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Horticulture Research Feb 2024Two decades have passed since the strawberry () disease caused by , a necrotrophic soilborne fungal pathogen, began surfacing in California, Florida, and elsewhere. This...
Transgressive segregation, hopeful monsters, and phenotypic selection drove rapid genetic gains and breakthroughs in predictive breeding for quantitative resistance to in strawberry.
Two decades have passed since the strawberry () disease caused by , a necrotrophic soilborne fungal pathogen, began surfacing in California, Florida, and elsewhere. This disease has since become one of the most common causes of plant death and yield losses in strawberry. The problem emerged and expanded in the wake of the global phase-out of soil fumigation with methyl bromide and appears to have been aggravated by an increase in climate change-associated abiotic stresses. Here we show that sources of resistance to this pathogen are rare in gene banks and that the favorable alleles they carry are phenotypically unobvious. The latter were exposed by transgressive segregation and selection in populations phenotyped for resistance to under heat and drought stress. The genetic gains were immediate and dramatic. The frequency of highly resistant individuals increased from 1% in selection cycle 0 to 74% in selection cycle 2. Using GWAS and survival analysis, we found that phenotypic selection had increased the frequencies of favorable alleles among 10 loci associated with resistance and that favorable alleles had to be accumulated among four or more of these loci for an individual to acquire resistance. An unexpectedly straightforward solution to the disease resistance breeding problem emerged from our studies, which showed that highly resistant cultivars can be developed by genomic selection or marker-assisted stacking of favorable alleles among a comparatively small number of large-effect loci.
PubMed: 38487295
DOI: 10.1093/hr/uhad289 -
International Journal of Molecular... Jan 2024In this work, we present the effect of graphene nanoplatelets (GnPs) modification with ionic liquids (ILs). The textural properties of graphene nanoplatelets (GnPs) used...
In this work, we present the effect of graphene nanoplatelets (GnPs) modification with ionic liquids (ILs). The textural properties of graphene nanoplatelets (GnPs) used as styrene-butadiene rubber's filler and the thermal properties of the composites obtained with the use of the mentioned fillers were investigated. GnPs were modified with 1-butylpyridinium bromide (BPyBr) and 4-methyl-1-butylpyridinium bromide (BmPyBr) through two different ways. One strategy has been to deposit the filler modifier from the solution. The second one involved the modification of the filler with ionic liquids in bulk during the preparation of elastomer blends. Settlement of the proposed ionic liquids onto the GnPs' surface led to significant changes in the textural characteristics. BPyBr has restricted the filler's microporosity, whereas BmPyBr has caused the formation of a more opened filler structure without the increase in its average pore size. GnPs modified with ILs led to reducing the temperature of vulcanization of SBR compounds and affected the thermal stability of the composites.
Topics: Bromides; Graphite; Ionic Liquids; Elastomers; Excipients; Hydrocarbons, Brominated
PubMed: 38255957
DOI: 10.3390/ijms25020885 -
Insects Jan 2024Pineapple mealybug, (Hemiptera: Pseudococcidae), is a significant pest in pineapple production and a key trade barrier. We explored the potential use of ethyl formate...
Pineapple mealybug, (Hemiptera: Pseudococcidae), is a significant pest in pineapple production and a key trade barrier. We explored the potential use of ethyl formate (EF) as a methyl bromide alternative for the postharvest fumigation of in imported pineapples. When treated at 8 °C for 4 h, EF fumigation was effective against with LCt the lethal concentration × time product of EF necessary to achieve 99% mortality of nymphs and adults at 64.2 and 134.8 g h/m, respectively. Sorption trials conducted with 70 g/m EF for 4 h at 8 °C using 7.5, 15 and 30% pineapple loading ratios (/) indicated that loading ratio lower than 30% is necessary to achieve the LCt values required to control . In a scaled up trial using 1 m chamber, EF fumigation with 70 g/m for 4 h at 8 °C with 20% pineapple loading ratio (/) resulted in a complete control of treated. There were no significant differences in hue values, sugar contents, firmness, and weight loss between EF-treated and untreated pineapples. Our results suggest that EF is a promising alternative to methyl bromide fumigation for the postharvest phytosanitary disinfection of in pineapples.
PubMed: 38249030
DOI: 10.3390/insects15010025 -
Research in Microbiology 2024This review summarizes the literature on efficacy of techniques to sterilize soil. Soil may need to be sterilized if contaminated with pathogens such as Bacillus... (Review)
Review
This review summarizes the literature on efficacy of techniques to sterilize soil. Soil may need to be sterilized if contaminated with pathogens such as Bacillus anthracis. Sterilizing soil in-situ minimizes spread of the bio-contaminant. Soil is difficult to sterilize, with efficacy generally diminishing with depth. Methyl bromide, formaldehyde, and glutaraldehyde are the only soil treatment options that have been demonstrated at full-scale to effectively inactivate Bacillus spores. Soil sterilization modalities with high efficacy at bench-scale include wet and dry heat, metam sodium, chlorine dioxide gas, and activated sodium persulfate. Simple oxidants such as chlorine bleach are ineffective in sterilizing soil.
