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1.
Sci Rep ; 14(1): 11010, 2024 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-38745019

RESUMEN

The presence of incompatibility alleles in primary amphidiploids constitutes a reproductive barrier in newly synthesized wheat-rye hybrids. To overcome this barrier, the genome stabilization process includes large-scale chromosome rearrangements. In incompatible crosses resulting in fertile amphidiploids, the elimination of one of the incompatible alleles Eml-A1 or Eml-R1b can occur already in the somatic tissue of the wheat × rye hybrid embryo. We observed that the interaction of incompatible loci Eml-A1 of wheat and Eml-R1b of rye after overcoming embryo lethality leads to hybrid sterility in primary triticale. During subsequent seed reproductions (R1, R2 or R3) most of the chromosomes of A, B, D and R subgenomes undergo rearrangement or eliminations to increase the fertility of the amphidiploid by natural selection. Genotyping-by-sequencing (GBS) coverage analysis showed that improved fertility is associated with the elimination of entire and partial chromosomes carrying factors that either cause the disruption of plant development in hybrid plants or lead to the restoration of the euploid number of chromosomes (2n = 56) in the absence of one of the incompatible alleles. Highly fertile offspring obtained in compatible and incompatible crosses can be successfully adapted for the production of triticale pre-breeding stocks.


Asunto(s)
Cromosomas de las Plantas , Cruzamientos Genéticos , Hibridación Genética , Secale , Triticum , Triticum/genética , Secale/genética , Cromosomas de las Plantas/genética , Alelos , Técnicas de Genotipaje
2.
Plant Cell Environ ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38600764

RESUMEN

The restriction of plant-symbiont dinitrogen fixation by an insect semiochemical had not been previously described. Here we report on a glycosylated triketide δ-lactone from Nephrotoma cornicina crane flies, cornicinine, that causes chlorosis in the floating-fern symbioses from the genus Azolla. Only the glycosylated trans-A form of chemically synthesized cornicinine was active: 500 nM cornicinine in the growth medium turned all cyanobacterial filaments from Nostoc azollae inside the host leaf-cavities into akinetes typically secreting CTB-bacteriocins. Cornicinine further inhibited akinete germination in Azolla sporelings, precluding re-establishment of the symbiosis during sexual reproduction. It did not impact development of the plant Arabidopsis thaliana or several free-living cyanobacteria from the genera Anabaena or Nostoc but affected the fern host without cyanobiont. Fern-host mRNA sequencing from isolated leaf cavities confirmed high NH4-assimilation and proanthocyanidin biosynthesis in this trichome-rich tissue. After cornicinine treatment, it revealed activation of Cullin-RING ubiquitin-ligase-pathways, known to mediate metabolite signaling and plant elicitation consistent with the chlorosis phenotype, and increased JA-oxidase, sulfate transport and exosome formation. The work begins to uncover molecular mechanisms of cyanobiont differentiation in a seed-free plant symbiosis important for wetland ecology or circular crop-production today, that once caused massive CO2 draw-down during the Eocene geological past.

3.
GigaByte ; 2024: gigabyte112, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38496214

RESUMEN

This work is an update and extension of the previously published article "Ultralong Oxford Nanopore Reads Enable the Development of a Reference-Grade Perennial Ryegrass Genome Assembly" by Frei et al. The published genome assembly of the doubled haploid perennial ryegrass (Lolium perenne L.) genotype Kyuss (Kyuss v1.0) marked a milestone for forage grass research and breeding. However, order and orientation errors may exist in the pseudo-chromosomes of Kyuss, since barley (Hordeum vulgare L.), which diverged 30 million years ago from perennial ryegrass, was used as the reference to scaffold Kyuss. To correct for structural errors possibly present in the published Kyuss assembly, we de novo assembled the genome again and generated 50-fold coverage high-throughput chromosome conformation capture (Hi-C) data to assist pseudo-chromosome construction. The resulting new chromosome-level assembly Kyuss v2.0 showed improved quality with high contiguity (contig N50 = 120 Mb), high completeness (total BUSCO score = 99%), high base-level accuracy (QV = 50), and correct pseudo-chromosome structure (validated by Hi-C contact map). This new assembly will serve as a better reference genome for Lolium spp. and greatly benefit the forage and turf grass research community.

