scholarly journals Relationship Between Efficacy of Fusarium Head Blight Chemical Control and Deoxynivalenol Contamination on Wheat Kernels

2020 ◽  
Vol 12 (9) ◽  
pp. 227
Author(s):  
Erlei Melo Reis ◽  
Mateus Zanatta ◽  
Andrea Camargo Reis

In field experiment carried out in the 2018 growing season we tried to show the inverse relation between the efficacy of fusarium head blight (FHB) chemical control and the deoxynivalenol (DON) concentration in harvested kernels. The wheat cultivar Tbio Mestre was established under no-till in soybean residues and in winter rotation with black oats. The leaf rust and yellow spot control was performed during the vegetative stage by spraying the whole experimental area with three applications of epoxiconazole + krezoxim methyl (0.7 L/ha). The most potent fungicides metconazole + pyraclostrobin (1.0 L/ha) + mancozeb (2.0 kg/ha), prothioconazole + trifloxystrobin (0.4 L/ha) and pydiflumetofen (1.0 L/ha) were compared to control FHB. Disease incidence in spikes, incidence in spikelets, or spikes severity, grain weight and yield were evaluated. DON concentration was. Using the most efficient technology available for FHB control, the hypothesis of the inverse relationship between disease intensity occurring naturally in spikes, and deoxinivalenol (DON) concentration in the harvested grains was confirmed. DON concentration in unsprayed grains was 3,675 and in the best treatments 821 to 1,067 ppb.

2015 ◽  
Vol 105 (2) ◽  
pp. 246-254 ◽  
Author(s):  
Emerson M. Del Ponte ◽  
Piérri Spolti ◽  
Todd J. Ward ◽  
Larissa B. Gomes ◽  
Camila P. Nicolli ◽  
...  

A multiyear survey of >200 wheat fields in Paraná (PR) and Rio Grande do Sul (RS) states was conducted to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in the southern Brazilian wheat agroecosystem. Five species and three trichothecene genotypes were found among 671 FGSC isolates from Fusarium head blight (FHB)-infected wheat heads: F. graminearum (83%) of the 15-acetyldeoxynivalenol (15-ADON) genotype, F. meridionale (12.8%) and F. asiaticum (0.4%) of the nivalenol (NIV) genotype, and F. cortaderiae (2.5%) and F. austroamericanum (0.9%) with either the NIV or the 3-ADON genotype. Regional differences in FGSC composition were observed, with F. meridionale and the NIV type being significantly (P < 0.001) more prevalent in PR (>28%) than in RS (≤9%). Within RS, F. graminearum was overrepresented in fields below 600 m in elevation and in fields with higher levels of FHB incidence (P < 0.05). Species composition was not significantly influenced by previous crop or the stage of grain development at sampling. Habitat-specific differences in FGSC composition were evaluated in three fields by characterizing a total of 189 isolates collected from corn stubble, air above the wheat canopy, and symptomatic wheat kernels. Significant differences in FGSC composition were observed among these habitats (P < 0.001). Most strikingly, F. meridionale and F. cortaderiae of the NIV genotype accounted for the vast majority (>96%) of isolates from corn stubble, whereas F. graminearum with the 15-ADON genotype was dominant (>84%) among isolates from diseased wheat kernels. Potential differences in pathogenic fitness on wheat were also suggested by a greenhouse competitiveness assay in which F. graminearum was recovered at much higher frequency (>90%) than F. meridionale from four wheat varieties inoculated with an equal mixture of F. graminearum and F. meridionale isolates. Taken together, the data presented here suggest that FGSC composition and, consequently, the trichothecene contamination in wheat grown in southern Brazil is influenced by host adaptation and pathogenic fitness. Evidence that F. meridionale and F. cortaderiae with the NIV genotype are regionally significant contributors to FHB may have significant implications for food safety and the economics of cereal production.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Gaetano Bentivenga ◽  
Alfio Spina ◽  
Karim Ammar ◽  
Maria Allegra ◽  
Santa Olga Cacciola

In 2009, a set of 35 cultivars of durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) of Italian origin was screened for fusarium head blight (FHB) susceptibility at CIMMYT (Mexico) and in the 2019–20 cropping season, 16 of these cultivars, which had been included in the Italian National Plant Variety Register, were tested again in southern and northern Italy. Wheat cultivars were artificially inoculated during anthesis with a conidial suspension of Fusarium graminearum sensu lato using a standard spray inoculation method. Inoculum was a mixture of mono-conidial isolates sourced in the same areas where the trials were performed. Isolates had been characterized on the basis of morphological characteristics and by DNA PCR amplification using a specific primer set and then selected for their virulence and ability to produce mycotoxins. The susceptibility to FHB was rated on the basis of the disease severity, disease incidence and FHB index. Almost all of the tested cultivars were susceptible or very susceptible to FHB with the only exception of “Duprì”, “Tiziana” and “Dylan” which proved to be moderately susceptible. The susceptibility to FHB was inversely correlated with the plant height and flowering biology, the tall and the late heading cultivars being less susceptible.


