Comparative Insights into Photosynthetic, Biochemical, and Ultrastructural Mechanisms in Hibiscus and Pelargonium Plants.

Understanding photosynthetic mechanisms in different plant species is crucial for advancing agricultural productivity and ecological restoration. This study presents a detailed physiological and ultrastructural comparison of photosynthetic mechanisms between Hibiscus (Hibiscus rosa-sinensis L.) and Pelargonium (Pelargonium zonale (L.) L'Hér. Ex Aiton) plants. The data collection encompassed daily photosynthetic profiles, responses to light and CO2, leaf optical properties, fluorescence data (OJIP transients), biochemical analyses, and anatomical observations. The findings reveal distinct morphological, optical, and biochemical adaptations between the two species. These adaptations were associated with differences in photochemical (AMAX, E, Ci, iWUE, and α) and carboxylative parameters (VCMAX, ΓCO2, gs, gm, Cc, and AJMAX), along with variations in fluorescence and concentrations of chlorophylls and carotenoids. Such factors modulate the efficiency of photosynthesis. Energy dissipation mechanisms, including thermal and fluorescence pathways (ΦPSII, ETR, NPQ), and JIP test-derived metrics highlighted differences in electron transport, particularly between PSII and PSI. At the ultrastructural level, Hibiscus exhibited optimised cellular and chloroplast architecture, characterised by increased chloroplast density and robust grana structures. In contrast, Pelargonium displayed suboptimal photosynthetic parameters, possibly due to reduced thylakoid counts and a higher proportion of mitochondria. In conclusion, while Hibiscus appears primed for efficient photosynthesis and energy storage, Pelargonium may prioritise alternative cellular functions, engaging in a metabolic trade-off.

Genetic diversity, relationships among traits and selection of tropical maize inbred lines for low-P tolerance based on root and shoot traits at seedling stage.

The tropical maize breeding for low-P tolerance and good performance under low-P stress environments can be achieved through selection based on root morphology traits at seedling stage. Here, we assessed the genotypic variation and genetic diversity of a panel of 151 tropical maize inbred lines for root and shoot seedling traits, investigated the relationship among traits and selected a set of promising inbred lines for low-P tolerance and performance. We evaluated the inbred lines at seedling stage in a greenhouse experiment under two conditions: applied P (AP) and non-applied P (NAP). A mixed model approach was used to estimate variance components and predict the genotypic values of each inbred line. The genetic diversity among inbred lines based on root and shoot traits was assessed, and correlations were estimated between tested traits under AP and NAP. Our panel of inbred lines showed huge genetic variability for all traits and presented large genetic diversity under both P conditions. Variance components due to the inbred line × P condition interaction were also highly significant (P < 0.01) for all traits. Root dry weight (RDW) was positively associated with stalk dimeter (SD), shoot dry weight (SDW) and root length, volume, and area under both P conditions. Also, the SD and SDW were associated with most root traits under AP. Based on low-P tolerance and performance indices, we selected a set of top 20 inbred lines to be used in our maize breeding program. We therefore concluded that there is a significant genetic diversity in the tropical maize inbred lines which have the genetic potential to be use in association mapping studies and also to develop improved low-P tolerant and P-efficient hybrids and maize breeding populations for low-P stress environments.

Genome-wide association study of cassava brown streak disease resistance in cassava germplasm conserved in South America.

Cassava (Manihot esculenta Crantz) is a vital carbohydrate source for over 800 million people globally, yet its production in East Africa is severely affected by cassava brown streak disease (CBSD). Genebanks, through ex-situ conservation, play a pivotal role in preserving crop diversity, providing crucial resources for breeding resilient and disease-resistant crops. This study genotyped 234 South American cassava accessions conserved at the CIAT genebank, previously phenotyped for CBSD resistance by an independent group, to perform a genome-wide association analysis (GWAS) to identify genetic variants associated with CBSD resistance. Our GWAS identified 35 single nucleotide polymorphism (SNP) markers distributed across various chromosomes, associated with disease severity or the presence/absence of viral infection. Markers were annotated within or near genes previously identified with functions related to pathogen recognition and immune response activation. Using the SNP candidates, we screened the world's largest cassava collection for accessions with a higher frequency of favorable genotypes, proposing 35 accessions with potential resistance to CBSD. Our results provide insights into the genetics of CBSD resistance and highlight the importance of genetic resources to equip breeders with the raw materials needed to develop new crop varieties resistant to pests and diseases.

