Horticulture Research

Carmenere is a widely cultivated and internationally recognized grapevine cultivar in Chile, yet genetic variation among its clones remains poorly characterized. Early studies based on SSR and AFLP markers detected limited polymorphism, but these approaches interrogate only a small fraction of the genome, leaving the extent of clonal diversity unresolved. Here, we generated an improved chromosome-scale diploid genome assembly of Carmenere FPS clone 02 and characterized clonal genomic diversity by sequencing 36 biological replicates representing 12 clones maintained in Chile, including heritage selections rescued from old producer vineyards by Vina Santa Carolina as part of its Bloque Herencia conservation program, and commercial nursery-derived clones. Focusing on low-frequency variants and using replicate-aware consensus calling, we identified more than 9,000 private single nucleotide variants (SNVs) and small indels per clone, providing high-resolution markers for clonal identification. Although most variants were located in repetitive or intergenic regions, a subset affected coding sequences, with genes involved in plant-pathogen interactions, transport, and secondary metabolism most frequently impacted. While variant-affected genes associated with wine anthocyanin content, TA, pH, and alcohol percentage were identified, broader phenotypic characterization will be required to assess their biological significance. Overall, this study provides a genome-wide characterization of extant clonal diversity in Carmenere, with implications for clonal selection and genetic resource conservation.

Pepper (Capsicum annuum L.) is a recalcitrant species regarding shoot regeneration, a trait that serves as a major bottleneck for the application of genetic engineering tools. In this study, comparative genetic analysis between a rare high-regeneration cultivar and a common low-efficiency cultivar identified a single nucleotide polymorphism (SNP) in PHYTOCHROME A SIGNAL TRANSDUCTION 1 (CaPAT1) that determines shoot regeneration efficiency. The T478C SNP in the high-efficiency cultivar converts a stop codon into an Arg codon, leading to translational read-through into the neighboring gene and forming an intact GRAS domain. This SNP-mediated formation of full-length CaPAT1 is essential for its dimerization. Notably, the overexpression of CaPAT1T478C in multiple low-efficiency cultivars, including both hot and bell peppers, significantly improved both shoot regeneration and transformation efficiency in the transformed T0 generation. These findings demonstrate the pivotal role of CaPAT1 in enhancing shoot regeneration and provide a robust strategy to overcome recalcitrance in pepper.

We present a global soybean haplotype map generated from whole-genome sequencing of 1,278 Glycine max and Glycine soja accessions, comprising 11.37 million SNPs and 2.05 million short insertions and deletions. This map (GmHapMap-II) captures unprecedented worldwide genetic diversity, reflecting the broad extent of the global soybean gene pool. Population structure analyses revealed six geographically distinct subpopulations that affected the linkage and shaped the recombination. The haplotype variation map was used to identify novel genomic regions associated with crude protein content on chromosome 15 that were not detected by a lower SNP density array. LD-based haplotype analysis revealed a superior haplotype for crude protein content. The constructed haplotype map enabled detailed characterization of haplotype diversity and copy number polymorphism at the SCN-associated rhg-1 and Rhg-4 loci, revealing both novel haplotype structures and germplasm lines with elevated CNV relative to previously characterized genotypes. We employed the HapMap matrix for a multi-class variations ML-based genomic prediction approach to predict phenotypes for SCN and catalogued the gene-centric haplotypes in a user-friendly database. The analysis revealed the extent of deleterious alleles present in the soybean germplasm and how breeders have deployed beneficial alleles and purged deleterious ones. The haplotype map will serve as a major genomic resource for trait-based mapping, enhancing efforts in the genomics-enabled development of improved cultivars.

