scholarly journals An Efficient in vitro Assay to Predict Resistance and Pathogenicity in the Fusarium Head Blight-Hordeum Vulgare Pathosystem

2020 ◽  
Vol 14 (1) ◽  
pp. 87-97
Author(s):  
Nachaat Sakr
Keyword(s):  
Hordeum Vulgare ◽  
Fusarium Head Blight ◽  
Quantitative Resistance ◽  
Individual Plant ◽  
Root Weight ◽  
Head Blight ◽  
Vitro Assay ◽  
Barley Cultivars ◽  
Infection Assay

Background: Barley (Hordeum vulgare L.) worldwide is affected seriously by Fusarium Head Blight (FHB) disease caused by several Fusarium species. In vitro assays permitting for easy, efficient and reliable prediction of the head blight reaction in the whole plant should be investigated. Objective and Methods: The in vitro ability of 16 fungal isolates of four FHB species to confer disease on individual plant organs was evaluated using a coleoptile infection assay. Four quantitative components (Seed Germination (SG), Coleoptile Length (CL), Coleoptile Weight (CW) and Root Weight (RW)) were analyzed in two widely cultivated barley cultivars, Arabi Aswad (AS) and Arabi Abiad (AB), with known quantitative resistance. Results: Differences in inoculated pathogenicity and resistance treatments were observed on young plant parts relative to water controls, indicating that these FHB species were found to be suitable for the differential expression of all tested quantitative components. There was a wide variation in pathogenicity among the 16 FHB isolates and susceptibility among AS and AB. The 16 FHB isolates can be separated into the first group with larger number of isolates, upon infection with which AB really was more susceptible to FHB infection than AS, and isolates of the second group with leaser number of isolates for which AS and AB react was the opposite. On AB, rather susceptible, inoculation with FHB species resulted in significantly less SG, CL, CW and RW, compared with AS, which showed a greater resistance. The very good resistance of AS was confirmed by the measurements of quantitative resistance components described in this study. When infected with FHB isolates, all indicators of a more susceptible cultivar seemed to be 10-20% less than those of a resistant cultivar. Moreover, the values of all analyzed components were significantly correlated with the data of pathogenic indices generated in vitro, and under controlled and field conditions with a large diversity depending on AS and AB. Conclusion: Appropriate in vitro conditions were determined for the coleoptile infection assay to maximize differences in disease reactions components among FHB isolates and the two barley cultivars. Results suggest that all measured components predict resistance and pathogenicity occurring at the earliest and latest barley development stages during FHB infection. Our data also highlighted, for the first time, the utility of CW and RW for the determination of resistance and pathogenicity in the FHB-barley pathosystem. The coleoptile infection test was confirmed to be adequate to in vitro, growth chamber and field data by the presence of the first group, which prevailed in all other tests generated under different experimental conditions. The in vitro coleoptile infection assay may offer a real possibility of simple, rapid and reliable screening of resistance in barley cultivars and pathogenicity of FHB species.

scholarly journals Assessment and Introduction of Quantitative Resistance to Fusarium Head Blight in Elite Spring Barley

2013 ◽  
Vol 103 (12) ◽  
pp. 1252-1259 ◽  
Author(s):  
A. Linkmeyer ◽  
M. Götz ◽  
L. Hu ◽  
S. Asam ◽  
M. Rychlik ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Quantitative Resistance ◽  
Spring Barley ◽  
Laser Scanning Microscopy ◽  
Economic Losses ◽  
Head Blight ◽  
Fusarium Spp ◽  
Barley Cultivars ◽  
Spray Inoculation ◽  
Fhb Resistance

Breeding for resistance is a key task to control Fusarium head blight (FHB), a devastating disease of small cereals leading to economic losses and grain contamination with mycotoxins harmful for humans and animals. In the present work, FHB resistance of the six-rowed spring barley ‘Chevron’ to FHB in Germany was compared with those of adapted German spring barley cultivars. Both under natural infection conditions and after spray inoculation with conidia of Fusarium culmorum, F. sporotrichioides, and F. avenaceum under field conditions, Chevron showed a high level of quantitative resistance to the infection and contamination of grain with diverse mycotoxins. This indicates that Chevron is not only a little susceptible to deoxynivalenol-producing Fusarium spp. but also to Fusarium spp. producing type A trichothecenes and enniatins. Monitoring the initial infection course of F. culmorum on barley lemma tissue by confocal laser-scanning microscopy provided evidence that FHB resistance of Chevron is partially mediated by a preformed penetration resistance, because direct penetration of floral tissue by F. culmorum was observed rarely on Chevron but was common on susceptible genotypes. Alternatively, F. culmorum penetrated Chevron lemma tissue via stomata, which was unusual for susceptible genotypes. We generated double-haploid barley populations segregating for the major FHB resistance quantitative trait loci (QTL) Qrgz-2H-8 of Chevron. Subsequently, we characterized these populations by spray inoculation with conidia of F. culmorum and F. sporotrichioides. This suggested that Qrgz-2H-8 was functional in the genetic background of European elite barley cultivars. However, the degree of achieved resistance was very low when compared with quantitative resistance of the QTL donor Chevron, and the introgression of Qrgz-2H-8 was not sufficient to mediate the cellular resistance phenotype of Chevron in the European backgrounds.