Influence of different environmental challenges on the expression of reproductive traits in Holstein cattle in Southern Brazil.

The aim of this study was to assess the impact of genotype-environment interaction (GEI) on the manifestation of traits such as age at first calving (AFC), age at first service (AFS), and calving interval (CI) through the application of the reaction norm model in Holstein cattle raised in Paraná state, Brazil. Utilizing data from the milk testing service of the Paraná Association of Holstein Cattle Breeders (APCBRH), this study analyzed records from 179,492 animals undergoing their first, second, and third lactations from the years 2012 to 2022. These animals were part of 513 herds spread across 72 municipalities in Paraná. The environmental gradient was established by normalizing contemporary group solutions, derived from the animal model, with the 305-day-corrected milk yield serving as the dependent variable. Subsequently, reaction norms were determined utilizing a Random Regression Model. Spearman's correlation was then applied to compare the estimates of breeding values across different environmental gradients for the studied traits. The highest EG (+ 4) indicates the least challenging environments, where animals experience better environmental conditions. Conversely, lower EG (-4) values represent the most challenging environments, where animals endure worse conditions. The only trait that exhibited a moderate heritability magnitude was AFC (0.23) in the least challenging environmental condition. The other traits were classified as having low heritability magnitudes regardless of the evaluated environmental gradient. While minimal evidence was found for the influence of GEI on CI, a clear GEI effect was observed for AFC and AFS across all environmental gradients examined. A reversal in genotype ranking occurred under extreme environmental conditions. The findings suggest that the best-performing genotype under one environmental gradient may not necessarily excel under another.

Genetic resources of African mahogany in Brazil: genomic diversity and structure of forest plantations.

BACKGROUND: African mahogany species (Khaya sp.) have been introduced to Brazil gaining increasing economic interest over the last years, as they produce high quality wood for industrial applications. To this date, however, the knowledge available on the genetic basis of African mahogany plantations in Brazil is limited, which has driven this study to examine the extent of genetic diversity and structure of three cultivated species (Khaya grandifoliola, Khaya senegalensis and Khaya ivorensis) and their prospects for forest breeding. RESULTS: In total, 115 individuals were genotyped (48 of K. grandifoliola, 34 of K. senegalensis and 33 of K. ivorensis) for 3,330 filtered neutral loci obtained from genotyping-by-sequencing for the three species. The number of SNPs varied from 2,951 in K. ivorensis to 4,754 in K. senegalensis. Multiloci clustering, principal component analysis, Bayesian structure and network analyses showed a clear genetic separation among the three species. Structure analysis also showed internal structure within each species, highlighting genetic subgroups that could be sampled for selecting distinct genotypes for further breeding, although the genetic distances are moderate to low. CONCLUSION: In our study, SNP markers efficiently assessed the genomic diversity of African mahogany forest plantations in Brazil. Our genetic data clearly separated the three Khaya species. Moreover, pairwise estimates of genetic distances among individuals within each species showed considerable genetic divergence among individuals. By genotyping 115 pre-selected individuals with desirable growth traits, allowed us not only to recommend superior genotypes but also to identify genetically distinct individuals for use in breeding crosses.

The annual ovarian cycle in Northern pit vipers (Bothrops atrox) using serum steroids and ultrasound of the female reproductive tract.

Knowledge on hormonal regulation of reproductive cycles in viperid snakes is still incipient, especially when it comes to females and tropical species. There is an urgent need to understand the reproduction of venomous snakes to improve assisted reproduction techniques and optimize the maintenance of these animals in captivity. With this in mind, we monitored Northern pit viper females year-round throughout different seasons via serum levels of progesterone (P4) and estradiol (E2) in conjunction with ultrasound examinations. Ovarian follicles were classified according to their size and stage of vitellogenesis in F-I and F-II (non-vitellogenic phase) or in F-III and F-IV (vitellogenic phase). During autumn and winter, five adult males were rotated among these females for reproductive pairing, which resulted in 17 copulations and 2 pregnancies in the first year and 12 copulations and 5 pregnancies in the second year. Then, we assessed changes in P4 and E2 levels according to seasons, predominant ovarian structures and the presence of embryos or eggs in the oviduct. Our findings showed high levels of E2 when a greater number of vitellogenic follicles were detected, indicating a possible influence of E2 on vitellogenesis and higher levels of P4 whenever eggs and embryos were visualized in the oviduct, implying its role in maintaining pregnancy. Descriptive analysis of the vipers' ovarian cycles revealed a greater number of vitellogenic follicles during winter, probably as a result of increases in E2; whereas pregnancies occurred predominantly in spring, under the influence of P4. The use of ultrasound images, as a minimally invasive methodology, associated with serum steroid levels has proven to be an efficient approach in the reproductive monitoring of Northern pit vipers in vivo. In addition, these data suggest that female pit vipers under human care display a seasonal reproductive cycle, despite earlier studies involving captive males of the species indicating a lack of seasonality in sperm production and quality.

