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ABSTRACT.- Pears are widely cultivated in the world. Uruguayan production covers 628 ha. Practically, in its entirety, European-type pear trees (Pyrus communis L.) are grown, and the most planted cultivar is Williams. Most of the orchards in Uruguay are managed without the use of pollinating cultivars. Pear production in recent years has not been stable, with the lack of pollinators one of the main factors that could be influencing this. The aim of this study was to evaluate the phenology and the potential of different pear cultivars to increase fruit set in the climatic conditions of Uruguay. The study was carried out during the 2020/2021 and 2021/2022 growing seasons in pear orchards at "Instituto Nacional de Investigación Agropecuaria", Canelones, Uruguay. 'Williams' and 'Early Bon Chretien' pears were used as main cultivars. Treatments consisted of different pollen sources, in addition to spontaneous self-pollination, forced self-pollination and emasculation. Controlled pollinations were carried out between 10 September and 20 October, and 15 September and 4 October in the 2020/2021 and 2021/2022 growing seasons, respectively. The flowering period in 2021/2022 was shorter than in 2020/2021, where some cultivars presented a decrease in the bloom period of 10 days or more. Generally, in both growing seasons all pollen sources increased fruit set of 'Williams' and 'Early Bon Chretien' pears compared to unpollinated or self-pollinated treatments. Collectively, with the results of both seasons, the pollinizers 'Santa Maria' and 'Devoe' were the most efficient in increasing fruit set of 'Williams' pears, while for 'Early Bon Chretien' the best pollinizers were 'Forelle', 'Abate Fétel' and Pyrus calleryana. © 2024 International Society for Horticultural Science. All rights reserved.

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ABSTRACT.- Paspalum L. is a genus of the Poaceae family, with many species serving as well-adapted forage plants in subtropical climates and continuous grazing systems. However, Claviceps paspali, an ascomycete of the order Hypocreales, represents a major threat to Paspalum species. This fungus induces ergot disease, characterized by the replacement of infected flower seeds with sclerotia, which adversely affects seed production and animal health through mycotoxin production. Although ergot disease is reported in many countries, no totally resistant Paspalum cultivars have been reported for commercial use. This study comparatively evaluated disease development in six Paspalum species under greenhouse conditions with three specific isolates of C. paspali, along with field trials. In addition, field isolates of C. paspali were analyzed for phenotypic characteristics and phylogenetic relationships. Greenhouse evaluation revealed variable susceptibility among Paspalum species, with P. malacophyllum,P. notatum and P. umbrosum being the most resistant. In field trials P. dilatatum showed the highest severity index, while P. umbrosum and P. malacophyllum were less affected. Phenotypic characterization of 22 C. paspali isolates showed variability in pigmentation and growth rates, with PDA being the culture medium where the highest growth rate was observed. Phylogenetic analysis of the isolates identified two well-supported lineages between C. paspali species. This research reports an ergot resistance gradient among Paspalum species, identifying genuine sources of resistance. In addition, virulent isolates of C. paspali potentially useful for rapid screening of accessions or crosses in Paspalum breeding programs were identified. © 2024 The American Phytopathological Society

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ABSTRACT.- Tree plantations are expanding in southern South America and their effects on ecosystem services, particularly climate regulation, are still not well understood. Here, we used remote sensing techniques and a paired design to analyze 33,000 ha of Pinus plantations along a broad geographical and environmental gradient (26-43° South latitude, 54?72° West longitude). Radiation interception, surface temperature, evapotranspiration, and albedo were assessed both in tree plantations stands and in adjacent uncultivated areas. Additionally, the climatic impact of tree plantations was quantified by analyzing changes in atmospheric radiative forcing and its carbon (C) equivalent. Tree plantations intercepted more radiation when replacing steppes, grasslands, and shrublands but not when replacing forests. The control exerted on radiation interception by precipitation decreased in both space and time after tree plantation. Furthermore, evapotranspiration notably increased in tree plantations. The lower albedo of tree plantations compared to uncultivated adjacent areas induces global warming through the biophysical pathway. Thus, the climate benefits of afforestation through C sequestration can be counteracted by 18 to 83 % due to albedo changes. It is necessary to fully consider the biophysical effects and water footprint of tree plantations in public policies that promote them, as well as in international carbon accounting mechanisms. © 2024 Elsevier B.V.

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ABSTRACT.- Crop type classification with satellite imageries is widely applied to support sustainable agricultural practices and for continuous crop monitoring [1], [2], [3]. In this work, we present a study for the classification of winter crops on a nationwide perspective for Uruguay. We have analyzed Uruguay's three most widely extended winter crops: wheat, barley, and rapeseed. We have trained a classifier based on XGBoost that uses temporal series built from Sentinel-2 image data. For training, we used the information from previous years and reported the results the following year. To our knowledge, this is the first work that proposes a clear and systematic way to classify winter crops in Uruguay based on historical data without needing samples of the actual year. We have obtained high precision and recall values for rapeseed and results comparable with other regions' work for wheat and barley. © 2024 IEEE.