Climate change increasingly threatens global Capsicum (pepper) production. Accelerating the deployment of climate-resilient cultivars requires effective use of genetic diversity conserved in genebanks. We implement a "turbocharging" strategy in Capsicum by integrating genome-wide association studies and genomic prediction in a core collection (n = 423), followed by genomic prediction across the global collection (n = 10,250) using the core as a training population. We generated genomic estimated breeding values (GEBVs) for 31 high-accuracy traits (r > 0.5) encompassing hyperspectral phenotypes (heat/control), agronomic performance (heat/control) and fruit quality. To enhance accessibility and decision-making, we developed a large language model (LLM) integrated application that enables flexible, preference-based selection of candidates. By narrowing the parental decision space, this framework streamlines screening of large germplasm collections while balancing climate resilience, quality attributes and market demands. Our approach provides a scalable decision-support system to accelerate climate-resilient Capsicum breeding and maximize global genetic resources.

The narrow genetic base of cultivated tomato (Solanum lycopersicum L.) represents a major constraint on crop improvement, necessitating the exploitation of wild relatives to broaden allelic diversity. Here we present SABER (Solanum lycopersicum Allele Biodiversity Enriched Resources), a novel eight-founder Multiparent Advanced Generation Intercross (MAGIC) population that, for the first time, incorporates the Galapagos wild relative Solanum cheesmaniae as a founder alongside seven elite S. lycopersicum lines. Following a structured crossing scheme and Single Seed Descent advancement, F6 recombinant inbred lines were genotyped at 5,850 high-confidence SNP markers using Single Primer Enrichment Technology (SPET). Population structure analyses confirmed low residual heterozygosity, limited substructure among offspring, and successful introgression of S. cheesmaniae alleles across all twelve chromosomes. Mapping performance was validated through three Mendelian traits with known genetic determinants, all of which resolved to genomic positions consistent with the literature. QTL mapping for quantitative agronomic traits identified known loci for fruit epicarp and flesh color, and two novel QTL for days to flowering, number of leaves before flowering, and soluble solids content. Together, these results demonstrate that SABER is a powerful and reliable platform for high-resolution QTL mapping and candidate gene discovery, and establish a replicable framework for integrating wild germplasm into multiparental tomato breeding resources

Common buckwheat (Fagopyrum esculentum Moench) is a globally cultivated pseudocereal with a high nutritional quality and economic value. Due to its self-incompatibility, common buckwheat exhibits a high level of heterozygosity, making genome assembly challenging. Consequently, reference-level haplotype-resolved assemblies of common buckwheat are scarce, hindering research and genomics-assisted breeding. Here, we present a near-complete, chromosome-level, haplotype-resolved assembly of a common buckwheat F1 genotype (named Tuka), generated using a trio-binning approach that integrated parental Illumina short-read data with PacBio HiFi and Hi-C data from Tuka. The Tuka assembly comprises two haplomes, Tuka_h1 and Tuka_h2, both showing high contiguity (contig N50 of 76.68 Mb and 84.57 Mb, respectively), high completeness (assembly sizes of 1.28 Gb and 1.23 Gb with BUSCO scores of 96.9% and 96.8%, respectively), high base-level accuracy (QV of 59.08 and 63.03, respectively), and few gaps (35 and 30, respectively). This near-complete assembly of Tuka serves as a valuable genomic resource for common buckwheat, enabling advanced genomic analyses and accelerating research and breeding using state-of-the-art genomic tools.

Climate change is reshaping the adaptive landscape of forest ecosystems, demanding more efficient strategies to identify and deploy resilient tree genotypes. Genomic prediction offers a powerful framework to accelerate selection for complex physiological traits underlying climate adaptability in long-lived species such as sessile oak (Quercus petraea (Matt.) Liebl.). Here, we conducted genomic prediction for three key physiological traits carbon isotope composition, nitrogen isotope composition, and the carbon-to-nitrogen content ratio (C/N ratio) measured in 746 trees genotyped with dense genome-wide markers ([~]580,000 SNPs). High genomic heritabilities were estimated across traits, with within-year prediction accuracies (Pearsons r between genomic estimated values and observed phenotypes) reaching 0.77. Notably, across-year and across-provenance predictions remained substantial (0.41 < r < 0.82), with predictability declining with increasing genetic distance (FST) between training and test provenances for nitrogen isotope composition and C/N ratio. In addition, GWAS-guided SNP preselection increased heritability capture by [~]15% relative to random SNP subsets. And, the pronounced provenance-by-environment interactions observed indicated substantial phenotypic plasticity in these traits. These results demonstrate the strong potential of applying genomic prediction to foliar physiological traits as polygenic predictors for climate adaptation in plants, support provenance-aware breeding to improve forest establishment, and provide practical strategies for deploying genomic prediction in long-lived species.