Enhancing genomic prediction with Stacking Ensemble Learning in Arabica Coffee.

Coffee Breeding programs have traditionally relied on observing plant characteristics over years, a slow and costly process. Genomic selection (GS) offers a DNA-based alternative for faster selection of superior cultivars. Stacking Ensemble Learning (SEL) combines multiple models for potentially even more accurate selection. This study explores SEL potential in coffee breeding, aiming to improve prediction accuracy for important traits [yield (YL), total number of the fruits (NF), leaf miner infestation (LM), and cercosporiosis incidence (Cer)] in Coffea Arabica. We analyzed data from 195 individuals genotyped for 21,211 single-nucleotide polymorphism (SNP) markers. To comprehensively assess model performance, we employed a cross-validation (CV) scheme. Genomic Best Linear Unbiased Prediction (GBLUP), multivariate adaptive regression splines (MARS), Quantile Random Forest (QRF), and Random Forest (RF) served as base learners. For the meta-learner within the SEL framework, various options were explored, including Ridge Regression, RF, GBLUP, and Single Average. The SEL method was able to predict the predictive ability (PA) of important traits in Coffea Arabica. SEL presented higher PA compared with those obtained for all base learner methods. The gains in PA in relation to GBLUP were 87.44% (the ratio between the PA obtained from best Stacking model and the GBLUP), 37.83%, 199.82%, and 14.59% for YL, NF, LM and Cer, respectively. Overall, SEL presents a promising approach for GS. By combining predictions from multiple models, SEL can potentially enhance the PA of GS for complex traits.

Development and characterisation of novel durum wheat-H. chilense 4Hch chromosome lines as a source for resistance to Septoria tritici blotch.

The use of wild species as a source of genetic variability is a valued tool in the framework of crop breeding. Hordeum chilense Roem. et Schult is a wild barley species that can be a useful genetic donor for sustainable wheat breeding which carries genes conferring resistance to some diseases or increasing grain quality, among others. Septoria tritici blotch (STB), caused by the Zymoseptoria tritici fungus, is one of the most important wheat diseases worldwide, affecting both bread and durum wheat and having a high economic impact. Resistance to STB has been previously described in H. chilense chromosome 4Hch. In this study, we have developed introgression lines for H. chilense chromosome 4Hch in durum wheat using interspecific crosses, advanced backcrosses, and consecutive selfing strategies. Alien H. chilense chromosome segments have been reduced in size by genetic crosses between H. chilense disomic substitution lines in durum wheat and durum wheat lines carrying the Ph1 deletion. Hordeum chilense genetic introgressions were identified in the wheat background through several plant generations by fluorescence in situ hybridisation (FISH) and simple sequence repeat (SSR) markers. An STB infection analysis has also been developed to assess STB resistance to a specific H. chilense chromosome region. The development of these H. chilense introgression lines with moderate to high resistance to STB represents an important advance in the framework of durum breeding and can be a valuable tool for plant breeders.

Factor analytic selection tools and environmental feature-integration enable holistic decision-making in Eucalyptus breeding.

Understanding the genotype-by-environment interaction (GEI) and considering it in the selection process is a sine qua non condition for the expansion of Brazilian eucalyptus silviculture. This study's objective is to select high-performance and stable eucalyptus clones based on a novel selection index that considers the Factor Analytic Selection Tools (FAST) and the clone's reliability. The investigation explores the nuances interplay of GEI and extends its insights by scrutinizing the relationship between latent factors and real environmental features. The analysis, conducted across seven trials in five Brazilian states involving 78 clones, employs FAST. The clonal selection was performed using an extended FAST index weighted by the clone's reliability. Further insights about GEI emerge from the integration of factor loadings with 25 environmental features through a principal component analysis. Ten clones, distinguished by high performance, stability, and reliability, have been selected across the target population of environments. The environmental features most closely associated with factor loadings, encompassing air temperature, radiation, and soil characteristics, emerge as pivotal drivers of GEI within this dataset. This study contributes insights to eucalyptus breeders, equipping them to enhance decision-making by harnessing a holistic understanding-from the genotypes under evaluation to the diverse environments anticipated in commercial plantations.

