Search Results (305)

Cavity limitations and interspecific competition render large macaws valuable models for elucidating the integration of parental care, pair-bond maintenance, and nest defense across reproductive stages. Through continuous video monitoring of a single artificial polyvinyl chloride nest box in the Tambopata National Reserve, Peru, we quantified the complete breeding cycle of a resident green-winged macaw (Ara chloropterus) pair and the visitation behavior of a sympatric scarlet macaw (Ara macao) pair within the same cavity. We constructed daily time budgets for 17 behaviors, categorized into seven functional groups, from motion-triggered video clips; employed multivariate tests; and generalized additive models with beta error distribution to describe the temporal changes across the five reproductive stages. The resident A. chloropterus exhibited a significant reorganization of parental investment, with early courtship behaviors transitioning to peak nest attendance and sentinel vigilance during incubation and early brooding. In later stages, locomotion increased significantly, associated with chick provisioning, whereas the frequency of allopreening remained relatively constant throughout the cycle. The visiting A. macao displayed a brief, behaviorally rich prospecting phase, characterized by nest inspection and locomotion, followed by a sharp decline in minimal activity. These divergent strategies align with owner–intruder asymmetries and floater dynamics, indicating that artificial cavities can support A. chloropterus breeding, while suggesting that additional cavities may redistribute breeding opportunities among competing macaws, a hypothesis necessitating multi-nest and multi-year evaluation. Full article

In this study, we conducted a comprehensive characterization of avocado accessions from the Canary Islands, focusing on molecular, morphological, phenological, and agronomic traits. A total of 311 trees were initially prospected across Tenerife, La Palma, Gran Canaria, and La Gomera Islands. DNA was extracted from young leaves, and genetic diversity was assessed using 28 microsatelites primers, 14 of which were highly polymorphic, revealing 6937 amplified fragments, 137 of which were polymorphic. The average polymorphism percentage was 85.68%, with an expected heterozygosity of 0.68, indicating high genetic diversity. A dendrogram based on genetic data identified four main groups, two of which are closely related to the most widely cultivated avocado cultivars: ’Hass’, ’Fuerte’, and ’Pinkerton’. Morphological analysis (over three years), using 91 descriptors, revealed a clear differentiation between accessions, with several groups corresponding to specific commercial cultivars. Morphotypes that deviated from the main groupings were specimens obtained through sexual propagation. Principal component analysis revealed that fruit characteristics such as length-to-diameter ratio, seed size, and fruit weight were the most discriminating traits, consistent with findings in the Persea genus. These results highlight the genetic and morphological diversity within the Canary Islands avocado germplasm, providing valuable insights for future breeding and conservation efforts. Full article

The Cavalier King Charles Spaniel (CKCS) exhibits an unusually high prevalence of myxomatous mitral valve disease (MMVD). A potential link to MMVD for risk allele variants near the heart-specific nebulette (NEBL) gene has been identified. Although these risk allele variants seemed fixed in the CKCS, wild-type (i.e., healthy) allele variants at NEBL1-3 have likewise been found in a larger cohort, in which it was associated with less severe heart enlargement. The frequency of the wild-type allele variants in the asymptomatic breeding population is unknown. Therefore, the aim of this study was to investigate the wild-type allele variants frequency through prospective genetic testing in a large sample of CKCS that were intended for breeding in both the Netherlands and Australia. Blood samples of 370 CKCS with an unknown genetic status were collected, of which 175 from the Netherlands, and 195 from Australia. Deoxyribonucleic acid (DNA) was extracted for the genotyping of NEBL allele variants. No dog was homozygous for the wild-type allele variants. Only one dog from the Netherlands was heterozygous, while nine dogs from Australia were heterozygous. The prevalence of heterozygous dogs in the Australian breeding population was low (4.6%), but significantly higher compared to the prevalence in the Dutch breeding population (0.57%). In conclusion, selective breeding for the wild-type allele variants on its own would significantly reduce the number of breeding individuals and would add to the existing genetic bottleneck. The selective breeding of CKCS for wild-type allele variants should not be undertaken on its own due to the low prevalence in this breed and the polygenic character of the disease. Full article

