scholarly journals In Vitro Quantitative Resistance Components in Wheat Plants to Fusarium Head Blight

2019 ◽  
Vol 13 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Nachaat Sakr

Background: In vitro tools have proved to be very useful in identifying quantitative resistance in wheat to Fusarium Head Blight (FHB) infection. However, there is a need to understand how the different in vitro and in planta tests correlate to describe the level of wheat resistance to FHB infection. Objective and Methods: We evaluated the correlation between in vitro symptom assessment using nine quantitative resistance criteria and in planta disease severity for Type II resistance assessment using a set of 16 FHB isolates across two widely grown Syrian wheat cultivars: Cham1 (durum) and Cham6 (bread). Results: Cultivar differences after inoculation with fungal isolates in seedlings and adult plants relative to the controls were detected. There were significant differences in the resistance of two wheat cultivars as measured by adult FHB resistance, Latent Period (LP) of detached leaf inoculation and standardized Area Under Disease Progress Curve (AUDPCstandard) of modified Petri-dish inoculation. Correlation coefficients between FHB severity and the two in vitro components LP and AUDPCstandard were significant (r=0.545 with p<0.05, and r=0.659 with p<0.01, respectively). No significant differences in the resistance of Cham6 and Cham1 were indicated for the other seven in vitro components: incubation period and lesion length of detached leaf inoculation, germination rate reduction and coleoptile length reduction of modified Petri-dish inoculation and lesion length of clip-dipping inoculation and percentage of infected seedlings of foliar-spraying and pin-point inoculations. Results from these seven components were not correlated with adult FHB resistance. Longer latent period and less AUDPCstandard were related to greater FHB disease-type II resistance. Conclusion: LP and AUDPCstandard are indicators of mechanisms of resistance occurring in the whole plant during FHB infection. Therefore, the idea of using in vitro components is based on their predictive ability of in planta adult FHB resistance.

2014 ◽  
Vol 40 (4) ◽  
pp. 353-357 ◽  
Author(s):  
Camila Turra ◽  
Erlei M. Reis ◽  
Amarilis L. Barcellos

The method of preserving detached wheat leaves in Petri dish was used for the inoculation and development of the fungus Puccinia triticina, the causal agent of wheat leaf rust. The reaction of 26 wheat cultivars was compared by using seedlings cultivated in pots (in vivo) and detached leaves (in vitro) inoculated with four physiological races of the pathogen. After inoculation, the material was kept in a growth chamber for 15 days. The reaction was evaluated on the 15th day after inoculation. Results for each race in the evaluated genotypes confirmed the efficiency of the detached leaf method in assessing the reaction of wheat cultivars.


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.


Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 399
Author(s):  
Hiroyuki Morimura ◽  
Michihiro Ito ◽  
Shigenobu Yoshida ◽  
Motoo Koitabashi ◽  
Seiya Tsushima ◽  
...  

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.


2017 ◽  
Vol 10 (3) ◽  
pp. 285-293 ◽  
Author(s):  
F. Dong ◽  
S. Wang ◽  
M. Yu ◽  
Y. Sun ◽  
J. Xu ◽  
...  

Deoxynivalenol (DON) is a major mycotoxin found in wheat infected with Fusarium fungi. DON can be converted by plant detoxification into a form of ‘masked mycotoxin’ termed deoxynivalenol-3-glucoside (DON-3G). To recommend appropriate wheat cultivars for planting in order to reduce DON contamination in Jiangsu province, where a traditional Fusarium head blight (FHB) epidemic area is located in the lower reaches of Yangtze-Huaihe, we evaluated the capacity of various wheat cultivars to transform DON into DON-3G under field conditions. We collected and evaluated samples from 11 major wheat cultivars grown in 63 experimental stations in Jiangsu province in 2015 and 2016. All samples were contaminated with DON, with an average concentration of 2,087±112 and 2,601±126 µg/kg in 2015 and 2016, respectively. DON-3G was detected in 425 (96%) and 405 (97%) samples in 2015 and 2016, with an average concentration of 545±28 and 819±44 µg/kg, respectively. The DON-3G/DON ratio ranged from 5 to 84% (average, 30%) in 2015 and from 0 to 71% (average, 31%) in 2016. DON levels were highly correlated with DON-3G concentrations (P<0.01), and the FHB resistance of the wheat cultivars was proportional to their capacity to convert DON to DON-3G. Importantly, region, cultivar, and region × cultivar interaction all significantly affected DON and DON-3G concentrations and DON-3G/DON ratios. In general, FHB-resistant cultivars, such as Sumai 188 and Ningmai 13, had lower levels of DON and DON-3G than the others. However, additional factors, including the growing region and environmental variables, were important for wheat management when other wheat cultivars were evaluated.


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.


Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1271-1279 ◽  
Author(s):  
N. A. Foroud ◽  
S. P. McCormick ◽  
T. MacMillan ◽  
A. Badea ◽  
D. F. Kendra ◽  
...  

The role of Fusarium graminearum trichothecene-chemotypes in disease outcomes was evaluated by point inoculation in a series of wheat lines with different levels of resistance to Fusarium head blight (FHB). Four inocula, each consisting of a composite of four strains with either 15-acetyldeoxynivalenol (ADON) chemotypes from “traditional” or emergent populations, a 3-ADON chemotype, or a nivalenol (NIV) chemotype, were compared. The evaluated wheat included Canadian lines with different levels of FHB resistance/susceptibility and double haploid lines developed from crosses of these lines. Highly resistant lines were resistant to infection by all of the F. graminearum chemotypes evaluated. In the moderately susceptible/resistant wheat lines, the 3-ADON producers and the emergent 15-ADON population were, in some instances, more aggressive and resulted in higher Fusarium damaged kernel scores and levels of trichothecene accumulation. The data presented in this study demonstrate the importance of growing highly resistant wheat cultivars in the current climate of an evolving F. graminearum population, and suggest that moderate levels of FHB resistance may not be sufficient to minimize trichothecene contamination of grain from F. graminearum–infected wheat.


Sign in / Sign up

Export Citation Format

Share Document