Plant Disease

Beyond the significant impact of Cassava witches broom disease (CWBD), caused by the fungus Rhizoctonia (syn. Ceratobasidium) theobromae on cassava cultivation in French Guiana and Brazil, this disease also poses a potential threat to cacao trees in the region, since the fungus is responsible for Vascular Streak Dieback (VSD) of cacao in South East Asia. Cross-pathogenicity trials were conducted in several cassava fields in French Guiana by planting young cacao plants adjacent to diseased cassava plants. Vascular necrosis was observed in some cacao plants, and the presence of R. theobromae in the cacao tissues was confirmed through PCR diagnostics using primers specific to the fungus. Sequence analysis indicated 100% similarity between samples from both hosts and 97.53 to 99.74% identity with R. theobromae isolates previously reported from cassava in the Americas and Southeast Asia. Additionally, symptomatic cacao in a mixed cacao-cassava farm yielded R. theobromae-positive PCR results, suggesting a natural infection. Ongoing work includes artificial inoculations and controlled cross-pathogenicity trials under screenhouse conditions to attempt reproduction of the symptoms. While current data do not yet establish definitive causality, the findings indicate potential host jump and warrant rapid communication to researchers, policy makers, and farmers to safeguard cacao production and Theobroma biodiversity in the Amazon region.

Australia is the largest producer of Pyrethrum (Tanacetum cinerariifolium) globally. Amongst the constraints on production are the fungal pathogens Didymella tanaceti and Stagonosporopsis tanaceti, which pose a significant threat to the industry, causing substantial yield losses. While the infection biology of S. tanaceti is well characterised, knowledge of D. tanaceti and its potential interaction with S. tanaceti on plants remains limited, hindering disease management. We developed fluorescently labelled strains of both pathogens via Agrobacterium tumefaciens-mediated transformation (ATMT). Binary vectors carrying the mNeonGreen or tdTomato fluorescent protein genes were introduced into D. tanaceti and S. tanaceti, respectively, and expression of the fluorescent proteins was confirmed by microscopy. Genome sequencing revealed single-copy T-DNA insertions in all transformants, with minor genomic rearrangements at insertion sites. Detached leaf assays demonstrated that transformed strains retained pathogenicity, producing disease symptoms indistinguishable from those of the wild type. These fluorescently labelled variants enabled detailed visualisation of D. tanaceti infection biology and its interactions with S. tanaceti, including co-infection dynamics. Co-infection assays using fluorescent strains further facilitated simultaneous visualisation and differentiation of both pathogens within host tissues. Importantly, these tools also allowed the first description of the early stages of infection by D. tanaceti in pyrethrum leaves. This study represents the first successful transformation of D. tanaceti and S. tanaceti, providing valuable resources to investigate their infection processes.

Leaf diseases pose a serious threat to faba bean production. Leaf blotch of faba bean, caused by Alternaria spp., has become increasingly widespread and destructive in several countries. Leaf diseases pose a serious threat to faba bean production. The infection of plant by pathogens can be influenced by various factors associated with the host plant, environmental conditions and presence of other microorganisms. The phyllosphere and endosphere play a critical role in plant health and disease development. This study aimed to evaluate the factors shaping the structure and diversity of fungal communities associated with faba beans. Plant samples were collected in 2004 from two intensively managed faba bean production fields in the central region of Latvia. Fungal assemblages were characterized using an ITS region metabarcoding approach based on Illumina MiSeq sequencing. Among the assigned amplicon sequence variant (AVS), 65% belonged to the phylum Ascomycota, while approximately 4% were classified as Basidiomycota. Alternaria and Cladosporium were the dominant genera across samples. The alfa and beta diversities of fungal communities was higher during flowering of faba beans to compare with ripening. The higher abundance of Basidiomycota yeasts were observed during flowering, in contrast, Cladosporium genus was significantly more abundant during ripening. Alternaria DNA was found on leaves that showed no symptoms of the disease. The diversity and composition of fungal communities were significantly influenced by sampling time and presence of leaf blotch, caused by Alternaria spp.