Anaesthetic-related mortality in cats is uncommon, yet concerns persist regarding potential breed predispositions and the influence of brachycephalic conformation. This study evaluated breed-specific peri-anaesthetic death before and after adjustment for American Society of Anesthesiologists (ASA) physical status. It explored whether genomic lineage or brachycephalic phenotype was associated with mortality. A prospective, multicentre cohort of general anaesthetics from 198 centres was analysed. Anaesthetic-related death was defined as death during anaesthesia or within 48 h after extubation, excluding euthanasia and deaths attributed to non-anaesthetic causes. Breeds were grouped into four genomic lineages and three brachycephalic phenotypes. Mortality proportions (Wilson 95% confidence intervals) were calculated, and relative risks (RR) were estimated using Poisson regression with robust standard errors, adjusting for ASA class. Among 14,964 cats, 94 deaths occurred (0.63%; 95% CI 0.51–0.77), with mortality increasing from 0.07% (ASA I) to 33.33% (ASA V). After ASA adjustment, most breeds did not differ from European/Domestic Shorthair cats, but Persians remained at increased risk (RR 2.22; 95% CI 1.11–4.46). Mortality did not differ between genomic lineages. Moderate brachycephaly was not associated with an increased risk, whereas brachycephalic breeds (Persian, Exotic Shorthair, Himalayan) showed a higher adjusted risk (RR = 2.33; 95% CI, 1.17–4.63). Full article

Pigmentary keratitis (PK) is a prevalent ocular surface disease in Pug dogs, yet comparative evidence on topical immunosuppressants remains limited. This prospective comparative clinical study evaluated the efficacy and safety of two agents with distinct mechanisms—tacrolimus, a calcineurin inhibitor, and sirolimus, an mTOR inhibitor—for the treatment of PK. Thirty-two Pugs (63 eyes) were randomly assigned to receive either 0.03% tacrolimus or 0.03% sirolimus three times daily for six months. Tear film quantity and quality were assessed using the Schirmer tear test, tear break-up time, and Ferning patterns, alongside serial clinical scoring of corneal pigmentation and ocular surface signs. Both treatments improved tear-film parameters, although only tacrolimus produced statistically significant increases in tear production and more frequent formation of a pigment-free “clear line,” indicating enhanced pigment regression. Pigment lightening and transparency recovery improved similarly in both groups. Adverse events—including blepharospasm, diffuse corneal oedema, and complicated ulcers—occurred more frequently in the sirolimus group, suggesting a comparatively less favorable short-term safety profile. Overall, both tacrolimus and sirolimus demonstrated therapeutic benefit in PK, although tacrolimus showed superior quantitative efficacy and better tolerability. Further long-term studies are warranted to clarify safety considerations and to optimize immunomodulatory strategies for this breed-specific condition. These findings suggest tacrolimus may be considered a first-line immunomodulatory therapy for PK in Pug dogs. Full article

Conventional rice breeding predominantly relies on hybridization techniques, with hybrid progenies typically requiring 8 to 10 generations of selfing to achieve genetically stable homozygous lines. In contrast, haploid breeding enables the derivation of stable doubled haploid (DH) lines from hybrid progeny in just one generation, substantially shortening the breeding cycle. Haploid breeding comprises two core steps: haploid induction and chromosome doubling, with efficient haploid induction being pivotal to the success of this technology. Currently, anther culture, due to its relatively mature and stable protocol, has become the primary method for obtaining haploids in rice haploid breeding. This review systematically summarizes the research progress in rice anther culture, focusing on the fundamental steps and applications of haploid breeding, the developmental history of anther culture, factors influencing anther culture efficiency and their underlying genetic mechanisms, current challenges and potential countermeasures, and future prospects for rice anther culture technology. Full article

Aquilegia (Ranunculaceae), a genus of perennial herbs characterized by elegant leaves and unique flowers, exhibits promising application prospects in Northeast China. Chalcone synthase participates in the first enzymatic reaction of the anthocyanin biosynthesis pathway and plays a crucial role in flower color formation. In the present study, eight AoCHSs were identified and a comprehensive analysis of AoCHSs was then carried out, considering physical and chemical properties, conservative motifs, phylogenetic relationships, and cis-acting elements. The expression patterns of the AoCHSs were analyzed based on the transcriptome of A. oxysepala, which differs in sepal color between two species, to identify the candidate genes involved in flower color variation. AoCHS2/3/5 expression levels were found to be upregulated at PrA stage in A. oxysepala with dark purple sepals, while remaining consistently low in the pale-yellow species. Combining KEGG annotations and expression patterns, AoCHS5 was identified as a key gene for anthocyanin biosynthesis in Aquilegia that could play a role in the variation in flower color. The results of correlation network analysis showed that AoCHS5 was highly associated with MYB, bHLH, and WRKY. These results provided genetic resources for accelerating the molecular breeding of innovative Aquilegia flower colors. Full article

