scholarly journals The Source of Rag5-Mediated Resistance to Soybean Aphids Is Located in the Stem

2021 ◽  
Vol 12 ◽  
Author(s):  
Kumud Joshi ◽  
Joshua L. Baumgardner ◽  
Madison MacPhail ◽  
Shailesh R. Acharya ◽  
Elizabeth Blotevogel ◽  
...  
Keyword(s):  
Management Strategies ◽  
The United States ◽  
Electrical Penetration Graph ◽  
Feeding Behaviors ◽  
Soybean Aphids ◽  
Whole Plant ◽  
Detached Leaves ◽  
Root Stock ◽  
Plant Assays ◽  
Whole Plants

The soybean aphid (Aphis glycines) continues to threaten soybean production in the United States. A suite of management strategies, such as planting aphid-resistant cultivars, has been successful in controlling soybean aphids. Several Rag genes (resistance against A. glycines) have been identified, and two are currently being deployed in commercial soybean cultivars. However, the mechanisms underlying Rag-mediated resistance are yet to be identified. In this study, we sought to determine the nature of resistance conferred by the Rag5 gene using behavioral, molecular biology, physiological, and biochemical approaches. We confirmed previous findings that plants carrying the Rag5 gene were resistant to soybean aphids in whole plant assays, and this resistance was absent in detached leaf assays. Analysis of aphid feeding behaviors using the electrical penetration graph technique on whole plants and detached leaves did not reveal differences between the Rag5 plants and Williams 82, a susceptible cultivar. In reciprocal grafting experiments, aphid populations were lower in the Rag5/rag5 (Scion/Root stock) chimera, suggesting that Rag5-mediated resistance is derived from the shoots. Further evidence for the role of stems comes from poor aphid performance in detached stem plus leaf assays. Gene expression analysis revealed that biosynthesis of the isoflavone kaempferol is upregulated in both leaves and stems in resistant Rag5 plants. Moreover, supplementing with kaempferol restored resistance in detached stems of plants carrying Rag5. This study demonstrates for the first time that Rag5-mediated resistance against soybean aphids is likely derived from stems.

scholarly journals Location, location, location: Feeding site affects aphid performance by altering access and quality of nutrients

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245380
Author(s):  
Vamsi J. Nalam ◽  
Jinlong Han ◽  
William Jacob Pitt ◽  
Shailesh Raj Acharya ◽  
Punya Nachappa
Keyword(s):  
Feeding Behavior ◽  
Negative Impact ◽  
Electrical Penetration Graph ◽  
Soybean Aphids ◽  
Whole Plant ◽  
Leaf Surfaces ◽  
Aphid Feeding ◽  
And Performance ◽  
Plant Assays

Aphid feeding behavior and performance on a given host plant are influenced by the plants’ physical and chemical traits, including structural characters such as trichomes and nutritional composition. In this study, we determined the feeding behavior and performance of soybean aphids (Aphis glycines) on the stem, the adaxial (upper), and the abaxial (lower) leaf surfaces during early vegetative growth of soybean plants. Using the electrical penetration graph technique, we found that aphids feeding on the stem took the longest time to begin probing. Once aphids began probing, the sieve elements were more conducive to feeding, as evidenced by less salivation on the stem than either leaf surface. In whole-plant assays, stems harbored higher aphid populations, and aphids had shorter development time on stems than the adaxial and the abaxial leaf surfaces. We compared trichome density and length on the stem, the adaxial, and the abaxial leaf surfaces to investigate whether plant trichomes affected aphid feeding and performance. There were higher density and longer trichomes on stems, which likely resulted in aphids taking a longer time to probe. Still a negative impact on aphid population growth was not observed. Analysis of phloem sap composition revealed that vascular sap-enriched exudates from stems had higher sugars and amino acids than exudates from leaves. In artificial diet feeding assays, the population of aphids reared on a diet supplemented with stem exudates was higher than on a diet supplemented with leaf petiole exudates which is in agreement with results of the whole-plant assays. In summary, our findings suggest that the performance of soybean aphids on a specific plant location is primarily driven by accessibility and the quality of phloem composition rather than structural traits.

