• The Plant Pathology Journal
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• v.35 no.3
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• pp.200-207
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• 2019

Fusarium head blight (FHB) is a devastating wheat disease with a significant economic impact. Fhb1 is the most important large effect and stable QTL for FHB resistance. A pore-forming toxin-like (PFT) gene was recently identified as an underlying gene for Fhb1 resistance. In this study, we developed and validated a PFT-based Kompetitive allele specific PCR (KASP) marker for Fhb1. The KASP marker, PFT_KASP, was used to screen 298 diverse wheat breeding lines and cultivars. The KASP clustering results were compared with gelbased gene specific markers and the widely used linked STS marker, UMN10. Eight disagreements were found between PFT_KASP and UMN10 assays among the tested lines. Based on the genotyping and sequencing of genes in the Fhb1 region, these genotypes were found to be common with a previously characterized susceptible haplotype. Therefore, our results indicate that PFT_KASP is a perfect diagnostic marker for Fhb1 and would be a valuable tool for introgression and pyramiding of FHB resistance in wheat cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.191-196
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• 2005

Fusarium head blight (FHB) is a severe disease problem that affects the quality and yield of barley grain. The evaluation of FHB resistance is difficult because environmental conditions greatly influence FHB infection and development. The objectives of this study were to: 1) establish an efficient screening method for selecting resistant barley to FHB, 2) compare FHB severity between the cut-spike method and pot-plant method for development of mass screening, and 3) estimate FHB resistance for barley germplasms. Barley cultivars and lines were evaluated for reaction to FHB in controlled-greenhouse condition. Spikes were spray-inoculated with a suspension $(5.0\times10^5\;macroconidia\;mL^{-1})$ of Fusarium graminearum SCK-O4 strain, and then kept in a greenhouse at $18-25^{\circ}C$ with $80-100\%$ relative humidity. Inoculation were employed at 3 different heading growth stages (heading date, three days after heading, and five days after heading). The inoculation was performed in 2 consecutive days in order to avoid escapes. The inoculated plants were maintained in the greenhouse at 4 different free moisture periods (1, 3, 5, and 7 days). The percentage of FHB severity was scored from 0 to 9 according to the rate of infected kernels per spike, and three spikes were evaluated per replication with 3 replicates. There were significant differences of FHB severity depending on the different free moisture periods, but not by the inoculation at different heading stages. The optimum evaluation point of FHB severity in the greenhouse condition was on the 7th day under free moisture condition after inoculation at the heading date. Infection level in cut-spike method highly correlated with that in pot-plant method. This suggested that cut-spike method is useful in evaluating of FHB resistance in barley. Six cultivars, such as Jinkwang, Buheung, Atahualpha 92, Chevron-b, Gobernadora-d, and MNBrite-c, were selected as resistant varieties to FHB. Correlation coefficient for the FHB severity evaluated by the pot-plant method between two seasons was 0.794, indicating the stability and accuracy of the screening method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.295-302
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• 2018

This study was conducted to investigate effect of feeding fermented hulless barley (FHB) on growth performance and blood metabolites in growing pigs. Forty-five pigs (LYD; initial body weight, $30.33{\pm}0.05kg$) were randomly allotted into three dietary treatments that consisted of 0, 0.5 and 1.0% of the FHB in the basal diets. The pigs fed 0.5% FHB showed higher average daily gain than the 0 and 1% FHB treatments, although there was not significant among the treatments. Similarly, average daily feed intake and feed conversion ratio were not different among the treatments. Blood white blood cells, neutrophil, lymphocyte, monocyte, eosinophil and basophil were ranged to reference values, but not difference among the treatments. Serum glucose was increased in the control compared with 0.5 and 1.0% FHB. However, parameters related to protein, lipid and mineral also were not different among the treatments. These results indicate the FHB has no significant effect of growth performance and metabolizable responses in growing-finishing pigs.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.558-569
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• 2020

