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A non-destructive, fast, inexpensive, non-toxic chelating resin-based DNA extraction protocol for insect voucher specimens and associated microbiomes
Get PDFIdentifying a DNA extraction method that yields high quantity and quality DNA is a crucial component of molecular ecological studies; and the best suited method can vary greatly depending on research priorities. Here, we propose a nondestructive extraction method for insect museum vouchers aimed at analyzing gut-associated microbiomes. The leafhopper Euscelidius variegatus (Kirschbaum) (Hemiptera: Cicadellidae) associated with the bacterial plant pathogen Flavescence dor & eacute;e phytoplasma, a member of the genus 'Candidatus Phytoplasma' (Mollicutes: Acholeplasmataceae), was used as an experimental model. We developed and refined a resin-based DNA extraction protocol by testing the effects of prelysis bleaching and postlysis proteinase K inactivation on DNA quality and yield. We found that bleaching did not compromise the integrity of insect and associated bacterial DNA and that excluding the inactivation of proteinase K did not interfere with quantitative polymerase chain reaction analysis. Based on our findings, we recommend a DNA extraction protocol for insect voucher specimens and associated microbiomes that includes a prelysis bleaching step to chemically degrade external contaminants without proteinase K inactivation, thereby reducing processing time. Our refined protocol resulted in a high DNA yield, which we successfully analyzed using quantitative polymerase chain reaction analysis and other downstream molecular applications, including targeted high-throughput sequencing
Knowledge-implementation processes in crop protection literature
Get PDFPurposeThe purpose of this paper is to explore how new research on crop protection practices is communicated to end-users by investigating which knowledge-implementation processes are recommended in crop protection literature.Design/methodology/approachThis analysis is completed through a qualitative systematic review of literature on knowledge-implementation in crop protection where six knowledge-implementation processes are identified from 65 articles: information and communication technologies (ICT), management models and approaches, education platforms and events, advisory and extension services, networks, and collaborative approaches. We place special emphasis on the gaps and trends around networks and collaborative processes, building on communication theory research.FindingsWhile many articles discussed multiple knowledge-implementation processes, it was found that most of the processes discussed aligned with a transmission communication model and the traditional agricultural knowledge and innovation system. While 11 articles described networks and 22 articles described collaborative processes in line with a constitutive model of communication, these tended to provide limited advice on how these processes could be achieved in practice, identifying a need for further investigation of how multilateral communication can be used to better crop protection practice.Practical ImplicationsThese findings can help facilitate better communication between researchers and farmers, promoting processes that include farmers and other actors as sources of knowledge and improving the efficiency and effectiveness of crop protection practices.Theoretical implicationsThis study enhances the understanding of knowledge-implementation in agriculture, emphasizing the need to draw on multiple forms of communication to address the knowledge-to-action gap.Originality/ValueThere is limited research that examines the knowledge-to-action gap in agriculture, particularly in relation to crop-protection practices. As a review study, this manuscript provides an overview of how this topic is described in the field
Global equine parasite control guidelines: Consensus or confusion?