scholarly journals Use of Mycelium and Detached Leaves in Bioassays for Assessing Resistance to Boxwood Blight

Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1622-1626 ◽  
Author(s):  
Yonghong Guo ◽  
Richard T. Olsen ◽  
Matthew Kramer ◽  
Margaret Pooler
Keyword(s):  
The United States ◽  
Screening Assay ◽  
Disease Symptoms ◽  
Detached Leaf ◽  
Whole Plant ◽  
Detached Leaves ◽  
Time Of Year ◽  
Stem Lesions ◽  
Whole Plants ◽  
Plant Inoculation

Boxwood blight caused by Calonectria pseudonaviculata is a newly emergent disease of boxwood (Buxus spp. L.) in the United States that causes leaf drop, stem lesions, and plant death. A rapid and reliable laboratory assay that enables screening hundreds of boxwood genotypes for resistance to boxwood blight is needed to enable breeding and selection of resistant cultivars. Using eight boxwood cultivars with differing susceptibilities, we examined parameters for a screening assay comparing whole plant inoculation with detached leaf inoculation, use of mycelium versus spores as the inoculum, comparison of times of the year for inoculation, and comparison of two leaf inoculation methods. Inoculation of detached leaves gave comparable results to inoculation of whole plants when compared across genotypes, although the detached leaf assay resulted in greater percentages of symptom expression. The time of year of plant inoculation (spring, summer, or winter) did not affect the relative expression of symptoms among the most resistant and susceptible genotypes. Inoculating plants with mycelium was as effective as spore inoculation for causing disease symptoms and allowed us to distinguish the more resistant genotypes, yet mycelium inoculation was much easier to prepare in large quantities for multiple assays.

scholarly journals Management of Insecticide-Resistant Soybean Aphids in the Upper Midwest of the United States

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Robert L Koch ◽  
Erin W Hodgson ◽  
Janet J Knodel ◽  
Adam J Varenhorst ◽  
Bruce D Potter
Keyword(s):  
United States ◽  
Pyrethroid Resistance ◽  
Management Strategies ◽  
The United States ◽  
Soybean Aphid ◽  
Upper Midwest ◽  
Pyrethroid Insecticides ◽  
Soybean Aphids ◽  
Development Of Resistance ◽  
Laboratory Confirmation

Abstract Since the first observation of soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in North America in 2000, it has become the most economically damaging insect of soybean in the Upper Midwest of the United States. For the last 17 yr, soybean aphid management has relied almost entirely on the use of foliar-applied broad-spectrum insecticides. However, in 2015 in Minnesota, failures of foliar-applied pyrethroid insecticides were reported and pyrethroid resistance was confirmed with laboratory bioassays using lambda-cyhalothrin and bifenthrin. In 2016 and 2017, further reports of failures of pyrethroid insecticides and/or laboratory confirmation of resistance occurred in Iowa, North Dakota, South Dakota, and Manitoba. In response to the challenge posed by insecticide-resistant soybean aphids, we recommend several management strategies for minimizing further development of resistance and subsequent pest-induced crop losses: 1) scout and use the economic threshold to determine when to apply insecticides, 2) apply the insecticides properly, 3) assess efficacy 3–5 d after application, and 4) alternate to a different insecticide group if another application is required. In the long term, soybean aphid management must move beyond insecticide-based management to true integrated pest management by incorporating multiple tactics.

scholarly journals Comparison of Whole Plant and Detached Leaf Screening Techniques for Identifying Anthracnose Resistance in Strawberry Plants

Plant Disease ◽  
2018 ◽  
Vol 102 (11) ◽  
pp. 2112-2119
Author(s):  
Melinda A. Miller-Butler ◽  
Barbara J. Smith ◽  
Ebrahiem M. Babiker ◽  
Brian R. Kreiser ◽  
Eugene K. Blythe
Keyword(s):  
Relative Humidity ◽  
Disease Severity ◽  
Conidial Suspension ◽  
Severity Rating ◽  
Detached Leaf ◽  
Whole Plant ◽  
Germplasm Line ◽  
Detached Leaves ◽  
Whole Plants ◽  
Leaf Symptoms

