Aug 2026· Plants· Vol 15, pp. 2479· 0 citations· 51 references
Medicine
TL;DR
Findings identify useful genetic targets and molecular markers for improving soybean resistance to root rot caused by F. graminearum.
Abstract
Soybean root rot caused by Fusarium graminearum is an important soil-borne disease. It hinders seedling establishment and ultimately reduces soybean yield. Resistant germplasm and reliable molecular markers are therefore needed for resistance breeding. In this study, 336 soybean accessions were evaluated for resistance to F. graminearum root rot using the disease severity index (DSI), which ranged from 5.71 to 100.00 across the association panel. Genome-wide association analysis was performed using resequencing-based single nucleotide polymorphism (SNP) data with mixed linear model (MLM) and Fixed and random model Circulating Probability Unification (FarmCPU) models, which detected 117 and 113 candidate resistance-associated SNPs, respectively. Among these, 105 shared SNPs were used to define candidate genomic intervals containing 247 annotated genes. Based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, functional annotation, and allelic-effect analysis, six candidate genes and their associated exonic SNPs were prioritized. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed infection-responsive expression patterns for all six candidate genes, with Glyma.17g202500 and Glyma.18g266700 showing stronger induction in the resistant accession. Two SNPs in these genes were converted into Kompetitive allele-specific PCR (KASP) assays. KASP-S17_32244510 and KASP-S18_55105706 were successfully developed for genotype screening, with screening efficiencies of 73.08% and 74.29%, respectively. These findings identify useful genetic targets and molecular markers for improving soybean resistance to root rot caused by F. graminearum.
Fusarium root rot, primarily caused by Fusarium solani, is a damaging soil-borne disease that restricts soybean growth and reduces yield. In the present study, a panel of 330 soybean germplasm accessions was inoculated with F. solani. Disease responses were evaluated using the disease severity index (DSI). The soybean accessions displayed substantial variation in their susceptibility to F. solani. Based on DSI, 39 accessions were classified as highly resistant, 94 as resistant, 125 as susceptible, and 72 as highly susceptible, accounting for 11.82%, 28.48%, 37.88%, and 21.82% of the panel, respectively. The genome-wide association study (GWAS) was performed using a genotyping dataset of 627,436 high-quality single nucleotide polymorphisms (SNPs) and two models, Fixed and random model Circulating Probability Unification (FarmCPU) and mixed linear model (MLM). Both GWAS models detected putative SNP associations across seven chromosomes. Based on SNP allelic-effect analysis and gene function annotation, eight genes were prioritized and subsequently evaluated by quantitative reverse transcription PCR (qRT-PCR) for their responses to F. solani infection. Two Kompetitive allele-specific PCR (KASP) markers, KASP-S13_37431242 and KASP-S13_37529208, were developed from resistance-associated SNPs on chromosome 13 and evaluated across the diverse soybean association panel used in this study. Accessions carrying the favorable genotypes of these markers were enriched for resistant germplasm, with positive predictive values of 65.52% and 66.67%, respectively, indicating their potential value for preliminary favorable-allele tracking and germplasm prioritization. Collectively, these results improve our understanding of the genomic components underlying soybean responses to F. solani. The identified loci, candidate genes, and KASP assays provide a basis for further functional validation and the development of multi-locus strategies for improving soybean resistance to Fusarium root rot.
Net form net blotch (NFNB), caused by
Pyrenophora teres
f.
teres
(
Ptt
), is a major constraint to barley production. However, the genetic basis of adult plant resistance (APR) and seedling resistance remains incompletely understood. This study aimed to dissect the genetic architecture of NFNB resistance in a diverse panel of 273 spring barley accessions.
APR was evaluated in two contrasting field environments in Kazakhstan, whereas seedling resistance was assessed under greenhouse conditions using two
Ptt
races. Genotyping with the 50K SNP array yielded 31,834 high-quality SNPs. Genome-wide association analyses were performed using four models – MLM, MLMM, FarmCPU, and BLINK – that accounted for population structure and kinship. Candidate genes within QTL intervals were prioritized using transcriptomic data from 16 barley tissues and co-expression network analysis.
Substantial phenotypic variation was observed, with moderate heritability for APR (
h
2
= 50.6%) and seedling resistance (
h
2
= 41.3%), together with strong genotype × environment and genotype × race interactions. In total, 275 marker–trait associations were detected for APR and 48 for seedling resistance. These associations were consolidated into 57 genome-wide significant (P < 1.57E–6) or multi-model-supported QTLs across all seven barley chromosomes, including 39 APR and 18 seedling-resistance QTLs. Forty QTLs co-localized with known resistance genes (
Rpt1
,
Rpt2
,
Rpt3
,
Rpt4
,
Rpt6
,
Rpt8
,
Rpt9
, and
SPN1
) or previously reported net blotch QTLs, whereas 17 were potentially novel. Transcriptomic integration identified 87 highly expressed genes within APR QTL regions and 42 within seedling-resistance QTLs. The potentially novel QTLs
Q_NB_1H.6
,
Q_NB_2H.3
, and
Q_NB_3H.1
harbored genes encoding proteins previously associated with pathogen resistance and stress responses. Co-expression analysis revealed stage-specific transcriptional patterns, with APR-associated genes enriched in regulatory functions and seedling-resistance genes enriched in metabolic and structural functions.