We present a genome assembly from a specimen of Quercus canariensis (Fagaceae; Fagales; Magnoliopsida). The assembly was generated using PacBio HiFi long reads with an approximate sequencing depth of 39X and scaffolded using a reference-guided approach. The genome sequence has a total length of 816.0 megabases for haplotype 1 and 804.8 megabases for haplotype 2. The two haplotypes are each resolved into 12 chromosomal pseudomolecules, with only 3.48% and 1.36% of sequences remaining unplaced in haplotypes 1 and 2, respectively. Assembly completeness is supported by BUSCO scores of 98.3% and 98.2% complete genes for haplotypes 1 and 2, respectively. Structural annotation identified 51,882 and 46,482 protein-coding genes in haplotypes 1 and 2, respectively. This genome assembly provides the first chromosome-scale reference genome for Q. canariensis, laying the base for future genomic and evolutionary studies in this understudied species of the hybridizing white oak species complex. TaxonomyLineage cellular organisms; Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae; rosids; fabids; Fagales; Fagaceae; Quercus EBI:txid568684 Quercus canariensis Willd. 1809 (Willdenow)

Potato common scab (Streptomyces sp.) is an economically important disease that reduces the quality and market value of tubers. A key aspect in developing management strategies involves accurately quantifying the disease. Due to the three-dimensional nature of the tuber and the heterogeneous distribution of lesions across its surface, visual estimates of severity can be challenging. Therefore, the objectives of this study were to develop and validate a standard area diagram (SAD) for estimating common scab severity on potato tubers and to compare validation outcomes obtained using real tubers and digital images. A SAD comprising six severity levels (from 1.3 to 66.8%) was developed based on image analysis of naturally infected tubers. Validation was conducted using two complementary approaches in which inexperienced raters evaluated either real potato tubers or digital images of the same tubers under unaided and aided conditions. Accuracy, bias components, and inter-rater reliability were quantified using absolute error metrics, Lins concordance correlation coefficient, intraclass correlation coefficients, and overall concordance correlation coefficients. Use of the SAD significantly improved accuracy, reduced systematic bias, and increased inter-rater reliability across both validation approaches. No significant differences were detected between assessments conducted on real tubers and images, although image-based evaluations showed a slight, non-significant tendency toward reduced scale and location bias under aided conditions. These results demonstrate that a dimension-aware SAD integrating information across the full tuber surface enhances the reliability and reproducibility of visual severity assessments and supports the use of image-based evaluations for training, large-scale surveys, and remote or collaborative applications involving three-dimensional plant organs.

Phytophthora species are globally significant soilborne oomycetes responsible for widespread ecosystem decline. Standard soil sampling protocols, originally developed for qualitative baiting assays, typically require collecting substantial soil volumes in order to capture viable propagules. While effective for culture-based detection, these protocols are labour-intensive and can damage the shallow root systems of sensitive host species such as New Zealand kauri (Agathis australis). Phytophthora agathidicida (PA), the pathogen associated with kauri dieback disease, is routinely surveyed using these methods. However, quantitative data describing the vertical distribution of PA in natural forest soils are lacking. Consequently, it remains unclear whether extensive depth sampling is necessary to ensure consistent molecular detection. In this study, we applied a quantitative oospore DNA (oDNA) qPCR assay to characterise the fine-scale vertical distribution of PA across four soil depth increments (0-5, 5-10, 10-15, 15-20 cm) from 12 kauri trees representing a range of disease stages. Results revealed distinct vertical stratification, with PA DNA concentrations peaking within the upper 0-10 cm of soil in non-symptomatic and possibly symptomatic trees. In symptomatic trees, the absolute peak occasionally reached 10-15 cm, while pathogen signals remained consistently detectable within the top 10 cm. Field validation from an additional eight trees confirmed that targeted 0-10 cm "shallow" sampling yielded higher PA concentrations than deeper sampling protocols. These findings provide a data-driven basis for refining soil sampling strategies, enabling more sensitive molecular detection while minimising disturbance and logistical effort in fragile ecosystems. IMPORTANCEPhytophthora species are among the most destructive soilborne pathogens globally, requiring robust diagnostic protocols for both agricultural and conservation settings. Traditional sampling frameworks were established to meet the biological requirements of baiting assays, which often necessitate collecting large soil volumes from broad depth profiles to ensure the capture of viable, infectious propagules. However, these extensive requirements are labour-intensive and can cause significant soil disturbance in sensitive forest ecosystems. Using P. agathidicida as a model, this study provides a high-resolution quantitative assessment of how pathogen DNA is distributed vertically across different disease stages. We demonstrate that while absolute peak abundance can shift within the 0-15 cm range as infection progresses, the pathogen signal remains consistently detectable within the top 10 cm. This evidence-based approach suggests that targeted, shallow sampling enhances sensitivity by reducing signal dilution, offering a lower-impact path for monitoring soilborne oomycetes worldwide.

