Lessons from 10 years of stakeholder adoption of a soil bioassay for assessing the risk of spinach Fusarium wilt     

Sanjaya Gyawali  Michael L. Derie  Emily W. Gatch  Dipak Sharma-Poudyal  Lindsey J. du Toit 《Plant pathology》2021,70(4):778-792

Although the maritime Pacific Northwest (PNW) is the only region of the United States suitable climatically for spinach seed production, the acidic soils are highly conducive to spinach Fusarium wilt caused by Fusarium oxysporum f. sp. spinaciae. A soil bioassay developed to quantify the risk of spinach Fusarium wilt in fields has been offered to seed growers annually since 2010. Soil sampled from growers' fields each winter was planted with highly susceptible, moderately susceptible, and partially resistant spinach inbred lines, and the plants rated weekly to calculate a Fusarium wilt severity index (FWSI) and the area under the disease progress curve (AUDPC). Results for 147 soils tested from 2010 to 2013 have been published. This study examined results for an additional 248 soils tested from 2014 to 2019 with the bioassay modified to include an option of agricultural limestone amendment to the soils tested. FWSI and AUDPC were affected significantly (p < .001) by the main effects of soil and spinach inbred line, and the interaction of these factors. Correlation analyses showed a range in degree of association of FWSI and AUDPC with spinach seed crop rotation duration and soil properties, depending on the spinach inbred line (r = −.255 to –.267, n = 172 soils with characteristics suitable for correlation analyses). Stepwise regression models for 172 soils with relevant parameters for regression analyses identified spinach seed crop rotation interval, rate of agricultural limestone amendment, soil pH, and soil Fe, Mn, and Zn concentrations as most strongly associated with FWSI and AUDPC. However, the models accounted for ≤33.4% (R²) of the variability in Fusarium wilt risk. The soil bioassay remains a primary tool for spinach seed growers to select fields with low risk of Fusarium wilt.  相似文献   

Seeing the forest for the trees: Use of phages to treat bacterial tree diseases     

Emily R. Grace  Mojgan Rabiey  Ville-Petri Friman  Robert W. Jackson 《Plant pathology》2021,70(9):1987-2004

Trees and woody plants can be attacked by many pests and pathogens either individually or as polymicrobial infections. In particular, infections caused by tree-specific bacterial pathogens have become more common during the last decade, causing serious concern for important tree and woody plant species in horticulture, urban environments, and forests. For example, Xylella and Pseudomonas bacteria are causing significant economic and ecological devastation throughout Europe in olive, cherry, and other stone fruits, mainly because of lack of efficient control methods and the emergence of bacterial resistance to traditional antimicrobial compounds such as copper and antibiotics. Hence, there is an urgent need for innovative approaches to tackle bacterial plant diseases. One way to achieve this could be through the application of biological control, which offers a more environmentally friendly and targeted approach for pathogen management. This review will explore recent advances in use of pathogen-specific viruses, bacteriophages (or phages), for the biocontrol of bacterial tree diseases. Phages are an important component of plant microbiomes and are increasingly studied in plant pathogen control due to their highly specific host ranges and ability to selectively kill only the target pathogenic bacteria. However, their use still poses several challenges and limitations, especially in terms of managing the bacterial diseases of long-lived trees. A particular insight will be given into phage research focusing on controlling Pseudomonas syringae pathovars, Erwinia amylovora, Xanthomonas species, Ralstonia solanacearum, and Agrobacterium tumefaciens. Recent milestones, current challenges, and future avenues for phage therapy in the management of tree diseases are discussed.  相似文献   

EFFECT OF DELAYED EMERGENCE ON CORN (ZEA MAYS L.) GRAIN YIELD     

Emily Rutto  Cody Daft  Jonathan Kelly  Bee Khim Chim  Jeremiah Mullock  Guilherme Torres 《Journal of plant nutrition》2014,37(2):198-208

Uneven crop stands result in a reduction in corn yield production. This study was conducted to determine the effect of delayed emergence on corn yields and the effect of nitrogen (N) applications to compensate for yield reductions. The design used was a randomized complete block, with 4 sequences of delayed planting (0,4,7,and 10 days after planting) and 3 rates of nitrogen fertilizer (0, 40, 80 kg N ha^?1). At maturity, individual plants were tagged in sets of three and hand harvested. Corn ears were shelled, and yield per plant calculated. Grain yield of the delayed plant compared to that of the neighbors was reduced by 27, 8, 20 and 12 kg ha^?1day^?1 for 2007 LCB1, 2007 LCB2, 2010 LCB1 and 2010 LCB2, respectively. Over locations and years, the mean grain yield decrease of the delayed plant versus neighboring plants for each day delay was 122 kg ha^?1.  相似文献   

Gradient analysis of an eastern sand savanna's woody vegetation,and its long-term responses to restored fire processes     

Alan Haney  Marlin Bowles  Steven Apfelbaum  Emily Lain  Tom Post 《Forest Ecology and Management》2008

