk and meteorological influences such as temperature and precipitation. Our results delineated the timing and location of several areas at high risk of West Nile disease and can be used to prioritize vaccination programs and optimize virus surveillance and monitoring.

scholarly journals Assessment of the Potential Risk of Rock-Climbing for Cliff Plant Species and Natural Protected Areas of Spain

2021 ◽  
Vol 9 ◽  
Author(s):  
Indradatta deCastro-Arrazola ◽  
Martí March-Salas ◽  
Juan Lorite
Keyword(s):  
Protected Areas ◽  
Plant Species ◽  
Potential Risk ◽  
Field Studies ◽  
Rock Climbing ◽  
Future Research ◽  
Small Scale ◽  
Potential Threat ◽  
Natural Protected Areas ◽  
Priority Species

In recent years, the popularity of rock-climbing has grown tremendously, setting an increasing pressure on cliff habitats. Climbing may be particularly harmful in the Mediterranean biome due to its appropriate environmental conditions for climbing. A few studies have identified the effect of climbing on plant diversity at a small-scale (namely locally or even just in specific climbing areas). However, no studies exist assessing the potential risk of rock-climbing on a broad-scale (e.g., regional or national). The study aims to identify the priority locations and priority cliff plant species in Spain to focus future study efforts. Spain was selected because it is a plant biodiversity hotspot, with a great diversity of endemic and endangered species, and one of the most popular destinations for climbers. We used a geographic information system-based approach to model the spatial concurrence among Spanish climbing areas (and climbing intensity), natural protected areas (NPAs), and distribution of threatened cliff plants (and their IUCN threat category). We found that 53.5% of climbing areas in Spain are located within a NPA, most of them falling into NPAs of medium protection level. We mapped 151 threatened cliff plants, identifying four medium priority Mediterranean locations and eight priority species in which future research efforts should be focused. High-priority study locations are absent in Spain according to our spatial modeling. For the first time on a national scale, this study identifies areas in which climbing represents a potential threat for cliff habitats and threatened plants. These findings contribute to designing field studies on the effects of rock-climbing on Mediterranean cliffs, laying the groundwork for a sustainable, yet challenging, balance between the protection of these unique habitats and rock-climbing.

Biogeography of island floras in the Great Lakes. I. Species richness and composition in relation to gull nesting activities

1989 ◽  
Vol 67 (4) ◽  
pp. 961-969 ◽  
Author(s):  
E. H. Hogg ◽  
J. K. Morton ◽  
Joan M. Venn
Keyword(s):  
Species Richness ◽  
Great Lakes ◽  
Plant Species ◽  
Vascular Plants ◽  
Soil Nutrient ◽  
Lake Huron ◽  
Great Lakes Region ◽  
Alien Plant ◽  
Species Area ◽  
The Difference

Species–area relations of vascular plants and the effect of nesting colonies of gulls on plant species composition were investigated for 77 islands in Georgian Bay and Lake Huron in the Great Lakes region of Canada. The percentage of plant species classed as alien, annual, or biennial was significantly greater on islands with gull colonies. The slope of the species–area curve was significantly steeper on islands supporting gull colonies compared with islands lacking gull colonies. The expected decline in species richness with increased island remoteness was not detected statistically using multiple regression analysis. The difference in species–area slopes does not appear to reflect a lower propagule immigration rate to islands with gull colonies, because gulls are important in the dispersal of alien plant species to these islands. Larger islands with gull colonies tended to have richer floras than islands of similar size without gull colonies. It is suggested that on these larger islands the presence of gull colonies produces a gradient of soil nutrient and disturbance regimes, thus increasing habitat heterogeneity and species richness.

scholarly journals Methodological Guidelines for Accurate Detection of Viruses in Wild Plant Species

2016 ◽  
Vol 82 (6) ◽  
pp. 1966-1975 ◽  
Author(s):  
Christelle Lacroix ◽  
Kurra Renner ◽  
Ellen Cole ◽  
Eric W. Seabloom ◽  
Elizabeth T. Borer ◽  
...  
Keyword(s):  
Plant Species ◽  
Disease Risk ◽  
Virus Detection ◽  
Plant Viruses ◽  
Wild Plants ◽  
Wild Plant ◽  
Content Type ◽  
Wild Plant Species ◽  
Methodological Guidelines ◽  
Wild Hosts

ABSTRACTEcological understanding of disease risk, emergence, and dynamics and of the efficacy of control strategies relies heavily on efficient tools for microorganism identification and characterization. Misdetection, such as the misclassification of infected hosts as healthy, can strongly bias estimates of disease prevalence and lead to inaccurate conclusions. In natural plant ecosystems, interest in assessing microbial dynamics is increasing exponentially, but guidelines for detection of microorganisms in wild plants remain limited, particularly so for plant viruses. To address this gap, we explored issues and solutions associated with virus detection by serological and molecular methods in noncrop plant species as applied to the globally importantBarley yellow dwarf virusPAV (Luteoviridae), which infects wild native plants as well as crops. With enzyme-linked immunosorbent assays (ELISA), we demonstrate how virus detection in a perennial wild plant species may be much greater in stems than in leaves, although leaves are most commonly sampled, and may also vary among tillers within an individual, thereby highlighting the importance of designing effective sampling strategies. With reverse transcription-PCR (RT-PCR), we demonstrate how inhibitors in tissues of perennial wild hosts can suppress virus detection but can be overcome with methods and products that improve isolation and amplification of nucleic acids. These examples demonstrate the paramount importance of testing and validating survey designs and virus detection methods for noncrop plant communities to ensure accurate ecological surveys and reliable assumptions about virus dynamics in wild hosts.

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