Multi-environment genome-wide association mapping of culm morphology traits in barley

Bretani, G.; Shaaf, S.; Tondelli, A.; Cattivelli, L.; Delbono, S.; Waugh, R.; Thomas, W. T. B.; Russel, J.; Bull, H.; Igartua, E.; Casas, A. M.; Gracia, P.; Rossi, R.; Schulman, A. H.; Rossini, L.

doi:10.1101/2022.03.30.486427

bioRxiv · 10.1101/2022.03.30.486427

Multi-environment genome-wide association mapping of culm morphology traits in barley

Bretani, G.·Shaaf, S.·Tondelli, A.·Cattivelli, L.·Delbono, S.·Waugh, R.·Thomas, W. T. B.·Russel, J.·Bull, H.·Igartua, E.·Casas, A. M.·Gracia, P.·Rossi, R.·Schulman, A. H.·Rossini, L.

View original source ↗Export metadata ↓

Abstract

In cereals with hollow internodes, lodging resistance is influenced by morphological characteristics such as internode diameter and culm wall thickness. Despite their relevance, knowledge of the genetic control of these traits and their relationship with lodging is lacking in temperate cereals such as barley. To fill this gap, we developed an image-analysis based protocol to accurately phenotype culm diameter and culm wall thickness across 261 barley accessions. Analysis of culm trait data collected from field trials in 7 different environments revealed genetic control as supported by high heritability values, as well as genotype-by-environment interactions. The collection was structured mainly according to row-type, which had a confounding effect on culm traits as evidenced by phenotypic correlations. In addition, culm traits showed strong negative correlations with lodging but weak correlations with plant height across row-types, indicating the possibility of improving lodging resistance independent of plant height. Using 50k iSelect SNP genotyping data, we conducted multi-environment genome-wide association studies using mixed model approach across the whole panel and row-type subsets: we identified a total of 192 QTLs for the studied traits, including subpopulation-specific QTLs and several main effect loci for culm traits showing negative effects on lodging without impacting plant height. Providing first insights into the genetic architecture of culm morphology in barley and the possible role of candidate genes involved in hormone and cell wall related pathways, this work supports the potential of loci underpinning culm features to improve lodging resistance and increase barley yield stability under changing environments. One-sentence summaryGenetic analysis of a diverse collection of European barleys reveals genomic regions underpinning stem morphological features associated with lodging resistance.

Source connections

Published article ↗

Explore related subjects

plant biology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Bretani, G., Shaaf, S., Tondelli, A., Cattivelli, L., Delbono, S., Waugh, R., Thomas, W. T. B., Russel, J., Bull, H., Igartua, E., Casas, A. M., Gracia, P., Rossi, R., Schulman, A. H., Rossini, L.. 2022-04-01. Multi-environment genome-wide association mapping of culm morphology traits in barley. https://doi.org/10.1101/2022.03.30.486427

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Molecular and phytochemical investigation of medicinal Rhododendron spp. in the Qinghai-Xizang Plateau: the botanical sources of the traditional Tibetan medicine "Tale"

The Qinghai-Xizang Plateau in China is a hotspot for Rhododendron species, with approximately 400 species distributed across the region. Various Rhododendron species in this area have been used medicinally in traditional Tibetan medicine for a long time and are collectively referred to as "Tale." Furthermore, "Tale" is classified as "Talegabao" or "Talenabao," depending on the species. These two types of medicine have similar but distinct properties, and "Talenabao" is usually used as an alternative to "Talegabao." However, differences in their phytochemical compositions and methods for discriminating between them have not been examined. To solve these problems limited the use of "Tale" medicines, 46 plant specimens belonging to nine Rhododendron species were collected from the Qinghai-Xizang Plateau. Molecular methods based on the internal transcribed spacer 2 (ITS2) region of nuclear DNA and psbA-trnH regions of chloroplast DNA were applied to these samples. In addition, 10 flavonoid compounds were quantitatively determined by HPLC. The results indicated psbA-trnH region successfully distinguished the species used as "Talegabao" or "Talenabao," whereas ITS2 failed to distinguish them because of its high degree of conservation. All 10 compounds were detected in all samples. However, the species used as "Talegabao" had more than twice the total content of the 10 flavonoid compounds observed in the species used as "Talenabao." Moreover, differences in the contents of certain compounds among species were detected, indicating potential chemical markers for the quality evaluation of "Tale" medicines. "Talegabao" is the first choice among "Tale" medicines. "Talenabao" can be used as an alternative to "Talegabao"; however, the appropriate dose requires further discussion in practical use. The psbA-trnH region is recommended as a DNA barcode for distinguishing between these two types of medicines.

plant biology↗

bioRxiv2026

Accessory B Chromosomes Alter Chromatin Accessibility and Gene Expression in Maize Pollen Nuclei

B chromosomes in maize (Zea mays L.) are supernumerary, nonessential chromosomes that exhibit non-Mendelian inheritance through chromosome drive. During the second pollen mitosis, they undergo nondisjunction, resulting in their preferential transmission via B-containing sperm cells. Although their transmission mechanisms have been extensively characterized, the effects on chromatin organization and transcriptional regulation in gametophytic cells remain poorly understood. Here, we combined flow cytometric sorting of pollen nuclei with an assay for transposase-accessible chromatin sequencing (ATAC-seq) and RNA sequencing (RNA-seq) to investigate the impact of B chromosomes on chromatin accessibility and gene expression in mature maize pollen. Using pollen nuclei isolated from a maize inbred line B73 carrying zero and two B chromosomes, we generated high-purity datasets suitable for integrated chromatin and transcriptomic analyses. We identified extensive chromatin accessibility and transcriptional activity at B-chromosome loci. Importantly, the presence of B chromosomes was also associated with altered chromatin accessibility and gene expression on the standard A chromosomes, revealing regulatory effects extending beyond the B chromosome itself. Together, these findings contribute to a broader understanding of effects of selfish genetic elements in plants.

plant biology↗

bioRxiv2026

Melanoidins Suppress Cucumber and Tomato Diseases Incited by Pathogens that are Oomycetes, Bacteria and a Virus

We recently reported that solutions of the nitrogenous compounds melanoidins (M), that are formed during the final stages of the Maillard Reaction, are inducers of plant resistance (Elad et al. 2026). M promoted immunity and induced disease resistance through an effect on the transcriptome, primarily through the salicylic acid pathway. Here we tested the effect of M on plant diseases that are caused by Oomycetes, bacteria and a tobamovirus. Drench and spray of M suppressed Pythium aphanidermatum damping off in cucumber, cucumber downy mildew (Pseudoperonospera cubensis), tomato late blight (Phytophthora infestans), bacterial speck (Pseudomonas syringae pv. tomato), bacterial canker (Clavibacter michiganensis subsp. michiganensis) and the Tobamovirus Tomato brown rugose fruit virus (ToBRFV) in tomato. In various experiments control was achieved by concentrations of 0.03 and 0.1% and on older and younger leaves and even in long term experiments where the M was applied for ca 11 weeks. It can be concluded that the disease resistance inducer M can suppress soilborne and foliar diseases that are caused by Oomycetes, bacteria and a virus of the genus Tobamovirus, in addition to the fungal pathogen Botrytis cinerea reported earlier.

plant biology↗