Phenotypic diversity and population structure of Pecan (Carya illinoinensis) collections reveals geographic patterns.

Pecan (Carya illinoinensis) is an economically important nut crop known for its genetic diversity and adaptability to various climates. Understanding the growth variability, phenological traits, and population structure of pecan populations is crucial for breeding programs and conservation. In this study, plant growth and phenological traits were evaluated over three consecutive seasons (2015-2017) for 550 genotypes from 26 provenances. Significant variations in plant height, stem diameter, and budbreak were observed among provenances, with Southern provenances exhibiting faster growth and earlier budbreak compared to Northern provenances. Population structure analysis using SNP markers revealed eight distinct subpopulations, reflecting genetic differentiation among provenances. Notably, Southern Mexico collections formed two separate clusters, while Western collections, such as 'Allen 3', 'Allen 4', and 'Riverside', were distinguished from others. 'Burkett' and 'Apache' were grouped together due to their shared maternal parentage. Principal component analysis and phylogenetic tree analysis further supported subpopulation differentiation. Genetic differentiation among the 26 populations was evident, with six clusters highly in agreement with the subpopulations identified by STRUCTURE and fastSTRUCTURE. Principal components analysis (PCA) revealed distinct groups, corresponding to subpopulations identified by genetic analysis. Discriminant analysis of PCA (DAPC) based on provenance origin further supported the genetic structure, with clear separation of provenances into distinct clusters. These findings provide valuable insights into the genetic diversity and growth patterns of pecan populations. Understanding the genetic basis of phenological traits and population structure is essential for selecting superior cultivars adapted to diverse environments. The identified subpopulations can guide breeding efforts to develop resilient rootstocks and contribute to the sustainable management of pecan genetic resources. Overall, this study enhances our understanding of pecan genetic diversity and informs conservation and breeding strategies for the long-term viability of pecan cultivation.

Wine metabolome and sensory analyses demonstrate the oenological potential of novel grapevine genotypes for sustainable viticulture in warm climates.

BACKGROUND: Genetic breeding is essential to develop grapevine genotypes adapted to warm climates and resistant to pathogens. Traditionally cultivated Vitis vinifera is susceptible to biotic and abiotic stresses. Winemakers and consumers, however, perceive wines from non-vinifera or hybrid cultivars as inferior. In this study, sensory analyses and comprehensive metabolite profiling by targeted and untargeted approaches were used to investigate the oenological potential of wines from grapes of genotypes developed throughout four breeding cycles to improve climate adaptation, sugar contents and berry color. RESULTS: Novel genotypes had higher yields and the wines exhibited increased contents of polyphenols, including anthocyanins. Volatile monoterpenes in the wines decreased throughout breeding cycles in the absence of selective pressure. Polyphenol contents were higher in intermediate wines, with hydroxytyrosol contents reaching up to three times reported values. Mouthfeel attributes astringency, leafy taste, flavor and body, and persistency showed significant correlation with untargeted features. Supervised model-based analyses of the metabolome effectively discriminate wines from distinct genetic origins. CONCLUSION: Taken together, the results demonstrate the potential of novel grapevine genotypes to a more sustainable viticulture and quality wine production in warm climates. Comprehensive metabolite profiling of the wines reveals that genotype clustering is dependent on the chemical class and that traits not submitted to selective pressure are also altered by breeding. Supervised multivariate models were effective to predict the genetic origin of the wines based on the metabolic profile, indicating the potential of the technique to identify biomarkers for wines from sustainable genotypes. © 2024 Society of Chemical Industry.

Recent advancements to increase success in assisted reproductive technologies in cattle.

