Diversity of Fusarium spp. associated with wheat node and grain in representative sites across the western Canadian Prairies.

2021 ◽  
Author(s):  
Mohamed Hafez ◽  
Ryan Gourlie ◽  
Melissa Telfer ◽  
Nicola Schatz ◽  
Kelly Turkington ◽  
...  

Fusarium head blight (FHB) and Fusarium crown and root rot (FCRR) are major wheat diseases worldwide. In this study, wheat node and grain samples were collected from four representative sites across the western Canadian prairies in 2018 growing season to characterize the major Fusarium spp. and other mycobiota associated with wheat in these regions. In total, 994 fungal isolates were recovered and based on culture and molecular diagnostic methods, three genera constituted over 90% of all fungal isolates, these were Alternaria (39.6%), Fusarium (27.8%), and Parastagonospora (23.9%). A qPCR was developed to quantify the most frequently isolated Fusarium spp. in infected wheat tissues: F. avenaceum, F. culmorum, F. graminearum and F. poae. The qPCR specificity was validated in silico, in vitro and in planta and proved specific to the target species.. The qPCR results showed that F. graminearum was not detected frequently in the four tested locations in this study. F. poae was the most abundant Fusarium species in grain samples in all tested locations. However, in node samples, F. culmorum (Beaverlodge and Scott) and F. avenaceum (Lacombe and Lethbridge) were the most abundant species. Trichothecene genotyping, showed that the 3ADON is the most dominant trichothecene genotype (68%), followed by type-A trichothecenes (29.5%), while the 15ADON trichothecene genotype was least dominant (2.5%) and the NIV genotype was not detected. Moreover, a total of 129 TEF1α sequences from nine Fusarium spp. were compared at haplotype level to evaluate genetic variability and haplotype distribution. F. avenaceum and F.poae exhibited higher diversity.

2003 ◽  
Vol 49 (4) ◽  
pp. 253-262 ◽  
Author(s):  
Yiu-Kwok Chan ◽  
Wayne A McCormick ◽  
Keith A Seifert

Bacteria were isolated from a cultivated soil and screened for antagonistic activity against Fusarium graminearum, a predominant agent of ear rot and head blight in cereal crops. Based on its in vitro effectiveness, isolate D1/2 was selected for characterization and identified as a strain of Bacillus subtilis by phenotypic tests and comparative analysis of its 16S ribosomal RNA gene (rDNA) sequence. It inhibited the mycelial growth of a collection of common fungal phytopathogens, including eight Fusarium species, three other ascomycetes, and one basidiomycete. The cell-free culture filtrate of D1/2 at different dilutions was active against macroconidium germination and hyphal growth of F. graminearum, depending on the initial macroconidium density. It induced the formation of swollen hyphal cells in liquid cultures of this fungus grown from macroconidia. A bioassay also demonstrated that D1/2 offered in planta protection against the damping-off disease in alfalfa seedlings caused by F. graminearum, while the type strain of B. subtilis was ineffective. Hence, B. subtilis D1/2 or its culture filtrate has potential application in controlling plant diseases caused by Fusarium.Key words: antifungal activity, Bacillus subtilis, biological control, biopesticide, Fusarium species.


2021 ◽  
Author(s):  
Mohamed Hafez ◽  
Ahmed Abdelmagid ◽  
Reem Aboukhaddour ◽  
Lorne R. Adam ◽  
Fouad Daayf

Soybean is threatened by many pathogens that negatively affect this crop's yield and quality, e.g., different Fusarium species that cause wilting and root rot diseases. Fusarium root rot (FRR) in soybean can be caused by F. graminearum and other Fusarium spp. that are associated with Fusarium head blight (FHB) in cereals. Therefore, it was important to enquire whether Fusarium pathogens from soybean can cause disease in wheat, and vice versa. Here, we investigated the Fusarium root rot complex in Manitoba (Canada) from symptomatic plants, using both culture- and molecular-based methods. We developed a molecular diagnostic toolkit to detect and differentiate between several Fusarium spp. involved in FHB and FRR, then we evaluated cross-pathogenicity of selected Fusarium isolates collected from soybean and wheat, and the results indicate that isolates recovered from one host can infect the other host. Trichothecene production by selected Fusarium spp. was also analyzed chemically using LC-MS in both soybean (root) and wheat (spike) tissues. Trichothecenes were also analyzed in soybean seeds from plants with FRR to check the potentiality of trichothecene translocation from infected roots to the seeds. All of the tested Fusarium isolates were capable of producing trichothecenes in wheat spikes and soybean roots, but no trichothecenes were detected in soybean seeds. This study provided evidence, for the first time, that trichothecenes were produced by several Fusarium spp. (F. cerealis, F. culmorum and F. sporotrichioides) during FRR development in soybean.


