Novel sources of turnip yellows virus resistance in Brassica and impacts of temperature on their durability

Plant Disease ◽  
2021 ◽  
Author(s):  
Benjamin Steven Congdon ◽  
Jono Baulch ◽  
Brenda Coutts

Turnip yellows virus (TuYV; family Solemoviridae, genus Polerovirus) is the most widespread and economically damaging virus of canola (Brassica napus L.) production in Australia. However, no Australian commercial seed companies currently market TuYV-resistant canola cultivars and little information is available on the susceptibility of those available. To identify potential sources of TuYV resistance, 100 B. napus accessions from the ERANET-ASSYST diversity set were screened in the field and five of these were selected for further phenotyping via aphid inoculation. Furthermore, 43 Australian canola cultivars, six B. napus genotypes with previously reported resistance, and 33 B. oleracea and B. rapa cultivars were phenotyped. All Australian cultivars were susceptible except for ATR Stingray. Stronger resistance to TuYV infection (IR) was identified in diversity set accessions Liraspa-A, SWU Chinese 3 and SWU Chinese 5. As indicated by lower relative ELISA absorbance values (R-E405) in infected plants, resistance to TuYV accumulation (AR) often accompanied IR. Moderate IR was identified in four B. oleracea and one B. rapa cultivars. Very strong AR was identified in four B. oleracea cultivars and AR of some degree was common across many cultivars of this species tested. The impact of temperature during the inoculation access period or post-inoculation incubation on the resistance identified was examined. Infection rates were significantly higher in resistant B. napus genotypes when inoculated at 16°C than at 26°C suggesting an increase in aphid transmission efficiency. IR in B. napus genotypes was strong when incubated at 16°C but weakened at elevated temperatures with almost total breakdown in most genotypes at 30°C. However, infected plants of B. napus and B. oleracea genotypes with AR maintained lower R-E405 than susceptible controls at all temperatures tested. Novel sources of resistance identified in this study offer potential as breeding material in Australia and abroad.

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 116-116
Author(s):  
Emma T Helm ◽  
Susanne J Lin ◽  
Nicholas Gabler ◽  
Eric R Burrough

Abstract Swine dysentery (SD) induced by Brachyspira hyodysentariae (Bhyo) causes colitis and mucohemorrhagic diarrhea in grow-finish pigs, however little is known about the physiological changes that occur to the gastrointestinal tract during Bhyo infection. Thus, the objective of this study was to evaluate the impact of a Bhyo challenge on intestinal function and integrity of pigs fed two divergent diets. A total of 36 Bhyo negative gilts (24.3 ± 3.6 kg BW) were selected and assigned to one of three treatment groups (n=12 pigs/trt): 1) Bhyo negative, 20% DDGS diet (CON), 2) Bhyo challenged, 20% DDGS diet (DDGS), and 3) Bhyo challenged, 10% DDGS, 5% beet pulp and 5% resistant potato starch diet (RS). Pigs were fed diets 21 days prior to challenge and on days post inoculation (dpi) 0 and 1, pigs were inoculated with Bhyo or sham. Fecal samples were collected for ATTD and pigs were euthanized for colon collection within 72 hours of initial observation of clinical SD, or at the end of the study (dpi 10-16). Tissues were assessed for ex vivo measures of intestinal integrity and mitochondrial function. The challenge resulted in high morbidity, with 88% of DDGS and RS pigs developing clinical SD. Colon transepithelial resistance was increased in DDGS pigs compared with CON and RS pigs (P=0.005), and colon macromolecule permeability was reduced in both DDGS and RS pigs compared with CON pigs (P=0.006), likely due to mucoid discharge. Colonic mitochondrial oxygen consumption was not impacted by treatment (P >0.10). Further, ATTD of DM, OM, N, and GE were reduced in DDGS pigs compared with CON pigs (P< 0.001), whilst nutrient digestibility was not reduced in RS pigs. Taken together, these data show Bhyo does not appear to reduce ex vivo colonic integrity. Further, the RS diet may reduce severity of a Bhyo challenge.


Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Emma T. Helm ◽  
Eric R. Burrough ◽  
Fernando L. Leite ◽  
Nicholas K. Gabler