Grain mold severely constrains sorghum [Sorghum bicolor (L.) Moench] productivity and grain quality in subhumid environments. Photoperiod-sensitive flowering plays a key role in mold avoidance and yield stability along north-south rainfall gradients. In response to the high susceptibility of elite cultivars in subhumid zones of Senegal, we developed and characterized a recombinant inbred line (RIL) population derived from Nganda (grain mold-susceptible) and Grinkan (photoperiod-sensitive) varieties. The population was evaluated across three distinct agro-ecological zones over two years. Environmental indices derived from genotype-environmental interactions, together with defined growth windows, strongly influenced flag leaf appearance (FLA), a photoperiodic flowering trait. Plasticity parameters (intercept and slope) for environmental indices, FLA, grain mold severity, and yield enabled identification of loci contributing to flowering response, mold resistance, and yield stability. The maturity gene Ma1 and two QTLs for FLA, qFLA6.2 and qFLA6.3, were identified, stable across environments, and colocalized with grain mold and yield QTLs. The wild-type Ma1 allele from Grinkan delayed FLA and reduced grain mold damage but was not associated with increased yield. The Ma1 effect was confirmed using the developed breeder-friendly KASP marker, Sbv3.1_06_40312464K, in 174 F3 three-way cross families. Photoperiod-sensitive lines with intermediate-to-late FLA alleles showed strong negative associations with mold damage. Overall, the identified stable loci and candidate lines provide foundations for effective molecular breeding of climate-resilient varieties. PLAIN LANGUAGE SUMMARYGrain mold is a fungal disease that reduces sorghum grain yield and quality, particularly in subhumid climates. With the limited number of resistant elite varieties, photoperiod-sensitive flowering to day length variation can contribute to grain mold escape at the end of rainy seasons. We characterized 286 sorghum recombinant inbred lines across three contrasting environments over two years along rainfall gradients in Senegal. Using flag leaf appearance (FLA), which is a photoperiodic flowering trait, strong genotype-environment interactions for FLA and genotypic plasticity were revealed. We identified and validated the common genomic locus associated with FLA variation and its plasticity across environments, the canonical maturity gene Ma1, which was influenced by temperature variation across environments. The presence of Ma1 in the background of photoperiod-sensitive lines enhances grain mold avoidance and yield stability along rainfall gradients in Senegal. CORE IDEASO_LIWe investigated photoperiodic flowering plasticity in sorghum as a contributor to grain mold resistance and yield stability along rainfall gradients. C_LIO_LIThe Maturity locus Ma1 (qFLA6.1) is the major contributor of photoperiodic flowering and its plasticity across semi-arid and subhumid environments. C_LIO_LIHybrid genotypes carrying two stable loci qFLA6.1 and qFLA6.2 sustain high grain mold avoidance in diverse environments. C_LIO_LIPhotoperiod-sensitive lines with medium to late flowering times are effective in avoiding grain mold, while maintaining yield stability in subhumid regions. C_LI