Assisted reproductive technologies (ART) are fundamental for cattle breeding and sustainable food production. Together with genomic selection, these technologies contribute to reducing the generation interval and accelerating genetic progress. In this paper, we discuss advancements in technologies used in the fertility evaluation of breeding animals, and the collection, processing, and preservation of the gametes. It is of utmost importance for the breeding industry to select dams and sires of the next generation as young as possible, as is the efficient and timely collection of gametes. There is a need for reliable and easily applicable methods to evaluate sexual maturity and fertility. Although gametes processing and preservation have been improved in recent decades, challenges are still encountered. The targeted use of sexed semen and beef semen has obliterated the production of surplus replacement heifers and bull calves from dairy breeds, markedly improving animal welfare and ethical considerations in production practices. Parallel with new technologies, many well-established technologies remain relevant, although with evolving applications. In vitro production (IVP) has become the predominant method of embryo production. Although fundamental improvements in IVP procedures have been established, the quality of IVP embryos remains inferior to their in vivo counterparts. Improvements to facilitate oocyte maturation and development of new culture systems, e.g. microfluidics, are presented in this paper. New non-invasive and objective tools are needed to select embryos for transfer. Cryopreservation of semen and embryos plays a pivotal role in the distribution of genetics, and we discuss the challenges and opportunities in this field. Finally, machine learning (ML) is gaining ground in agriculture and ART. This paper delves into the utilization of emerging technologies in ART, along with the current status, key challenges, and future prospects of ML in both research and practical applications within ART.

First report of thyroid goiter in the marine ornamental fish Gramma brasiliensis.

Enlargement of the thyroid gland is referred to as goiter. In captive fish, goiter may be associated with iodine deficiency in water or diet, exposure to goitrogenic factors such as a high environmental nitrate concentration or water treatment with ozone. This report describes the occurrence of goiter in a marine ornamental fish raised in a research laboratory, the Brazilian basslet Gramma brasiliensis. From 2016 to 2023, we observed progressively growing tumour-like masses in the pharyngeal cavity and along the gill arches of approximately 20 adult individuals. This abnormal growth impaired the ingestion of food and caused dyspnoea, leading the animals to death within a few months after the first appearance of the mass. The samples were submitted to histological analyses, which revealed moderate to severe, diffuse, hypertrophy and hyperplasia of thyroid follicular cells with most lacking colloids. This is the first report of goiter in the Brazilian basslet. Although it is not clear why this condition develops in this species, we recommend keeping nitrate levels to a minimum and monitoring water iodine concentrations regularly until future studies investigate the possible causes and adequate treatment for this species.

O aumento da glândula tireóide é conhecido como bócio. Em peixes em cativeiro, o bócio pode estar associado à deficiência de iodo na água ou na dieta, à exposição a fatores goitrogênicos, como alta concentração de nitrato ou ao tratamento da água com ozônio. O presente relato descreve a ocorrência de bócio em um peixe ornamental marinho criado em laboratório de pesquisa, o Gramma brasiliensis. De 2016 a 2023, observamos crescimento progressivo de massas semelhantes a tumores na cavidade faríngea e ao longo dos arcos branquiais de aproximadamente 20 indivíduos adultos. Esse crescimento anormal prejudicou a ingestão de alimentos e causou dispneia, levando os animais à morte em poucos meses, desde o início do aparecimento das massas. As amostras foram submetidas à análise histológica, evidenciando hipertrofia e hiperplasia moderada a grave, difusa, de células foliculares tireoidianas, sendo a maioria delas desprovida de colóide. Este é o primeiro relato de bócio em grama brasileiro. Apesar da razão pouco clara para o desenvolvimento desta condição nesta espécie, recomendamos manter os níveis de nitrato ao mínimo e monitorar regularmente as concentrações de iodo na água até que próximos estudos investiguem as possíveis causas e o tratamento adequado para esta espécie.

Stability and genetic parameters for cassava yield attributes in the tropical humid region of Brazil.