Biologia ◽  
2008 ◽  
Vol 63 (3) ◽  
Author(s):  
Antónia Šrobárová ◽  
Svetlana Šliková ◽  
Valéria Šudyova

AbstractSpecies associated with Fusarium head blight are depending on the production and edaphic conditions. The differences are found in the representation of various Fusarium spp. in the diseases, which sporadically occur all over the territory of Slovakia, in all agricultural production types. We identified fifteen Fusarium species during ten years of investigation. Most of the mentioned species F. culmorum (W.G. Smith) Sacc., F. graminearum Schwabe, recently F. cerealis (Cooke) Sacc. (crookwellense Burgess, Nelson & Tousson) and F. sambucinum Fuckel in diseased caryopsis are seed transmitted. The significant differences among species and intra species in cultural and pathogenicity assays in vitro and in vivo were correlated. Some of them are able to produce toxic metabolites — deoxynivalenone, which probably play a role in the aggressiveness of the pathogen and promote disease development and pathogen colonization.


2015 ◽  
Vol 81 (16) ◽  
pp. 5309-5317 ◽  
Author(s):  
Yit-Heng Chooi ◽  
Mariano Jordi Muria-Gonzalez ◽  
Oliver L. Mead ◽  
Peter S. Solomon

ABSTRACTAlternariol (AOH) is an important mycotoxin from theAlternariafungi. AOH was detected for the first time in the wheat pathogenParastagonospora nodorumin a recent study. Here, we exploited reverse genetics to demonstrate that SNOG_15829 (SnPKS19), a close homolog ofPenicillium aethiopicumnorlichexanthone (NLX) synthase genegsfA, is required for AOH production. We further validate thatSnPKS19is solely responsible for AOH production by heterologous expression inAspergillus nidulans. The expression profile ofSnPKS19based on previousP. nodorummicroarray data correlated with the presence of AOHin vitroand its absencein planta. Subsequent characterization of the ΔSnPKS19mutants showed thatSnPKS19and AOH are not involved in virulence and oxidative stress tolerance. Identification and characterization of theP. nodorumSnPKS19cast light on a possible alternative AOH synthase gene inAlternaria alternataand allowed us to survey the distribution of AOH synthase genes in other fungal genomes. We further demonstrate that phylogenetic analysis could be used to differentiate between AOH synthases and the closely related NLX synthases. This study provides the basis for studying the genetic regulation of AOH production and for development of molecular diagnostic methods for detecting AOH-producing fungi in the future.


2017 ◽  
Vol 6 (5) ◽  
pp. 186-193
Author(s):  
Vipin Panwar ◽  
Ashok Aggarwal ◽  
Surinder Paul ◽  
Virender Singh ◽  
Pankaj K. Singh ◽  
...  

Fusarium head blight (FHB) or head scab is emerging as a destructive disease affecting the quantity and quality of wheat worldwide. Several Fusarium spe-cies have been associated with the disease but their composition varies among geographical regions and years. Climatic factors like temperature, pH and humidity influence the growth, survival and infestation of Fusarium species. In the present study, response of thirty six isolates of three Fusarium spp. viz F. graminearum, F. oxysporum and F. pallidoroseum (F. semitectum) to different temperature and pH was assessed by analysing their in vitro growth rate (mm/day) on potato dextrose agar (PDA) medium. We found that all the isolates responded differentially but interestingly isolates of F. graminearum showed better tolerance at broader range of temperature and pH. This attributes make F. graminearum a widely distributed and potent pathogen of wheat.


Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 438
Author(s):  
Mary E. Ridout ◽  
Bruce Godfrey ◽  
George Newcombe

Fusarium species coexist as toxigenic, systemic pathogens in sweet corn seed production in southwestern Idaho, USA. We hypothesized that fungal antagonists of seedborne Fusarium would differentially alter production of Fusarium mycotoxins directly and/or systemically. We challenged the Fusarium complex by in vitro antagonism trials and in situ silk and seed inoculations with fungal antagonists. Fungal antagonists reduced growth and sporulation of Fusarium species in vitro from 40.5% to as much as 100%. Pichia membranifaciens and Penicillium griseolum reduced fumonisin production by F. verticillioides by 73% and 49%, respectively, while P. membranifaciens and a novel Penicillium sp. (WPT) reduced fumonisins by F. proliferatum 56% and 78%, respectively. In situ, pre-planting inoculation of seeds with Penicillium WPT systemically increased fumonisins in the resulting crop. Morchella snyderi applied to silks of an F1 cross systemically reduced deoxynivalenol by 47% in mature seeds of the F2. Antagonists failed to suppress Fusarium in mature kernels following silk inoculations, although the ratio of F. verticillioides to total Fusarium double with some inoculants. Fusarium mycotoxin concentrations in sweet corn seed change systemically, as well as locally, in response to the presence of fungal antagonists, although in Fusarium presence in situ was not changed.


Author(s):  
Tony Twamley ◽  
Mark Gaffney ◽  
Angela Feechan

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.


Biology ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 69
Author(s):  
Ben Kalman ◽  
Dekel Abraham ◽  
Shaul Graph ◽  
Rafael Perl-Treves ◽  
Yael Meller Harel ◽  
...  

Over the past decade, there have been accumulating reports from farmers and field extension personnel on the increasing incidence and spread of onion (Allium cepa) bulb basal rot in northern Israel. The disease is caused mainly by Fusarium species. Rotting onion bulbs were sampled from fields in the Golan Heights in northeastern Israel during the summers of 2017 and 2018. Tissue from the sampled onion bulbs was used for the isolation and identification of the infecting fungal species using colony and microscopic morphology characterization. Final confirmation of the pathogens was performed with PCR amplification and sequencing using fungi-specific and Fusarium species-specific primers. Four Fusarium spp. isolates were identified in onion bulbs samples collected from the contaminated field: F. proliferatum, F. oxysporum f. sp. cepae, and two species less familiar as causative agents of this disease, F. acutatum and F. anthophilium. Phylogenetic analysis revealed that these species subdivided into two populations, a northern group isolated from white (Riverside cv.) onion bulbs, and a southern group isolated from red (565/505 cv.) bulbs. Pathogenicity tests conducted with seedlings and bulbs under moist conditions proved that all species could cause the disease symptoms, but with different degrees of virulence. Inoculating seeds with spore suspensions of the four species, in vitro, significantly reduced seedlings’ germination rate, hypocotyl elongation, and fresh biomass. Mature onion bulbs infected with the fungal isolates produced typical rot symptoms 14 days post-inoculation, and the fungus from each infected bulb was re-isolated and identified to satisfy Koch’s postulates. The onion bulb assay also reflected the degree of sensitivity of different onion cultivars to the disease. This work is the first confirmed report of the direct and primary cause of Fusarium onion basal rot disease in northeastern Israel. These findings are a necessary step towards uncovering the mycoflora of the diseased onion plants and developing a preventive program that would reduce the disease damage.


Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1610-1615 ◽  
Author(s):  
Xiang-xiang Zhang ◽  
Hai-yan Sun ◽  
Cheng-mei Shen ◽  
Wei Li ◽  
Han-shou Yu ◽  
...  

Fusarium crown rot of wheat has become more prevalent in China. To investigate the phylogenetic structure of Fusarium causing wheat crown rot in China, wheat basal stems with symptoms of the disease were collected from 2009 to 2013 in Jiangsu, Anhui, Henan, Hebei, and Shandong provinces. In total, 175 Fusarium isolates were collected and their mycotoxin chemotypes and distribution were identified. Among the 175 isolates, 123 were Fusarium asiaticum; 95 of these were the chemotype 3-acetyl-deoxynivalenol (3-AcDON) and 28 were nivalenol (NIV). Thirty-seven isolates belonged to F. graminearum, which were all 15-AcDON. Smaller numbers of isolates consisted of F. acuminatum, F. pseudograminearum, and F. avenaceum. The virulence of F. asiaticum and F. graminearum isolates on wheat crowns and heads was comparable. The virulence of isolates of the DON and NIV chemotype were statistically similar, but DON tended to be more aggressive. The DON concentrations in grains from wheat heads inoculated with isolates causing either Fusarium head blight or crown rot were similar. In the five provinces, F. asiaticum of the 3-AcDON chemotype was the predominant pathogen causing crown rot, followed by F. graminearum. Recent changes in causal Fusarium species, chemotypes, and distribution in China are discussed.


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