Little information is available comparing historic and modern sand savannas, and how remnants respond to restored fire. We compared short- and long-term effects of restored fire on the Tefft Savanna, a 197 ha eastern sand savanna in northwest Indiana that had undergone three decades of fire protection. U.S. Public Land Survey data from Tefft in 1833 indicate black and white oak barrens, and pin oak savanna, with trees averaging 50 stems/ha and 4 m²/ha basal area. We used ordination and a digital elevation model to assess topographic distribution of tree species in 1986. In 1986, we also compared initial effects of high- and low-intensity dormant season fire on woody vegetation among nine blocks containing black oak, white oak, and pin oak stands. Twenty years later, we compared the same blocks, all of which had been burned three times per decade with low-intensity fires. In 1986, black oak, white oak and pin oak occurred across a gradient of decreasing elevation and slope. At that time, unburned black oak and white oak stands averaged >400 stems/ha and about 10 m²/ha basal area, and their smaller size classes contained non-oak woody vegetation that apparently had invaded with fire exclusion. After initial burns, black oak and white oak stands receiving high-intensity fire averaged <200 stems/ha and had significantly lower oak canopy cover and basal area than unburned stands. Stands receiving low-intensity fire had intermediate oak canopy cover, with basal area similar to unburned stands. Pin oak stands were more fire-resistant, apparently because spring flooding often reduced fire effects. Density, cover and basal area of non-oak tree species were much lower than oaks, and were not reduced by initial burning. Repeated low-intensity burning over 20 years tended to maintain structure caused by initial fires. However, it reduced lower size class stem densities, promoted post-fire sprouting into the shrub layer, and allowed oak basal area to increase in larger size classes. Time since fire regulated shrub layer structure on a 4-year cycle. Density and cover of trees and shrubs returned to pre-burn conditions by the second and fourth growing seasons after fire, respectively, with non-oak tree species exceeding pre-burn cover and density by the fourth season. These results suggest that high-intensity fire is more important than repeated low-intensity burning in structuring and restoring eastern sand savanna, and that non-oak tree species, once established, may be resistant to low-intensity fire.  相似文献   

Response of vegetation and birds to severe wind disturbance and salvage logging in a southern boreal forest     

Emily J. Lain  Alan Haney  John M. Burris  Julia Burton 《Forest Ecology and Management》2008

Vegetation and birds were inventoried on the same plot before and after a severe windstorm in 1999 disturbed a mature black spruce (Picea mariana)–jack pine (Pinus banksiana) forest in northern Minnesota. Following the storm, another plot was established in an adjacent portion of the forest that was salvage-logged. Birds were inventoried on both plots through 2002. The original unsalvaged plot was prescribed-burned in 2004, but vegetation was surveyed through 2003, and through 2005 on the salvaged plot. We examined the effects of wind disturbance by comparing the pre-storm bird and vegetation communities with those developing afterwards through 2002 and 2003, respectively, and the effects of salvage logging by comparing vegetation and the bird community on the unsalvaged plot with those in the salvaged area. Wind reduced the canopy of the forest by over 90% with a temporary increase in the shrub layer, mostly resulting from tip-ups. Several plant species, including jack pine and beaked hazel (Corylus americana), appeared temporarily in the ground layer (<1 m height), but did not persist through 2003. Quaking aspen (Populus tremuloides) root sprouts were abundant in 2001, but decreased dramatically by 2003. Delayed mortality of tipped trees resulted in reduction of the shrub layer to pre-storm levels, and release of advanced regeneration black spruce and balsam fir (Abies balsamea). Bird species using the forest changed from dominance by canopy-foraging species to ground-brush foraging species, with an overall increase in bird diversity. Salvage logging resulted in significant reduction in coarse woody debris, and successful recruitment of jack pine seedlings. Quaking aspen sprouts were nearly 30 times more abundant in the salvage-logged area compared to the unsalvaged control. Ruderal species, especially red raspberry (Rubus ideaus), fringed bindweed (Polygonum cilinode), and several sedges (Carex spp.), were significantly more abundant after salvage logging. The bird community, on the other hand, was greatly diminished by salvage logging, with a reduction in diversity, density, and overall richness of species.  相似文献   

Non-governmental Organizations and Government Agencies Lead in Cultivating Positive Sea Turtle Conservation Attitudes     

Emily L. Cella  E. C. M. Parsons  Larry L. Rockwood 《Human Dimensions of Wildlife》2016,21(5):391-402