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ABSTRACT.- The transformation of the existing agrifood system towards more sustainable systems requires sociotechnical strategies that can boost radical changes. In Uruguay there is a community of practice committed to the sustainable development of family livestock farming which has developed alternative production practices, that improve the sustainability of farms based on ecological intensification, for more than fifteen years. Co-innovation as a modality of intervention was a fundamental aspect in the results achieved, being the work on farms a key factor, with a very special bond between extensionist and family. Taking this community of practice as a case study, this text characterizes co-innovation as a modality of intervention for farm technical assistance, offering a vision to enhance the scaling of the interventions and contribute to the sustainable transformation of livestock farming. Results are presented on: 1) general characteristics of the intervention modality, 2) stages of work and practices on farms, 3) characteristics of the family-extensionist bond and 4) lessons learned. Finally, key aspects are pointed out to scale co-innovation, in order to contribute to a sustainability transition of Uruguayan family livestock farming. -.-.-.-.-.-.-.-.-.-.-.-.-. RESUMEN.- La transformación del sistema agroalimentario actual hacia sistemas más sostenibles requiere estrategias sociotécnicas que puedan impulsar cambios radicales. En Uruguay existe una comunidad de práctica comprometida con el desarrollo sostenible de la ganadería familiar que ha desarrollado prácticas productivas alternativas, que mejoran la sostenibilidad de los establecimientos con base en la intensificación ecológica, durante más de quince años. La coinnovación como modalidad de intervención fue un aspecto fundamental en los resultados alcanzados, fue clave el trabajo situado en los predios, con un vínculo muy especial entre extensionistas y familias. Tomando la comunidad de práctica como un estudio de caso, este texto caracteriza a la coinnovación como modalidad de intervención para la asistencia técnica predial, ofreciendo una visión para potenciar el escalamiento de las intervenciones y contribuir a la transformación sostenible de la ganadería. Se presentan resultados sobre: 1) características generales de la modalidad de intervención, 2) etapas de trabajo y prácticas en predios, 3) características del vínculo familia-extensionista y 4) lecciones aprendidas. Finalmente, se señalan aspectos clave para escalar la coinnovación, de manera de contribuir a una transición sostenible de la ganadería familiar uruguaya. © (2024), (SciELO-Scientific Electronic Library Online). All Rights Reserved.

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ABSTRACT.- We described the first case of rhinofacial pythiosis with dissemination in an adult horse in Uruguay. The affected horse presented a partially circumscribed mass measuring 30 x 23 x 9 cm affecting the right side of the face with involvement of cutaneous, subcutaneous, and muscular tissues, the right nasal cavity, and adjacent structures. At postmortem examination, the main lesions were "kunkers" characterized by pyogranulomatous and eosinophilic dermatitis, Splendore-Hoeppli reaction and numerous intralesional hyphae immunolabeling with polyclonal anti-Pythium insidiosum antibody. Similar lesions were observed in the lung and submandibular lymph nodes. The diagnosis was made by the characteristic histological lesions and the strong immunolabelling by anti-P. insidiosum antibody. ------------------ RESUMO.- Descreve-se o primeiro caso de pitiose rinofacial com disseminação em um equino adulto no Uruguai. O animal apresentava uma massa parcialmente circunscrita medindo 30 x 23 x 9 cm acometendo o lado direito da face e com envolvimento dos tecidos cutâneo, subcutâneo e muscular, cavidade nasal direita e estruturas adjacentes. Os principais achados patológicos incluem a formação de kunkers microscopicamente caracterizados por dermatite piogranulomatosa e eosinofilica, reação de Splendore-Hoeppli, e numerosas hifas intralesionais imunomarcadas com anticorpo policlonal anti-Pythium insidiosum. Lesões semelhantes foram observadas no pulmão e nos linfonodos submandibulares. O diagnóstico foi baseado nas lesões histológicas características e imunomarcação com anticorpo anti-P. insidiosum. © 2025, Universidade Federal de Santa Maria. All rights reserved.

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ABSTRACT.- This study aimed to estimate variance components (VCs) for growth and reproductive traits in Nellore cattle using two relationship matrices (pedigree relationship A matrix and pedigree plus genomic relationship H matrix), and records collected before and after genomic selection (GS) implementation. The study also evaluated how genomic breeding values (GEBV) are affected by variance components and discarding old records. The analysed traits were weight at 120 days (W120), weight and scrotal circumference at 450 days (W450 and SC450, respectively). Three datasets were used to estimate VCs, including all phenotypic information (All) or records for animals born before or after GS implementation (Before or After datasets, respectively). Both relationship matrices were considered for VC estimation, the A matrix was used in all three datasets and VC from each combination were named as A_Before, A_After, and A_All). The H was used in two datasets: H_All and H_After. Different VCs were used for GEBV prediction through ssGBLUP. This step used two possible Datasets, using all available phenotypic data (Dataset 1) or just records collected since GS implementation (Dataset 2). Validation was conducted using accuracy, bias and dispersion according to the LR method and prediction accuracy from corrected phenotypes. The heritability of all traits increased from A_Before to A_After, while estimates for A_All were intermediary. In the previous order, the estimates were 0.16, 0.17, and 0.15 for W120; 0.31, 0.39, and 0.35 for W450; 0.35, 0.47, and 0.41 for SC. For W450 and SC, using the H matrix reduced the heritability (0.33 and 0.32 for W450; 0.41 and 0.38 for SC for H_After and H_All, respectively). For W120, Dataset1 and VCs from A_After showed the highest accuracy for direct and maternal GEBV (0.953 and 0.868). For W450, Dataset 1 and VC from H_After allowed the highest accuracy (0.854) but use Dataset 2 and same VC source yield similar value (0.846). For SC, Dataset 2 with VC from H_After showed the highest accuracy (0.925). To use Dataset 2 does not cause important changes in bias or dispersion with respect to Dataset 1. The VC and genetic parameters changed for W120, W450, and SC450, using records before or after the GS implementation. For W450 and SC450, genetic variance and heritability estimates increased with the use of GS. For W120, genomic predictions were more accurate using A for VC estimation. Accuracy gains were observed for W450 and SC450 using H in VC estimation and/or discarding records before GS. It is possible to discard phenotypic records before GS implementation without generating bias or dispersion in the GEBV of young candidates. © 2024 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.