In vitro variation in pathogenicity of Fusarium species causing head blight in relation to their isolation from barley head

2021 ◽  
Author(s):  
Nachaat Sakr
Keyword(s):  
Quantitative Resistance ◽  
Fusarium Species ◽  
Fusarium Verticillioides ◽  
Fusarium Culmorum ◽  
Head Blight ◽  
Single Spore ◽  
Barley Cultivars ◽  
Growing Seasons ◽  
Depth Study

Abstract Till now, no published study is available on the variation in pathogenicity of Fusarium head blight (FHB) pathogens in relation to their isolation origin in barley head. To end this, two barley cultivars of contrasting quantitative resistance were artificially infected by four FHB species under field conditions over two consecutive growing seasons. Then, pathogenicity tests were conducted under in vitro conditions on single-spore cultures originated from both kernels and glumes in the heads. Different pathogenicity was detected among Fusarium species originated from both kernels and glumes, indicating that the same isolate from glumes and kernels differs in pathogenicity on leaves/seedlings. Isolates of Fusarium culmorum and Fusarium verticillioides originated from infected kernels had shorter latent periods and higher area under disease progress curves compared to isolates originated from glumes, and the reverse was observed for the Fusarium equiseti isolate. In the case of Fusarium solani, isolates originated from kernels or from glumes were equally pathogenic. Primarily findings in this first in-depth study have implications for breeding programs relied principally on actual quantification of pathogenicity in Fusarium species present in a given environment. The sampling of fungi should take into account the presence of Fusarium species of interest on kernels or glumes.

Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat

2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Spore Germination ◽  
Field Experiments ◽  
Synergistic Effects ◽  
Field Trials ◽  
Head Blight ◽  
Mycelium Growth ◽  
Key Aspects

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

scholarly journals A Microbial Fermentation Mixture Reduces Fusarium Head Blight and Promotes Grain Weight but does not impact Septoria tritici blotch

2021 ◽  
Author(s):  
Tony Twamley ◽  
Mark Gaffney ◽  
Angela Feechan
Keyword(s):  
Fusarium Head Blight ◽  
Fungal Pathogens ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Microbial Fermentation ◽  
In Planta ◽  
Head Blight ◽  
Zymoseptoria Tritici ◽  
The Impact

AbstractFusarium graminearum and Zymoseptoria tritici cause economically important diseases of wheat. F. graminearum is one of the primary causal agents of Fusarium head blight (FHB) and Z. tritici is the causal agent of Septoria tritici blotch (STB). Alternative control methods are required in the face of fungicide resistance and EU legislation which seek to cut pesticide use by 2030. Both fungal pathogens have been described as either hemibiotrophs or necrotrophs. A microbial fermentation-based product (MFP) was previously demonstrated to control the biotrophic pathogen powdery mildew, on wheat. Here we investigated if MFP would be effective against the non-biotrophic fungal pathogens of wheat, F. graminearum and Z. tritici. We assessed the impact of MFP on fungal growth, disease control and also evaluated the individual constituent parts of MFP. Antifungal activity towards both pathogens was found in vitro but MFP only significantly decreased disease symptoms of FHB in planta. In addition, MFP was found to improve the grain number and weight, of uninfected and F. graminearum infected wheat heads.

Fusarium head blight of small grains in Pennsylvania: unravelling species diversity, toxin types, growth and triazole sensitivity

2021 ◽  
Author(s):  
Maira R. Duffeck ◽  
Ananda Y. Bandara ◽  
Dilooshi K. Weerasooriya ◽  
Alyssa Collins ◽  
Philip J. Jensen ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Management Practices ◽  
Crop Residues ◽  
Head Blight ◽  
The North ◽  
Reproduction Traits ◽  
Small Grains ◽  
Ascospore Production ◽  
Growth And Reproduction

