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AoB PLANTS

◐ Oxford University Press (OUP)

Preprints posted in the last 30 days, ranked by how well they match AoB PLANTS's content profile, based on 13 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

1
Root Age Structure Governs Long-Term Architecture and Hydraulic Function in Perennial Plants: a Modelling Framework

Giraud, M.; Fichtl, L.; Leitner, D.; Schnepf, A.; Steng, K.; Friedel, M.

2026-10-06 plant biology 10.64898/2026.10.03.756415 medRxiv
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Background and aims: Perennial root systems develop over decades and exhibit continuous turnover of structural and absorptive components, yet most root architecture models treat woody roots as permanent and neglect root age structure. We developed an empirically constrained modelling framework that explicitly represents age-structured demography, growth regulation and dormancy in perennial root systems. Methods: We extended the functional-structural plant model CPlantBox to simulate perennial root development over decades by integrating age-dependent survival, secondary radial growth and climate-driven dormancy. The model was parameterised using unique three-dimensional root system data from young and mature grapevines, together with dendrochronological root age measurements, and coupled to root hydraulic properties. Key results: Empirical analyses revealed multi-cohort age distributions and substantial turnover of lignified structural roots, contradicting the assumption of a static woody scaffold. The model reproduced age distributions, order-specific survival probabilities and fine-to-structural root length ratios, and generated realistic, genotype-specific three-dimensional architectures. Simulated uptake profiles and hydraulic scenarios showed strong age- and architecture-driven effects. Conclusions: Explicitly representing woody root age distributions and age-dependent processes may fundamentally change predictions of perennial root system architecture and function. The framework advances root modelling beyond annual paradigms and provides a transferable tool for analysing long-term architectural and hydraulic consequences of genotype x climate interactions in perennial crops.

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Seeding paradise: germination ecophysiology of Xyris paradisiaca Wand. (Xyridaceae), an endangered endemic species from Central Brazil

Ordonez-Parra, C. A.; Bispo, M. R. B.; Amaral-Garcia, L.; Figueiredo, R.; Almeida, T. E. B.; Cortes, C. A.; Garcia, Q. S.

2026-09-28 plant biology 10.64898/2026.09.24.754203 medRxiv
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Seed ecophysiology is essential for understanding plant regeneration and developing effective conservation and ecological restoration strategies, yet knowledge remains scarce for most threatened Cerrado species. We characterised the germination niche, desiccation tolerance and storage behaviour of Xyris paradisiaca (Xyridaceae), an Endangered species endemic to Central Brazil, to assess whether its restricted distribution is associated with narrow germination requirements and to inform seed-based conservation. Germination was tested across light regimes, constant temperatures, decreasing water potentials and short-duration heat shocks, while thermal- and hydro-time models were used to quantify thermal and hydric thresholds. Seeds exhibited an absolute light requirement but broad abiotic tolerances. Germination remained >87% between 15 and 40 {degrees}C, with estimated cardinal temperatures of Tb = 8.94 {degrees}C, To = 33.13 {degrees}C and Tc = 45.53 {degrees}C. Germination remained similar to the control down to -0.6 MPa and exceeded 40% at -1.0 MPa, with a median base water potential of {Psi}b = -1.03 MPa. Germination also remained high after 1-min heat shocks up to 200 {degrees}C. Seeds were desiccation tolerant, with 100% germination after drying and a viability loss index of -0.04, and germination remained >90% after 24 months of ambient storage. Thus, the highly restricted distribution of X. paradisiaca is not driven by a narrow physiological germination niche. Its broad environmental tolerances, desiccation tolerance and favourable storage behaviour also highlight its unexplored potential for seed-based restoration, propagation and ex situ conservation.

3
Eco-Evolutionary Optimal Carbon Allocation in a MechanisticCrop Growth Model: Theory and Application to Wheat

Norton, A. J.; Borevitz, J. O.

