scholarly journals Impact of microalgal phenolic extracts on the control of Fusarium graminearum and deoxynivalenol contamination in wheat

2019 ◽  
Vol 12 (4) ◽  
pp. 367-378 ◽  
Author(s):  
P.T. Scaglioni ◽  
V. Scarpino ◽  
F. Marinaccio ◽  
F. Vanara ◽  
E. Badiale Furlong ◽  
...  

In this study, microalgal phenolic extracts (MPE) of Nannochloropsis sp. and Spirulina sp. were tested in in vitro experiments and, in comparison with synthetic fungicides, in field experiments, for their ability to control Fusarium graminearum development and limit deoxynivalenol (DON) contamination. In in vitro experiments, the Nannochloropsis and Spirulina extracts inhibited fungal biomass by 34 and 25%, respectively, compared with the untreated control. This effect was confirmed by a reduction in ergosterol production (-80% for Nannochloropsis and -75% for Spirulina) and in DON content (-97% for Nannochloropsis and -62% for Spirulina). In field experiments, application of the fungicide prothioconazole and prothioconazole + tebuconazole resulted in control of Fusarium head blight (FHB) and foliar disease, leading to a significant increase in grain yield (+13%) and a reduction in DON content (-46%) compared to the untreated control. The application of MPE at wheat flowering reduced the severity of FHB compared with the control (-35% for Spirulina and -39% for Nannochloropsis). However, the MPE did not significantly control foliar diseases (Septoria tritici blotch) and therefore did not enhance the grain yield. Moreover, no effect in reducing the DON content in comparison to the control was observed in the field. In view of that, the use of MPE in wheat fields as real alternatives to conventional fungicides requires the discovery of solutions to empower their persistence and efficacy.

2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang

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.


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.


2010 ◽  
Vol 46 (No. 1) ◽  
pp. 21-26 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
O. Veškrna ◽  
L. Bobková

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.


2018 ◽  
Vol 132 (4) ◽  
pp. 1121-1135 ◽  
Author(s):  
Cathérine Pauline Herter ◽  
Erhard Ebmeyer ◽  
Sonja Kollers ◽  
Viktor Korzun ◽  
Tobias Würschum ◽  
...  

Plant Disease ◽  
2020 ◽  
Author(s):  
Jiao-Sheng Li ◽  
Luo-Yu Wu ◽  
Hui Zhang ◽  
Xiu-Shi Song ◽  
Jian-Xin Wang ◽  
...  

Phenamacril is a cyanoacrylate fungicide that provides excellent control of Fusarium head blight (FHB) or wheat scab, which is caused predominantly by Fusarium graminearum and Fusarium asiaticum. Previous studies revealed that codon mutations of the myosin-5 gene of Fusarium spp. conferred resistance to phenamacril in vitro lab experiments. In this study, PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) was developed to detect three common mutations (A135T, GCC to ACC at codon 135; S217L, TCA to TTA at codon 217, and E420K, GAA to AAA at codon 420) in F. graminearum induced by fungicide domestication in vitro. PCR products of 841 bp (for mutation of A135T), 802 bp (for mutation of S217L) or 1649 bp (for mutation of E420K) in myosin-5 gene were amplified respectively by appropriate primer pairs. Restriction enzyme KpnⅠ, TasⅠ or DraⅠ was used to distinguish phenamacril-sensitive and -resistant strains with mutation genotypes of A135T, S217L and E420K, respectively. KpnⅠ digested the 841 bp PCR products of phenamacri-resistant strains with codon mutation A135T into two fragments of 256 bp and 585 bp. In contrast, KpnⅠ did not digest the PCR products of sensitive strains. TasⅠ digested the 802 bp PCR products of phenamacril-strains with codon mutation S217L into three fragments of 461 bp, 287bp and 54 bp. In contrast, TasⅠ digestion of the 802 bp PCR products of phenamacril-sensitive strains resulted in only two fragments of 515bp and 287bp. DraⅠ digested the 1649 bp PCR products of phenamacril-resistant strains with codon mutation E420K into two fragments of 932 bp and 717 bp, while the PCR products of phenamacril-sensitive strains was not digested. The three genotypes of resistance mutations were determined by analyzing electrophoresis patterns of the digestion fragments of PCR products. The PCR-RFLP method was evaluated on 48 phenamacril-resistant strains induced by fungicide domestication in vitro and compared with the conventional method (mycelial growth on fungicide-amended agar). The accuracy of the PCR-RFLP method for detecting the three resistant mutation genotypes of F. graminearum to phenamacril was 95.12% compared with conventional method. Bioinformatics analysis revealed that the PCR-RFLP method could also be used to detect the codon mutations of A135T and E420K in F. asiaticum.


2017 ◽  
Author(s):  
Graeme J. Kettles ◽  
Carlos Bayon ◽  
Caroline A. Sparks ◽  
Gail Canning ◽  
Kostya Kanyuka ◽  
...  