The year 2025 marks two significant milestones for aflatoxin research: 65 years since aflatoxin was first identified in 1960, and 50 years of focused research on preharvest aflatoxin contamination since it was first recognized in 1975. Studies in the 1970s revealed that A. flavus could infect crops like maize and produce aflatoxin in the field before harvest and made it possible to investigate the potential genetic resistance in crops to mitigate the issues. Tremendous efforts have been made to learn about the process and regulation of aflatoxin production along with interactions between A. flavus and host plants as influenced by environmental factors. This has allowed for the breeding of more resistant crops and investigations into the underlying genetic and genomic components of resistance mechanisms in crops like maize and peanut. However, despite decades of studies, many questions remain. One established “dogma” is that drought stress, especially when combined with high temperatures, is the single greatest contributing factor to preharvest aflatoxin contamination and is a perennial risk faced throughout the major agricultural production regions of the world. Although there are many reviews summarizing the decades’ long wealth of information about A. flavus, aflatoxin biosynthesis, management and host plant resistance, there are few reports that put the spotlight on why aflatoxin contamination is exacerbated by drought stress, which places plants under severe physiological stress and weakens immune systems. Therefore, here we will focus on three major areas of research in maize: the “living embryo” theory and host resistance mechanisms, the “Key Largo hypothesis” and the causes of drought-exacerbated aflatoxin contamination, and recent advancements in CRISPR-based genome editing for enhancing drought tolerance and increasing plant immune responses. This will highlight key breakthroughs and future prospects for the continuing development of superior crop germplasm and cultivars and for mitigating aflatoxin contamination in food and feed supply chains. Full article

Drought is one of the most severe abiotic stresses limiting agricultural productivity and threatening global food security. As the central organelle responsible for photosynthesis and stress perception, the chloroplast is highly sensitive to drought, and its structural and functional stability directly determines plant adaptability. Recent studies have revealed that chloroplasts undergo pronounced ultrastructural alterations under drought stress, including thylakoid membrane shrinkage, disorganization of grana stacks, and accumulation of reactive oxygen species (ROS). Excessive ROS production causes oxidative damage to lipids, proteins, and nucleic acids, whereas moderate ROS levels act as retrograde signals to regulate nuclear gene expression. In parallel, calcium (Ca²⁺) oscillations and retrograde signaling pathways—such as those mediated by GENOMES UNCOUPLED PROTEIN1 (GUN), 3′-phosphoadenosine-5′-phosphate (PAP), and Methylerythritol cyclodiphosphate (MecPP)—integrate chloroplast-derived stress cues with nuclear responses. To counteract drought-induced damage, plants activate a series of antioxidant systems—both enzymatic (Superoxide Dismutase (SOD), Ascorbate Peroxidase (APX), Catalase (CAT)) and non-enzymatic (Ascorbic Acid (ASA), (Glutathione) GSH, tocopherols, carotenoids)—along with protective proteins such as fibrillins (FBNs) and WHIRLYs that stabilize thylakoid and membrane structures. In addition, autophagy and plastid degradation pathways selectively remove severely damaged chloroplasts to maintain cellular homeostasis. Exogenous substances, including melatonin, 5-aminolevulinic acid (ALA), and Zinc oxide (ZnO) nanoparticles, have also been shown to enhance chloroplast stability and antioxidant capacity under drought stress. In this review, we discuss the structural and functional changes in chloroplasts, signaling networks, and protective repair mechanisms under drought stress. Furthermore, we highlight future research prospects for enhancing plant stress resilience through multi-omics integration, application of functional regulators, and molecular design breeding. Full article