Considerable research has been conducted analyzing how demographic characteristics influence the public’s attitudes toward wildlife; however, less research of this type has been conducted in locations having long-standing species conservation efforts. Questionnaires were completed by residents living adjacent to such a location, the Archie Carr National Wildlife Refuge (ACNWR), to investigate which demographics explained residents’ knowledge of, attitudes toward, willingness to act for, and participation in sea turtle conservation. Residents who had a non-governmental organization (NGO) or government agency as their sea turtle information source had stronger positive attitudes toward sea turtles. Residents who possessed strong positive attitudes were more willing to engage in pro–sea turtle conservation behaviors. Overall, this research demonstrated that ACNWR residents’ source of sea turtle information being an NGO or government agency played a significant role in increasing residents’ knowledge of, attitudes toward, willingness to volunteer for, and participation in sea turtle conservation.  相似文献   

Reactive mesothelial hyperplasia associated with chronic peritonitis in a 20-year-old Quarter horse     

Laura L. Hoon-Hanks  Emily D. Rout  Linda M. Vap  Tawfik A. Aboellail  Diana M. Hassel  Yvette S. Nout-Lomas 《The Canadian veterinary journal. La revue veterinaire canadienne》2016,57(5):492-496

A 20-year-old gelding was diagnosed with peritonitis and severe reactive mesothelial hyperplasia. Exploratory laparotomy findings were suggestive of a neoplastic etiology; however, additional diagnostics ruled this out and the horse made a full recovery. This report demonstrates the difficulty and value of differentiating between reactive and neoplastic mesothelial processes.  相似文献   

Correlation of distraction index with arthroscopic findings in juvenile dogs with hip dysplasia     

Emily H. Ulfelder  Caleb C. Hudson  Brian S. Beale 《Veterinary surgery : VS》2019,48(6):1050-1057

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Comparisons between elastographic stiffness scores for benign versus malignant lymph nodes in dogs and cats          下载免费PDF全文

Gabriela S. Seiler  Emily Griffith 《Veterinary radiology & ultrasound》2018,59(1):79-88

Lymph node evaluation is an important component of oncology staging in dogs and cats, however diagnosis of malignancy currently requires cytology or histopathology. Elastography is an ultrasound technique that allows estimation of tissue stiffness. In people, it has been shown to increase the sensitivity of sonography in detection of metastatic lymph nodes. The objective of this prospective, cross‐sectional study was to determine if elastographic stiffness differs for malignant versus benign canine and feline lymph nodes that were considered abnormal in gray‐scale ultrasound imaging. Animals scheduled for ultrasound‐guided fine needle aspirates of a lymph node at a single center were prospectively enrolled. Elastography was performed by a board‐certified veterinary radiologist (G.S.) prior to tissue sampling. Softness was scored qualitatively as 1–4 (1 = hard; 4 = soft) on an image depicted by a color scale (blue = hard, red = soft). Quantitative analysis was performed using custom‐made software. Fifty‐one lymph nodes were included in the evaluation, 21 had benign and 30 had neoplastic cytology. Benign lymph nodes were softer (median score of 2.5, range 1–4) than malignant lymph nodes (median = 2, range 1–3), and differences were significant in qualitative and quantitative analyses (P < 0.01). Of the lymph nodes with a score of 2 or below (hard), 19/25 (76%) were malignant, of the lymph nodes with a score over 2 (soft), 24/36 (67%) were benign. Findings indicated that elastographic stiffness scores differed between benign and malignant lymph node groups; however overlapping scores for the two groups limited the use of this technique for routine clinical diagnosis of malignancy.  相似文献   

Genetic analysis of optic nerve head coloboma in the Nova Scotia Duck Tolling Retriever identifies discordance with the NHEJ1 intronic deletion (collie eye anomaly mutation)          下载免费PDF全文

Emily A. Brown  Sara M. Thomasy  Christopher J. Murphy  Danika L. Bannasch 《Veterinary ophthalmology》2018,21(2):144-150

Collie eye anomaly (CEA) encompasses a spectrum of different ophthalmic phenotypes from clinically inconsequential choroidal hypoplasia to blindness from coloboma of the optic nerve head (ONH). A previous study found a 7.8‐kb deletion in intron 4 of the NHEJ1 gene to be associated with CEA. A genetic test based on this association is recommended for many breeds, including the Nova Scotia Duck Tolling Retriever (NSDTR). Collection of ONH coloboma‐affected NSDTR showed lack of concordance of the NHEJ1 intronic deletion with ONH coloboma. Using genomewide single nucleotide polymorphism (SNP) genotyping in 7 ONH coloboma‐affected NSDTR cases and 47 unaffected NSDTR controls with no ophthalmic signs, one SNP, located on chromosome 7, demonstrated genomewide significance. However, high genomic inflation may have confounded the results. Therefore, the genomewide association study was repeated using EMMAX to control for population structure in the cohort of 7 cases and 47 controls. However, no regions of the genome were significantly associated with ONH coloboma. These results failed to document significant association with the CEA locus. Due to the complex genetic etiology of ONH coloboma, the NHEJ1 intronic deletion test results should be carefully considered when making breeding decisions. If the goal is to select for visually competent dogs, our data suggest that eye examinations of puppies would be more effective as a guide in selection of breeding pairs than relying solely on currently available genetic tests.  相似文献