Anthracnose is a destructive disease of strawberry caused by several Colletotrichum species including C. acutatum, C. fragariae, and C. gloeosporioides. Identification of anthracnose resistant strawberry germplasm has commonly relied on inoculation of whole plants with isolates of these pathogens. In this study, whole plants and detached leaves from 81 germplasm lines were inoculated with a conidial suspension of isolates of C. acutatum, C. fragariae, and C. gloeosporioides, incubated in the dark at 30°C, 100% relative humidity, for 48 h, and assessed for disease severity based on symptoms on inoculated petioles and leaves. The correlation between the disease severity ratings of the whole plants rated 30 days after inoculation and detached leaves rated 5 days after inoculation was determined. Based on leaf symptoms and petiole lesions, the association between the whole plant leaf disease severity rating (DSR) and detached leaf DSR was positive (rp = 0.70), and the association between the whole plant DSR and the detached leaf DSR was also positive (rp = 0.66). Whole plant and detached leaf DSRs were used to assign each germplasm line to a resistance category, and a posthoc Tukey’s test showed that the whole plant DSR means and the detached leaf DSR means for each resistance category differed significantly at p < 0.05. This research was used to develop a strawberry detached leaf assay which can reliably and quickly determine the degree of resistance of strawberry germplasm to anthracnose.

scholarly journals Identification of Bacterial Wilt (Erwinia tracheiphila) Resistances in USDA Melon Collection

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1972
Author(s):  
Bimala Acharya ◽  
Lucas Mackasmiel ◽  
Ali Taheri ◽  
Christine A. Ondzighi-Assoume ◽  
Yiqun Weng ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Fluorescent Microscopy ◽  
Management Strategies ◽  
The United States ◽  
United States Department ◽  
Department Of Agriculture ◽  
Erwinia Tracheiphila ◽  
Whole Plant ◽  
Colonization Dynamics ◽  
Controlled Environments

Bacterial wilt (BW) caused by the Gram-negative bacterium, Erwinia tracheiphila (Et.), is an important disease in melon (Cucumis melo L.). BW-resistant commercial melon varieties are not widely available. There are also no effective pathogen-based disease management strategies as BW-infected plants ultimately die. The purpose of this study is to identify BW-resistant melon accessions in the United States Department of Agriculture (USDA) collection. We tested 118 melon accessions in two inoculation trials under controlled environments. Four-week-old seedlings of test materials were mechanically inoculated with the fluorescently (GFP) labeled or unlabeled E. tracheiphila strain, Hca1-5N. We recorded the number of days to wilting of inoculated leaf (DWIL), days to wilting of whole plant (DWWP) and days to death of the plant (DDP). We identified four melon lines with high resistance to BW inoculation based on all three parameters. Fluorescent microscopy was used to visualize the host colonization dynamics of labeled bacteria from the point of inoculation into petioles, stem and roots in resistant and susceptible melon accessions, which provides an insight into possible mechanisms of BW resistance in melon. The resistant melon lines identified from this study could be valuable resistance sources for breeding of BW resistance as well as the study of cucurbit—E. tracheiphila interactions.

Study of Vidanga on Krimi Roga w.s.r. to Round Worms

2017 ◽  
Vol 2 (04) ◽  
Author(s):  
Abhilasha . ◽  
Vijay Shankar Dubey
Keyword(s):  
Public Health Problem ◽  
Intestinal Wall ◽  
Major Public Health Problem ◽  
Embelia Ribes ◽  
Worm Infestation ◽  
Whole Plant ◽  
The Face ◽  
Whole Plants ◽  
Recurrent Nature ◽  
Weak Resistance