Get PDFEquine parasite control has historically been characterized by confusing and conflicting information, posing significant challenges for veterinarians and horse owners to make evidence-based decisions. Since 2012, equine parasite control guidelines have been developed and published for different parts of the world to address this situation and provide trusted sources of current guidance. At the 2024 International Equine Infectious Disease Conference in Deauville, Normandy, France, lead authors of equine parasite control guideline documents published in the USA, UK, Sweden, Denmark, the Netherlands, Australia, and Europe convened and presented their guidelines. This led to a discussion of differences and similarities between the guidelines and an effort to identify current research needs in this area. In general, all guidelines recommend a surveillance-based approach for equine parasite control, emphasizing the importance of anthelmintic resistance testing. Some guidelines have a focus on controlling Strongylus vulgaris, while others primarily focus on cyathostomins, ascarids and tapeworms. Although the same four anthelmintic drug classes are marketed in most countries, there are some differences between product portfolios available, most notably between Australia and other countries. European countries have various degrees of prescription-only restrictions on anthelmintic products, whereas products are available over the counter in Australia and the USA. Commercially available diagnostic portfolios differed somewhat between countries and affected recommendations made as well. In conclusion, the guidelines are in general agreement and are based on the same general principles. One major challenge is communicating the recommendations effectively to end-users, which should be made a priority going forward
Considering greenhouse gas emissions from feed production in diet formulation for dairy cows as a means of reducing the carbon footprint
Get PDFDairy production often faces conflicting goals, such as reducing greenhouse gas emissions, increasing food production and achieving self-sufficiency without transgressing planetary boundaries. This study examined ways to decrease emissions intensity per kg of milk from high-producing cows by selecting feed ingredients with a low carbon footprint while also considering local alternatives. Diets comprising of grass-legume mixture silage and three concentrate mixtures (standard commercial, based on byproducts, and domestic crops grown on-farm) were randomly allotted to three groups of highproducing Swedish Holstein cows (N = 48). Over 7 weeks, no differences were observed (mean +/- SEM) in feed DM intake (commercial: 24.3, by-products: 24.7, domestic: 24.2 kg/day, +/- 0.51 kg/day), energycorrected milk (ECM) yield (commercial: 38.3, by-products: 38.5, domestic: 37.8, +/- 0.98 kg/day) or enteric methane production (commercial: 387, by-products: 378, domestic: 402 g/day, +/- 17.3 g/day) among the diets. However, an evaluation of the primary carbon footprint of feed production (excluding transportation emissions) showed that the by-products and domestic diets gave lower emissions than the commercial diet, 9.4, 10.2, and 11.9 Feed CO2 equivalents (CO2-eq) kg/day, respectively (SEM: +/- 0.38 Feed CO2-eq kg/day). The emission intensity, expressed as feed emissions per kilogram of ECM yield, showed that the by-product-based and domestic diets generated lower carbon footprints, with emissions of 254 and 284 g Feed CO2-eq/kg ECM, respectively, in comparison to 320 g Feed CO2-eq/kg ECM observed for the commercial diet (SEM: +/- 10.7 g Feed CO2-eq/kg ECM). Considering greenhouse gas emissions from feed production in diet formulation resulted in a lower overall feed carbon footprint and lower emission intensity per ECM. These findings can assist in formulating dairy rations for high-yielding dairy cows that balance conflicting goals while maintaining productivity. (c) 2025 The Author(s). Published by Elsevier B.V. on behalf of The animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Pelagisk fisk i Mälaren 2024
Get PDFSötvattenslaboratoriet vid Institutionen för akvatiska resurser, SLU, genomförde i september 2024 en hydroakustisk undersökning med pelagisk provtrålning i Mälaren. Fältarbetet ägde rum mellan 16 och 19 september 2024, som en del av de årliga hydroakustiska undersökningarna i Mälaren, Vättern och Vänern. De delområden som undersöktes var Ekoln, Granfjärden, Görväln och Prästfjärden. Analyserna av 2024 års data omfattade de pelagiska fiskarterna nors, siklöja och gös, uppdelade i åldersklasserna årsyngel (0+) samt ettåriga och äldre individer (>0+), samt braxen och storspigg. Övriga arter fångades inte i tillräckligt antal för att möjliggöra analys. För att dra slutsatser om beståndens utveckling avseende rekrytering och beståndsstorlek, samt förändringar i fiskarnas längd, genomfördes två typer av analyser: Korttidstrender analyserades genom att jämföra medelvärden för fisktäthet under de två senaste åren (2023 och 2024) med medelvärdet för de fem föregående åren (2018–2022). Långtidstrender (sedan 2012) analyserades med hjälp av linjär regression, där antalet fiskar förklarades av årtal. Utöver analyserna av fiskantal presenteras även utvecklingen över tid för storleksindex, ålder och kondition, samt för total biomassa och antal fiskar uppdelat i storleksklasser. Resultaten var:• På kort sikt har antalet fiskar under 17 cm ökat i Görväln, medan antalet större fiskar har minskat i Prästfjärden. I Prästfjärden och Ekoln fanns icke statistiskt säkerställda indikationer på att den totala biomassan per hektar har minskat. Under samma period har braxen minskat i samtliga delområden utom Granfjärden, och storspigg har minskat i Görväln och Prästfjärden. Även siklöjan visar minskning i Prästfjärden. I Granfjärden finns tendenser till ökning av antalet vuxna individer av både nors och gös, och i Görväln ökar både antalet vuxna och antalet årsungar av nors.