Whole-genome studies in cattle play a key role in exploring both individual and population-level genetic variability. Recently, low-coverage whole-genome sequencing (0.5–2×) has been considered as an alternative to traditional approaches. Low-coverage whole-genome sequencing (lcWGS), which provides uniform coverage of the entire genome at relatively low cost, combined with subsequent imputation, enables the reconstruction of genotypes with high accuracy and density. lcWGS enables detection of rare and functionally important variants and provides exploratory potential for structural variation analysis; however, accurate SV imputation still presents significant challenges. The aim of this review is to analyze the potential and prospects of lcWGS as a tool for genomic selection and genetic studies in cattle. The review systematizes current advances in the application of lcWGS in cattle, focusing on imputation accuracy, factors affecting it, and the comparative efficiency of different software solutions. A literature survey was conducted using PubMed and Google Scholar databases, with preference given to original studies, systematic reviews, and large-scale projects addressing imputation accuracy, reference panel composition and size, cost-effectiveness, and practical applications of lcWGS in cattle genomics. Key factors influencing efficiency include sequencing depth, reference panel size and composition, as well as the choice of imputation algorithm. lcWGS represents a cost-effective and powerful alternative to traditional genome-wide approaches, capable of capturing rare and breed-specific variants; however, its application to structural variation still requires methodological improvement and integration with high-resolution reference pangenomes or long-read sequencing. Despite significant progress and the high potential of lcWGS in cattle genomics, several challenges and limitations remain, requiring further investigation and resolution to fully realize the advantages of this technology. Addressing these challenges will enable more efficient use of lcWGS for genetic research and accelerate genetic progress in cattle breeding. Full article

Germplasm collections are a treasure trove of humanity. The accessions constituting those collections (wild crop relatives, landraces, cultivars, etc.) contain genes and allelic variants, which evolved prior to or post domestication, in the course of adaptation and selection, and can be used in breeding to address current and future needs. Precise characterisation of genetic diversity is essential for the efficient conservation of genetic resources and their effective utilisation in crop improvement. Detailed genetic profiles resulting from DNA genotyping constitute a basis for establishing the level of genetic diversity of a collection, analysing population structure, identifying redundancies, performing genome-wide association scans (given the availability of phenotypic information), detecting loci under selection, and many other applications. To obtain an accurate picture of genetic diversity (at the DNA sequence level), robust, high-density, high-throughput, and cost-effective methods are needed. With the advances in the next-generation sequencing, new genotyping approaches emerged (such as genotyping-by-sequencing, whole genome resequencing), which provide excellent genome coverage and low cost per datapoint (with tens of thousands to millions of loci analysed in a single assay). Crop-specific, custom, microarray-based genotyping solutions were also developed. The aim of this review is to provide a comparative description of the genome-wide, high-density genotyping technologies that are most frequently used nowadays, comprising their advantages and drawbacks, as well as factors that determine, which of the methods will best suit the particular germplasm characterisation project. Further, we characterise the current role of these methods in addressing the challenges related to the effective management and use of genetic resources and present recent examples of their application in selected crop plant groups. Finally, we briefly describe constraints to germplasm characterisation and future prospects. Full article

Developing reliable in vitro propagation methods for rowanberry genotypes is essential for their use in breeding and horticultural programs. While different rowanberry species and cultivars are primarily valued for their ornamental and forestry properties, poor seed germination and the low success rate of conventional vegetative techniques constrain their propagation. Micropropagation offers a practical approach to obtaining uniform, disease-free plant material for selection, hybridization, and the subsequent horticultural use of particular valuable genotypes. Shoot multiplication of a prospective sweet rowanberry cultivar ‘Discolor’ was studied on a Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP) at concentrations of 1, 2, and 4 mg L⁻¹, thidiazuron (TDZ) at concentrations of 0.5 and 1 mg L⁻¹, and 6-(γ,γ-dimethylallylamino)purine (2iP) at a concentration of 10 mg L⁻¹. Root induction was evaluated on a half-strength MS medium (50% MS) supplemented with 1 mg L⁻¹ of naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA), or indole-3-acetic acid (IAA). TDZ at 1 mg L⁻¹ yielded the highest multiplication coefficient. However, media with TDZ at a lower concentration (0.5 mg L⁻¹) or BAP (2–4 mg L⁻¹) provided the best balance between proliferation rate and shoot quality. These media promoted the growth of vigorous, well-elongated shoots with minimal callus formation. In contrast, the phytohormone 2iP did not elicit physiological response in the in vitro multiplication of explants. The best rooting results were obtained using a 50% MS medium supplemented with 1 mg L⁻¹ IAA, which provided the highest rooting percentage and root quality. IBA produced slightly lower, though comparable, results, while NAA resulted in weak, sporadic root formation. The established protocol enables the efficient in vitro propagation of the studied cultivar. This system supports its application in breeding and fruit production programs, as well as in maintaining valuable genetic resources within the genus Sorbus. Full article