DNA methylation plays a central role in the regulation of gene expression. In plants, methylation occurs in the CG, CHG and CHH contexts, via distinct DNA methyltransferases including MET1, CMT3 and the RNA-directed DNA Methylation (RdDM) pathway via DRM2. In interspecific hybrids, these epigenetic mechanisms are confronted to a mixed small RNA population and two subgenomes harbouring specific methylation patterns, therefore generating unique expression profiles. The aim of this work was to understand these regulations by analysing gene expression, DNA methylation and small RNAs in a Citrus hybrid resulting from the cross between C. reticulata (mandarin) and C. australasica (finger lime). Haplotype-resolved subgenomes assembly identified hundreds of allele-specifically expressed genes. Asymmetric reprogramming of methylation was observed, in particular an increase in CHH in C. australasica haplotype. Surprisingly, CHH methylation, usually associated with gene silencing, was correlated here with increased expression, but also 24nt small RNA populations at their promoter regions. Similar analyses of the parental lines and other citrus species suggest the correlation between CHH methylation-enriched promoter and high expression level is not due to the hybridization, but seem to be generally true for all citrus. These observations suggest that, in citrus fruit, RdDM could activate transcription. This work also provides a full pipeline to analyse the expression profiles and DNA methylation in complex hybrids, which could be crucial for anticipating varieties resistant to diseases and the current threats affecting citriculture such as the Huanglongbing disease.

Barley (Hordeum vulgare L.) is an important crop in the world and its seed dormancy is primarily controlled by a Mitogen-Activated Protein Kinase Kinase 3 (MKK3) gene. Although kinase activity of MKK3 and its roles in barley post-domestication have been widely studied, the pre-domestication evolution of MKK3 and the spread of nondormant alleles among global barley varieties remain largely unexplored. In this study, we analyzed MKK3 sequences in barley and its wild progenitor (H. spontaneum) and identified two polymorphic miniature inverted-repeat transposable elements (MITEs). Comparative analyses indicated that the insertions/excision of the MITEs predated the current estimates of barley domestication. Examination of the barley pangenomes coupled with droplet digital (dd) PCR revealed extensive copy number variation of MKK3 and suggested that transposons likely drove tandem amplification of the MKK3 gene on chromosome 5H. Additionally, approximately 1-Kb MKK3 sequences were found on chromosomes 1H and 6H. Further analysis indicated that these short MKK3 sequences were captured by a CACTA transposon that also contained fragments from four other expressed genes. The acquisition of MKK3 was estimated to be between 1.9-2.5 million years ago. Together, these findings illuminate the dynamic pre-domestication evolution of the MKK3 gene and suggest three independent origins of highly nondormant barley worldwide including a unique lineage predominant in Ethiopian germplasm. This study reveals the pivotal roles of transposons in MKK3 evolution and provide helpful information for understanding the complex history of MKK3 gene in barley and also for improving preharvest sprouting (PSH) tolerant varieties under distinct natural conditions.

Flexible developmental programs enable plants to customize their organ size and cellular composition. In leaves of eudicots, the stomatal lineage produces two essential cell types, stomata and pavement cells, and plants can adjust the total numbers and ratios of these cell types in response to external cues. Central to this flexibility is the stomatal lineage-initiating transcription factor, SPEECHLESS (SPCH). Here we explore the mechanisms underlying SPCHs involvement in environmental response. Using multiplexed CRISPR/Cas9 editing of SlSPCH cis-regulatory sequences in tomato, we identified variants with altered stomatal development responses to drought, light and temperature cues. By creating and live-cell tracking translational reporters of SlSPCH and its paralogues SlMUTE and SlFAMA, we revealed the corresponding cellular events that lead to the environmental change-driven responses in stomatal production and leaf form. Plants bearing the novel reporters and SlSPCH variants are powerful resources for fundamental and applied studies of tomato resilience in response to climate change.