2026-09-23 plant biology 10.64898/2026.09.20.753045 medRxiv
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Carbon allocation governs how plants partition assimilates among leaves, roots, stems, and reproductive organs, directly shaping growth and yield. Most crop models represent this partitioning using fixed or empirically derived coefficients, which limits their ability to predict how allocation responds to genotype, environment, or their interaction. Eco-evolutionary optimality theory offers an alternative where the allocation strategy is allowed to emerge from the marginal costs and benefits of investing carbon in each organ. While this approach has been applied successfully to trees, it has not previously been developed for herbaceous plants. Here, we present DAESIM2-Plant, a mechanistic plant growth model that couples physiological processes including photosynthesis, stomatal conductance, plant hydraulics, and canopy radiative transfer, with an eco-evolutionary optimal allocation scheme for leaves and roots. This is applied to wheat by coupling it to a source-sink grain production module. Using a series of idealized sensitivity experiments, we show that the model reproduces well-documented patterns of plasticity in carbon allocation: diminishing returns on leaf investment as canopy closure and water limitation are approached, a shift in allocation toward roots under drier conditions, and a root:shoot response that depends jointly on soil moisture and the plant's existing root:leaf balance. Simulating a full growing season across a gradient of soil moisture levels reveals a threshold-like response in canopy development, biomass accumulation, and grain yield, with yield constrained by the same assimilate supply that governs vegetative growth during the critical period and grain filling. This provides a promising basis for generalizing model behaviour across a wide range of environmental conditions. Evaluating these results against experimental and field trial data remains an important next step.

4
User-friendly software for high-throughput processing of chlorophyll fluorescence images to assess plant stress responses: fvfmPy and fvfmR packages

Garen, J. C.; Arnold, P. A.; Crous, K. Y.

2026-10-09 plant biology 10.64898/2026.10.06.757212 medRxiv
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Chlorophyll fluorescence imaging is a powerful tool used to characterize abiotic and biotic stress response of photosynthesis in plants. However, extracting metrics such as Fv/Fm (maximum quantum yield of photosystem II) from chlorophyll fluorescence images remains a substantial bottleneck in large measurement campaigns, often requiring significant manual effort. To resolve this issue, we developed fvfmPy, a user-friendly program which enables rapid analysis of chlorophyll fluorescence images of arrays of leaf discs. fvfmPy uses algorithmic image segmentation to identify regions of interest and extract fluorescence metrics from tens or hundreds of leaf samples per image with little to no manual input. fvfmPy is developed in Python and includes a graphical user interface enabling intuitive parameter adjustment and real-time quality control checking. We additionally developed fvfmR, an R wrapper package for fvfmPy. Fv/Fm values extracted with fvfmPy were indistinguishable from those obtained using manual methods (r2 > 0.99) but required 94% less time to complete (13 s vs. 200 s per 100 measurements). fvfmPy and fvfmR were built to directly integrate with existing fluorescence software packages and can greatly increase throughput of fluorescence measurements to help address key challenges in agriculture and ecology.

5
Studying the role of climate and sex in flowering dynamics of black poplar across time and space

Cazenave, X.; Marc, V.; Julien, D.; Veronique, J.; Durufle, H.

2026-10-06 plant biology 10.64898/2026.10.05.756621 medRxiv
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Global change has a major impact on rivers and their associated terrestrial compartment, the riparian forest. The black poplar (Populus nigra L.), the dominant species of the European riparian forest, is considered an indicator of the biodiversity dynamics of these ecosystems, but is threatened with extinction in several parts of its range. The species is dioecious and shows wide variability in many traits, enabling it to adapt to a broad range of environmental conditions. A detailed characterization of this natural variability is therefore a key issue both for the conservation of natural populations and for biological engineering aimed at restoring riverbanks. Phenology is both an indicator of climate change and an adaptation lever for populations, particularly in perennial species such as trees. In this study, we characterized the spatial and temporal variability in flowering phenology by studying 13 natural black poplar populations along the Loire River, France. Flowering date and duration showed substantial variability both within and between populations, and males generally flowered earlier than females. Despite this variability, the ranking of individual trees' flowering dates was highly consistent across years. Most male-female pairs shared several days of overlapping flowering each year, and this overlap was moderately stable across years. Flowering dates advanced by about five to six days per degree Celsius during early spring, with no detectable difference in sensitivity between sexes. This work contributes to the characterization of flowering variability in an economically important tree species and may inform both the conservation of genetic resources and breeding.

6
Temperature and management reduce the abundance of the invasive Argentine ant (Linepithema humile)

Sanchez-Garcia, D.; Cerda, X.; Angulo, E.