The performance differences in cassava genotypes arising from genotype vs. environment interactions (G × E) often lead to responses that are significantly lower than expected for selection. The objective of this study was to evaluate different stability methods, both parametric and non-parametric, such as additive main-effects and multiplicative interaction (AMMI), main effect of genotypes plus G × E (GGE), and weighted average of absolute scores (WAASB), in order to quantify the G × E in multi-environmental trials. A total of 12 genotypes were assessed across 12 environments using a completely randomized block design, with three replicates for traits such as fresh root yield (FRY) and dry matter content in the roots (DMC). The data were subjected to analysis of variance and the Scott Knott test (p < 0.05). The sum of squares (SQ) of genotypes, environment, and G × E effects were equally distributed for FRY, whereas for DMC, these effects accounted for 64.1%, 21.9%, and 13.8% of the SQ, respectively, indicating a lower environmental effect on this characteristic. Using the AMMI, GGE, and WAASB methods, genotypes with high agronomic performance and stability for FRY (BR11-34-41 and BR11-34-69) (> 32 t ha-1) and DMC (BRS Novo Horizonte, BR12-107-002, and BR11-24-156) (> 37%) were identified. The broad-sense heritability ( h 2 ) for FRY and DMC was estimated to be 0.45 and 0.75, respectively. Approximately 72% of the methods identified BRS Novo Horizonte as the genotype with the highest stability and performance for DMC, while 47% identified genotypes BR11-34-41 and BR11-34-69 for FRY and intermediate DMC. Genotype BR11-24-156 exhibited high static stability according to 50% of the methods. Significant correlations were observed between stability and agronomic performance across the different methods, enabling the formation of groups based on stability concepts. Additionally, it was found that two mega-environments existed for FRY, whereas DMC displayed a single mega-environment with similar patterns, indicating an absence of G × E. We identified superior genotypes that could be promoted to national performance trials to develop stable cultivars with better yield attributes in cassava. Supplementary Information: The online version contains supplementary material available at 10.1007/s10681-024-03384-5.

GIS-based G × E modeling of maize hybrids through enviromic markers engineering.

Through enviromics, precision breeding leverages innovative geotechnologies to customize crop varieties to specific environments, potentially improving both crop yield and genetic selection gains. In Brazil's four southernmost states, data from 183 distinct geographic field trials (also accounting for 2017-2021) covered information on 164 genotypes: 79 phenotyped maize hybrid genotypes for grain yield and their 85 nonphenotyped parents. Additionally, 1342 envirotypic covariates from weather, soil, sensor-based, and satellite sources were collected to engineer 10 K synthetic enviromic markers via machine learning. Soil, radiation light, and surface temperature variations remarkably affect differential genotype yield, hinting at ecophysiological adjustments including evapotranspiration and photosynthesis. The enviromic ensemble-based random regression model showcases superior predictive performance and efficiency compared to the baseline and kernel models, matching the best genotypes to specific geographic coordinates. Clustering analysis has identified regions that minimize genotype-environment (G × E) interactions. These findings underscore the potential of enviromics in crafting specific parental combinations to breed new, higher-yielding hybrid crops. The adequate use of envirotypic information can enhance the precision and efficiency of maize breeding by providing important inputs about the environmental factors that affect the average crop performance. Generating enviromic markers associated with grain yield can enable a better selection of hybrids for specific environments.

Outbreak of Chlamydia psittaci Infection in a Commercial Psittacine Breeding Aviary in Argentina.

Chlamydiosis, caused by Chlamydia psittaci is a bacterial infection found in at least 465 species of birds worldwide. It is highly contagious among birds and can spread to humans. In birds, the disease can manifest itself in acute, subacute, and chronic forms with signs including anorexia, diarrhea, lethargy, weight loss, or, occasionally, mucopurulent or serous oculonasal discharge. This article describes an outbreak of chlamydiosis that occurred in a commercial psittacine breeding aviary in 2021 in Buenos Aires province, Argentina. In total, 16 juvenile blue-fronted parrots, more than 60 blue-fronted parrot chicks, and 2 adult macaws died during the outbreak. In all cases, clinical signs were weight loss, diarrhea, yellowish green excrement, and respiratory distress. The necropsy of four juvenile blue-fronted parrots, two blue-fronted parrot chicks, and two adult macaws revealed cachexia, hepatomegaly, splenomegaly, splenic petechial hemorrhages, ascites, pulmonary edema, and hydropericardium. Histologically, multifocal lymphoplasmacytic and heterophilic airsaculitis, multifocal lymphoplasmacytic and necrotizing hepatitis with intracytoplasmic elementary bodies, multifocal necro-heterophilic hepatitis, multifocal lymphoplasmacytic nephritis, and diffuse heterophilic pneumonia were found. A presumptive diagnosis was established based on gross and microscopic lesions, and it was confirmed using immunohistochemistry and polymerase chain reactions. The sequencing and phylogenetic analysis of the ompA gene revealed genotype A and B of Chlamydia psittaci.

Identification of SNP Markers and Candidate Genes Associated with Major Agronomic Traits in Coffea arabica.