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ABSTRACT.- Waterlogging is a critical abiotic stress increasing in importance due to more intense, erratic rainfall associated with climate change. Waterlogging leads to significant yield losses in sensitive crops, such as soybean (Glycine max [L.] Merr.). Identifying soybean genotypes and traits associated with better waterlogging tolerance is of high interest. We assessed the response of six soybean genotypes, selected from a field screening of over 190 genotypes, to 10 days of waterlogging at the R1 (onset of flowering) and R4 (grain filling) stages. We evaluated yield and its components, as well as shoot and root dry weights (DW) at the end of the waterlogging treatments and at maturity, along with morphological traits such as plant branch number, stem diameter and plant height. By integrating all these traits, a waterlogging tolerance index (WTI) was calculated for each genotype to rank their sensitivity. The WTI showed variations among genotypes from 0.61 to 0.77, indicating genotypic variation in response to waterlogging. Greater reductions in root DW compared to shoot DW were observed immediately after waterlogging. By maturity, shoot DW of waterlogged plants was more severely reduced than root DW in all genotypes. Despite similar DW losses at R1 and R4 at physiological maturity, seed number per plant and 100-seed weight responses differed between the treatments. Genotypes that performed well under control conditions suffered significant yield reductions of 70%-85% after waterlogging, mainly due to fewer fertile nodes and seeds per pod, with some also experiencing a notable decrease in 100-seed weight. In contrast, other genotypes had milder responses, with less severe reductions in seed and pod traits. Identifying breeding soybean genotypes tolerant to waterlogging during reproductive stages that maintain the number of fertile nodes and pods per node without changes in seeds per pod could significantly mitigate yield losses from waterlogging. © 2024 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.

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ABSTRACT.- Question: Understanding the patterns of alien plant invasions and their underlying drivers is a key step in conserving the remaining native grasslands of Uruguay. We addressed the level of invasion by considering the four invasive alien plants of these ecosystems, Cynodon dactylon, Eragrostis plana, Senecio madagascariensis and Ulex europaeus, throughout the country. Location: Remnant native grasslands of Uruguay, constituting part of the Río de la Plata grasslands. Methods: Extensive fieldwork was carried out over five years of data collection, including hierarchically randomized observations (around 2000) nested in 137 10 × 10-km2 squares covering different geomorphological regions. For each invasive alien species, we constructed distribution maps to show their patterns; for the two most abundant, we fitted models to identify the main explanatory variables at different spatial scales. Results: We found that 77% of the squares were invaded by at least one target species. The level of invasion varied between regions and target plants. The most abundant invasive alien species were Cynodon dactylon and Senecio madagascariensis; while Eragrostis plana and Ulex europaeus were scarce. Cynodon dactylon cover was related to a set of variables at different spatial scales, including climate, topography and several local community descriptors. Senecio madagascariensis cover was positively associated with grassland fragmentation and anthropic disturbance at the landscape, and a few local descriptors. Conclusions: The large sampling effort at the country level, with a randomized design, allowed for a reliable assessment of the level of invasion of Uruguayan grasslands and its possible drivers. This is an important step in the design of policies to conserve Uruguay's remaining native grasslands. We suggest that the prevention should focus on the Basaltic Cuestas region, while control and containment should prioritize the eastern and south-central parts of the country, focusing mainly on Cynodon dactylon management. © 2024 International Association for Vegetation Science.

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ABSTRACT.- South American beef production varies due to diverse climates, environmental conditions, animal breeds (Bos indicus, Bos taurus and crossbreeds), management strategies, and nutritional sources. Applying technology in the South American beef production system can significantly enhance efficiency, sustainability, and profitability. Reproductive efficiency is a significant challenge, especially in cow-calf operation systems conducted under adverse conditions. Consequently, implementing effective assisted reproduction technologies (ART) can make a significant contribution. In the last two decades, the development of fixed-time artificial insemination (FTAI) protocols permitted the widespread application of artificial insemination for breeding management and genetic improvement in beef herds in South America. Nowadays, FTAI is being applied in South America in large-scale programs, with around 20 % of heifers and cows receiving this technology every year. This results in a greater calving rate and significant genetic gain occurring in this territory. Also, in vitro embryo production, mainly using sex-selected sperm has been widely applied in this region, leading to significant improvements in herd genetics and productivity. Recently, 94 % of all embryo transfers in South America consist of in vitro-produced embryos (41,429 being in vivo-derived and 650,782 being in vitro-produced embryos), mainly using fixed-time embryo transfer technology (FTET). Genomic selection combined with in vitro embryo production with oocytes from heifer calves provides a powerful technology platform to reduce generation interval and significantly increase the rate of genetic gain in beef cattle. Emerging biotechnologies, such as genome editing via the CRISPR/Cas system, are being developed to enhance productivity, confer resilience to adverse environmental conditions, increase disease resistance, and control pest species that affect livestock. Finally, while all these technologies offer significant potential, further progresses are needed to transform livestock production. The vast geographical scale and diverse climates of South America make regional knowledge crucial for aligning beef production with sustainability goals and supporting global food security. © 2024

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ABSTRACT.- Numerous conservation and regeneration practices are recognized as effective strategies in the management of soil health (SH), a critical factor for ensuring the sustainability of food production systems. Despite their acknowledged importance, the multifaceted impacts of these practices often lead to confounding effects, and reliance on generic categorization of agronomic practices often falls short in portraying the drivers of SH. We advocate for a paradigm shift from a label-centric approach to one rooted in processes. Our study underscores the pivotal role of aboveground biomass cycling as an indicator for assessing the potential of agronomic management practices to instigate shifts in carbon balances, and, consequently SH. © 2024 The Authors. Published by Elsevier B.V.