2026-10-09 ecology 10.64898/2026.10.08.756264 medRxiv
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BACKGROUND: The Argentine ant (Linepithema humile) is among the world's worst invasive species. In the Donana Biological Reserve (Spain), it is associated with human structures that provide the mild, moist conditions it needs within the hot, dry scrubland. We evaluated a habitat-modification treatment, predicting that removing this suitable habitat would eradicate the invader locally. Over an 18-year period, we monitored ant communities at a treated and an untreated site, at different distances from the human structures, before and after treatment, and analysed how temperature and worker numbers affected encounters at baits between the Argentine ant and native ants. RESULTS: Distance to the human structures shaped ant communities at both sites, but only the treated site changed after treatment. There, the Argentine ant decreased close to the human structure and almost disappeared farther from it, whereas the endemic Cataglyphis tartessica and C. floricola recovered, especially close to the structure. At baits, the outcome of encounters depended mainly on how temperature changes favoured each species relative to its maximum activity temperature: Cataglyphis spp. displaced the Argentine ant in the morning, as temperature increased, and the Argentine ant recovered the baits in the late afternoon. Numerical advantage favoured only the Argentine ant. CONCLUSION: Habitat modification reduced the Argentine ant and allowed endemic ants to recover, but did not eradicate the invader, which persisted at low abundance 13 years after treatment. In protected areas, habitat management should be combined with eradication, monitoring and prevention of spread.

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Genetic dissection of grafting traits reveals regulators of graft union formation in grapevine

Camboue, M.; Morel, M.; Zehraoui, E.; Lafargue, M.; Hevin, C.; Hocquard, N.; Tandonnet, J.-P.; Ollat, N.; Marguerit, E.; Cookson, S. J.

2026-10-06 plant biology 10.64898/2026.10.06.757043 medRxiv
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Understanding how grafts form has fascinated scientists for over a century, and numerous transcription regulators involved in wound healing, callus formation, and grafting have been identified in model plants. However, the genetic architecture underlying grafting traits remains poorly characterized. To address this gap, we aimed to identify quantitative trait loci (QTLs) associated with grafting success rates and grafting-related traits (including callus formation, mechanical strength of the graft union, and post-grafting growth) in a grapevine rootstock mapping population, Vitis berlandieri x V. rupestris. Although no QTLs were identified for grafting success rate, QTLs were identified for component traits revealing a genetic architecture that would have remained hidden when considering grafting success as a single composite phenotype. By integrating QTL and transcriptome data, we identified regulators potentially mediating grafting-related traits. We then showed that one transcription factor that regulates callus formation and grafting in Arabidopsis potentially has a similar role in grapevine by silencing with exogenous double-stranded RNAs and that exogenous application of methyl jasmonate increases callus development at the graft interface. Candidate transcriptional regulators located within QTLs and evidence from gene silencing and hormone treatments suggest the conservation of regulatory mechanisms underlying wound-induced callus formation across plant species.

8
TPCdesign: A guide to designing informative thermal performance experiments

Lyberger, K.; Nell, L. A.; Paaijmans, K. A.

2026-09-30 ecology 10.64898/2026.09.29.755419 medRxiv
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1. Thermal performance curves (TPCs) are widely used to quantify temperature dependence of biological traits, but estimating them requires experiments across multiple temperatures. Because these experiments can be costly, researchers must balance the number and placement of temperature treatments against replication within treatments. Evenly spaced temperatures are a common default, but may allocate effort inefficiently when thermal responses are nonlinear or strongly asymmetric. 2. We developed TPCdesign, an R package for planning temperature-trait experiments. TPCdesign uses a pseudo-Bayesian (robust) D-optimal experimental design to identify sets of temperatures expected to provide the most information about a TPC, while allowing users to incorporate prior knowledge of thermal limits and curve shape, uncertainty in that knowledge, available numbers of treatments, and practical restrictions on temperature spacing. 3. Using simulation-based worked examples, we show that optimized designs can recover TPCs more accurately than evenly spaced designs, particularly for asymmetric curves and when the number of available temperature treatments is modest. Optimization primarily improves resolution of regions where performance changes rapidly and can substantially improve estimation of upper thermal limits while retaining information across the rest of the curve. 4. TPCdesign provides a practical framework for allocating limited experimental resources according to the biological response researchers seek to estimate. Rather than prescribing a universal set of temperatures, it allows experimental designs to reflect existing biological knowledge, uncertainty, and logistical constraints, improving the information gained from costly thermal performance experiments.