Individual phenotypes often depend on the genotypes of other individuals within a group. These phenomena are termed indirect genetic effects (IGEs) and have been distinguished from direct genetic effects (DGEs) using quantitative genetic models. Recent studies have utilized high-resolution polymorphism data to enable genomic prediction (GP) and genome-wide association study (GWAS) of IGEs, but unified methods remain limited. Here we integrate polygenic and oligogenic IGEs using a multi-kernel mixed model incorporating two random effects with a single covariance parameter. Underlying this implementation, the Ising model of ferromagnetics enabled us to simplify locus-wise and background IGEs for GWAS and GP, respectively. Our simulations demonstrated that, while the previous and present models exhibited similar performance, the present model can infer a trade-off between DGEs and IGEs. By applying this method to three species of woody plants, we found evidence for intergenotypic competition in aspen and apple trees, but limited evidence in climbing grapevines. Based on GWAS, we also detected significant variants associated with the competitive IGEs on the apple trunk growth. Our study offers a flexible implementation for GWAS/GP of IGEs, thereby providing an effective tool to dissect the genetic architecture of group performance.

Grapevine cluster architecture is a key selection target in breeding programs because it influences disease susceptibility, yield stability and juice quality. High-throughput phenotyping offers a rapid and non-destructive approach to capture biochemical and structural variation in these traits, yet the influence of plant organ reflectance and data partitioning strategies on trait prediction remains poorly understood. In this study, we evaluated how hyperspectral reflectance from different grapevine organs contributes to the prediction of cluster architecture and juice quality traits in two clonal populations of Riesling and Pinot. Using partial least squares regression (PLSR), we assessed the prediction accuracy of eight cluster architecture and six juice quality traits under two data partitioning strategies. Models based on cluster reflectance outperformed those using dry leaf reflectance for most traits, except for pH. Partitioning the dataset by cluster type increased trait variance and improved predictions for number of berries (R{superscript 2} = 0.53), berry diameter (R{superscript 2} = 0.79), and total acidity (R{superscript 2} = 0.48). Visible, red-edge and NIR spectra were most informative regions to predict the traits studied. Together, our results highlight the importance of organ-specific data and appropriate calibration strategies to improve phenomic models for the development of scalable proxies for grapevine improvement. HighlightSpectral phenomics reveals that prediction accuracy in grapevine depends on organ spectral signatures and traits, with cluster reflectance outperforming leaves, informing new phenotyping strategies for breeding improvement.

The cGAS-STING pathway has been widely recognized as a critical DNA-sensing pathway that plays a broad-spectrum antiviral role. Livestock, especially pigs, represents one of the most important meat sources. In this study, we identified a key lysine 61 (K61) of porcine STING (pSTING) that plays an essential role in its degradation and antiviral signaling in a species-specific manner, with K61 as the major lysine of pSTING for K48-linked ubiquitination. After virus infection, pSTING recruits the E3 ligase, RNF5, which specifically assembles a K48-linked ubiquitin chain at K61, thereby mediating pSTING proteasomal degradation and reducing its antiviral activity. Meanwhile, the deubiquitylation of K61 is mediated mainly by deubiquitinase USP20, which enhances the stability and antiviral activity of pSTING. Together, given the relatively few lysine numbers in livestock STINGs and species-specific K61 regulation of pSTING stability and antiviral function, the K61 and its specific regulatory enzymes of pSTING could serve as potential targets for breeding of antiviral pigs and design of antiviral drugs, respectively.