4.
Mol Biol Evol ; 41(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38243866

RESUMEN

Vascular plants have segmented body axes with iterative nodes and internodes. Appropriate node initiation and internode elongation are fundamental to plant fitness and crop yield; however, how these events are spatiotemporally coordinated remains elusive. We show that in barley (Hordeum vulgare L.), selections during domestication have extended the apical meristematic phase to promote node initiation, but constrained subsequent internode elongation. In both vegetative and reproductive phases, internode elongation displays a dynamic proximal-distal gradient, and among subpopulations of domesticated barleys worldwide, node initiation and proximal internode elongation are associated with latitudinal and longitudinal gradients, respectively. Genetic and functional analyses suggest that, in addition to their converging roles in node initiation, flowering-time genes have been repurposed to specify the timing and duration of internode elongation. Our study provides an integrated view of barley node initiation and internode elongation and suggests that plant architecture should be recognized as a collection of dynamic phytomeric units in the context of crop adaptive evolution.


Asunto(s)
Adaptación Biológica , Hordeum , Hordeum/genética , Hordeum/crecimiento & desarrollo , Domesticación
5.
Sci Data ; 11(1): 66, 2024 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-38216606

RESUMEN

Barley genomic resources are increasing rapidly, with the publication of a barley pangenome as one of the latest developments. Two-row spring barley cultivars are intensely studied as they are the source of high-quality grain for malting and distilling. Here we provide data from a European two-row spring barley population containing 209 different genotypes registered for the UK market between 1830 to 2014. The dataset encompasses RNA-sequencing data from six different tissues across a range of barley developmental stages, phenotypic datasets from two consecutive years of field-grown trials in the United Kingdom, Germany and the USA; and whole genome shotgun sequencing from all cultivars, which was used to complement the RNA-sequencing data for variant calling. The outcomes are a filtered SNP marker file, a phenotypic database and a large gene expression dataset providing a comprehensive resource which allows for downstream analyses like genome wide association studies or expression associations.


Asunto(s)
Genoma de Planta , Hordeum , Estudio de Asociación del Genoma Completo , Genómica , Genotipo , Hordeum/genética , ARN
6.
Microbiol Resour Announc ; 12(12): e0061423, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-37991356

RESUMEN

We report 10 particle-associated metagenome-assembled genomes (MAGs) from the mesopelagic zone of Pacific Ocean seawaters. MAGs comprise members of Flavobacteria Halomonas, Blastomonas, Brevundimonas, Alteromonas, Shingomonas, Sphingopyxis, Tabrizicola, Proteobacteria, and Gammaproteobacteria. Functional annotation suggests that these bacteria are involved in central particulate organic carbon conversion, nitrogen cycling, and phosphorus cycling.

7.
Front Plant Sci ; 14: 1227656, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37701801

RESUMEN

Genome-wide prediction is a powerful tool in breeding. Initial results suggest that genome-wide approaches are also promising for enhancing the use of the genebank material: predicting the performance of plant genetic resources can unlock their hidden potential and fill the information gap in genebanks across the world and, hence, underpin prebreeding programs. As a proof of concept, we evaluated the power of across-genebank prediction for extensive germplasm collections relying on historical data on flowering/heading date, plant height, and thousand kernel weight of 9,344 barley (Hordeum vulgare L.) plant genetic resources from the German Federal Ex situ Genebank for Agricultural and Horticultural Crops (IPK) and of 1,089 accessions from the International Center for Agriculture Research in the Dry Areas (ICARDA) genebank. Based on prediction abilities for each trait, three scenarios for predictive characterization were compared: 1) a benchmark scenario, where test and training sets only contain ICARDA accessions, 2) across-genebank predictions using IPK as training and ICARDA as test set, and 3) integrated genebank predictions that include IPK with 30% of ICARDA accessions as a training set to predict the rest of ICARDA accessions. Within the population of ICARDA accessions, prediction abilities were low to moderate, which was presumably caused by a limited number of accessions used to train the model. Interestingly, ICARDA prediction abilities were boosted up to ninefold by using training sets composed of IPK plus 30% of ICARDA accessions. Pervasive genotype × environment interactions (GEIs) can become a potential obstacle to train robust genome-wide prediction models across genebanks. This suggests that the potential adverse effect of GEI on prediction ability was counterbalanced by the augmented training set with certain connectivity to the test set. Therefore, across-genebank predictions hold the promise to improve the curation of the world's genebank collections and contribute significantly to the long-term development of traditional genebanks toward biodigital resource centers.