9
Genetic Mapping Reveals a Major Locus for Boron Exclusion in Wild Vitis

Lupo, Y.; Sharma, S.; Munoz, J. R.; Nunez, V.; Gaspar, A.; Cochetel, N.; Cantu, D.; McElrone, A. J.; Diaz-Garcia, L.

2026-10-05 plant biology 10.64898/2026.10.01.756076 medRxiv
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Boron toxicity constrains grapevine (Vitis) production in irrigated arid and semi-arid regions, yet most available rootstocks are sensitive to excessive boron. Although underutilized Vitis species may harbor sources of adaptation, the genetic basis of natural variation in boron exclusion remains poorly understood, limiting the development of boron-tolerant rootstocks. We screened 267 wild Vitis accessions representing 16 species for their ability to limit leaf boron accumulation under excess boron conditions. Leaf boron concentration varied 190-fold among accessions and was highly heritable (entry-mean H^2 = 0.71). Its correlation with stomatal conductance was modest (r = 0.34), indicating that transpiration rate explained only a small proportion of the variation in leaf boron accumulation. Leaf boron was correlated with leaf chloride (r = 0.36), but their largely non-overlapping association profiles supported distinct genetic control. Genome-wide association analysis identified a suggestive association on chromosome 11. Independent quantitative trait locus mapping in a full-sib F1 population (n = 158) derived from Longii-9018 (V. acerifolia) x GRN3 (commercial rootstock) identified qBEx11.1 in the same syntenic region on chromosome 11, which explained 19.5% of the phenotypic variance. Positional candidate genes near the association peak included a pectinesterase and a MATE efflux transporter, suggesting roles for cell wall modification and membrane transport. Leaf spectral reflectance was associated with leaf boron concentration in both populations, particularly at visible and red-edge wavelengths, indicating potential for high-throughput phenotyping. Together, these findings identify qBEx11.1 as a priority locus for boron exclusion and support integrated genetic and spectral approaches for breeding boron-tolerant grapevine rootstocks.

10
Towards an understanding of the taxonomy of the Eurasian montane riparian genus Myricaria (Tamaricaceae) through Angiosperms353 herbariomics

Weitkaemper, K.; Lyakh, E.; Morales-Briones, D. F.; Weitkaemper, F.; Werth, S.

2026-10-06 plant biology 10.64898/2026.10.03.751413 medRxiv
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Myricaria Desv. (Tamaricaceae) is a genus of shrubs that play a keystone role in montane riparian ecosystems across Eurasia, shaping riverine habitats and supporting ecological function. The genus has a centre of origin in the Qinghai-Tibetan Plateau and exhibits a broad distribution, but many species boundaries are unresolved. Here, we present the first phylogenomic analysis of Myricaria using the Angiosperms353 target enrichment bait set, with sampling across its full geographic range. Off-target plastid loci were extracted from next-generation sequencing data using the CAPTUS bioinformatics pipeline. We infer species relationships using ASTRAL-IV and network analysis with SplitsTree, in conjunction with morphology. We also provide a taxonomic treatment of the genus, integrating our morphological observations and phylogenomic analyses for species delimitations. Based on our analyses, recognise two infrageneric sections: sect. Parallelantherae (containing only M. elegans) and sect. Myricaria (the remainder of the genus, with type species M. germanica). We also propose synonymising M. davurica, M. bracteata and M. squamosa with M. germanica. Although species boundaries in the Asian highlands remain unresolved, we conclude that the species M. elegans, M. germanica, M. laxiflora, M. longifolia, M. platyphylla, and M. pulcherrima are well-supported both phylogenomically and morphologically.

11
Challenges and opportunities for integrating genetic diversity monitoring in megadiverse countries: reflections from Mexico

Mastretta-Yanes, A.; Arredondo Amezcua, L.; Llanes-Quevedo, A.; Latorre-Cardenas, M. C.; Ornelas, J. F.; Ramirez Barahona, S.; Zarza, E.; Amaro-Garcia, R.; Acevedo Gasman, F.; Alavez, V.; Burgeff, C.; Cruz-Angon, A.; Contreras-Diaz, R. G.; Orjuela Restrepo, M. A.; Oliveros-Galindo, O.; Rios-Lopez, M.; Rivera-Rodriguez, D. M.; Sanchez-Gonzalez, J. d. J.; Suarez-Acuna, S.; da Silva, J. M.; Hoban, S.; Koppa, V.; Laikre, L.; Wegier, A.