The results demonstrate that NFNB resistance is polygenic and developmentally stage-dependent, with partly distinct mechanisms underlying adult plant and seedling resistance. The identified QTLs and prioritized candidate genes provide targets for independent validation, functional characterization, and the development of molecular markers to support breeding for durable NFNB resistance in barley.
Y. Genievskaya, A. Maulenbay, A. Zatybekov et al.· Frontiers in Agronomy· 0 citations
Vanilla planifolia suffers major losses from root and stem rot (RSR) caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv), amplified by low genetic diversity. We dissected quantitative resistance by phenotyping a selfed population AF_CR0040 (n = 115) inoculated with three Forv isolates (Fo166, Fo254, Fo297). Five traits were scored: symptoms at 5, 10 and 15 days post-inoculation (dpi), the area under the disease progress curve (AUDPC) and the day of mycelium appearance (d.myc). Multiple quantitative trait locus (QTL) mapping (MQM) was realized on a high-density genotyping-by-sequencing (GBS) map. QTL were anchored to the CR0040 genome to identify candidates. We detected 121 QTL across isolates and traits, explaining 2.5 to 21.8% of phenotypic variance, including 39 major loci (≥ 10%). Stable hotspots were shared by several isolates and traits, isolate-specific loci were also identified. Standardizing effects showed 44% of QTL carried favorable alleles (51% among major loci), with frequent dominance, consistent with transgressive segregation. In total, 837 genes lay within QTL windows. Top multi-QTL candidates encoded a calcium-dependent ADP-ribosylation factor GTPase-activating protein (ARF-GAP), three ATP-binding cassette (ABC) transporters, a basic helix-loop-helix (bHLH) transcription factor, a uridine kinase, and a leucine-rich repeat receptor-like kinase (LRR-RLK). These findings reveal coexisting generalist and isolate-specific resistance modules and provide genome-anchored targets for functional validation, gene pyramiding, and marker-assisted selection in vanilla.
Quentin Da Silva, Lucy Marcadé, Elisabeth Hoareau et al.· Euphytica· 0 citations
Root biomass is an important determinant of seedling vigor that contributes to water and nutrient acquisition in rice (Oryza sativa L.). In this study, we evaluated the total root weight (TRW) of 127 Korean rice cultivars, comprising 110 temperate japonica (TEJ) and 17 Tongil-type cultivars, under hydroponic conditions. Population structure analysis separated the accessions into two major groups corresponding primarily to the TEJ and Tongil-type cultivars. A genome-wide association study (GWAS) was conducted using the FarmCPU, BLINK, and MLM approaches, all three of which detected a common association signal for TRW on chromosome 7. Further GWAS analysis using only the 110 TEJ cultivars revealed an association signal in the same genomic region, thereby providing evidence of a possible relationship between this region and the variation in TRW within the TEJ cultivars. Additionally, by performing linkage disequilibrium block analysis, we identified a candidate region spanning approximately 369 kb, containing 43 genes. On the basis of gene expression and haplotype analyses, Os07g0517000, Os07g0520400, and Os07g0520900 were selected as putative candidate genes. However, given that the observed haplotype differences were partially associated with the varietal-group composition, their effects should be interpreted with caution. These results will provide genomic information for gaining a better understanding of variations in seedling root biomass and contribute to further validation of genes associated with root development in rice.
Junghyun Gong, Han-gyeol Kim, Dongryung Lee et al.· Korean Journal of Breeding S...· 0 citations
The genetic architecture and core candidate genes for shoot length (SL) and root length (RL) at the germination stage are dissected and seven core candidate genes for SL and 13 for RL are identified, including three pleiotropic genes regulating both traits.
Rice blast, caused by Pyricularia oryzae (syn. Magnaporthe oryzae), remains one of the most destructive diseases of rice worldwide. Developing resistant varieties is a sustainable strategy for disease management, and information on the diversity of blast resistance genes is important for selecting breeding parents. This study evaluated the effectiveness of functional sequence-tagged site (STS) markers for resolving genetic diversity among advanced rice lines derived from multiple-cross populations. A total of 104 genotypes, comprising 100 advanced lines and four parental varieties (Ciherang, Inpari 13, Inpari 10, and Situ Bagendit), were analyzed using eight gene-specific STS markers associated with four blast resistance genes (Pii, Pia, Pikp, and Pita). Polymorphism information content (PIC) values ranged from 0.80 to 0.96, with a mean of 0.89. UPGMA cluster analysis separated the genotypes into two major groups at a similarity coefficient of 0.90, although most lines occurred in one group and lines with the same parental background were distributed among different subgroups. Observed heterozygosity was low (Ho = 0.09), indicating limited resolution for distinguishing closely related lines despite the high PIC values. Functional STS markers were informative for detecting allelic variation but were insufficient for resolving fine-scale relationships within this genetically narrow breeding population. Combining marker analysis with phenotypic evaluation and higher-resolution markers is therefore recommended to improve selection for blast resistance.
A. Prihaningsih, S. Yuriyah, Joko Prasetyo et al.· Vegetalika· 0 citations
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