8.
Int J Mol Sci ; 24(15)2023 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-37569441

RESUMEN

Plants respond to drought by the major reprogramming of gene expression, enabling the plant to survive this threatening environmental condition. The phytohormone abscisic acid (ABA) serves as a crucial upstream signal, inducing this multifaceted process. This report investigated the drought response in barley plants (Hordeum vulgare, cv. Morex) at both the epigenome and transcriptome levels. After a ten-day drought period, during which the soil water content was reduced by about 35%, the relative chlorophyll content, as well as the photosystem II efficiency of the barley leaves, decreased by about 10%. Furthermore, drought-related genes such as HvS40 and HvA1 were already induced compared to the well-watered controls. Global ChIP-Seq analysis was performed to identify genes in which histones H3 were modified with euchromatic K4 trimethylation or K9 acetylation during drought. By applying stringent exclusion criteria, 129 genes loaded with H3K4me3 and 2008 genes loaded with H3K9ac in response to drought were identified, indicating that H3K9 acetylation reacts to drought more sensitively than H3K4 trimethylation. A comparison with differentially expressed genes enabled the identification of specific genes loaded with the euchromatic marks and induced in response to drought treatment. The results revealed that a major proportion of these genes are involved in ABA signaling and related pathways. Intriguingly, two members of the protein phosphatase 2C family (PP2Cs), which play a crucial role in the central regulatory machinery of ABA signaling, were also identified through this approach.


Asunto(s)
Hordeum , Hordeum/metabolismo , Ácido Abscísico/farmacología , Ácido Abscísico/metabolismo , Código de Histonas , Sequías , Transcriptoma , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estrés Fisiológico/genética
9.
Front Cell Infect Microbiol ; 13: 1165017, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37265503

RESUMEN

Orthopaedic implant-associated infections (OIAIs) due to Cutibacterium acnes can be difficult to diagnose. The aim of this pilot study was to determine if metagenomic next-generation sequencing (mNGS) can provide additional information to improve the diagnosis of C. acnes OIAIs. mNGS was performed on sonication fluid (SF) specimens derived from 24 implants. These were divided into three groups, based on culture results: group I, culture-negative (n = 4); group II, culture-positive for C. acnes (n = 10); and group III, culture-positive for other bacteria (n = 10). In group I, sequence reads from C. acnes were detected in only one SF sample, originating from a suspected case of OIAIs, which was SF and tissue culture-negative. In group II, C. acnes sequences were detected in 7/10 samples. In group III, C. acnes sequence reads were found in 5/10 samples, in addition to sequence reads that matched the bacterial species identified by culture. These samples could represent polymicrobial infections that were missed by culture. Taken together, mNGS was able to detect C. acnes DNA in more samples compared to culture and could be used to identify cases of suspected C. acnes OIAIs, in particular regarding possible polymicrobial infections, where the growth of C. acnes might be compromised due to a fast-growing bacterial species. However, since SF specimens are usually low-biomass samples, mNGS is prone to DNA contamination, possibly introduced during DNA extraction or sequencing procedures. Thus, it is advisable to set a sequence read count threshold, taking into account project- and NGS-specific criteria.