Pepino mosaic virus (PepMV) is a highly infectious potexvirus that poses a significant threat to tomato cultivation in greenhouses worldwide. The threat posed by this virus is attributed to by its genetic complexity, characterized by the presence of multiple genotypes in circulation, mixed infections, and ongoing genotype turnover. Surveys of wild Solanum species have identified promising sources of resistance; however, this resistance is often incomplete, manifesting as symptomless, yet virus-positive, plants. When resistance is identified, introgressing of these traits into elite backgrounds is frequently impeded by reproductive barriers and linkage drag. Consequently, there are currently no commercially available cultivars with durable resistance to PepMV. Current control measures rely on stringent hygiene practices, seed health protocols, and the use of mild isolate cross-protection, which can mitigate fruit symptoms when carefully genotype-matched and closely monitored. Looking forward, achieving durable control will likely require host-centered strategies. Loss-of-susceptibility mutations and RNA interference-based approaches have demonstrated strong potential in experimental studies. Future solutions may involve the integration of genome editing with RNA-based technologies, supported by regulatory harmonization and socioeconomic viability considerations. Full article

Animal breeding has undergone profound transformations from its origins in phenotypic observation to the integration of genomic and machine learning techniques. This review paper explores the progression of livestock breeding, tracing its roots to the domestication of animals during the Neolithic Revolution. Gregor Mendel’s foundational work with pea plants established key principles of Mendelian genetics, which initially focused on discrete qualitative traits. However, the advancement of quantitative genetics has shifted the focus to continuous traits, such as body weight and milk yield, which are influenced by multiple genes. QTL mapping revolutionized breeding by shifting from phenotype- to genotype-based selection, enhancing accuracy through genomic predictions like GEBV under GBLUP. The strongest QTL associations on chromosome 18 linked local GEBV with FUK and DDX19B expression. In recent years, machine learning and artificial intelligence have transformed genomic prediction into livestock breeding by efficiently handling high-dimensional data and capturing complex genetic relationships. Notably, a deployed deep learning model achieved an average correlation of up to 0.643 between actual and predicted values. This review highlights the integration of machine learning approaches in animal breeding, showcasing advancements in milk and meat production, and the improvement of disease management through multi-omics strategies. The paper underscores the shift towards innovative methods and their impact on advancing animal breeding practices, offering insights into prospects for enhancing productivity, health, and welfare in livestock. Full article

Grain legume crops are rich in nutritional value and play a crucial role in global food sustainability. Like many other crops, they are affected by various abiotic stresses that reduce yield and seed quality, thereby threatening food security. Several strategies have been proposed to mitigate these effects and enhance yield. Among them, the use of biostimulants offers a sustainable and efficient approach to improving stress tolerance in the short term. However, the molecular mechanisms underlying the effects of individual or combined molecules remain poorly understood and could significantly influence the development of edited crops with enhanced stress tolerance in the long term. Melatonin (MT) has emerged as a versatile biostimulant, providing multiple benefits across different crop species. Given its key role in plant physiological processes, along with endogenous production, receptor identification, and signaling functions, it has been suggested to act as a hormone-like molecule. Nonetheless, the molecular response triggered by its application remains under investigation, particularly in grain legume species. This review explores the current state of MT applications for alleviating abiotic stress in grain legume crops, with emphasis on drought, salinity, metals/metalloids, and heat stress. We integrate biochemical, molecular, and physiological evidence to highlight the main scientific gaps regarding MT function in grain legumes. Finally, we discuss the biotechnological prospects of combining MT with modern breeding tools, as well as strategies for its delivery and sustainable production. Full article