2026-10-01 evolutionary biology 10.64898/2026.09.26.754592 medRxiv
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Megadiverse countries concentrate most of the World's biodiversity. These countries encompass different levels of research infrastructure, and nearly all of them have been historically committed to the Convention of Biological Diversity, often setting precedents and leading new approaches. Here, we ask whether the assessment of genetic diversity indicators provide novel insights for biodiversity management and conservation in one of those countries, Mexico. We evaluated the first national application of the Kunming-Montreal Global Biodiversity Framework (GBF), genetic diversity indicators in Mexico. The data covered 97 taxa across diverse ecosystem types and taxonomic groups, including crop wild relatives, to assess the capacity of genetic diversity indicators to provide novel insights, as well as their relevance for strengthening national conservation strategies. We calculated two indicators: the proportion of populations with an effective population size greater than 500 (Ne 500) and the proportion of populations maintained (PM). Data were sufficient to estimate the Ne 500 indicator for 47 taxa and the PM for 28 taxa, with mean indicator values of 0.217 and 0.936, respectively. Species' geographic range was positively associated with Ne 500, whereas national endemicity had no significant effect. Comparisons with the IUCN Red List and Mexico's national extinction-risk legislation revealed that genetic vulnerability occurs even among taxa not currently recognized as threatened. Our findings highlight a gap in legal recognition of genetic diversity protection that could be strengthened by incorporating population-level assessments focused on maintaining adaptive potential in the long-term. Additionally, the indicators allowed to highlight conservation concerns within crop wild relatives, though fully realizing their potential requires integrating the entire wild-to-domesticated complex. The Mexican experience highlights that the main challenge for scaling the monitoring of genetic diversity is not only generating new data, but integrating existing information into systems that strengthen collaboration and communication among researchers, local communities, and government institutions.

12
Sugarcane's drought memory legacy: how past stress shapes future resilience

Pissolato, M. D.; Martins, T. S.; Miranda, M. T.; Pires, G. S.; Almeida, R. L.; Cruz, L. P.; Sousa, L. P.; Domingues-Jr, A. P.; Machado, E. C.; Fernie, A. R.; Ribeiro, R.

2026-09-30 plant biology 10.64898/2026.09.29.755288 medRxiv
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Plants frequently experience recurrent drought events separated by periods of rehydration. Although drought imposes strong constraints on plant physiology, prior exposure may alter subsequent stress responsiveness through memory-based mechanisms. Here, we investigated whether recurrent drought at distinct developmental stages establishes stress memory in sugarcane and whether this response persists across vegetative propagation. Two genotypes contrasting in drought tolerance and productivity (IACCTC07-8008 and IACSP95-5000, respectively) were grown under greenhouse conditions and subjected to three drought cycles imposed either at tillering or maturation stage. Gas exchange, photochemical performance, leaf water status, primary metabolite profile, and growth traits were assessed across cycles, and vegetative propagules were subsequently evaluated under renewed drought. The first drought cycle imposed strong limitations on carbon assimilation and photochemistry in both genotypes and developmental stages. However, subsequent cycles resulted in attenuated reductions in A and g, improved intrinsic water use efficiency, and partial stabilization of PSII performance, indicating a modified stress-response trajectory. Young plants displayed earlier improvements (from the second cycle), whereas in mature plants this shift was evident mainly during the third cycle. Recurrent drought promoted sustained reorganization of amino acid, carbohydrate, organic acid and polyol metabolism alongside increased root biomass and higher relative water content during later cycles. Importantly, propagules derived from drought-conditioned plants exhibited faster recovery of photosynthetic performance and reduced cumulative physiological impairment under renewed drought, despite showing similar stress sensitivity at maximum water deficit. This persistence of enhanced recovery capacity across vegetative propagation indicates that drought-induced memory was maintained beyond the initially stressed plants. Together, our findings demonstrate that recurrent drought establishes a metabolically imprinted state in clonal sugarcane, integrating physiological adjustment, metabolic reprogramming, and whole-plant acclimation. These results highlight the potential of stress memory as a mechanism supporting resilience in perennial crops exposed to increasingly recurrent drought events.