Asunto(s)
Coinfección , Ortopedia , Infecciones Relacionadas con Prótesis , Humanos , Infecciones Relacionadas con Prótesis/diagnóstico , Infecciones Relacionadas con Prótesis/microbiología , Sonicación , Proyectos Piloto , Propionibacterium acnes/genética , Bacterias/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Metagenómica
10.
Nat Commun ; 14(1): 3502, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37311740

RESUMEN

The centromere is the chromosome region where microtubules attach during cell division. In contrast to monocentric chromosomes with one centromere, holocentric species usually distribute hundreds of centromere units along the entire chromatid. We assembled the chromosome-scale reference genome and analyzed the holocentromere and (epi)genome organization of the lilioid Chionographis japonica. Remarkably, each of its holocentric chromatids consists of only 7 to 11 evenly spaced megabase-sized centromere-specific histone H3-positive units. These units contain satellite arrays of 23 and 28 bp-long monomers capable of forming palindromic structures. Like monocentric species, C. japonica forms clustered centromeres in chromocenters at interphase. In addition, the large-scale eu- and heterochromatin arrangement differs between C. japonica and other known holocentric species. Finally, using polymer simulations, we model the formation of prometaphase line-like holocentromeres from interphase centromere clusters. Our findings broaden the knowledge about centromere diversity, showing that holocentricity is not restricted to species with numerous and small centromere units.


Asunto(s)
Proteínas de Ciclo Celular , Centrómero , Centrómero/genética , División Celular , Cromátides , Heterocromatina/genética
11.
Nature ; 615(7953): 652-659, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36890232

RESUMEN

Increasing the proportion of locally produced plant protein in currently meat-rich diets could substantially reduce greenhouse gas emissions and loss of biodiversity1. However, plant protein production is hampered by the lack of a cool-season legume equivalent to soybean in agronomic value2. Faba bean (Vicia faba L.) has a high yield potential and is well suited for cultivation in temperate regions, but genomic resources are scarce. Here, we report a high-quality chromosome-scale assembly of the faba bean genome and show that it has expanded to a massive 13 Gb in size through an imbalance between the rates of amplification and elimination of retrotransposons and satellite repeats. Genes and recombination events are evenly dispersed across chromosomes and the gene space is remarkably compact considering the genome size, although with substantial copy number variation driven by tandem duplication. Demonstrating practical application of the genome sequence, we develop a targeted genotyping assay and use high-resolution genome-wide association analysis to dissect the genetic basis of seed size and hilum colour. The resources presented constitute a genomics-based breeding platform for faba bean, enabling breeders and geneticists to accelerate the improvement of sustainable protein production across the Mediterranean, subtropical and northern temperate agroecological zones.


Asunto(s)
Productos Agrícolas , Diploidia , Variación Genética , Genoma de Planta , Genómica , Fitomejoramiento , Proteínas de Plantas , Vicia faba , Cromosomas de las Plantas/genética , Productos Agrícolas/genética , Productos Agrícolas/metabolismo , Variaciones en el Número de Copia de ADN/genética , ADN Satélite/genética , Amplificación de Genes/genética , Genes de Plantas/genética , Variación Genética/genética , Genoma de Planta/genética , Estudio de Asociación del Genoma Completo , Geografía , Fitomejoramiento/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Recombinación Genética , Retroelementos/genética , Semillas/anatomía & histología , Semillas/genética , Vicia faba/anatomía & histología , Vicia faba/genética , Vicia faba/metabolismo
12.
Nucleic Acids Res ; 51(6): 2641-2654, 2023 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-36864547

RESUMEN

Chromatids of mitotic chromosomes were suggested to coil into a helix in early cytological studies and this assumption was recently supported by chromosome conformation capture (3C) sequencing. Still, direct differential visualization of a condensed chromatin fibre confirming the helical model was lacking. Here, we combined Hi-C analysis of purified metaphase chromosomes, biopolymer modelling and spatial structured illumination microscopy of large fluorescently labeled chromosome segments to reveal the chromonema - a helically-wound, 400 nm thick chromatin thread forming barley mitotic chromatids. Chromatin from adjacent turns of the helix intermingles due to the stochastic positioning of chromatin loops inside the chromonema. Helical turn size varies along chromosome length, correlating with chromatin density. Constraints on the observable dimensions of sister chromatid exchanges further supports the helical chromonema model.