AbstractLawsonia intracellularis is endemic to swine herds worldwide, however much is still unknown regarding its impact on intestinal function. Thus, this study aimed to characterize the impact of L. intracellularis on digestive function, and how vaccination mitigates these impacts. Thirty-six L. intracellularis negative barrows were assigned to treatment groups (n  =  12/trt): (1) nonvaccinated, L. intracellularis negative (NC); (2) nonvaccinated, L intracellularis challenged (PC); and (3) L. intracellularis challenged, vaccinated (Enterisol® Ileitis, Boehringer Ingelheim) 7 weeks pre-challenge (VAC). On days post-inoculation (dpi) 0 PC and VAC pigs were inoculated with L. intracellularis. From dpi 19–21 fecal samples were collected for apparent total tract digestibility (ATTD) and at dpi 21, pigs were euthanized for sample collection. Post-inoculation, ADG was reduced in PC pigs compared with NC (41%, P  <  0.001) and VAC (25%, P  <  0.001) pigs. Ileal gross lesion severity was greater in PC pigs compared with NC (P  =  0.003) and VAC (P  =  0.018) pigs. Dry matter, organic matter, nitrogen, and energy ATTD were reduced in PC pigs compared with NC pigs (P  ≤  0.001 for all). RNAscope in situ hybridization revealed abolition of sucrase-isomaltase transcript in the ileum of PC pigs compared with NC and VAC pigs (P  <  0.01). Conversely, abundance of stem cell signaling markers Wnt3, Hes1, and p27Kip1 were increased in PC pigs compared with NC pigs (P  ≤  0.085). Taken together, these data demonstrate that reduced digestibility during L. intracellularis challenge is partially driven by abolition of digestive machinery in lesioned tissue. Further, vaccination mitigated several of these effects, likely from lower bacterial burden and reduced disease severity.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 234
Author(s):  
Jakob Kraner ◽  
Jožef Medved ◽  
Matjaž Godec ◽  
Irena Paulin

Additive manufacturing is a form of powder metallurgy, which means the properties of the initial metal powders (chemical composition, powder morphology and size) impact the final properties of the resulting parts. A complete characterization, including thermodynamic effects and the behavior of the metal powders at elevated temperatures, is crucial when planning the manufacturing process. The analysis of the Fe-Mn and Fe-Mn-Ag powder mixtures, made from pure elemental powders, shows a high susceptibility to sintering in the temperature interval from 700 to 1000 °C. Here, numerous changes to the manganese oxides and the αMn to βMn transformation occurred. The problems of mechanically mixed powders, when using selective laser melting, were highlighted by the low flowability, which led to a less controllable process, an uncontrolled arrangement of the powder and a large percentage of burnt manganese. All this was determined from the altered chemical compositions of the produced parts. The impact of the increased manganese content on the decreased probability of the transformation from γ-austenite to ε-martensite was confirmed. The ε-martensite in the microstructure increased the hardness of the material, but at the same time, its magnetic properties reduce the usefulness for medical applications. However, the produced parts had comparable elongations to human bone.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1239
Author(s):  
Chouaïb Meziadi ◽  
Julie Lintz ◽  
Masoud Naderpour ◽  
Charlotte Gautier ◽  
Sophie Blanchet ◽  
...  

In the context of climate change, elevated temperature is a major concern due to the impact on plant–pathogen interactions. Although atmospheric temperature is predicted to increase in the next century, heat waves during summer seasons have already become a current problem. Elevated temperatures strongly influence plant–virus interactions, the most drastic effect being a breakdown of plant viral resistance conferred by some major resistance genes. In this work, we focused on the R-BPMV gene, a major resistance gene against Bean pod mottle virus in Phaseolus vulgaris. We inoculated different BPMV constructs in order to study the behavior of the R-BPMV-mediated resistance at normal (20 °C) and elevated temperatures (constant 25, 30, and 35 °C). Our results show that R-BPMV mediates a temperature-dependent phenotype of resistance from hypersensitive reaction at 20 °C to chlorotic lesions at 35 °C in the resistant genotype BAT93. BPMV is detected in inoculated leaves but not in systemic ones, suggesting that the resistance remains heat-stable up to 35 °C. R-BPMV segregates as an incompletely dominant gene in an F2 population. We also investigated the impact of elevated temperature on BPMV infection in susceptible genotypes, and our results reveal that elevated temperatures boost BPMV infection both locally and systemically in susceptible genotypes.