Topics: Bacillus anthracis; Spores, Bacterial; Soil Microbiology; Sterilization; Disinfectants
PubMed: 38141796
DOI: 10.1016/j.resmic.2023.104175 -
Animals : An Open Access Journal From... Oct 2023The storage mite infests a wide range of food products including pet food. Control of this mite depends on chemical methods such as fumigation and spraying with...
The storage mite infests a wide range of food products including pet food. Control of this mite depends on chemical methods such as fumigation and spraying with insecticides. Methyl bromide was used as a fumigant for high-value stored products, especially to control mite infestation in dry-cured hams and cheeses, but it is now banned for most uses in many countries because of its atmospheric ozone-depleting effects. Effective alternatives to methyl bromide are needed to develop integrated pest management programs for this pest. Liquid smoke is a naturally derived flavoring and preservative with known antimicrobial properties. The objective of this study was to investigate the efficacy of liquid smoke preparations, with varying phenol and carbonyl concentrations and pH, on the survivability and orientation behavior of in a model semi-moist pet food. The mite survivability assays using liquid smoke-treated and untreated semi-moist pet food samples indicated that there was no difference among treatments ( > 0.05) for mite infestation and survival. Two-choice behavioral assays using semi-moist pet food cubes dipped in varying concentrations (0%, 0.3%, 1%, 5%, 10%, 25%, 50%, or 100% /) of liquid smoke preparations found that some of the liquid smoke preparations containing medium to high carbonyl content repelled the mites. In conclusion, liquid smoke did not kill or inhibit the mite population growth in semi-moist pet food. However, some liquid smoke fractions containing medium to high carbonyl content were repellent to mites and may retard mite infestation in stored semi-moist foods.
PubMed: 37893912
DOI: 10.3390/ani13203188 -
The Science of the Total Environment Jan 2024Salt marshes are sensitive highly productive habitats crucial for carbon cycling. This study presents a comprehensive analysis of organic geochemical indicators and...
Salt marshes are sensitive highly productive habitats crucial for carbon cycling. This study presents a comprehensive analysis of organic geochemical indicators and geochronology in the Mira salt marsh (SW Portugal) over eight centuries. The closely intertwined carbon and bromine (Br) biogeochemical cycles in these environments can influence the fluxes of volatile compounds such as ozone-depleting methyl bromide, emphasizing the importance of understanding sediment organic matter (OM) origin, budget, and composition in salt marshes. To characterize the strong Br-OM relationship, we used n-alkane signatures, bulk elemental data (total carbon, total nitrogen, C/N ratio), and stable isotopes (δN, δC) from a sediment core. Findings revealed a mixed composition of terrestrial and marine OM, posing challenges in distinguishing ex situ higher plant sources from in situ production by marsh vegetation. n-Alkanes (C to C) were found in all the sediment samples, predominantly C-C. Changes in their presence were linked to marsh succession, evolving from a vegetation-free tidal flat to a C halophyte-dominated high marsh ecosystem. Despite the area's low industrial and population impact, regulation of water flow through the dam affected the balance between continental and marine waters. This study aimed to create a cost-effective predictive model for total Br, enhancing paleoclimatic studies using sedimentary samples. The n-alkane model had limited resolution, but an alternative infrared (IR) spectroscopy-based model, requiring less time and smaller sample sizes, was developed. Combining FT-IR spectra with statistical analysis enabled the creation of a reliable total Br concentration prediction model (mean absolute error = 14.39). These findings have implications for controlling Br enrichment in marsh environments and can be applied in various coastal wetlands with different mineralogical and organic characteristics.
PubMed: 37863236
DOI: 10.1016/j.scitotenv.2023.167931 -
Frontiers in Public Health 2023Methyl bromide (MB) is worldwide the only effective fumigant heavily used for quarantine pre-shipment treatment and has a critical use exemption for soil fumigations due...
Methyl bromide (MB) is worldwide the only effective fumigant heavily used for quarantine pre-shipment treatment and has a critical use exemption for soil fumigations due to its excellent permeability and insecticidal effect. However, MB should be replaced as it is an an ozone-depleting substance and also highly toxic to humans. Recently, MB has been shown to be hazardous even for asymptomatic workers, affecting their central and autonomic nervous systems. However, the effects of MB exposure on vascular health have not been explored. This study aimed to determine whether MB affects the arterial system of asymptomatic workers. We measured the second derivative of the photoplethysmogram (SDPTG) indices, which are indicators of vascular load and aging, and urinary bromide ion (Br) concentrations in 44 fumigators (study group) and 20 inspectors (control group) before and after fumigation. In fumigators, the mean values of post-work SDPTG indices (b/a, c/a, d/a, e/a, and SDPTG aging index) and Br levels were significantly changed compared to their pre-work values ( < 0.05), indicating a negative effect on their cardiovascular health. In contrast, SDPTG indices and Br levels in inspectors did not show any differences before and after work. All SDPTG indices except c/a showed significant correlations with Br levels in all individuals ( < 0.05). In conclusion, the Br levels and SDPTG indices of fumigators varied after MB work, and they experienced negative effects on their health despite being asymptomatic.