Fusarium head blight (FHB) is a devastating fungal disease of wheat (Triticum aestivum L.). The lack of genetic resources with stable FHB resistance combined with a reliable and rapid screening method to evaluate FHB resistance is a major limitation to the development of FHB resistant wheat germplasm. The present study utilized an immature wheat spike culture method to screen wheat spike culture derived variants (SCDV) for FHB resistance. Mycotoxin concentrations determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) correlated significantly (P < 0.01) with FHB severity and disease progression during in vitro spike culture. Selected SCDV lines assessed for FHB resistance in a Fusarium field disease nursery in Carman, Manitoba, Canada in 2016 showed significant (P < 0.01) correlation of disease severity to the in vitro spike culture screening method. Selected resistant SCDV lines were also crossed with an elite cv. CDC Hughes and the progeny of F₂ and BC₁F₂ were screened by high resolution melt curve (HRM) analyses for the wheat UDP-glucosyl transferase gene (TaUGT-3B) single nucleotide polymorphism to identify resistant (T-allele) and susceptible (G-allele) markers. The progeny from the crosses were also screened for FHB severity using the immature spike culture method and identified resistant progeny grouped according to the HRM genotyping data. The results demonstrate a reliable approach using the immature spike culture to screen for FHB resistance in progeny of crosses in early stage of breeding programs.

• The Plant Pathology Journal
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• v.30 no.1
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• pp.25-32
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• 2014

Fusarium head blight (FHB; scab) caused mainly by Fusarium graminearum is a devastating disease of wheat and barley around the world. FHB causes yield reductions and contamination of grain with trichothecene mycotoxins such as deoxynivalenol (DON) which are a major health concern for humans and animals. The objective of this research was to develop an easy seed or seedling inoculation assay, and to compare these assays with whole plant resistance of twenty-nine Korean winter wheat cultivars to FHB. The clip-dipping assay consists of cutting off the coleoptiles apex, dipping the coleoptiles apex in conidial suspension, covering in plastic bag for 3 days, and measuring the lengths of lesions 7 days after inoculation. There were significant cultivar differences after inoculation with F. graminearum in seedling relative to the controls. Correlation coefficients between the lesion lengths of clip-dipping inoculation and FHB Type II resistance from adult plants were significant (r=0.45; P<0.05). Results from two other seedling inoculation methods, spraying and pin-point inoculation, were not correlated with adult FHB resistance. Single linear correlation was not significant between seed germination assays (soaking and soak-dry) and FHB resistance (Type I and Type II), respectively. These results showed that clip-dipping inoculation method using F. graminearum may offer a real possibility of simple, rapid, and reliable for the early screening of FHB resistance in wheat.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.106-114
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• 2024

Fusarium head blight (FHB), predominantly caused by Fusarium graminearum and F. asiaticum, is a significant fungal disease impacting small-grain cereals. The absence of highly resistant cultivars underscores the need for vigilant FHB surveillance to mitigate its detrimental effects. In 2023, a notable FHB outbreak occurred in the southern region of Korea. We assessed FHB disease severity by quantifying infected spikelets and grains. Isolating fungal pathogens from infected samples often encounters interference from various microorganisms. We developed a cost-effective, selective medium, named BGT (Burkholderia glumae Toxoflavin) medium, utilizing B. glumae, which is primarily known for causing bacterial panicle blight in rice. This medium exhibited selective growth properties, predominantly supporting Fusarium spp., while substantially inhibiting the growth of other fungi. Using the BGT medium, we isolated F. graminearum and F. asiaticum from infected wheat and barley samples across Korea. To further streamline the process, we used a direct PCR approach to amplify the translation elongation factor 1-α (TEF-1α) region without a separate genomic DNA extraction step. Phylogenetic analysis of the TEF-1α region revealed that the majority of the isolates were identified as F. asiaticum. Our results demonstrate that BGT medium is an effective tool for FHB diagnosis and Fusarium strain isolation.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.52-58
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• 2013

Fusarium head blight (FHB) caused by the filamentous fungus Fusarium graminearum is one of the most severe diseases threatening the production of small grains. Infected grains are often contaminated with mycotoxins such as zearalenone and trichothecences. During survey of contamination by FHB in rice grains, we found a bacterial isolate, designated as BN1, antagonistic to F. graminearum. The strain BN1 had branching vegetative hyphae and spores, and its aerial hyphae often had long, straight filaments bearing spores. The 16S rRNA gene of BN1 had 100% sequence identity with those found in several Streptomyces species. Phylogenetic analysis of ITS regions showed that BN1 grouped with S. sampsonii with 77% bootstrap value, suggesting that BN1 was not a known Streptomyces species. In addition, the efficacy of the BN1 strain against F. graminearum strains was tested both in vitro and in vivo. Wheat seedling length was significantly decreased by F. graminearum infection. However, this effect was mitigated when wheat seeds were treated with BN1 spore suspension prior to F. graminearum infection. BN1 also significantly decreased FHB severity when it was sprayed onto wheat heads, whereas BN1 was not effective when wheat heads were point inoculated. These results suggest that spraying of BN1 spores onto wheat heads during the wheat flowering season can be efficient for plant protection. Mechanistic studies on the antagonistic effect of BN1 against F. graminearum remain to be analyzed.