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ABSTRACT.- The purpose of this work is to describe the creation process of the first long-term experimental platform designed for interdisciplinary studies of Silvopastoral Systems (SPS) in Uruguay and to highlight its relevance on filling knowledge gaps across different areas. This experiment involves professionals from diverse fields working together to generate knowledge for sustainable agriculture. The focus is on understanding long-term interactions in SPS, emphasizing native ecosystem conservation and increased agricultural productivity. Covering 30.24 ha, this experimental platform incorporates three treatments, implemented in a randomized complete block design with three replications: (1) a natural grassland without trees, (2) a two-row SPS with 160 tree/ha, and (3) a four-row SPS with 240 trees/ha. The platform's design involves the exploration of variables such as aboveground biomass and botanical composition, microclimate, silviculture, livestock performance, soil carbon dynamics, ecosystem integrity index, monitoring ecological indicators such as amphibian and spiders' diversity, optimizing modeling and economic benefit and social aspects. This platform will enable the analysis of changes resulting from the incorporation of trees at two different densities into livestock systems. Additionally, we aim to identify the best combination of activities to optimize the farmers income, considering the relevance of a positive impact on social aspects, such as increased demand of employment, adoption by farmers, and the interest of new generations. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.

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ABSTRACT.- Heme and iron metabolic pathways are highly intertwined, both compounds being essential for key biological processes, yet becoming toxic if overabundant.Their concentrations are exquisitely regulated, including via dedicated two-component systems (TCSs) that sense signals and regulate adaptive responses.HemKR is a TCS present in both saprophytic and pathogenic Leptospira species, involved in the control of heme metabolism.However, the molecular means by which HemKR is switched on/off in a signal-dependent way, are still unknown.Moreover, a comprehensive list of HemKR-regulated genes, potentially overlapped with iron-responsive targets, is also missing. © 2024 Imelio et al.

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ABSTRACT.- Symbiosis plays a critical role in plant biology. Temperate grasses often associate with several symbiotic fungi simultaneously, including Epichloë endophytes and arbuscular mycorrhizal (AM) fungi, in shoots and roots, respectively. These symbionts often modulate plant-herbivore interactions by influencing nutritional traits (i.e. AM fungi-mediated nutrient uptake) and/or the secondary chemistry (i.e. endophytic alkaloids) of their host plant. Moreover, such grasses also accumulate large amounts of silicon (Si) from the soil, which can be deposited in tissues to act as a physical anti-herbivore defence. Recent evidence suggests that both endophytes and AM fungi independently facilitate Si uptake. However, the consequences of their interactions with piercing-sucking insects (i.e. aphids), or whether Si supply, endophytes, and AM fungi interact in this regard, are currently unknown. While Si deposition may be less effective against aphids than other herbivores (i.e. chewing caterpillars), Si supply can also alter plant secondary metabolite defences, which could affect sucking insects. In a factorial greenhouse experiment, we evaluated whether these components, acting alone or in combination, altered (1) foliar primary chemistry, (2) Si and symbiont-chemical (endophytic alkaloids) defences, as well as (3) performance of the bird cherry-oat aphid (Rhopalosiphum padi) feeding on tall fescue (Festuca arundinacea). Endophytes decreased all aphid performance parameters, including population growth and reproduction by 40%, but their impact was reversed by the presence of AM fungi, leading to a 52% increase in aphid performance compared with plants solely hosting endophytes. This improvement in performance was associated with reduced loline alkaloid levels and higher shoot nitrogen in AM-endophytic plants. Endophytes and AM fungi exhibited antagonism, with endophytes reducing AM colonization by 34% and AM presence decreasing endophyte loline alkaloids by 44%. While both fungi jointly increased Si accumulation by 39% under Si-supplied conditions, Si had no noticeable effects on aphids. Moreover, although Si supply had no identifiable effects on AM colonization, it reduced endophyte peramine alkaloids by 24%. Synthesis. Our findings indicate that symbiotic fungal partnerships and silicon provision may benefit plants but could weaken anti-herbivore defences when combined. Revealing the complex interactions among diverse fungal symbionts and showcasing their effects on different anti-herbivore defences (chemical and physical) and herbivore performance for the first time. © 2024 The Author(s). Journal of Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

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ABSTRACT.- The impact of forestry practices was evaluated on Eucalyptus?s growth variables and mortality dynamics. An experiment was conducted in Uruguay over sixteen years, sixteen spacing and thinning treatments were compared depending on the genetic material and productive objective. Tree height and diameter at breast height were assessed annually. All variables were analyzed using linear mixed models. Kaplan-Meier survival analysis and the Log Rank test were used to compare tree survival. © (2024), (Universidade Federal Rural do Rio de Janeiro (UFRRJ)). All Rights Reserved.