13
Acclimation to enhanced photorespiratory conditions increases the effectiveness of C2 photosynthesis in C3-C4 intermediates

Leung, A.; Ludwig, M.; Sage, T. L.; Sage, R. F.

2026-09-23 plant biology 10.64898/2026.09.22.753555 medRxiv
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- C2 photosynthesis reduces photorespiratory carbon loss by shuttling glycine from mesophyll (M) to bundle sheath (BS) tissues, where glycine decarboxylase (GDC) releases CO2 that accumulates around rubisco. C2 photosynthesis has been considered a constitutive character, but as a metabolic trait, it may acclimate to the rate of photorespiratory glycine production. - We grew eleven species from two eudicot and two grass lineages spanning C3 to C2 phenotypes at 32 {degrees}C days and 200 or 800 {micro}mol mol-1 CO2. Acclimation was assessed using leaf gas exchange, GDC P-protein immunolocalization, M and BS ultrastructure, photosynthetic enzyme activity, and photosynthesis modelling. - Low relative to high growth CO2 enhanced C2-related phenotypes in sub-C2 and C2 species but not C3 or proto-Kranz species. Sub-C2 species positioned chloroplasts closer to mitochondria and had lower modelled BS conductance. C2 species increased rubisco capacity and GDC allocation to the BS. Aspartate aminotransferase activity increased in both sub-C2 and C2 species. - Acclimation to greater photorespiratory conditions strengthens C2 photosynthesis, but only in species whose BS has crossed a threshold of organelle and GDC investment. We hypothesize that acclimation could expose C2-related traits to selection and facilitate the origin of C4 photosynthesis.

14
Breedbase 2.0 - expanding the functionality for traditional breeding and transgenics

Karaikal, S. K.; Preble, R.; Waring, D. J.; Simoes, C. C.; Tecle, I. Y.; Menda, N.; Tantikanjana, T.; Zhang, J.; Eaton, K.; Corak, K.; Birkett, C.; Krill Brown, A.; Feldmann, M.; Lamm, C.; Thieme, M.; Peteti, P.; Manching, H.; Powell, A.; Hulse-Kemp, A. M.; Jannink, J.-L.; Mueller, L. A.

2026-10-03 bioinformatics 10.64898/2026.09.28.755108 medRxiv
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Breedbase ( is a comprehensive, web-based, open-source breeding management and analysis software for plant breeding that was introduced to address gaps with existing software for plant breeding data. Breedbase is continually improved and developed, with new features being added as required by the breeding community. Since its inception, the capabilities of Breedbase were improved to better serve the diverse data modeling needs of additional crops beyond our original ensemble of cassava, banana, yam, sweet potato, tomato, rice, and wheat. We describe here major updates that have been made in the past 4 years, including (1) improved handling of repetitive measurements; (2) a redesigned experimental treatments interface; (3) a more fine-grained user permission system; (4) improved trial quality control workflows; (5) intercropping support; (6) the addition of a decision meeting feature that helps decision makers make the best selection with the available data; (7) transgenics and tracking tools and finally, (8) an improved field layout tool which consolidates several trials in one field. These new features integrate seamlessly with the previous feature set of Breedbase - making it one of the most feature rich breeding management softwares available.

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Piloting floral-visitor assemblages: Camera-based monitoring in the cliff-dwelling Eastern Alpine endemic Physoplexis comosa (Campanulaceae)

Iberl, K.; Kirschner, P.; Koc, A.; Hasakova, T.; Wellstein, C.; Stenc, J.