Asunto(s)
Cromátides , Hordeum , Metafase , Cromátides/química , Cromatina/genética , Cromosomas , Microscopía , Intercambio de Cromátides Hermanas , Cromosomas de las Plantas , Hordeum/citología
13.
Sci Adv ; 9(9): eadd0324, 2023 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-36867700

RESUMEN

Flowering plants with indeterminate inflorescences often produce more floral structures than they require. We found that floral primordia initiations in barley (Hordeum vulgare L.) are molecularly decoupled from their maturation into grains. While initiation is dominated by flowering-time genes, floral growth is specified by light signaling, chloroplast, and vascular developmental programs orchestrated by barley CCT MOTIF FAMILY 4 (HvCMF4), which is expressed in the inflorescence vasculature. Consequently, mutations in HvCMF4 increase primordia death and pollination failure, mainly through reducing rachis greening and limiting plastidial energy supply to developing heterotrophic floral tissues. We propose that HvCMF4 is a sensory factor for light that acts in connection with the vascular-localized circadian clock to coordinate floral initiation and survival. Notably, stacking beneficial alleles for both primordia number and survival provides positive implications on grain production. Our findings provide insights into the molecular underpinnings of grain number determination in cereal crops.


Asunto(s)
Grano Comestible , Hordeum , Productos Agrícolas , Alelos , Cloroplastos
14.
Appl Environ Microbiol ; 89(1): e0142822, 2023 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-36541797

RESUMEN

The number of genes encoding ß-oxidation enzymes in Cupriavidus necator H16 (synonym, Ralstonia eutropha H16) is high, but only the operons A0459-A0464 and A1526-A1531, each encoding four genes for ß-oxidation enzymes, were expressed during growth with long-chain-length fatty acids (LCFAs). However, we observed that C. necator ΔA0459-A0464 ΔA1526-A1531 and C. necator H16 showed the same growth behavior during growth with decanoic acid and shorter FAs. The negative effect of the deletion of these two operons increased with an increasing chain length of the utilized FAs. Transcriptome sequencing (RNA-Seq) revealed the expression profiles of genes involved in the catabolism of medium-chain-length fatty acids (MCFAs) in C. necator H16. Operon A0459-A0464 was expressed only during growth with nonanoic acid, whereas operon A1526-A1531 was highly expressed during growth with octanoic and nonanoic acid. The gene clusters B1187-B1192 and B0751-B0759 showed a log2 fold change in expression of up to 4.29 and 4.02, respectively, during growth with octanoic acid and up to 8.82 and 5.50, respectively, with nonanoic acid compared to sodium gluconate-grown cells. Several acyl-CoA ligases catalyze the activation of MCFAs with coenzyme A (CoA), but fadD3 (A3288), involved in activation of LCFAs, was not detected. The expression profiles of C. necator strain ΔA0459-A0464 ΔA1526-A1531 showed that the growth with nonanoic acid resulted in the expression of further ß-oxidation enzyme-encoding genes. Additional insights into the transport of FAs in C. necator H16 revealed the complexity and putative involvement of the DegV-like protein encoded by A0463 in the transport of odd-chain-length FAs and of siderophore biosynthesis in the transport mechanism. IMPORTANCE Although Cupriavidus necator H16 has been used in several studies to produce polyhydroxyalkanoates from various lipids, the fatty acid metabolism is poorly understood. The ß-oxidation of long-chain-length FAs has been investigated, but the tremendous number of homologous genes encoding ß-oxidation enzymes hides the potential for variances in the expressed genes for catabolism of shorter FAs. The catabolism of medium-chain-length FAs and connected pathways has not been investigated yet. As more sustainable substrates such as lipids and the production of fatty acids and fatty acid derivates become more critical with the dependency on fossil-based substances, understanding the complex metabolism in this highly diverse workhorse for biotechnology, C. necator, is inevitable. For further metabolic engineering and construction of production strains, we investigated the metabolism during growth on medium-chain-length FAs by RNA-Seq.


