The first nested association mapping (NAM) population for outbreeding Italian ryegrass reveals candidate genes for seed shattering and related traits
Authors: Kiesbauer, J., Grieder, C., Sindelar, M., Schlatter, L. H., Ariza-Suarez, D., Yates, S., Stoffel-Studer, I., Copetti, D., Studer, B., Koelliker, R.
The study generated the first nested association mapping (NAM) population in the outcrossing forage grass Italian ryegrass (Lolium multiflorum) to investigate seed shattering and related traits, using ddRAD sequencing of 708 F2 individuals combined with whole-genome sequencing of 24 founders to obtain over 3 million SNPs for population structure, parentage, and GWAS analyses. Seven QTL were identified for seed shattering and other agronomic traits, leading to the discovery of candidate genes, including one associated with ripening pathways that explained 10% of phenotypic variance, demonstrating the utility of NAM for dissecting complex traits in outcrossing grasses.
The study developed a high-throughput phenotyping platform to assess root infestation by Orobanche cumana in a diverse sunflower association mapping population and applied a dual GWAS using SNPs and k-mers to uncover resistance loci. It validated known QTLs with higher resolution, identified novel candidate genes such as leucine‑rich repeat receptor kinases, and highlighted introgressed segments from wild Helianthus species that contribute to broomrape resistance.
An Axiom SNP genotyping array for potato: development, evaluation and applications
Authors: Baig, N., Thelen, K., Ayenan, M. A. T., Hartje, S., Obeng-Hinneh, E., Zgadzaj, R., Renner, J., Muders, K., Truberg, B., Rosen, A., Prigge, V., Bruckmueller, J., Luebeck, J., Van Inghelandt, D., Stich, B.
The study reports the creation and validation of a high‑density Axiom SNP array for Solanum tuberosum, based on 10X Genomics sequencing of 108 diverse clones and integration of existing Illumina markers. The array demonstrated high reproducibility and, after filtering, provided 206,616 informative markers for population structure analysis, GWAS of polyphenol oxidase activity, and genomic prediction with accuracies up to 0.86.
Identification of a novel link connecting indole-3-acetamide with abscisic acid biosynthesis and signaling
Authors: Moya-Cuevas, J., Ortiz-Garcia, P., Gonzalez Ortega-Villizan, A., Viguera-Leza, I., Perez-Gonzalez, A., Paz-Ares, J., Alonso-Blanco, C., Vicente-Carbajosa, J., Pollmann, S.
A genome-wide association study of 166 Iberian Arabidopsis accessions identified loci, including ABA3 and GA2ox2, that modulate the inhibitory effect of the auxin precursor indole-3-acetamide (IAM) on primary root elongation. Integrating sequence analysis, transcriptomics, 3D protein modeling, and mutant physiology revealed that IAM promotes ABA biosynthesis and signaling, uncovering a novel node of hormone crosstalk.
Whole genome sequencing-based multi-locus association mapping for kernel iron, zinc and protein content in groundnut
Authors: Sagar, U. N., Parmar, S., Gangurde, S. S., Sharma, V., Pandey, A. K., Mohinuddin, D. K., Dube, N., Bhat, R. S., John, K., Sreevalli, M. D., Rani, P. S., Singh, K., Varshney, R. K., Pandey, M. K.
The study used multi‑season phenotyping for iron, zinc, and protein content together with whole‑genome re‑sequencing of a groundnut mini‑core collection to conduct a genome‑wide association study, identifying numerous marker‑trait associations and candidate genes linked to nutrient homeostasis. SNP‑based KASP markers were designed for nine loci, of which three showed polymorphism and are ready for deployment in genomics‑assisted breeding for nutrient‑rich groundnut varieties.
The study integrates genome, transcriptome, and chromatin accessibility data from 380 soybean accessions to dissect the genetic and regulatory basis of symbiotic nitrogen fixation (SNF). Using GWAS, TWAS, eQTL mapping, and ATAC-seq, the authors identify key loci, co‑expression modules, and regulatory elements, and validate the circadian clock gene GmLHY1b as a negative regulator of nodulation via CRISPR and CUT&Tag. These resources illuminate SNF networks and provide a foundation for soybean improvement.
The study generated a phenotypic dataset for 550 Lactuca accessions, including 20 wild relatives, and applied an iterative two‑step GWAS using a jointly processed SNP set for cultivated lettuce (L. sativa) and its wild progenitor (L. serriola) to dissect trait loci. Known and novel QTLs for anthocyanin accumulation, leaf morphology, and pathogen resistance were identified, with several L. serriola‑specific QTLs revealing unique genetic architectures, underscoring the breeding value of wild lettuce species.
The study used chlorophyll fluorescence imaging to map non-photochemical quenching (NPQ) gradients along barley leaf axes and found heat stress attenuates NPQ induction, revealing spatial heterogeneity in stress responses. Genome‑wide association and transcriptomic analyses identified candidate genes, notably HORVU.MOREX.r3.3HG0262630, that mediate region‑specific heat responses, highlighting pathways for improving cereal heat resilience.
The study applied Spatial Analysis of Field Trials with Splines (SpATS) and Neighbor Genome-Wide Association Study (Neighbor GWAS) to barley field data, revealing that neighboring genotypes contribute to spatial variation in disease damage. Neighbor GWAS identified variants on chromosome 7H that modestly affect net form net blotch and scald resistance, suggesting that genotype mixtures could mitigate pest damage.
The study evaluated natural genetic variation in non-photochemical quenching and photoprotection across 861 sorghum accessions grown in the field over two years, revealing moderate to high broad-sense heritability for chlorophyll fluorescence traits. By integrating genome-wide association studies (GWAS) with transcriptome-wide association studies (TWAS) and covariance analyses, the authors identified 110 high-confidence candidate genes underlying photoprotection, highlighting a complex, polygenic architecture for these traits.