Krimi have been considered a major public health problem through out the world (WHO, 1967 Wandan, 1983 McLaren, 1984). In our country this problem is equally significant. It effects the children more frequently than adult (CCRAS 1987). Krimi hamper growth and development of a person, create malnutritional condition and decrease immunity thus the effective solution of this problem is necessary. Of all the herbs used in treating worm infestation, Vidanga is the best. So, Vidanga was selected for the present study. Whole plant of Embelia ribes Linn. were used as materials, as whole plants are used as medicine. Acharya Charaka describe Krimiroga in Vimanasthana. In most of patients, who are suffering from worm infestation have an Vivarnata (discolouration) on the face. “Vivarnata” had been described by Acharya Charaka under the Lakshana of Purishaja Krimi and it has been also described in Rasavaha Srotodusti Lakshana. Krimis robe the digestive nutritive assets through the intestinal wall, which we are making with high effort. So the deficiency of Rasa Dhatu create. According to Dhatu Poshana Nyaya if the Rasa Dhatu is not sufficient then other Dhatu can’t form properly and ultimate weak resistance and poor immunity develops and it is one cause of recurrent nature of disease. Prakriti Vighata and Nidana Parivarjana eradicate Krimiroga from the base.

scholarly journals Exploring the Use of Ecosystem Services Conceptual Models to Account for the Benefits of Public Lands: An Example from National Forest Planning in the United States

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 267
Author(s):  
Lydia Olander ◽  
Katie Warnell ◽  
Travis Warziniack ◽  
Zoe Ghali ◽  
Chris Miller ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Ecosystem Service ◽  
Management Strategies ◽  
Public Lands ◽  
The United States ◽  
Forest Planning ◽  
National Forest ◽  
Planning Team ◽  
National Forest Planning

A shared understanding of the benefits and tradeoffs to people from alternative land management strategies is critical to successful decision-making for managing public lands and fostering shared stewardship. This study describes an approach for identifying and monitoring the types of resource benefits and tradeoffs considered in National Forest planning in the United States under the 2012 Planning Rule and demonstrates the use of tools for conceptualizing the production of ecosystem services and benefits from alternative land management strategies. Efforts to apply these tools through workshops and engagement exercises provide opportunities to explore and highlight measures, indicators, and data sources for characterizing benefits and tradeoffs in collaborative environments involving interdisciplinary planning teams. Conceptual modeling tools are applied to a case study examining the social and economic benefits of recreation on the Ashley National Forest. The case study illustrates how these types of tools facilitate dialog for planning teams to discuss alternatives and key ecosystem service outcomes, create easy to interpret visuals that map details in plans, and provide a basis for selecting ecosystem service (socio-economic) metrics. These metrics can be used to enhance environmental impact analysis, and help satisfy the goals of the National Environmental Policy Act (NEPA), the 2012 Planning Rule, and shared stewardship initiatives. The systematic consideration of ecosystem services outcomes and metrics supported by this approach enhanced dialog between members of the Forest planning team, allowed for a more transparent process in identification of key linkages and outcomes, and identified impacts and outcomes that may not have been apparent to the sociologist who is lacking the resource specific expertise of these participants. As a result, the use of the Ecosystem Service Conceptual Model (ESCM) process may result in reduced time for internal reviews and greater comprehension of anticipated outcomes and impacts of proposed management in the plan revision Environmental Impact Statement amongst the planning team.

Cyber Place Management and Crime Prevention: The Effectiveness of Cybersecurity Awareness Training Against Phishing Attacks

2021 ◽  
pp. 104398622110016
Author(s):  
Sinchul Back ◽  
Rob T. Guerette
Keyword(s):  
Crime Prevention ◽  
Research University ◽  
Management Strategies ◽  
Large Body ◽  
The United States ◽  
Place Management ◽  
Online Setting ◽  
Using Data ◽  
Virtual Domain ◽  
The Impact

Criminologists and crime prevention practitioners recognize the importance of geographical places to crime activities and the role that place managers might play in effectively preventing crime. Indeed, over the past several decades, a large body of work has highlighted the tendency for crime to concentrate across an assortment of geographic areas, where place management tends to be absent or weak. Nevertheless, there has been a paucity of research evaluating place management strategies and cybercrime within the virtual domain. The purpose of this study was to investigate the effectiveness of place management techniques on reducing cybercrime incidents in an online setting. Using data derived from the information technology division of a large urban research university in the United States, this study evaluated the impact of an anti-phishing training program delivered to employees that sought to increase awareness and understanding of methods to better protect their “virtual places” from cybercrimes. Findings are discussed within the context of the broader crime and place literature.