2026-10-02 ecology 10.64898/2026.10.01.756015 medRxiv
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Understanding floral visitor dynamics along elevational gradients is essential for assessing potential implications for pollen limitation and population genetic processes in fragmented populations of cliff-dwelling alpine endemics. Physoplexis comosa (Campanulaceae) is a chasmophytic paleoendemic restricted to vertical rock faces on dolomitic and limestone bedrock from 200 to 2,800 m a.s.l. The species exhibits a specific floral morphology with fused corolla apices, basal openings for nectar access, and secondary pollen presentation, yet its functional floral visitor assemblage has remained poorly characterized across the species' elevational range. In this pilot study, we tested a two-tier camera-monitoring setup combining action cameras for diurnal monitoring with Raspberry Pi-based systems equipped with IR illumination for combined diurnal and nocturnal recording. We conducted monitoring across five elevational sites (1,480 to 2,400 m a.s.l.) in the Eastern Alps. Recorded video material was downsampled and annotated using the Addax platform alongside manual cross-validation to record physical contact events. Preliminary results confirm the technical feasibility of continuous monitoring in steep terrain and suggest possible elevational variation in diurnal visitors, alongside nocturnal activity by Geometridae moths. Camera-based observations provided higher functional resolution and revealed a different visitor assemblage than previous eDNA metabarcoding trials. This proof-of-concept establishes a methodological foundation for forthcoming multi-day monitoring campaigns and complements ongoing studies of the mating system and population-genetic analyses.

16
Domestication, spread, and improvement have shaped biological nitrogen fixation traits in Zea taxa

Maleki, K.; Connolly, L.; Lorenz, N.; Amphonechit, T.; Lindsey, A.; Perales, H.; Bernau, V.; Dick, R.; Mercer, K.

2026-10-06 ecology 10.64898/2026.09.30.755791 medRxiv
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Synthetic nitrogen fertilizers enhance maize (Zea mays ssp. mays) productivity but impose substantial environmental and economic costs. Some Mexican maize landraces support biological nitrogen fixation (BNF) in aerial root mucilage, raising the question of how much variation exists in this trait and how domestication, geographic spread, and improvement have shaped BNF-related traits across Zea in the Americas. We evaluated aerial root traits and BNF capacity across the maize domestication continuum using 60 Zea accessions grown in field experiments over two years under low-N conditions. Some accessions of wild Zea, landraces from Mexico and South America, and improved varieties had elevated nitrogen derived from the atmosphere (%Ndfa), ranging from 20 to 40%; some of these also had greater %Ndfa than typical improved varieties. Spread and improvement appear to have significantly reduced the number of aerial root-bearing nodes, with wild Zea and Mexican landraces consistently producing more. Nevertheless, the proportion of nitrogen derived from the atmosphere (%Ndfa) does not vary systematically across the domestication continuum. Thus, crop evolution shaped aerial root phenotypes more than associative BNF capacity. The persistence of substantial within-group variation indicates that the genetic potential for enhanced BNF remains within the Zea gene pool, providing opportunities to encourage and improve nitrogen use efficiency in maize cropping systems.

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Climate of origin constrains phenological tracking of temperature in a California endemic oak (Quercus lobata)

Goetz, A. R. B.; Sork, V. L.; Canning, C. A.; Ivey, C. T.; Carlisle, E.; Wada, E.; Wright, J. W.

2026-09-28 plant biology 10.64898/2026.09.26.754716 medRxiv
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Premise of the study. Phenotypic plasticity is advantageous for many plants that experience environmental fluctuations, but strong selection pressures can establish limits to plasticity. In deciduous trees, the ability to time leaf elongation in response to spring temperatures can extend the length of the growing season for a given year's climate. However, emergence timing may have undergone strong selection by factors like cold temperatures, limiting the capacity of locally adapted populations to adjust via plasticity to new conditions. Methods. Using a nine-year dataset of 659 families of Quercus lobata in two common gardens, we tested how climate of origin and annual temperatures at the gardens affected variation in phenology. We then examined whether leaf emergence timing was under selection in the gardens by testing its effects on growth. Finally, we tested whether among-year plasticity in leaf emergence timing conferred a growth benefit. Key results. Year-to-year environmental variation explained more phenological variation than genetic differences associated with climate of origin, yet trees from cooler climates were more constrained in their ability to track temperature than trees from warmer climates. We found evidence of weak stabilizing and directional selection on phenology, suggesting that strong selection in favor of earlier phenology is unlikely. Finally, we found no evidence that selection has favored increased plasticity in Q. lobata. Conclusions. Phenological plasticity remains a key driver of plants' response to changing temperatures, but it is constrained by natural selection. As temperatures rise, these processes may disproportionately limit the ability of trees adapted to cooler climates to shift their phenology to match spring temperatures.

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Plant Water-Carbon Relations In Huanglongbing-Affected Citrus Trees And The Impact Of Hlb Exposure Duration, Fruit Developmental Stage, And Source-Sink Manipulation On These Relations

Alade, D. O.; Vashisth, T.; Vincent, C.