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ABSTRACT.- Achieving sustainable food and nutritional security requires a transformation of the existing agrifood system. In livestock farming based on natural grassland in Uruguay, an ecological intensification strategy could play a radical role in the transition towards more sustainable systems. This study analyzes the continuity of interconnected projects that used co-innovation approaches to promote and evaluate ecological intensification strategies over a period of 15 years (2004-2019). The purpose of the article is to provide evidence on the development of a socio-technical niche in sustainable livestock farming and to identify anchoring points for further regime transformation. Our contention is that interactive research in the context of application based on a sequence of co-innovation projects has the potential to trigger a sustainability transition through ecological intensification of livestock farming based on natural grassland. The research followed a single-case study design with multiple units of analysis, based on the study of documents produced by the different projects and semi-structured interviews. In addition, network analysis was used to examine the linkage of persons and projects. Results show that a socio-technical niche in sustainable livestock farming base on natural grassland was developed in Uruguay, promoted by research institutions and progressively involving other social actors throughout the process. The continuity of projects over 15 years, was fundamental to achieve the three essential processes for a niche conformation: i) an alignment of expectations and the development of a common vision, linked to the sustainable development of family-farming; ii) the creation and expansion of a network of stakeholders, comprising researchers, farmers, extensionists, and other relevant actors; iii) the development of learning processes through interaction, accumulating knowledge around two main axes: a new way of promoting innovation through research in application contexts associated with co-innovation, and a new way of sustainable livestock farming associated with ecological intensification. This study reveals the importance of sequencing co-innovation projects and continuity in the negotiation of visions of change, the creation of a community committed with the direction of change, and the promotion of interdisciplinarity and interactive learning, that foster changes at a socio-technical level. Anchoring challenges, and therefore advancement of the transition process, face the need for significantly expanding trained research and extension personnel to implement co-innovation and ecological intensification practices in livestock systems, and the organization of an extension program to sustain long term transformation of livestock farming in Uruguay. © 2022 Elsevier Ltd. All rights reserved.

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ABSTRACT.- Background: Eucalyptus globulus Labill. is a species of great interest to the pulp industry. However, it has a low rooting capacity, which makes it difficult to clone on a commercial scale. In micropropagation, the supply of cytokinins is necessary to stimulate proliferation, but the type and concentration of cytokinins can negatively affect adventitious rooting. This study evaluated the effect of metatopoline (mT) and benzyladenine (BA) on in vitro multiplication, elongation, and rooting of E. globulus clones. In the multiplication medium, concentrations of 0.44 and 0.88 µmol BA, 0.41 and 0.83 µmol mT, and a control medium without cytokinins were supplied. Results: During the multiplication phase, mT increased the proliferation rate. In addition, mT presented lower production of small explants, less than 0.5 cm in height. In the rooting phase, easy rooting clones treated with 0.41 µmol of mT reached rooting percentages of 91%, while with the use of BA it was 50%. However, in clones with difficult rooting, no differences were observed in relation to the type of cytokinin. Explants treated with mT developed longer roots than those originated with BA, which presented roots similar to those of the control treatment (T). Conclusion: With the use of mT in the multiplication medium, the in vitro elongation, proliferation and rooting of E. globulus was improved, therefore improving the quality of the in vitro explants for the acclimatization stage. © 2024, Federal University of Lavras. All rights reserved.

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ABSTRACT.- The intensification of droughts due to climate change is a global concern, and many plant species face increasing water deficits. Understanding the role of phenotypic plasticity in plant adaptation to these changing conditions is crucial. This research focuses on Bromopsis erecta, a dominant perennial grass in European and Mediterranean grasslands, to predict its potential adaptation to climate change. We assessed plants from shallow and deep soils (i.e., with contrasting water reserves) of a Mediterranean rangeland in southern France, and tested the effect of six years of experimentally increased summer drought compared to the ambient conditions on plant traits, survival and abundance. In both field and common garden experiments, we measured water-related traits, including static traits under non-limiting water conditions, and dynamic traits, such as rates of trait variation during drought. Trait plasticity was determined as a reaction norm to increasing soil water stress and was tested against changes in B. erecta abundance over the past decade, including the study period. Trait plasticity was detected only for leaf dry matter content (LDMC), revealing that the resource strategy of B. erecta became more conservative over less than a decade with higher LDMC and leaf thickness according to the plant economic spectrum. No plasticity was found for osmotic potential or specific leaf area. The variability of other traits was ascribed to the possible lagging effect of previous water stress and was associated more with soil depth than with previous summer drought intensity. The abundance decline of B. erecta, which dropped from 20 % to around 5 % in shallow soils, was not associated with the plasticity of LDMC but was positively correlated with variations in leaf base membrane damage, meaning unexpectedly, that plants exposed to the most severe summer drought also had the most sensitive leaf base membranes, a possible sign of maladaptive trait plasticity in the population. This key trait response reveals boundaries to the adaptive capacity of this perennial grass to survive pluri-annual drought. © 2024 The Authors