Topics: Humans; Photoplethysmography; Aging; Hydrocarbons, Brominated; Insecticides
PubMed: 37818301
DOI: 10.3389/fpubh.2023.1224143 -
Sangyo Eiseigaku Zasshi = Journal of... Mar 2024A new system for the regulation of chemical substances was introduced in Japan in April 2023. Unlike delineated rules, the new system does not specify any specific...
OBJECTIVE
A new system for the regulation of chemical substances was introduced in Japan in April 2023. Unlike delineated rules, the new system does not specify any specific measures for individual substances, but is rather based on the management of health through the voluntary implementation of measures in order to reduce exposure to all dangerous/hazardous chemical substances. Regarding specific methods, exposures will be mainly elucidated through the measurement of a work environment. However, the necessity of biological monitoring should also be considered. This study aimed to identify the importance of biological monitoring by reviewing changes made over time in biological monitoring methods used for occupational poisoning.
METHOD
The study presents occupational poisoning by several compounds (methyl bromide, polycyclic aromatic hydrocarbons, and MOCA) and the corresponding biological monitoring methods utilized, as researched by the author. Changes in biological monitoring based on the history of the Study Group on Occupational Poisoning and Biological Monitoring of the Japan Society for Occupational Health are also introduced.
RESULTS
The areas of occupational poisoning at different times and cases of occupational cancer caused by exposure to chemical substances were presented in lectures held by the Study Group on Occupational Poisoning and Biological Monitoring. These lectures showed that although biological monitoring was previously implemented primarily by measuring the urinary metabolites of the exposed substance, the monitoring methods used have changed as the nature of exposure has changed, leading to the development of new tools that detect trace, low concentration, and mixed exposures.
CONCLUSION
The health management of workers handling chemical substances at occupational sites will be shifted to autonomous management. However, it should be noted that only biological monitoring can detect and prove true exposure. Particularly, risk assessment by biological monitoring is necessary for substances that are suspected to be absorbed through the skin, and the measurement methods used should continue to be developed and refined. The significance of biological monitoring will continue to increase.
Topics: Humans; Occupational Exposure; Biological Monitoring; Hazardous Substances; Occupational Health; Polycyclic Aromatic Hydrocarbons; Environmental Monitoring
PubMed: 37766566
DOI: 10.1539/sangyoeisei.2023-026-A -
Applied and Environmental Microbiology Sep 2023The application of microfluidic techniques in experimental and environmental studies is a rapidly emerging field. Water-in-oil microdroplets can serve readily as...
The application of microfluidic techniques in experimental and environmental studies is a rapidly emerging field. Water-in-oil microdroplets can serve readily as controllable micro-vessels for studies that require spatial structure. In many applications, it is useful to monitor cell growth without breaking or disrupting the microdroplets. To this end, optical reporters based on color, fluorescence, or luminescence have been developed. However, optical reporters suffer from limitations when used in microdroplets such as inaccurate readings due to strong background interference or limited sensitivity during early growth stages. In addition, optical detection is typically not amenable to filamentous or biofilm-producing organisms that have significant nonlinear changes in opacity and light scattering during growth. To overcome such limitations, we show that volatile methyl halide gases produced by reporter cells expressing a methyl halide transferase (MHT) can serve as an alternative nonoptical detection approach suitable for microdroplets. In this study, an MHT-labeled reporter strain was constructed and characterized. Protocols were established for the encapsulation and incubation of in microdroplets. We observed the complete life cycle for including the vegetative expansion of mycelia, mycelial fragmentation, and late-stage sporulation. Methyl bromide (MeBr) production was detected by gas chromatography-mass spectrometry (GC-MS) from gas reporters incubated in either liquid suspension or microdroplets and used to quantitatively estimate bacterial density. Overall, using MeBr production as a means of quantifying bacterial growth provided a 100- to 1,000-fold increase in sensitivity over optical or fluorescence measurements of a comparable reporter strain expressing fluorescent proteins. IMPORTANCE Quantitative measurement of bacterial growth in microdroplets is desirable but challenging. Current optical reporter systems suffer from limitations when applied to filamentous or biofilm-producing organisms. In this study, we demonstrate that volatile methyl halide gas production can serve as a quantitative nonoptical growth assay for filamentous bacteria encapsulated in microdroplets. We constructed an gas reporter strain and observed a complete life cycle for encapsulated in microdroplets, establishing microdroplets as an alternative growth environment for spp. that can provide spatial structure. We detected MeBr production from both liquid suspension and microdroplets with a 100- to 1,000-fold increase in signal-to-noise ratio compared to optical assays. Importantly, we could reliably detect bacteria with densities down to 10 CFU/mL. The combination of quantitative gas reporting and microdroplet systems provides a valuable approach to studying fastidious organisms that require spatial structure such as those found typically in soils.
Topics: Emulsions; Fluorescence; Gases; Transferases
PubMed: 37699129
DOI: 10.1128/aem.00764-23