2021 ◽  
Author(s):  
Matthew Saunders ◽  
Ruchita Ingle ◽  
Shane Regan

&lt;p&gt;Peatland ecosystems are integral to the mitigation of climate change as they represent significant terrestrial carbon sinks. In Ireland, peatlands cover ~20% of the land area but hold up to 75% of the soil organic carbon stock however many of these ecosystems (~85% of the total area) have been degraded due to anthropogenic activities such as agriculture, forestry and extraction for horticulture or energy. Furthermore, the carbon stocks that remain in these systems are vulnerable to inter-annual variation in climate, such as changes in precipitation and temperature, which can alter the hydrological status of these systems leading to changes in key biogeochemical processes and carbon and greenhouse gas exchange.&amp;#160; During 2018 exceptional drought and heatwave conditions were reported across Northwestern Europe, where reductions in precipitation coupled with elevated temperatures were observed. Exceptional inter-annual climatic variability was also observed at Clara bog, a near natural raised bog in the Irish midlands when data from 2018 and 2019 were compared. Precipitation in 2018 was ~300 mm lower than 2019 while the average mean annual temperature was 0.5&amp;#176;C higher. The reduction in precipitation, particularly during the growing season in 2018, consistently lowered the water table where ~150 consecutive days where the water table was &gt;5cm below the surface of the bog were observed at the central ecotope location. The differing hydrological conditions between years resulted in the study area, as determined by the flux footprint of the eddy covariance tower, acting as a net source of carbon of 53.5 g C m&lt;sup&gt;-2&lt;/sup&gt; in 2018 and a net sink of 125.2 g C m&lt;sup&gt;-2&lt;/sup&gt; in 2019. The differences in the carbon dynamics between years were primarily driven by enhanced ecosystem respiration (R&lt;sub&gt;eco&lt;/sub&gt;) and lower rates of Gross Primary Productivity (GPP) in the drier year, where the maximum monthly ratio of GPP:R&lt;sub&gt;eco&lt;/sub&gt; during the growing season was 0.96 g C m&lt;sup&gt;-2&lt;/sup&gt; month in 2018 and 1.14 g C m&lt;sup&gt;-2&lt;/sup&gt; month in 2019. This study highlights both the vulnerability and resilience of these ecosystems to exceptional inter-annual climatic variability and emphasises the need for long-term monitoring networks to enhance our understanding of the impacts of these events when they occur.&lt;/p&gt;


Author(s):  
Hiro Yoshida ◽  
Takashi Nakashima ◽  
Makoto Yoshida ◽  
Yasushi Hara ◽  
Toru Shimamori

A new high quality turbine system using monolithic silicon-nitride ceramic is under development. In this study particle impact tests of the silicon-nitride have been tried at room and elevated temperatures with and without tensile load, which simulates centrifugal force of blade rotation. In the experiment 1 mm diameter particle is impacted at velocities up to 900 m s−1. In this paper, critical velocities for bending fracture and Hertzian cracks are examined. Moreover, strength degradation at elevated temperature and spall fracture of the blade are discussed. The main results are: 1) The bending fracture mode critical impact velocity for soft particles is higher than that for hard particles. 2)The impact parameter ϕ for initiation of Hertzian cracks ranges 1.08×10−5 – 1.56×10−5 for the materials tested. 3)Strength degradation at elevated temperature was clearly observed. 4) In the impact tests on blades spall fracture, which was caused by interaction of stress waves, appeared.


Plant Disease ◽  
1998 ◽  
Vol 82 (12) ◽  
pp. 1371-1374 ◽  
Author(s):  
Carmen Gispert ◽  
George N. Oldfield ◽  
Thomas M. Perring ◽  
Rebecca Creamer

Experiments were undertaken to elucidate the characteristics of the transmission of peach mosaic virus (PMV) by Eriophyes insidiosus. Transmission efficiency by single E. insidiosus was as high as 17%. The minimum inoculation access period was between 3 and 6 h. E. insidiosus acquired the virus after a minimum acquisition access period of 3 days. No latent period was demonstrated. While most plant viruses which are transmitted by eriophyid mites are transmitted in a persistent mode, our data are more consistent with a semipersistent model.


2020 ◽  
pp. 1-22
Author(s):  
Grisel Meléndez-Ramos

This paper explores succession phenomena in four Puerto Rican businesses. The main conclusion is that there are differences between the succession pro-cess for daughters and sons because of a stereotypical concept of women’s role and leadership within businesses. Daughters appear to have full access to presidency only when the father dies. Before that, daughters exercise a periph-eral leadership within the organization to construct their leadership space and, at the same time, transmit the values of the business. Opposed to daughters, sons achieve full presidency power and leadership upon confrontation with the father. Main sources of resistance in leadership transition from father to daughters came from external constituencies.


2021 ◽  
Author(s):  
Karolina E. Mazur ◽  
Aleksandra Borucka ◽  
Paulina Kaczor ◽  
Szymon Gądek ◽  
Stanislaw Kuciel

Abstract In the study, polylactide-based (PLA) composites modified with natural particles (wood, bamboo, and cork) and with different levels of infilling (100%, 80%, and 60%) obtained by additive methods were tested. The effect of type fiber, infill level and crystallization rate on the mechanical properties were investigated by using tensile, flexural, and impact tests. The materials were subjected to mechanical tests carried out at 23 and 80 °C. Furthermore, hydrothermal degradation was performed, and its effect on the properties was analyzed. The addition of natural fillers and different level of infilling result in a similar level of reduction in the properties. Composites made of PLA are more sensitive to high temperature than to water. The decrease in Young's modulus of PLA at 80 °C was 90%, while after 28 days of hydrodegradation ~ 9%. The addition of fibers reduced this decrease at elevated temperatures. Moreover, the impact strength has been improved by 50% for composites with cork particles and for other lignocellulosic composites remained at the same level as for resin.


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