This study investigated the mutagenic effects of ethyl methane sulfonate (EMS) on the M{square} generation in cowpea (Vigna unguiculata (L.) Walp.) cultivar Wang Kae. A total of 275 M{square} seeds were treated with EMS concentrations of 20 mM, 40 mM, and 80 mM (75 seeds per treatment) by soaking for six hours, while 50 untreated seeds served as the control (0 mM). Phenological, yield-related and yield traits were recorded, and data were analysed using Jamovi 2.7.15 and JASP 0.95.4.0 through one-way ANOVA with post hoc contrast, principal component biplot, and cluster analyses. No optimal mutagenic concentration (LD50) was identified. Seed germination and seedling survival rates increased with increasing EMS concentration, ranging from 70.00% and 62.00% in the control (0 mM) to 89.33% and 74.67% at 80 mM, following the trend 0 mM < 20 mM < 40 mM < 80 mM. Significant differences (P < 0.05) were observed among treatments for all phenological traits, pod length, locule number, seed traits, and yield per plant. Yield was significantly higher (P = 0.047) at 20 mM (61.19 {+/-} 3.34 g) compared to the control. Contrast analysis identified genotypes B33 and D56 as the most productive mutants, with yields of 125.44 g and 111.85 g, respectively. Principal component analysis extracted eighteen components, with the first four cumulatively explaining 50.60% of total variation. Biplot analysis of PC1 and PC2 captured all phenological traits, key seed traits, and yield attributes, highlighting the superior performance of B33 and D56. Cluster analysis partitioned the 190 genotypes into six groups, with B33 and D56 constituting distinct clusters. EMS mutagenesis effectively induced heritable phenotypic variation, with putative superior genotypes identified for advancement to M{square} and evaluation in replicated multi-environment trials toward the development of farmer- and consumer-preferred cowpea varieties.

CoverCress is a new winter annual oilseed crop developed from field pennycress within the past 20 years. Field pennycress is commonly considered to be self-pollinated but little basic research has been published and there is some misalignment of conclusions. Our experience working with pennycress plant growth in greenhouse and field conditions over the past 13 years suggests that outcrossing is uncommon. We conducted lab, greenhouse, and field experiments to strengthen the body of work. Pollen viability kinetics analysis showed that longevity of pollen viability is negatively impacted by increasing temperatures and by direct exposure to light. Samples treated at 4C declined to 50% viability in 12 hours while it took just 2.5 hrs at 37C, and 1.6 hrs in full sunlight on a cool early April day. Cross-pollination was absent among greenhouse-grown plants flowering inside an agitated plastic pollen-containment covering. Across greenhouse tests, high rates of cross-pollination occurred only in an emasculation treatment that rendered flowers male sterile and opened the pistil to cross-fertilization. Field trials designed to measure pollen flow distance using a trackable fae1 knockout reporter gene failed to show detectable movement of pollen under field conditions in two locations. This data strongly suggests that domesticated field pennycress may be considered a self-pollinated crop and managed as such.

Grapevine Trunk diseases (GTDs) represent a major threat for the wine industry. Despite several break-through, their etiology remains unclear and no curative treatment is currently available. Wood anatomy and water transport contribute to the symptoms of young plant decline. This study investigates wood anatomical alterations in two Alsatian grapevine cultivars presenting different susceptibility to GTDs, focusing on wood structure over six months of vegetative growth and in response to infection. Using a validated FasGa staining protocol, wood sections from transverse, tangential, and radial directions were stained to differentiate lignified and cellulosic tissues. Microscopic analysis was performed at x4, x10, and x40 magnifications, yielding a dataset of 4771 images. To support this high-throughput quantitative analysis of microscopy images, a computational model was developed, enabling reliable and efficient assessment of anatomical traits. Pre-established woody tissues presented higher xylem vessels diameter in Gewurztraminer than Riesling, with a dorsoventral arrangement whereas the number of vessels remained the same all over the cross section. No significant anatomical changes were observed in established woody tissues, whereas newly formed xylem anatomy showed a possible rearrangement during infection, especially in Gewurztraminer cultivar. Furthermore, colorimetric analysis quantified the lignification of woody tissues in response to wounding damage compared to un-treated plants. While definitive conclusions remain limited due to the experimental timeframe and sample variability, the findings highlight the need for longer-term studies and broader cultivar evaluation. Code and microscopy images have been made publicly available, providing a scalable digital tool for future research in plant vascular systems.