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ABSTRACT.- In a previous study, we reported the in vitro potential probiotic and gamma-aminobutyric acid (GABA) production, of several strains from a collection of Lactiplantibacillus (Lpb) strains within the community of natural whey starters from the artisanal cheese industry. GABA is a non-protein amino acid widely distributed in nature and produced in animals, plants, and microorganisms. However, the best known role of GABA is its function as the major inhibitory neurotransmitter of the central nervous system. Preclinical and clinical evidence suggests that the GABAergic system has a relevant role in mental health disorders, such as anxiety and major depression. The modulation of the GABAergic system has been suggested as a potential strategy for treatment, one such mechanism of modulation is the influence of the microbiota-gut-brain axis through probiotic treatments. The present study was designed to investigate the in vivo probiotic potential of LPB145, a Lactiplantibacillus strain previously characterised as a GABA-producing potentially probiotic strain. Therefore, we evaluated the behavioural effects of chronic oral administration of LPB145 on rats' anxiety- and depression-like behaviours, using the elevated plus maze, open field, and the forced swimming test. The impact of LPB145 strain treatment on the gut microbiota structure and diversity was assessed to discern a possible mechanism of action of the LPB145 treatment through the microbiota-gut-brain axis. Our results showed that LPB145 administration induced an antidepressive-like behaviour without changes in locomotor activity. In contrast, the treatment did not modify the experimental anxiety. The structure and diversity of the intestinal microbiota remained unaffected by the treatment when compared to the control. However, specific clades that could be implicated in the behavioural changes did show differences in their relative abundance. These findings provide evidence regarding the potential of probiotic strains isolated from alimentary sources, to modulate the microbiota-gut-brain axis and positively impact mental health. © J. LOZANO et al., 2024.

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ABSTRACT.- The present article describes the development of an improved Pinus taeda clonal seed orchard adapted to the edaphoclimatic conditions of Uruguay. Initially, 2068 hectares distributed in nine companies were prospected, and 124 plus trees were identified based on growth, straightness, and health traits. These trees were clonally propagated via grafting to establish a clonal seed orchard. For the genetic evaluation of the orchard, two progeny tests were carried out in the Rivera and Paysandú municipalities. Quantitative genetic analyses allowed us to identify a simple genotype-environment interaction and an expected genetic gain for volumes of 17%, 13%, and 8% for selection intensities of 12%, 25%, and 50%, respectively. Moreover, the genetic diversity of the 124 clones of the orchard was assessed using 10 microsatellite markers. The fingerprinting profiles allowed us to identify a total of 224 alleles. The polymorphism information content of the different markers was in the range of 0.594 to 0.895. The combined probability of identity and probability of identity among siblings had a discrimination power of 8.26 × 10-14 and 5.91 × 10-5, respectively. Analysis of the genetic structure demonstrated that the seed orchard population was not structured by the supplier. Copyright: © 2024 by the authors.

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ABSTRACT. - Wheat yellow (stripe) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat worldwide. Pst populations are composed of multiple genetic groups, each carrying one or more races characterized by different avirulence/virulence combinations. Since the severe epidemics in 2017, yellow rust has become the most economically important wheat foliar disease in Uruguay. A set of 124 Pst isolates collected from wheat fields in Uruguay between 2017 and 2021 were characterized phenotypically, and 27 of those isolates were subsequently investigated in-depth by additional molecular genotyping and race phenotyping analyses. Three genetic groups were identified, PstS7, PstS10, and PstS13, with the latter being the most prevalent. Two races previously reported in Europe, Warrior (PstS7) and Benchmark (PstS10), were detected in four and two isolates, respectively. A third race, known as Triticale2015 (PstS13), that was first detected in Europe in 2015 and in Argentina in 2017 was detected at several locations. Additional virulence to Yr3, Yr17, Yr25, Yr27, or Yr32 was detected in three new race variants within PstS13. The identification of these new races, which have not been reported outside South America, provides strong evidence of the local evolution of virulence in Pst during the recent epidemic years. © 2024 The American Phytopathological Society

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ABSTRACT.- The microbiota composition of the bovine female reproductive tract influences reproductive efficiency, susceptibility to genital pathogens, and the health of newborn calves. However, knowledge about cervico-vaginal microbiota during gestation is scarce. Therefore, the present study aimed to analyze the taxonomic profile of the cervico-vaginal bovine microbiota throughout pregnancy and after calving using high-throughput sequencing of a fragment of the 16S ribosomal RNA gene. Healthy nulliparous Holstein heifers (n = 13) with similar age and body conditional score were selected to collect samples from the cervico-vaginal area with a sterile swab at 5 timepoints. We sequenced the V1-V2 region of the 16S ribosomal RNA gene and analyzed data using the DADA2, phyloseq and vegan R Studio packages. No differences were observed in alpha and beta diversity across sampling points, accounting for the stability of the microbiota throughout pregnancy. The most abundant phyla are Firmicutes, Bacteroidota, Proteobacteria and Actinobacteria, and are present as the main taxa in all five sampling points. Also, several of the least abundant taxa can be observed to change with time. Our comprehensive study of the cervico-vaginal bacterial microbiota during the gestation period contributes to the knowledge of microbiota dynamics on the bovine reproductive tract during and after pregnancy and can serve as a baseline for future research and the development of potential therapeutic interventions. © 2024 The Authors. Published by Elsevier B.V.