Genome-wide association studies (GWASs) allow for inferences about the relationships between genomic variants and phenotypic traits in natural or breeding populations. However, few have used this methodology in Coffea arabica. We aimed to identify chromosomal regions with significant associations between SNP markers and agronomic traits in C. arabica. We used a coffee panel consisting of 195 plants derived from 13 families in F2 generations and backcrosses of crosses between leaf rust-susceptible and -resistant genotypes. The plants were phenotyped for 18 agronomic markers and genotyped for 21,211 SNP markers. A GWAS enabled the identification of 110 SNPs with significant associations (p < 0.05) for several agronomic traits in C. arabica: plant height, plagiotropic branch length, number of vegetative nodes, canopy diameter, fruit size, cercosporiosis incidence, and rust incidence. The effects of each SNP marker associated with the traits were analyzed, such that they can be used for molecular marker-assisted selection. For the first time, a GWAS was used for these important agronomic traits in C. arabica, enabling applications in accelerated coffee breeding through marker-assisted selection and ensuring greater efficiency and time reduction. Furthermore, our findings provide preliminary knowledge to further confirm the genomic loci and potential candidate genes contributing to various structural and disease-related traits of C. arabica.

Impacts of cattle management and agricultural practices on water quality through different approaches: physicochemical and ecotoxicological parameters.

The intensification of livestock farming can pose risks to the environment due to the increased use of veterinary products and the generation of waste in confined areas. The quality of water bodies near livestock establishments (Areco River (A) and Doblado stream (D), San Antonio de Areco, Buenos Aires, Argentina) was studied by physicochemical parameters, metals, pesticides, emerging contaminants, and lethal and sublethal toxicity (neurotoxicity and oxidative stress) in larvae of the native amphibian Rhinella arenarum. Six sites were selected: upstream (S1A and S1D), at the level (S2A and S2D), and downstream (S3A and S3D) from the establishments. A low concentration of dissolved oxygen was observed in Doblado stream (< 2.34 mg/L). Cu, Mn, V, and Zn exceeded the limits for the protection of aquatic life at various sites. Between 24 and 34 pesticides were detected in all sites, with 2,4-D, atrazine, and metolachlor being the most recurrent. In water and sediment, the concentrations of ivermectin (S2A, 1.32 µg/L and 58.18 µg/kg; S2D, 0.8 µg/L and 85.22 µg/kg) and oxytetracycline (S2A, < 1 mg/L and < 1 mg/kg; S2D, 11.8 mg/L and 39 mg/kg) were higher at sites near the establishments. All sites caused between 30 and 38.3% of lethality and produced neurotoxicity and alterations in the reduced glutathione content. Moreover, larvae exposed to samples from all sites incorporated ivermectin. These results demonstrate the degradation of the studied sites in relation to the agricultural activities of the area, highlighting the need to take measures to protect and preserve aquatic ecosystems.

Drought Resilience in Oil Palm Cultivars: A Multidimensional Analysis of Diagnostic Variables.

Water scarcity is a significant constraint on agricultural practices, particularly in Colombia, where numerous palm cultivators rely on rainfed systems for their plantations. Identifying drought-tolerant cultivars becomes pivotal to mitigating the detrimental impacts of water stress on growth and productivity. This study scrutinizes the variability in drought responses of growth, physiological, and biochemical variables integral to selecting drought-tolerant oil palm cultivars in the nursery. A comprehensive dataset was compiled by subjecting seedlings of eleven cultivars to four soil water potentials (-0.05 MPa, -0.5 MPa, -1 MPa, and -2 MPa) over 60 days. This dataset encompasses growth attributes, photosynthetic parameters like maximum quantum yield and electron transfer rate, gas exchange (photosynthesis, transpiration, and water use efficiency), levels of osmolytes (proline and sugars), abscisic acid (ABA) content, as well as antioxidant-related enzymes, including peroxidase, catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase. Principal Component Analysis (PCA) elucidated two principal components that account for approximately 65% of the cumulative variance. Noteworthy enzyme activity was detected for glutathione reductase and ascorbate peroxidase. When juxtaposed with the other evaluated cultivars, one of the cultivars (IRHO 7001) exhibited the most robust response to water deficit. The six characteristics evaluated (photosynthesis, predawn water potential, proline, transpiration, catalase activity, sugars) were determined to be the most discriminant when selecting palm oil cultivars with tolerance to water deficit.