Spinach (Spinacia oleraceae) is a principal vegetable crop commercially grown in Controlled Environment Agriculture (CEA). Recent research suggests that root morphological and architectural differences among crop species influence yield, resource use efficiency, and environmental stress tolerance. These root traits may be exploited to increase yield, promote efficient nutrient use, and mitigate environmental stressors. This study measured differences between various spinach cultivars in CEA systems to reveal morphological and anatomical variation. We grew three spinach cultivars with different reported growing rates ( Income, Darkside, and El-Majestic) under NFT hydroponic and substrate-based systems in a controlled greenhouse environment over 45 days with destructive harvests at days 15, 30, and 45. Supplemental light (250 {micro}mol/m2/s) with 12-hour photoperiod and periodic fertigation was used. Harvests included the collection of leaf and root biomass, and scanning of root systems in WinRhizo software, measuring ten variables. On day 45, root cross-sections from orders 1-5 were embedded in JB-4 resin, sectioned, stained, and analyzed for diameter, vasculature, and rhizodermis characteristics. Results indicate that in spinach, differences in root system morphology are linked to cultivation systems over cultivar identity. Vascular and root anatomical alterations are minor compared to morphological differences in response to the cultivation system. Hydroponic-style growth systems are associated with the proliferation of fine-root ideotypes compared with substrate-based conditions. Such findings affirm previous studies, which suggest plastic root morphology in response to growth systems, and may be used to help create more resilient, resource-efficient cultivars. HighlightsO_LIIn spinach, root system morphology differences are linked to cultivation systems. C_LIO_LIRoot vascular and anatomical alterations are minor in response to cultivation system. C_LIO_LIHydroponic growth systems are linked to fine-root ideotype proliferation in spinach. C_LIO_LIFine-root ideotype proliferation may be a breeding target for CEA spinach. C_LI

RNA viruses are common in tephritid fruit flies including the Queensland fruit fly, Australias most significant horticultural pest. For many their transmission, tissue tropism and load across host development remain unexplored. Yet these factors are important for host biology, ecology and pest management. We investigated Bactrocera tryoni orbivirus (OV), Bactrocera tryoni xinmovirus (XV), Bactrocera tryoni toti-like virus (TLV) and Bactrocera tryoni iflavirus species 2 (IVsp.2) that commonly coinfect B. tryoni laboratory populations. OV and XV transmission was vertical within and on eggs, while TLV transmission was vertical within eggs. IVsp.2 was not detected in eggs but was present in adults; however, IVsp.2 was horizontally transmitted, with viral load increasing with cohabitation time with infected flies. Horizontal transmission was not observed for the other viruses. OV had a similar load across all tissues, while XV was consistently more abundant in ovaries. TLV had a high viral load in the brain whereas IVsp.2 was abundant in the thorax, foregut and midgut. Besides differences in eggs, the viruses were detected in all other developmental stages, but viral load patterns differed: viral load remained constant for TLV, fluctuated for OV and XV, and was low in pre-adult stages and high in adults for IVsp.2. Our findings demonstrate distinct transmission strategies and tissue tropism among the viruses, providing new insights into their epidemiology and role in host biology. Furthermore, contrary to prevailing views that viruses are generally horizontally transmitted, most known RNA viruses of B. tryoni are vertically transmitted affecting the evolution of host-virus interactions.

Borealpox virus (BRPV; formerly Alaskapox) is an orthopoxvirus that has caused seven reported human infections in Alaska since 2015, including a fatal case in 2023. The natural reservoir of BRPV is unknown, although previous investigations have raised the possibility of wild small mammals transmitting the virus to humans, either through direct contact or via domestic cats and dogs. To understand which species may be involved in the maintenance and/or spillover of BRPV in Alaska, we trapped and sampled wild small mammals (including voles, shrews, and squirrels) in 2021 and 2024 near reported human case locations in Fairbanks and the Kenai Peninsula, respectively. We found evidence of previous exposure to orthopoxviruses in five species (including the House Mouse, Mus musculus) and detected BRPV DNA as well as viable virus in Northern Red-backed Voles (Clethrionomys rutilus). Further, screening of tissues from historical museum specimens revealed BRPV DNA in C. rutilus specimens collected in Denali National Park and Preserve in 1998 and 1999, 17 years before the first reported human case of BRPV. Phylogenomic analysis of all human and animal BRPV isolates strongly supports the hypothesis of local human infections through multiple spillover events. These findings suggest C. rutilus as a possible reservoir species for BRPV and indicate that BRPV has been present in Alaskan wild small-mammal populations for at least 25 years. Our study highlights the potential of museum collections to elucidate the temporal, spatial, and host ranges of emerging pathogens. Further museum- and field-based sampling will clarify the true geographic range of BRPV, which is closely related to Old World orthopoxviruses and may be circulating beyond North America.