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ABSTRACT. - Olive anthracnose caused by Colletotrichum spp. is the most important olive fruit disease worldwide. We hypothesize that induced water deficit in olive trees generates anatomical and biochemical changes which contribute to anthracnose fruit rot resistance. A three-year experiment was conducted in Arbequina under two irrigation treatments: fully irrigated (no water stress) and non-irrigated (moderate water stress), from pit hardening until harvest. At harvest, fruits were inoculated both in planta and in vitro with an isolate of C. acutatum s.l. Our results showed that fruits grown under moderate water stress had significantly lower disease incidence and severity compared to those grown without water stress. Additionally, moderate water stress increased the activity of the enzymes related to hydrogen peroxide scavenging (Catalase and Peroxidase) and enhanced cuticle fruit thickness. Together, these factors contributed to a greater resistance to C. acutatum s.l. infection, both in vitro and in planta, reflected by different area under the disease progress curve (averaging 45% and 30% lower incidence and severity, respectively). These findings could explain differences in disease expression observed in olive orchards across seasons and managements practices. © Koninklijke Nederlandse Planteziektenkundige Vereniging 2024.

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ABSTRACT. - Studies of oriental fruit moth (OFM), Grapholita molesta (Busck), and codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae), both important pests of pome fruit, evaluated the addition of low-intensity light-emitting diode (LED) to delta traps baited with 3 commercial monitoring lures. Studies were conducted in 9 orchards treated with and without sex pheromone mating disruption for one or both species. OFM was monitored with a two-part pheromone/kairomone lure (OFM Combo Dual), while CM was monitored with either a two-part kairomone lure (CM Dual 4 K) or a sex pheromone lure (CM PH). Both pests were monitored with or without the addition of three types of a low power LED light with peak intensity at 395 (UV-A), 458 (blue), and 516 (green) nm. The UV-A LED was found to be the most effective among the three lights for OFM. Unexpectedly, traps with the OFM Combo Dual lure plus UV-A LED caught similar numbers of CM as traps baited with the CM Dual 4 K and CM PH lures alone. They also caught other pest species, such as oblique banded leafroller (OBLR), Choristoneura rosaceana (Harris), and peach twig borer (PTB), Anarsia lineatella (Zeller). Interestingly, in different trials the OFM Combo Dual combined with UV-A LED light caught significantly more OFM and/or CM females compared to the OFM Combo Dual lure without light, opening the perspective for a female-oriented monitoring and for a "female removal" management approach of these pests. The development of inexpensive, dual-modality traps adding a light stimulus to a pheromone/kairomone lure may reduce monitoring costs in orchards with multiple moth pests, improving the trapping efficiency. © 2024 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.

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ABSTRACT.- This study evaluates nutritional and management strategies aimed at exploiting compensatory growth (CG) in weanling-to-beef systems in Uruguay. The evaluation encompassed productivity, economic viability, and environmental impact. The Grange Beef System Model, augmented with Uruguayan national technical coefficients, was used. Four weanling-to-beef systems were modeled: 1) forage only with no CG (FNC), 2) forage only with management improvements to exploit CG (forage with CG; FWC), 3) forage with concentrate supplementation during two winter feeding periods (forage with supplementation; FWS), and 4) forage with supplementation during the first winter followed by feedlot finishing (forage with feedlot; FWF). The systems purchased spring-born Angus calves at 8 months of age and 180 kg live weight (LW) and finished with a slaughter weight of 550 kg. FWS system was used as reference with the performance parameters obtained during 5 years of systems experimentation. FNC used the performance parameters of FWS but during winter periods, LW gain was lower due to the absence of concentrate supplementation. FWC used the previous FNC performance parameters, but increased LW gain after the first and second winter restriction period due to improved grazing management practices thereby exploiting CG. FWF is based on the FWS system but instead of moderate supplementation during the second winter (concentrate: 3.0 kg/d/head), steers are feedlot finished (concentrate: 9.5 kg/d/head) exploiting CG due to previous summer-autumn restriction period. FNC and FWC increased age at slaughter, reducing net beef production by 21 and 11 % relative to FWS, respectively. In contrast, FWF reduced age at slaughter, increasing beef production by 93 % compared to FWS. FWS and FNC had similar profitability expressed in net margin; however, FWC and FWF increased net margin by 33 and 107 % compared to the FWS, respectively. FNC and FWC increased greenhouse gas (GHG) emissions intensity per beef produced by 17 and 3 % relative to FWS, respectively; meanwhile, FWF reduced GHG intensity by 10 % relative to FWS. Due to the inclusion of concentrates in the diet for FWS and FWF systems, the only net producers of human edible energy and protein were the forage-only systems (FNC and FWC). In summary, strategically harnessing CG in both pasture and feedlot finishing stages within a weanling-to-beef system in Uruguay successfully increased profitability. Feedlot finishing reduced GHG emissions per beef produced. However, the forage-only farm systems emerged as the only net producers of human-edible energy and protein. © 2024 The Author(s)

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ABSTRACT.- Stockpiling forage (i.e., deferring grazing) is one way to provide forage for livestock during intervals of low pasture growth, but there are trade-offs as nutrient content declines with increasing forage maturity. Phosphorous (P) concentration, crude protein (CP) content and organic matter digestibility (OMD) were evaluated in two C3 and four C4 grasses native to the South American Campos grasslands. These were: Bromus auleticus (BROAUL) and Nasella neessiana (NASNEE) as C3 grasses and Andropogon lateralis (ANDLAT), Mnesithea selloana (MNESEL), Paspalum dilatatum (PASDIL), and Paspalum notatum (PASNOT) as C4 grasses. The grasses were grown in pots during five stockpiling periods (450, 900, 1350, 1800 and 2250 degree days, approximately 20, 40, 60, 80 and 100 days). As the forage deferment increased, the nutritional value decreased more in C4 than in C3 grasses. Short rest periods (approximately 40 days) are recommended for PASDIL and MNESEL, and medium rest periods (approximately 80 days) for ANDLAT and PASNOT. However, the C3 grasses BROAU and NASNEE maintained high P and CP concentrations and may be the most appropriate option for long rest periods (>=;100 days). This information is important to manage different Campos grassland communities for the optimal rest period according to the dominant species. © 2024 by the authors.