Fusarium graminearum is the main causal species of Fusarium head blight (FHB) globally. Recent changes in the trichothecene (toxin) types in the North American FHB pathogens support the need for continued surveillance. In this study, 461 isolates were obtained from symptomatic spikes of wheat, spelt, barley, and rye crops during 2018 and 2019. These were all identified to species and toxin types using molecular-based approaches. An additional set of 77 F. graminearum isolates obtained from overwintering crop residues during Winter 2012 were molecularly identified to toxin types. A subset of 31 F. graminearum isolates (15 15ADON and 16 3ADON) were assessed for mycelial growth, macroconidia, perithecia, and ascospore production, and sensitivity to two triazole fungicides. Ninety percent of isolates obtained from symptomatic spikes (n = 418) belonged to F. graminearum, with another four species found at a lower frequency (n = 39). F. graminearum isolates from symptomatic spikes were mainly of the 15ADON (95%), followed by 3ADON (4%), NIV (0.7%), and NX-2 (0.3%) toxin types. All F. graminearum isolates obtained from overwintering residue were of the 15ADON type. Toxin types could not be differentiated based on multivariate analysis of growth and reproduction traits. All isolates were sensitive to tebuconazole and metconazole fungicides in vitro. This study confirms the dominance of F. graminearum and suggests ecological and environmental factors that lead to similar composition of toxin types in Northern U.S. Our results are useful to assess the sustainability of FHB management practices and provide a baseline for future FHB surveys.

Chemotype and aggressiveness evaluation of Fusarium graminearum and Fusarium culmorum isolates from wheat fields in Wisconsin

Plant Disease ◽  
2021 ◽  
Author(s):  
Brian Mueller ◽  
Carol Groves ◽  
Damon L. Smith
Keyword(s):  
Growth Rate ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Fusarium Culmorum ◽  
Head Blight ◽  
Growing Seasons ◽  
Progress Curve ◽  
Sporulation Capacity ◽  
Derivatives Of

Fusarium graminearum commonly causes Fusarium head blight (FHB) on wheat, barley, rice, and oats. Fusarium graminearum produces nivalenol and deoxynivalenol (DON) and forms derivatives of DON based on its acetylation sites. The fungus is profiled into chemotypes based on DON derivative chemotypes (3 acetyldeoxynivalenol (3ADON) chemotype; 15 acetyldeoxynivalenol (15ADON) chemotype) and/or the nivalenol (NIV) chemotype. The current study assessed the Fusarium population found on wheat and the chemotype profile of the isolates collected from 2016 and 2017 in Wisconsin. Fusarium graminearum was isolated from all locations sampled in both 2016 and 2017. Fusarium culmorum was isolated only from Door County in 2016. Over both growing seasons, 91% of isolates were identified as the 15ADON chemotype while 9% of isolates were identified as the 3ADON chemotype. Aggressiveness was quantified by area under disease progress curve (AUDPC). The isolates with the highest AUDPC values were from the highest wheat producing cropping districts in the state. Deoxynivalenol production in grain and sporulation and growth rate in vitro were compared to aggressiveness in the greenhouse. Our results showed that 3ADON isolates in Wisconsin were among the highest in sporulation capacity, growth rate, and DON production in grain. However, there were no significant differences in aggressiveness between the 3ADON and 15ADON isolates. The results of this research detail the baseline frequency and distribution of 3ADON and 15ADON chemotypes observed in Wisconsin. Chemotype distributions within populations of F. graminearum in Wisconsin should continue to be monitored in the future.

scholarly journals In Vitro Assessment of Biocontrol Effects on Fusarium Head Blight and Deoxynivalenol (DON) Accumulation by DON-Degrading Bacteria

Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 399
Author(s):  
Hiroyuki Morimura ◽  
Michihiro Ito ◽  
Shigenobu Yoshida ◽  
Motoo Koitabashi ◽  
Seiya Tsushima ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Leaf Growth ◽  
Severe Disease ◽  
Petri Dish ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Head Blight ◽  
Control Approach ◽  
Degrading Bacteria

Fusarium head blight (FHB) of cereals is a severe disease caused by the Fusarium graminearum species complex. It leads to the accumulation of the mycotoxin deoxynivalenol (DON) in grains and other plant tissues and causes substantial economic losses throughout the world. DON is one of the most troublesome mycotoxins because it is a virulence factor to host plants, including wheat, and exhibits toxicity to plants and animals. To control both FHB and DON accumulation, a biological control approach using DON-degrading bacteria (DDBs) is promising. Here, we performed a disease control assay using an in vitro petri dish test composed of germinated wheat seeds inoculated with F. graminearum (Fg) and DDBs. Determination of both grown leaf lengths and hyphal lesion lengths as a measure of disease severity showed that the inoculation of seeds with the DDBs Devosia sp. strain NKJ1 and Nocardioides spp. strains SS3 or SS4 were protective against the leaf growth inhibition caused by Fg. Furthermore, it was as effective against DON accumulation. The inoculation with strains SS3 or SS4 also reduced the inhibitory effect on leaves treated with 10 µg mL−1 DON solution (without Fg). These results indicate that the DDBs partially suppress the disease by degrading DON.

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