• På längre sikt (sedan 2012) har antalet fiskar per hektar i storleksintervallet 4–8 cm har ökat i Ekoln, och antalet fiskar i storleksintervallet 8–17 cm har ökat i Görväln. Uppdelat på arter har antalet vuxen nors i Görväln ökat kontinuerligt sedan 2012, medan det finns en icke statistiskt säkerställd tendens till att antalet vuxen gös har minskat i Prästfjärden.• Vuxen gös medianlängd har ökat i östra Mälaren (Görväln och Prästfjärden) och längden hos de största individerna har ökat både i östra Mälaren och i Granfjärden. För årsungar av gös verkar tillväxten ha ökat i Granfjärden. Längden hos vuxen nors har minskat i Ekoln, medan längden hos årsungar av nors har ökat både i Ekoln och i östra Mälaren. Även årsungar av siklöja har ökat i längd i östra Mälaren. Däremot har konditionen hos vuxen siklöja försämrats i östra Mälaren
Environmental Filtering Effect Drives the Plant Species Distribution in Alpine Grasslands on the Qinghai-Tibetan Plateau
Get PDFExploring community assembly is essential for understanding the mechanisms of biodiversity maintenance and species coexistence. In general, stochastic (e.g., dispersal limitation) and deterministic (e.g., environmental filtering) effects have been identified as the two key processes driving community assembly. However, the relative contributions of these two processes and how they vary across different spatial scales remain poorly understood, especially for the high-diversity grassland ecosystems on Qinghai-Tibetan Plateau (QTP), which plays a critical role in global climate regulation. In this study, a total of 27 study sites were established along a north-south transect and a west-east transect across the eastern QTP; the two furthest sites were more than 1000 km apart. We analyzed the taxonomic, functional, and phylogenetic diversity and structure of these communities to elucidate the relative importance of dispersal limitation and environmental filtering effects that shape plant distributions at the regional (i.e., encompassing all sites) and the transect scales. A total of 181 species belonging to 99 genera and 34 families of vascular plants were found across all sample sites. Both at the regional and the transect scale, environmental variables were shown to account for a larger proportion of the variation in species composition than spatial variables. Likewise, the plant species diversity (i.e., taxonomic, functional, and phylogenetic diversity) was also primarily influenced by soil and climatic variables rather than by spatial factors. Specifically, mean annual precipitation, mean annual temperature, and soil total carbon content emerged as critical determinants of plant species diversity at the regional scale, while the mean annual temperature was identified as the most important factor at the transect scale. Our results highlight the significance of environmental filtering, rather than dispersal limitation, in shaping plant community dynamics across various spatial scales within the alpine grassland ecosystem, which has crucial implications for plant conservation and biodiversity maintenance under global change scenarios
Unraveling the dynamics of lignin chemistry on decomposition to understand its contribution to soil organic matter accumulation
Get PDFAims Plant inputs are the primary organic carbon source that transforms into soil organic matter (SOM) through microbial processing. One prevailing view is that lignin plays a major role in the accumulation of SOM. This study investigated lignin decomposition using wood from different genotypes of Populus tremula as the model substrate. The genotypes naturally varied in lignin content and composition, resulting in high and low lignin substrates.Methods The wood was inoculated with fresh soil and decomposition was interpreted through mass loss and CO2 produced during a 12-month lab incubation. Detailed information on the decomposition patterns of lignin was obtained by Two-dimensional Nuclear magnetic resonance (2D NMR) spectroscopy on four occasions during the incubations.Results The lignin content per se did not affect the overall decomposition and similar to 60% of the mass was lost in both substrates. In addition, no differences in oxidative enzyme activity could be observed, and the rate of lignin decomposition was similar to that of the carbohydrates. The 2D NMR analysis showed the oxidized syringyl present in the initial samples was the most resistant to degradation among lignin subunits as it followed the order p-hydroxybenzoates > syringyl > guaiacyl > oxidized syringyl. Furthermore, the degradability of beta-O-4 linkages in the lignin varied depending on the subunit (syringyl or guaiacyl) it is attached to.Conclusions Our study demonstrates that lignin contains fractions that are easily degradable and can break down alongside carbohydrates. Thus, the initial differences in lignin content per se do not necessarily affect magnitude of SOM accumulation