2026-10-06 plant biology 10.64898/2026.10.01.755948 medRxiv
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Bulk phloem flow is driven by pressure gradients generated by water drawn from the xylem, coupling source-sink transport with water status. Huanglongbing (HLB), a phloem-affecting bacterial disease of citrus, disrupts phloem transport, and causes canopy water deficit. Although improved water management can enhance HLB-affected tree health, the effects of HLB on water-driven source-sink relations are unknown. Fruits function as both carbon sink and water reservoir, but the role of fruit in regulating whole-tree water status remain poorly understood. We examined leaf-fruit water relations in HLB-affected citrus and evaluated how HLB exposure duration, fruit developmental stage, and source-sink manipulation shape these dynamics. Source-sink relations were manipulated in branches of symptomatic trees with long-term (four years) and recent (six months) HLB exposure. We girdled branches with a single fruit as the sink and defoliated at (0%, 50%, or 75%), and an ungirdled, non-defoliated branch served as control. We measured stomatal conductance, leaf hydraulic traits, leaf and fruit soluble sugars, diurnal fruit shrinkage (to estimate xylem backflow) and fruit water loss. Source-sink manipulation did not affect shoot total soluble sugar. HLB-exposure resulted in less negative osmotic potential, more negative turgor potential and reduced modulus of elasticity and relative water content at turgor loss point. HLB exposure also increased diurnal fruit shrinkage, with shrinkage responses to source-sink manipulation varying across fruit development stages. Collectively, these findings suggest that long-term HLB exposure promotes leaf acclimation to water deficits, however, high sink demand may diminish the leaf water status regulation at Stage II, when fruit sink carbon demand is highest.

19
Chaotic dynamics in blooms of Ostreopsis cf. ovata modelled from environmental time series using ordinary differential equations systems

De Almeida, A.; Hocquart, S.; Rosalie, M.

2026-09-28 plant biology 10.64898/2026.09.25.754431 medRxiv
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Blooms of the toxic dinoflagellate Ostreopsis cf. ovata can cause respiratory irritation in beach users, yet their environmental drivers and temporal dynamics remain poorly understood. Here, we use a dynamical-systems approach to investigate how environmental conditions shape bloom dynamics from long-term time series of algal abundance and abiotic variables. Using the global modelling framework GPoM, we reconstruct nonlinear ordinary differential equation systems and identify candidate models capable of reproducing key features of the observed dynamics, including chaotic behaviour. Topological and statistical analyses reduce the candidate models to two systems that best capture the observed distributions and dynamical patterns. These models reveal distinct combinations of environmental conditions associated with bloom occurrence and amplitude, providing a framework for interpreting bloom trajectories and a potential basis for short-term prediction.

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QTL analysis of essential oil, seed shattering, thousand-grain weight and stalk attachment rate in Carum carvi

von Maydell, D.; Zimmer, J.; Pinnuri, A.; Lim, F.-S.; Junghanns, M.; Marthe, F.

2026-10-06 genetics 10.64898/2026.10.01.755638 medRxiv
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Caraway (Carum carvi L., 2n = 2x = 20) is a medicinal and aromatic plant of the Apiaceae family valued for its essential oil with the major terpenoids carvone and limonene. While the essential oil content represents an important quality trait, low seed shattering and high thousand-grain weight (TGW) are key determinants of seed yield. As molecular tools remain scarce within Apiaceae breeding beyond carrot, we conducted a QTL mapping for these seed-related traits using two previously established F2 populations (Effective N(P1) = 236; N(P2) = 266). In P1 with the non-shattering maternal parent Rekord, QTL mapping revealed at least one shattering locus on LG03 (PVE: 9.9%). In addition, loci associated with essential oil (LG08, 10.5% PVE) and TGW (LG09, 11.1% PVE) were detected. In P2, we identified six essential-oil loci (LG02-06, LG10; combined PVE: 49.2%), with five loci affecting both carvone and limonene, and one (LG03) exclusively limonene. Additionally, a major QTL for TGW mapped to LG02 (PVE: 15.6%). For stalk attachment rate one minor QTL was detected (LG07, 8.5% PVE), while no QTL co-localized with the major shattering locus. To pave the path towards fine-mapping, we designed and validated 26 diagnostic PACE markers covering five key QTLs.