Enset (Ensete ventricosum), a multipurpose crop domesticated exclusively in Ethiopia, serves as a staple food for millions of smallholder farmers. It is primarily cultivated as a monocrop in homegardens, leaving it vulnerable to climate change risks. One potential nature-based solution involves agroforestry systems; however, ensets response to canopy cover remains unclear. This study examined how scattered trees in enset farms affected microclimate and enset morpho-physiology in South Ethiopia. Trees significantly modified the microclimate conditions in enset homegardens. The average daily reductions in air, soil surface, and soil temperatures ranged from -0.5 to -1.9 {degrees}C, -0.4 to -2.1 {degrees}C, and +0.4 to -1.0 {degrees}C, respectively. The minimum soil moisture offset ranged from +0.8% to +5.7%. Although the tree identity effect on enset growth was negligible, planting position relative to the overstory trees significantly influenced enset responses. Most morphophysiological traits were higher under tree canopies, with progressively lower values at the edge and outside the tree canopy. In contrast, leaf dry matter content exhibited an inverse trend, aligning with the leaf economics spectrum. These results demonstrate ensets adaptability to canopy shade, suggesting potential for agroforestry expansion. Cultivar-specific shade tolerance and ideal shade levels to maintain enset productivity should be investigated further.

IntroductionAntimicrobial Resistance (AMR) presents a critical public health challenge, particularly in smallholder broiler farming, where antibiotics are often used preventively in the absence of effective biosecurity measures. ObjectiveThis study investigates the adoption of biosecurity practices as a sustainable alternative to antibiotics through Participatory Systems Mapping and Experimental Games. MethodsA participatory mixed-methods study was conducted in southern Bangladesh (September 2024-June 2025). Causal Loop Diagrams (CLDs) were co-created with farmers, dealers, and veterinary officers. Ten broiler farmers from single village were selected via purposive and snowball sampling. Experimental games simulated four production cycles where farmers chose Option A (biosecurity, adopters) or Option B (antibiotics, non-adopters) after several interactive trainings. Key metrics including biosecurity compliance (0-12 scale), mortality, FCR, antibiotic use, outbreak history, and economic outcomes were recorded. ResultsCLD analysis revealed a reinforcing loop of increased antibiotic reliance driven by fear of mortality, and balancing loops involving training, biosecurity practices, and consumer incentives to reduce use. Five farmers chose Option A, and both groups remained stable until Round 4. Adopters had flock sizes of 800-2000 birds (non-adopters, 600-1000; mean for both = 1000), were younger, and more educated compared to non-adopters. At baseline, both groups had similar biosecurity scores (0). Adopters had higher mean outbreaks (2 vs. 1.4), mortality (5.6 vs. 4.2), antibiotic use (3.6 vs. 3), and FCR (1.8 vs. 1.6) compared to non-adopters. By Round 4, adopters improved biosecurity scores by 125%, eliminated outbreaks, reduced mortality by 52.6%, stopped antibiotic use, improved FCR by 13.3%, and gained 71.72% profit per bird compared to non-adopters. Non-adopters, influenced by adopters, increased biosecurity scores by 25%, reducing outbreaks, mortality, antibiotic use, and FCR. Adopters also increased direct sales to consumers, yielding a 10%-16% profit gain per bird each round. ConclusionThis study highlights the successful adoption of biosecurity practices by farmers, replacing antibiotics and improving production outcomes. Farmer-driven adoption of these practices fosters long-term sustainability and supports a healthier planet within the One Health framework.