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ABSTRACT.- We estimate the implicit market price of soil erosion using quarterly data of 2824 agricultural farms traded in Uruguay between 2000 and 2014.Aunique feature of our estimation is that we allow for possible spatial spillovers. We find evidence of a negative and statistically significant association between erosion and land values. On average, an additional loss of 1% of the original topsoil due to erosion is associated with a direct (own) decrease of .24% in the per-hectare price of agricultural land (P-value: .012, 95% CI: -.0042, -.0005). In 2023 dollars, this is equivalent to a decrease of USD 8.7 in the average price per hectare, or USD 1130 in the price of the average farm. In terms of tons of soil, the average value is $.24 a ton. Finally, considering the 50 km radius of our spatial model, the value of losing 1% of topsoil is $15.8 million. The value of our estimates is sensitive to our measure of erosion and our specification of the spatial-temporal weighting matrix, but the statistical association is robust. © 2024 International Association of Agricultural Economists.

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ABSTRACT. - The demand for animal protein is rising, increasing pressure on animal production systems and ecological resources. Ethical and environmental concerns are also growing worldwide, pushing for more sustainable food production systems. The international scientific community has raised concerns about misinformation regarding meat production processes and their harmful impact on the environment, animal welfare and human health consumption. It is crucial to provide accurate information based on science, implement an active communication strategy, and foster collaboration across the meat supply chain to demonstrate that livestock farming is part of the solution to climate change and sustainability issues. As a fundamental pillar of sustainability, animal welfare plays a crucial role in this scrutiny. © 2024 Elsevier Ltd.

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ABSTRACT.- Microinjection of CRISPR/Cas9 requires the availability of zygotes that implies animal breeding, superovulation schemes, and embryo collection. Vitrification of zygotes may allow having ready-to-use embryos and to temporally dissociate the workload of embryo production from microinjection. In this study, fresh (F group) or vitrified (V group) zygotes were microinjected with CRISPR/Cas9 system to test the hypothesis that vitrified zygotes could be a suitable source of embryos for microinjection. @ Schlapp et al.

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ABSTRACT. - Context: Most deaths of lambs in the first days of life are due to failure to adapt to extrauterine life. Aims: This study aimed to test the hypothesis that adding magnesium sulfate (MgSO4) to the diet of twin-bearing ewes in the last week of gestation improves the adaptation to the extrauterine life of the lambs. © 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing.

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ABSTRACT.- Microinjection of CRISPR/Cas9 requires the availability of zygotes that implies animal breeding, superovulation schemes, and embryo collection. Vitrification of zygotes may allow having ready-to-use embryos and to temporally dissociate the workload of embryo production from microinjection. In this study, fresh (F group) or vitrified (V group) zygotes were microinjected with CRISPR/Cas9 system to test the hypothesis that vitrified zygotes could be a suitable source of embryos for microinjection. @ Schlapp et al.

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ABSTRACT.- The objective of this study was to identify genomic regions and genes associated with resistance to gastrointestinal nematodes in Australian Merino sheep in Uruguay, using the single-step GWAS methodology (ssGWAS), which is based on genomic estimated breeding values (GEBVs) obtained from a combination of pedigree, genomic, and phenotypic data. This methodology converts GEBVs into SNP effects. The analysis included 26,638 animals with fecal egg count (FEC) records obtained in two independent parasitic cycles (FEC1 and FEC2) and 1700 50K SNP genotypes. © 2024 by the authors.

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ABSTRACT.- Mediterranean ecosystems are predicted to undergo longer and more intense summer droughts. The mechanisms underlying the response of herbaceous communities to such drier environments should be investigated to identify the resilience thresholds of Mediterranean rangelands. A 5-year experiment was conducted in deep and shallow soil rangelands of southern France. A rainout shelter for 75 days in summer imposed drier and warmer conditions. Total soil water content was measured monthly to model available daily soil water. Aboveground net primary production (ANPP), forage quality, and the proportion of graminoids in ANPP were measured in spring and autumn. Plant senescence and plant cover were assessed in summer and spring, respectively. The experimental years were among the driest ever recorded at the site. Therefore, manipulated summer droughts were drier than long-term ambient conditions. Interactions between treatment, community type, and experimental year were found for most variables. In shallow soil communities, spring plant cover decreased markedly with time. This legacy effect, driven by summer plant mortality and the loss of perennial graminoids, led to an abrupt loss of resilience when the extreme water stress index exceeded 37 mm 10 day-1, characterized by a reduction of spring plant cover below 50% and a decreased ANPP in rainy years. Conversely, the ANPP of deep soil communities remained unaffected by increased summer drought, although the presence of graminoids increased and forage nutritive value decreased. This study highlights the role of the soil water reserve of Mediterranean plant communities in modulating ecosystem responses to chronically intensified summer drought. Communities on deep soils were resilient, but communities on shallow soils showed a progressive, rapid, and intense degradation associated with a loss of resilience capacity. Notably, indexes of extreme stress were a better indicator of tipping points than indexes of integrated annual stress. Considering the role of soil water availability in other herbaceous ecosystems should improve the ability to predict the resilience of plant communities under climate change. © 2024 The Author(s). Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.