O_LIHydroxycinnamic acid amides (HCAAs) are phenylpropanoid-derived metabolites with known antimicrobial and structural roles in plant defence against pathogens. However, their contribution to mechanical wound responses remains unclear, especially in terms of tissue regeneration and signalling. C_LIO_LIHere, we used tomato transgenic plants overexpressing the tyramine hydroxycinnamoyl transferase (THT), the key biosynthetic enzyme for HCAA production, to investigate the role of HCAAs in wound-induced responses, combining targeted metabolite profiling, gene expression, confocal microscopy, antioxidant assays, and volatile analyses. C_LIO_LIWe show that THT overexpression enhances wound-induced accumulation of HCAAs, promoting vascular lignification, suberization, callose deposition, and increased regeneration capacity. Additionally, 35S::THT plants display a distinct VOC profile that modulates defence gene expression in neighbouring wild-type plants, even in the absence of injury. C_LIO_LIThese results identify THT as a key regulator of structural reinforcement and defence priming after mechanical damage. Our findings highlight a novel role for HCAAs in wound healing and interplant signalling, with potential applications for improving crop resilience to mechanical stress. C_LI

Poplar seed fibers cause environmental and health concerns, yet their developmental mechanisms remain poorly understood. Here, we constructed a high-resolution spatiotemporal transcriptomic atlas of female poplar capsules by integrating single-nucleus and spatial transcriptomics. We delineated the developmental trajectory of seed fibers, confirming their origin from placenta cells, and identified three functionally distinct fiber cell subtypes involved in initiation, metabolic support, and elongation. Weighted gene co-expression network analysis (WGCNA) identified several hub transcription factors, including PtoMYB, PtoHDT1, PtoEIF6 and PtoPDF2, that may serve as key regulators of fiber development. Our study provides a cellular-resolution framework for understanding trichome development in woody perennials and offers candidate targets for functional characterization toward breeding low-fluff poplar cultivars. HighlightsO_LIA spatiotemporal transcriptomic atlas of poplar capsule development is constructed at single-cell resolution C_LIO_LIFiber cells originate from placenta cells and comprise three functionally distinct subtypes C_LIO_LIProvides molecular targets for breeding low-fluff poplar cultivars to mitigate environmental pollution C_LI

Sacha inchi (Plukenetia volubilis L.) is an emerging woody oilseed crop prized for its high alpha-linolenic acid (ALA) content. Despite its nutritional and economic value, the lack of high-quality genomic resources has hindered genetic improvement and the elucidation of its unique polyunsaturated fatty acid and lipid biosynthetic pathways. In this study, we report a high-quality, chromosome-scale genome assembly of sacha inchi with a total length of 710.62 Mb, integrated from Illumina, PacBio, and chromosome conformation capture (Hi-C) technology. The genome harbors 37,570 protein-coding genes, and 379.86 Mb (53.45%) of repetitive sequences. Phylogenomic analysis reveals that sacha inchi diverged from its closest relative Ricinus communis, [~] approximately 36.2 million years ago. Comparative genomics indicates that sacha inchi experienced only ancient whole genome duplication events. To elucidate the mechanisms governing ALA biosynthesis and triacylglycerol (TAG) accumulation in sacha inchi seeds, we performed temporal transcriptome profiling across six seed development stages. Our findings demonstrate that high TAG content is primarily driven by the sustained expression of biosynthetic genes and low activity of degradation genes during mid-to-late seed development. Notably, while genes encoding stearoyl-ACP desaturases (SADs) maintain the precursor pool, the expression of genes encoding fatty-acid desaturase 2 (FAD2) and fatty-acid desaturase 3 (FAD3) is positively correlated with the final accumulation of C18:2 and C18:3 fatty acids. We also identified lncRNAs as potential epigenetic regulators of these key pathways. This high-quality genome provides a critical foundation for elucidating the molecular mechanisms of seed growth and development in sacha inchi.