Asunto(s)
Cupriavidus necator , Polihidroxialcanoatos , Cupriavidus necator/metabolismo , Transcriptoma , Ácidos Grasos/metabolismo , Polihidroxialcanoatos/metabolismo
15.
Front Microbiol ; 13: 1070201, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36519178

RESUMEN

Staphylococcus saccharolyticus, a coagulase-negative staphylococcal species, has some unusual characteristics for human-associated staphylococci, such as slow growth and its preference for anoxic culture conditions. This species is a relatively abundant member of the human skin microbiota, but its microbiological properties, as well as the pathogenic potential, have scarcely been investigated so far, despite being occasionally isolated from different types of infections including orthopedic implant-associated infections. Here, we investigated the growth and biofilm properties of clinical isolates of S. saccharolyticus and determined host cell responses. Growth assessments in anoxic and oxic conditions revealed strain-dependent outcomes, as some strains can also grow aerobically. All tested strains of S. saccharolyticus were able to form biofilm in a microtiter plate assay. Strain-dependent differences were determined by optical coherence tomography, revealing that medium supplementation with glucose and sodium chloride enhanced biofilm formation. Visualization of the biofilm by confocal laser scanning microscopy revealed the role of extracellular DNA in the biofilm structure. In addition to attached biofilms, S. saccharolyticus also formed bacterial aggregates at an early stage of growth. Transcriptome analysis of biofilm-grown versus planktonic cells revealed a set of upregulated genes in biofilm-embedded cells, including factors involved in adhesion, colonization, and competition such as epidermin, type I toxin-antitoxin system, and phenol-soluble modulins (beta and epsilon). To investigate consequences for the host after encountering S. saccharolyticus, cytokine profiling and host cell viability were assessed by infection experiments with differentiated THP-1 cells. The microorganism strongly triggered the secretion of the tested pro-inflammatory cyto- and chemokines IL-6, IL-8, and TNF-alpha, determined at 24 h post-infection. S. saccharolyticus was less cytotoxic than Staphylococcus aureus. Taken together, the results indicate that S. saccharolyticus has substantial pathogenic potential. Thus, it can be a potential cause of orthopedic implant-associated infections and other types of deep-seated infections.

16.
Sci Data ; 9(1): 784, 2022 12 26.
Artículo en Inglés | MEDLINE | ID: mdl-36572688

RESUMEN

Plant genetic resources (PGR) stored at genebanks are humanity's crop diversity savings for the future. Information on PGR contrasted with modern cultivars is key to select PGR parents for pre-breeding. Genotyping-by-sequencing was performed for 7,745 winter wheat PGR samples from the German Federal ex situ genebank at IPK Gatersleben and for 325 modern cultivars. Whole-genome shotgun sequencing was carried out for 446 diverse PGR samples and 322 modern cultivars and lines. In 19 field trials, 7,683 PGR and 232 elite cultivars were characterized for resistance to yellow rust - one of the major threats to wheat worldwide. Yield breeding values of 707 PGR were estimated using hybrid crosses with 36 cultivars - an approach that reduces the lack of agronomic adaptation of PGR and provides better estimates of their contribution to yield breeding. Cross-validations support the interoperability between genomic and phenotypic data. The here presented data are a stepping stone to unlock the functional variation of PGR for European pre-breeding and are the basis for future breeding and research activities.


Asunto(s)
Fitomejoramiento , Triticum , Genotipo , Estaciones del Año , Triticum/genética
17.
Plants (Basel) ; 11(19)2022 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-36235399

RESUMEN

Improvement of grain yield is the ultimate goal for wheat breeding under water-limited environments. In the present study, a high-density linkage map was developed by using genotyping-by-sequencing (GBS) of a recombinant inbred line (RIL) population derived from the cross between Iranian landrace #49 and cultivar Yecora Rojo. The population was evaluated in three locations in Iran during two years under irrigated and water deficit conditions for the agronomic traits grain yield (GY), plant height (PH), spike number per square meter (SM), 1000 kernel weight (TKW), grain number per spike (GNS), spike length (SL), biomass (BIO) and harvest index (HI). A linkage map was constructed using 5831 SNPs assigned to 21 chromosomes, spanning 3642.14 cM of the hexaploid wheat genome with an average marker density of 0.62 (markers/cM). In total, 85 QTLs were identified on 19 chromosomes (all except 5D and 6D) explaining 6.06-19.25% of the traits phenotypic variance. We could identify 20 novel QTLs explaining 8.87-19.18% of phenotypic variance on chromosomes 1A, 1B, 1D, 2B, 3A, 3B, 6A, 6B and 7A. For 35 out of 85 mapped QTLs functionally annotated genes were identified which could be related to a potential role in drought stress.