Does the second wave of COVID-19 undermine corporate immunity? International evidence

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Huy Viet Hoang ◽  
Cuong Nguyen ◽  
Khanh Hoang
Keyword(s):  
Stock Returns ◽  
Stock Price ◽  
Fixed Effects ◽  
Management Strategies ◽  
The United States ◽  
Least Square ◽  
Content Type ◽  
The Impact ◽  
Second Wave ◽  
Practical Implications

PurposeThis study compares the impact of the COVID-19 pandemic on stock returns in the first two waves of infection across selected markets, given built-in corporate immunity before the global outbreak.Design/methodology/approachThe data are collected from listed firms in five markets that have experienced the second wave of COVID-19 contagion, namely the United States (US), Australia, China, Hong Kong and South Korea. The period of investigation in this study ranges from January 24 to August 28, 2020 to cover the first two COVID-19 waves in selected markets. The study estimates the research model by employing the ordinary least square method with fixed effects to control for the heterogeneity that may confound the empirical outcomes.FindingsThe analysis reveals that firms with larger size and more cash reserves before the COVID-19 outbreak have better stock performance under the first wave; however, these advantages impede stock resilience during the second wave. Corporate governance practices significantly influence stock returns only in the first wave as their effects fade when the second wave emerges. The results also suggest that in economies with greater power distance, although stock price depreciation was milder in the first wave, it is more intense when new cases again surge after the first wave was contained.Practical implicationsThis paper provides practical implications for corporate managers, policymakers and governments concerning crisis management strategies for COVID-19 and future pandemics.Originality/valueThis study is the first to evaluate built-in corporate immunity before the COVID-19 shock under successive contagious waves. Besides, this study accentuates the importance of cultural understanding in weathering the ongoing pandemic across different markets.

Foreign Body Ingestion

2015 ◽  
Author(s):  
Kunal Jajoo ◽  
Allison R Schulman
Keyword(s):  
Foreign Body ◽  
Foreign Bodies ◽  
Management Strategies ◽  
The United States ◽  
Foreign Body Ingestion ◽  
Gi Tract ◽  
Food Bolus ◽  
Therapeutic Decisions ◽  
Food Bolus Impaction ◽  
Bolus Impaction

Foreign-body ingestion and food bolus impaction are common causes of esophageal obstruction, with an annual incidence of 13 cases per 100,000, and represent approximately 4% of all emergency endoscopies. Although the majority of foreign bodies that travel to the gastrointestinal (GI) tract will pass spontaneously, 10 to 20% must be removed endoscopically, and 1 to 5% will require surgery. Key diagnostic and therapeutic decisions are based on common factors, including the type of ingested object, number of objects, timing between ingestion and presentation, anatomic location of the object, and presence or absence of symptoms. Complications relating to foreign-body ingestion are typically uncommon; however, the associated morbidity may be severe and occasionally life threatening, and despite the fact that overall mortality has been extremely low, it has been estimated that up to 1,500 deaths occur annually in the United States as a result of foreign-body ingestion. The initial and follow-up management strategies are crucial to preventing morbidity. This review details the epidemiology, etiology and pathophysiology, diagnosis, management, and complications of foreign-body ingestion. Figures show examples of foreign bodies in the esophagus and stomach, three esophageal areas where a foreign body is likely to be impacted, examples of a meat bolus in the esophagus, radiograph of a patient who swallowed one nail and three batteries, and examples of linear erosions of the esophagus and stomach. Tables list the most common GI pathology predisposing individuals to esophageal foreign-body impaction, timing and management of food bolus impaction and foreign-body ingestion, endoscopic management strategies for food bolus impaction and ingested foreign bodies, and radiographic and surgical management strategies for monitoring progress of foreign-body passage through the GI tract. This review contains 5 highly rendered figures, 4 tables, and 78 references.

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