Sesame (Sesamum indicum) is one of the earliest domesticated oilseed crops and is valued for antioxidant lignans that stabilize oil quality. However, the genomic and evolutionary history of the genus Sesamum, including the origin of its allotetraploid relative S. radiatum and the diversification of lignan metabolism, remains poorly understood owing to limited chromosome-scale genomic resources. Here we present chromosome-level genome assemblies for three wild Sesamum species, two Ceratotheca species and a Japanese sesame cultivar to reconstruct genome and karyotype evolution across the Sesamum-Ceratotheca complex. Comparative analyses show that the derived x=16 lineage originated from an ancestral x=13 karyotype through chromosome fission, fusion and translocation, whereas another x=13 lineage underwent extensive restructuring associated with retrotransposon expansion. Phylogenomics places Ceratotheca within the x=16 Sesamum clade and reveals that S. radiatum originated through hybridization involving a C. sesamoides-like ancestor. The antioxidative lignan gene CYP92B14 was reintroduced via the BB progenitor, linking hybridization with restoration of oil-stabilizing metabolism during sesame evolution.

Genomic selection holds the potential to serve as a strategic tool to enhance the genetic gain of complex traits in Miscanthus breeding programs. The development of improved cultivars requires their assessment for various traits across diverse environments to ensure suitable overall performance. Hence, the multi-trait multi-environment (MTME) genomic prediction (GP) models offer an opportunity to improve selection accuracy. This study aims to evaluate the potential of five GP models: (1) three MTME models including genotype-by-trait-by-environment interaction (GxExT) and (2) two single-trait multi-environment (STME) models (with and without GxE interaction). A Miscanthus sacchariflorus population comprising 336 genotypes evaluated in three environments and scored for four traits (biomass yield YDY, total culm number TCM, average internode length AIL, and culm node number CNN) was analyzed. The predictive ability of the models was evaluated considering three cross-validation schemes resembling realistic scenarios (CV1: predicting new genotypes, CVP: predicting missing traits in a given environment, and CV2: predicting partially observed genotypes). On average, in all cross-validation schemes compared to the STME the predictive ability of the MTME models was 10% to 70% higher for TCM and AIL. On the other hand, for YDY and CNN, both STME models performed similarly or slightly better (between 5 to 64%) than the MTME models in most environments. While the MTME models were not successful for all traits when compared to their STME counterparts, MTME models improved the prediction of the performance of genotypes that were untested across environments or lacked trait information in a specific environment. Overall, our study suggests that MTME GP models can be implemented in Miscanthus breeding programs to improve the predictive ability of the complex traits, shorten breeding cycles, and accelerate selection decisions.

Hi-C data is commonly used for reference-free de novo scaffolding. However, with the rapid increase in high-quality reference genomes, reference-guided workflows are now more practical for assembling large numbers of target genomes without relying on costly and labor-intensive Hi-C sequencing. Recently, a pangenome graph-based haplotype sampling algorithm was introduced to generate personalized graphs for target genomes. Such graphs have strong potential as references for reference-guided contig scaffolding. Here, we present noHiC, a reference-guided scaffolding pipeline supporting key steps of plant contig scaffolding. A distinctive feature of noHiC is the nohic-refpick script, generating a best-fit synthetic reference (synref) from a pangenome graph that is genetically close to the target contigs. This enables the integration of genetic information from many references (up to 48 in our tests) without using them separately during scaffolding. Synrefs showed advantages over highly contiguous conventional references in reducing false contig breaking during reference-based correction. Additionally, nohic-refpick can be combined with fast scaffolders (ntJoin) to rapidly produce highly contiguous assemblies using synrefs derived from pangenome graphs. The noHiC pipeline, used alone or in combination with ntJoin, can generally produce assemblies that are structurally consistent with public Hi-C-based or manually curated genomes. The pipeline is publicly available at https://github.com/andyngh/noHiC. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=82 SRC="FIGDIR/small/712436v1_ufig1.gif" ALT="Figure 1"> View larger version (9K): org.highwire.dtl.DTLVardef@40bd8forg.highwire.dtl.DTLVardef@5d2bbborg.highwire.dtl.DTLVardef@e214a3org.highwire.dtl.DTLVardef@b90b06_HPS_FORMAT_FIGEXP M_FIG C_FIG

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.