1) BackgroundUnderstanding how caterpillar communities vary within tree canopies is key to interpreting forest trophic dynamics and responses to environmental change, yet such variation remains poorly quantified due to the challenges of sampling in three dimensions. 2) AimsWe quantified within-canopy heterogeneity in caterpillar densities, diversity, and herbivory and explored relationships with host tree phenology and commonly used ground-based monitoring approaches. 3) MethodsUsing direct canopy access, we sampled branches from lower, middle, and upper canopy strata of 34 mature pedunculate oaks (Quercus robur) in Wytham Woods, UK, during the spring abundance peak over three consecutive years (2023-2025). We tested for vertical stratification in caterpillar community metrics, examined patterns in early instar distributions at emergence, assessed associations with host tree phenology across spatiotemporal scales, and evaluated how well ground-based methods (water and frass traps) reflect canopy communities. 4) ResultsVertical stratification was modest but varied among years: densities and species richness increased with canopy height in 2023, decreased in 2024, and were uniformly low across strata in 2025. Although within-crown budburst timing varied systematically, with upper branches bursting approximately two days earlier than lower branches, tree phenology did not explain within- or between-year variation in caterpillar communities. Frass trap data correlated moderately well with canopy caterpillar densities, whereas water traps showed weaker and less consistent relationships, reflecting behavioural and methodological biases. 5) ConclusionsCaterpillar communities showed no consistent patterns of vertical stratification across years, instead they are shaped more strongly by inter-annual and tree-level variation. Integrating targeted canopy sampling with scalable ground-based proxies could greatly improve monitoring of arboreal Lepidoptera and inform studies of trophic synchrony and wood-land resilience under environmental change.

Astyanax Baird & Girard, 1854 is a widely distributed and species-rich genus of Acestrorhamphidae, whose abundant populations in Neotropical basins play a crucial ecological role at the trophic level. Taxonomic uncertainties persist within the genus, as seen in Astyanax sp. (formerly designated as A. fasciatus) from the Magdalena basin in Colombia. Concerns about its genetic status are heightened due to ecological threats posed by hydroelectric dams, from habitat loss to river connectivity. We isolated and characterized 17 microsatellite loci to assess the population genetics of this species in a broad sample from the middle and lower sections of the Cauca River, now interrupted by the Ituango dam. Furthermore, a multidisciplinary approach integrating phylogenetic analyses of mitochondrial (COI) and nuclear (rag2) markers with geometric morphometric analyses was employed to evaluate potential cryptic diversity within Astyanax sp. Microsatellites revealed two genetic groups in the studied area, strongly supported as distinct lineages by phylogenetic analyses. Unexpectedly, one of these lineages of Astyanax sp. was recovered in an unresolved clade with samples of A. microlepis and allopatric samples of A. viejita from the Maracaibo Lake basin. Each genetic group showed high genetic diversity, but also evidence of recent bottleneck events and significant-high values of inbreeding. Morphometric analyses provided evidence of significant phenotypic differentiation among A. microlepis, Astyanax sp. 1 (Asp1), and Astyanax sp. 2 (Asp2). Morphological patterns ranged from the robust profile of A. microlepis to the streamlined shape of Astyanax sp. 2 (Asp2), with Astyanax sp. 1 (Asp1) displaying intermediate traits and localized differences in head length and fin placement. Statistical support from permutation tests and a high overall classification accuracy (95.65%) underscore the existence of distinct morphospecies, suggesting that phenotypic differentiation is well-established, despite the complex evolutionary history of the group. This study suggests the presence of cryptic diversity within Astyanax sp. and provides valuable genetic information for the conservation and management of their populations in the Magdalena basin.