Intra-and interspecific variations in flight performance of oak-associated Agrilinae (Coleoptera: Buprestidae) using computerised flight mills
Get PDFSeveral Agrilinae species (Coleoptera: Buprestidae) are thermophilous forest borers, and some are also major invasive pests. They are expected to be favoured by climate change and the global deterioration of forest health, and expand their range and damage. Flight behaviour and performance of these insects are poorly known despite their critical role in dispersal and their relevance to management. This study aimed to assess intra-and inter-specific variability in active flight of several Agrilinae species and effects of sex and mass on this variability. We assessed the flight performance of eleven oak-associated species (nine Agrilus, one Coraebus, one Meliboeus) plus one herb-associated Agrilus. Computer-monitored flight mills were used to measure flight parameters of 250 beetles. Overall, flight capacities were rather homogeneous among species, with a dominance of poor flyers and only Coraebus undatus showed outstanding performance. Beetles generally performed several short flight bouts within one trial, and only a few individuals sustained long flight. The maximal total distance covered across multiple assays until death ranged from 170 to 16 097 m, with a median between 35 and 966 m (excluding individuals that never flew). Add to this interspecific variability, flight distances varied greatly among individuals, but were not influenced by sex. Preflight body mass had mixed effects depending on the species, presumably related to dispersal patterns. In our experimental conditions, most species had limited average dispersal capacities over multiple flight trials. Overall, long-distance dispersal and colonisation events probably depend on a small proportion of individuals which largely exceeded the median performance
Comparative evaluation of digestate and reject water as nutrient media for syngas biomethanation in thermophilic trickle-bed reactors
Get PDFSyngas biomethanation facilitates the utilization of thermal gasification products. This study evaluated the performance of two liquid organic waste streams (manure-based digestate and reject water from digested sewage sludge) as nutrient media in thermophilic trickle-bed reactors (TBRs) over more than one year. Digestate achieved a Methane Evolution Rate (MER) of 4.5 L/(L-pbvd) with the highest so far published H-2 and CO conversion rates (>95 %). Reject water only led to a maximum MER of 1.0 L/(L-pbvd), while the addition of sulfur and phosphorus to the reject water resulted in improved MER of up to 3.1 L/(L-pbvd). The microbial analysis illustrated a similar microbial community structure and methanogenic abundance for both TBRs, with Methanothermobacter as the dominating methanogen both in the liquid phase and biofilm of the carriers. Carbon monoxide was likely converted to both methane and acetate
Nitrogen rate drives the effectiveness of 3,4-Dimethylpyrazole phosphate (DMPP) in reducing N2O emissions from limed soil subjected to temporary waterlogging
Get PDFSoil pH, moisture, and nitrogen (N) rate may affect the effectiveness of the nitrification inhibitor 3,4-Dimethyl-pyrazole phosphate (DMPP) in mitigating N2O release. Thus, the present study raised the question: do soil pH and N rate regulate the effect of DMPP on mitigating N2O production and promoting N2O reduction to N2 from soils subjected to temporary waterlogging? This was studied in a greenhouse experiment under semi-controlled conditions in which wheat was cultivated under aerobic conditions for 30 days, followed by a temporary waterlogging period of 5 days. The study investigated the factors of soil pH, which was manipulated by liming (unlimed and limed), application of the nitrification inhibitor DMPP, and N application rate (60 and 180 mg N kg soil-1), referred to as N60 and N180. The N source was ammonium sulfate. DMPP reduced the relative abundance of nitrifying bacteria such as Nitrospira and Nitrosospira and, therefore, suppressed nitrification in all treatments. After waterlogging, DMPP efficiently mitigated N2O-N release from unlimed soil (80 %), probably by suppressing fungal (Cladosporium, Chaetomium, and Fusarium) and bacterial (Bradyrhizobium) denitrifiers due to DMPP-induced lower NO3-concentrations. In addition, DMPP reduced cumulative N2O-N release by 94 % at the N180 rate but was ineffective at the N60 rate in the limed soil. In conclusion, DMPP was confirmed as an excellent mitigation measure for N2O release from unlimed soils subjected to waterlogging. However, our study demonstrated that relatively low N rates can lead to DMPP ineffectiveness in reducing N2O release from limed soil subjected to temporary waterlogging