• The Plant Pathology Journal
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• v.40 no.1
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• pp.83-97
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• 2024

Fusarium graminearum, the causal agent of Fusarium head blight (FHB) in cereal crops, employs the production of sexual fruiting bodies (perithecia) on plant debris as a strategy for overwintering and dissemination. In an artificial condition (e.g., carrot agar medium), the F. graminearum Z3643 strain was capable of producing perithecia predominantly in the central region of the fungal culture where aerial hyphae naturally collapsed. To unravel the intricate relationship between natural aerial hyphae collapse and sexual development in this fungus, we focused on 699 genes differentially expressed during aerial hyphae collapse, with 26 selected for further analysis. Targeted gene deletion and quantitative real-time PCR analyses elucidated the functions of specific genes during natural aerial hyphae collapse and perithecium formation. Furthermore, comparative gene expression analyses between natural collapse and artificial removal conditions reveal distinct temporal profiles, with the latter inducing a more rapid and pronounced response, particularly in MAT gene expression. Notably, FGSG_09210 and FGSG_09896 play crucial roles in sexual development and aerial hyphae growth, respectively. Taken together, it is plausible that if aerial hyphae collapse occurs on plant debris, it may serve as a physical cue for inducing perithecium formation in crop fields, representing a survival strategy for F. graminearum during winter. Insights into the molecular mechanisms underlying aerial hyphae collapse provides offer potential strategies for disease control against FHB caused by F. graminearum.

• Research in Plant Disease
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• v.17 no.3
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• pp.272-279
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• 2011

Fusarium species are worldwide causal agents of Fusarium head blight (FHB) in cereals such as barley and wheat. Their toxigenic potential is a health risk for both humans and animals. To survey the natural occurrence of FHB and mycotoxins produced by Fusarium, total 126 barley or wheat grains grown in 2009-2010 season in Korea were collected. The incidence of FHB was 30.7% in silage barley, 26.9% in wheat, 20.7% in naked barley, 19.4% in malting barley, 16.4% in unhulled barley. Overall FHB incidence of barley and wheat in 2010 was 23.0% and 10% higher than that of 2009. The incidences and level of deoxynivalenol (DON), nivalenol (NIV), and zearalenone (ZEA) were 34%, 0.89 mg/kg, 84.9%, 1.86 mg/kg, and 10.3%, 0.06 mg/kg respectively. The both levels and incidences of NIV were found to be highest in barley, whereas the level of DON was found to be highest in wheat. Incidences of DON and NIV and the level of NIV in the samples from southern regions of Korea were higher than those from central region, whereas the level of DON from central region was higher than that from southern regions. This is the first paper demonstrating regional difference in natural occurrence of DON and NIV in wheat and barley.

• Research in Plant Disease
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• v.22 no.3
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• pp.145-151
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• 2016

Chemical fungicides have reduced Fusarium head blight (FHB) severity. However, by the effects of fungicide residues, they can only be used up to 30 days before time of harvest. Therefore, the development of new biofungicides that are applicable until harvest is required. In order to select plant extracts having antifungal activity against Fusarium graminearum for the control of FHB, we investigated the inhibitory effects of 225 medicinal plant extracts on spore germination of F. graminearum. Of these plant extracts, the methanol extract of Cirsium japonicum (CJ) roots showed the strongest antifungal activity. Through solvent partitioning, repeated column chromatography, and spore germination bioassay, two chemicals were purified and then their chemical structures were identified as ciryneol C (CC) and 1-heptadecene-11,13-diyne-8,9,10-triol (HD-ol) which are polyacetylene substances. Two active compounds effectively inhibited the germination of F. graminearum macroconidia; HD-ol ($IC_{50}$ of $3.17{\mu}g/ml$) showed stronger spore germination inhibitory activity than that of CC ($IC_{50}$ of $28.14{\mu}g/ml$). In addition, the wettable powder type formulation of ethyl acetate extract of CJ roots suppressed the development of FHB in dose-dependent manner, with control values of 78.92% and 31.56% at 250- and 500-fold dilutions, respectively. Combining these findings suggest that the crude extract of CJ roots containing polyacetylene compounds could be used as botanical fungicide for the control of FHB.