18.
Nat Genet ; 54(10): 1544-1552, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36195758

RESUMEN

The great efforts spent in the maintenance of past diversity in genebanks are rationalized by the potential role of plant genetic resources (PGR) in future crop improvement-a concept whose practical implementation has fallen short of expectations. Here, we implement a genomics-informed prebreeding strategy for wheat improvement that does not discriminate against nonadapted germplasm. We collect and analyze dense genetic profiles for a large winter wheat collection and evaluate grain yield and resistance to yellow rust (YR) in bespoke core sets. Breeders already profit from wild introgressions but PGR still offer useful, yet unused, diversity. Potential donors of resistance sources not yet deployed in breeding were detected, while the prebreeding contribution of PGR to yield was estimated through 'Elite × PGR' F1 crosses. Genomic prediction within and across genebanks identified the best parents to be used in crosses with elite cultivars whose advanced progenies can outyield current wheat varieties in multiple field trials.


Asunto(s)
Fitomejoramiento , Triticum , Genómica , Plantas , Triticum/genética
19.
Plant J ; 112(4): 897-918, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36073999

RESUMEN

Breeding has increasingly altered the genetics of crop plants since the domestication of their wild progenitors. It is postulated that the genetic diversity of elite wheat breeding pools is too narrow to cope with future challenges. In contrast, plant genetic resources (PGRs) of wheat stored in genebanks are valuable sources of unexploited genetic diversity. Therefore, to ensure breeding progress in the future, it is of prime importance to identify the useful allelic diversity available in PGRs and to transfer it into elite breeding pools. Here, a diverse collection consisting of modern winter wheat cultivars and genebank accessions was investigated based on reduced-representation genomic sequencing and an iSelect single nucleotide polymorphism (SNP) chip array. Analyses of these datasets provided detailed insights into population structure, levels of genetic diversity, sources of new allelic diversity, and genomic regions affected by breeding activities. We identified 57 regions representing genomic signatures of selection and 827 regions representing private alleles associated exclusively with genebank accessions. The presence of known functional wheat genes, quantitative trait loci, and large chromosomal modifications, i.e., introgressions from wheat wild relatives, provided initial evidence for putative traits associated within these identified regions. These findings were supported by the results of ontology enrichment analyses. The results reported here will stimulate further research and promote breeding in the future by allowing for the targeted introduction of novel allelic diversity into elite wheat breeding pools.


Asunto(s)
Pan , Triticum , Triticum/genética , Alelos , Fitomejoramiento , Genoma de Planta/genética , Polimorfismo de Nucleótido Simple/genética
20.
Front Plant Sci ; 13: 906462, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35898222

RESUMEN

The use of wild plant species or their halophytic relatives has been considered in plant breeding programs to improve salt and drought tolerance in crop plants. Aeluropus littoralis serves as halophyte model for identification and isolation of novel stress adaptation genes. A. littoralis, a perennial monocot grass, grows in damp or arid areas, often salt-impregnated places and wasteland in cultivated areas, can survive periodically high water salinity, and tolerate high salt concentrations in the soil up to 1,100 mM sodium chloride. Therefore, it serves as valuable genetic resource to understand molecular mechanisms of stress-responses in monocots. The knowledge can potentially be used for improving tolerance to abiotic stresses in economically important crops. Several morphological, anatomical, ecological, and physiological traits of A. littoralis have been investigated so far. After watering with salt water the grass is able to excrete salt via its salt glands. Meanwhile, a number of ESTs (expressed sequence tag), genes and promoters induced by the salt and drought stresses were isolated, sequenced and annotated at a molecular level. Transfer of stress related genes to other species resulted in enhanced stress resistance. Here we describe the genome sequence and structure of A. littoralis analyzed by whole genome sequencing and histological analysis. The chromosome number was determined to be 20 (2n = 2x = 20). The genome size was calculated to be 354 Mb. This genomic information provided here, will support the functional investigation and application of novel genes improving salt stress resistance in crop plants. The utility of the sequence information is exemplified by the analysis of the DREB-transcription factor family.

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