Abstract-The fungus Zymoseptoria tritici is the causal agent of Septoria Tritici Blotch (STB) disease of wheat leaves. Z. tritici secretes many functionally uncharacterised effector proteins during infection. Here we characterised a secreted ribonuclease (Zt6) with an unusual biphasic expression pattern.-Transient expression systems were used to characterise Zt6, and mutants thereof, in both host and non-host plants. Cell-free protein expression systems monitored impact of Zt6 protein on functional ribosomes, and in vitro assays of cells treated with recombinant Zt6 determined toxicity against bacteria, yeasts and filamentous fungi.-We demonstrated that Zt6 is a functional ribonuclease and that phytotoxicity is dependent on both the presence of a 22-amino acid N-terminal “loop” region and its catalytic activity. Zt6 selectively cleaves both plant and animal rRNA species, and is toxic to wheat, tobacco, bacterial and yeast cells but not to Z. tritici itself.-Zt6 is the first Z. tritici effector demonstrated to have a likely dual functionality. The expression pattern of Zt6 and potent toxicity towards microorganisms suggests that whilst it may contribute to the execution of wheat cell death, it is also likely to have an important secondary function in antimicrobial competition and niche protection.


2019 ◽  
Vol 58 (1) ◽  
pp. 27-33
Author(s):  
S. Kildea ◽  
D.E. Bucar ◽  
F. Hutton ◽  
S. de la Rosa ◽  
T.E. Welch ◽  
...  

Abstract The emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain.


2021 ◽  
Author(s):  
Dinesh Kumar Saini ◽  
Amneek Chahal ◽  
Neeraj Pal ◽  
Puja Srivast ◽  
Pushpendra Kumar Gupta

Abstract In wheat, meta-QTLs (MQTLs), and candidate genes (CGs) were identified for multiple disease resistance (MDR). For this purpose, information was collected from 58 studies for mapping QTLs for resistance to one or more of the five diseases. As many as 493 QTLs were available from these studies, which were distributed in five diseases as follows: septoria tritici blotch (STB) 126 QTLs; septoria nodorum blotch (SNB), 103; fusarium head blight (FHB), 184; karnal bunt (KB), 66, and loose smut (LS), 14. Of these 493 QTLs, only 291 QTLs could be projected onto a consensus genetic map, giving 63 MQTLs. The CI of the MQTLs ranged from 0.04 to 15.31 cM with an average of 3.09 cM per MQTL. This is a ~ 4.39 fold reduction from the CI of initial QTLs, which ranged from 0 to 197.6 cM, with a mean of 13.57 cM. Of 63 MQTLs, 60 were anchored to the reference physical map of wheat (the physical interval of these MQTLs ranged from 0.30 to 726.01 Mb with an average of 74.09 Mb). Thirty-eight (38) of these MQTLs were verified using marker-trait associations (MTAs) derived from genome-wide association studies. As many as 874 CGs were also identified which were further investigated for differential expression using data from five transcriptome studies, resulting in 194 differentially expressed genes (DEGs). Among the DEGs, 85 genes had functions previously reported to be associated with disease resistance. These results should prove useful for fine mapping of MDR genes and marker-assisted breeding.


Plant Disease ◽  
2021 ◽  
Author(s):  
Brian Mueller ◽  
Carol Groves ◽  
Damon L. Smith

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.


Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1673
Author(s):  
Urszula Wachowska ◽  
Katarzyna Kucharska ◽  
Wioletta Pluskota ◽  
Sylwester Czaplicki ◽  
Kinga Stuper-Szablewska

Fusarium head blight (FHB) is the most dangerous spike disease of wheat, and triazole fungicides are generally recommended for FHB control. Bacteria isolates obtained from wheat grain were identified as members of the genus Sphingomonas based on 16S rDNA gene sequence analysis. The degradation of propiconazole and trichothecenes was analyzed by high-performance liquid chromatography. Two field experiments were conducted to determine the effectiveness of the biological treatment. All of the tested Sphingomonas isolates produced surfactin. Moreover, all strains were effective in degrading propiconazole and exhibited inhibitory effects on pathogens that cause FHB in wheat. Sphingomonas isolate S11 was selected for the field experiment because it inhibited the development of F. culmorum colonies in vitro by 48.80%, and degraded propiconazole in 15.13% after 48 h. The application of Sphingomonas S11 suspension during the growing season of winter wheat decreased the deoxynivalenol (DON) content of grain inoculated with F. culmorum more than 22-fold. Sphingomonas sp. strain S11 applied after fungicides also decreased the contamination of grain with fungi of the genus Fusarium and their mycotoxins. The analyzed bacteria can be potentially used to protect wheat against FHB pathogens, increase yields and improve grain quality by eliminating dangerous mycotoxins and propiconazole residues.


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