Potato (Solanum tuberosum L.) is a staple crop crucial to global food security, yet its production is severely threatened by late blight (LB), caused by Phytophthora infestans, one of the most destructive plant diseases worldwide. Breeding programs for LB resistance have traditionally relied on labor-intensive and subjective visual assessments, which limit scalability and consistency, particularly in early-generation trials. Unmanned aerial vehicle (UAV)-based remote sensing combined with machine learning (ML) offers a promising alternative for objective, high-throughput disease phenotyping. This study evaluated the potential of UAV-derived multispectral imagery and ML techniques to estimate LB severity across large and genetically diverse potato breeding populations, comprising 2,745 clones in one trial and 492 accessions in another, conducted in Oxapampa, Pasco, Peru. We compared vegetation index-based approaches with a machine learning framework that integrates K-means clustering and Kernel Ridge Regression (KRR) and assessed their ability to capture genotypic variation and support selection decisions. NDVI consistently showed a strong correlation with visually assessed LB severity, particularly at advanced stages of disease development, enabling objective discrimination between healthy and diseased canopy tissues. However, the KRR-based approach outperformed linear NDVI-based models by capturing nonlinear relationships between spectral responses and disease progression. Estimates of LB severity derived from NDVI and KRR models, expressed as best linear unbiased estimates (BLUEs), showed strong and biologically consistent relationships with the area under the disease progress curve (AUDPC), particularly during later UAV acquisitions. Selection coincidence between UAV-derived estimates and AUDPC-based rankings was substantially higher at intermediate to advanced stages of disease progression, suggesting that UAV assessments at these stages may capture sufficient phenotypic variation to distinguish genotypes. These findings indicate that UAV-based multispectral phenotyping, especially when integrated with ML, provides a practical and scalable approach for assessing LB severity in potato breeding programs while reducing the need for time-consuming field evaluations.

The pathways of non-target exposure to anticoagulant rodenticides (ARs) are poorly understood, and have yet to be examined in Ontario, Canada. The spillover of ARs into non-target rodents and high-risk landscapes has been investigated numerous times, but usually in agricultural regions as opposed to urban ones. We used snap traps to capture white-footed mice (Peromyscus leucopus) in urban wildland areas of Toronto and Vaughan, Ontario near ongoing rodenticide baiting programs. Our goal was to determine if second-generation anticoagulant (SGAR) baiting practices used by pest management professionals targeting commensal rodents may be causing rodenticide spillover into non-target rodents in urban wildland areas, which could act as a vector of ARs to predators. Only 11 out of 111 mature white-footed mice trapped near ongoing urban rodenticide operations tested positive for an anticoagulant, at five out of seven study sites. Concentrations were between 0.008-0.03 ppm, which may be sublethal for raptors. We did not detect brodifacoum, despite its detection in a recent study on Ontario raptors. Exposed individuals were caught at 0m, 5m, 20m, 40m, 70m and 100m from active rodenticide stations. They did not differ from unexposed individuals in terms of sex, age, body condition, distance to the AR source, capture date or capture site. This indicates that the pest management industrys use of rodenticides in urban and suburban settings is causing some degree of non-target spillover in Toronto and the Greater Toronto Area, and that SGAR usage should be avoided near naturalized landscapes.

Improving photosynthesis is a promising approach to enhance sugar beet productivity. However, genetic variation in leaf photosynthesis and its relationship with disease resistance remain underexplored. We evaluated 98 sugar beet genotypes representing different breeding categories, including commercial F1 hybrids, seed-parent lines, and pollinator lines, in Hokkaido, northern Japan. Leaf gas exchange was measured during early growth under field conditions around the infection period of Cercospora leaf spot (CLS). To account for fluctuating irradiance during large-scale phenotyping, we applied a multilevel mixed-effects light-response model to estimate genotype-specific photosynthetic characteristics. Substantial genotypic variations in photosynthetic characteristics were detected. F1 hybrids exhibited higher photosynthetic capacity than breeding lines, whereas differences among breeding categories were unclear due to large within-category variation. Some breeding lines exhibited photosynthetic rates higher than those of hybrids, indicating exploitable genetic resources within the present genetic panel. We did not detect statistically significant trade-off between leaf photosynthesis and CLS resistance among 98 genotypes; in a subset of 19 genotypes analysed in detail, the relationship was even synergistic. Our results highlight the genetic diversity of leaf photosynthesis and its category-dependent structure, and suggest that selection for enhanced photosynthesis can proceed without substantial trade-off with CLS resistance. HighlightLeaf photosynthesis of 98 sugar beet genotypes showed significant genetic variation and dependence on breeding category. Active photosynthesis incurred minimal trade-off with Cercospora leaf spot resistance.