Plant Disease ◽  
2021 ◽  
Author(s):  
Bhavit Chhabra ◽  
Lovepreet Singh ◽  
Sydney Wallace ◽  
Adam Schoen ◽  
Yanhong Dong ◽  
...  

Fusarium head blight (FHB) primarily caused by Fusarium graminearum is a key disease of small grains. Diseased spikes show symptoms of premature bleaching shortly after infection and have aborted or shriveled seeds, resulting in reduced yields. The fungus also deteriorates quality and safety of the grain due to production of mycotoxins, especially deoxynivalenol (DON), which can result in grain being docked or rejected at the point of sale. Genetic host resistance to FHB is quantitative and no complete genetic resistance against this devastating disease is available. Alternative approaches to develop new sources of FHB resistance are needed. In this study, we performed extensive forward genetic screening of the M4 generation of an EMS induced mutagenized population of cultivar Jagger to isolate variants with FHB resistance. In field testing, 74 mutant lines were found to have resistance against FHB spread and 30 lines out of these also had low DON content. Subsequent testing over two years in controlled greenhouse conditions revealed ten M6 lines showing significantly lower FHB spread. Seven and six lines out of those 10 lines also had reduced DON content and lower FDKs, respectively. Future endeavors will include identification of the mutations that led to resistance in these variants.


2016 ◽  
Vol 42 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Erlei Melo Reis ◽  
Cristina Boareto ◽  
Anderson Luiz Durante Danelli ◽  
Sandra Maria Zoldan

ABSTRACT Fusarium head blight of wheat (Triticum aestivum), caused by the fungus Gibberella zeae, is a floral infecting disease that causes quantitative and qualitative losses to winter cereals. In Brazil, the sanitary situation of wheat has led to research in order to develop strategies for sustainable production, even under adverse weather conditions. To increase the knowledge of the relationship among the presence of anthesis, the infectious process, the disease progress and the saprophytic fungi present in wheat anthers, studies were conducted in the experimental field of University of Passo Fundo (UPF), using the cultivar Marfim, in the 2011 growing season. The disease incidence in spikes and spikelets was evaluated. The presence of exserted anthers increased the spike exposure time to the inoculum. The final incidence of fusarium head blight, in the field, was dependent on the presence of exserted anthers. The disease followed an aggregation pattern and its evolution increased with time, apparently showing growth according to secondary cycles. The fungi isolated from exserted anthers (Alternaria sp., Fusarium sp., Drechslera spp. and Epicoccum sp.) did not compete for the infection site of fusarium head blight in wheat, not interfering with the incidence of F. graminearum.


2012 ◽  
Vol 102 (9) ◽  
pp. 867-877 ◽  
Author(s):  
A. B. Kriss ◽  
P. A. Paul ◽  
L. V. Madden

A multilevel analysis of heterogeneity of disease incidence was conducted based on observations of Fusarium head blight (caused by Fusarium graminearum) in Ohio during the 2002–11 growing seasons. Sampling consisted of counting the number of diseased and healthy wheat spikes per 0.3 m of row at 10 sites (about 30 m apart) in a total of 67 to 159 sampled fields in 12 to 32 sampled counties per year. Incidence was then determined as the proportion of diseased spikes at each site. Spatial heterogeneity of incidence among counties, fields within counties, and sites within fields and counties was characterized by fitting a generalized linear mixed model to the data, using a complementary log-log link function, with the assumption that the disease status of spikes was binomially distributed conditional on the effects of county, field, and site. Based on the estimated variance terms, there was highly significant spatial heterogeneity among counties and among fields within counties each year; magnitude of the estimated variances was similar for counties and fields. The lowest level of heterogeneity was among sites within fields, and the site variance was either 0 or not significantly greater than 0 in 3 of the 10 years. Based on the variances, the intracluster correlation of disease status of spikes within sites indicated that spikes from the same site were somewhat more likely to share the same disease status relative to spikes from other sites, fields, or counties. The estimated best linear unbiased predictor (EBLUP) for each county was determined, showing large differences across the state in disease incidence (as represented by the link function of the estimated probability that a spike was diseased) but no consistency between years for the different counties. The effects of geographical location, corn and wheat acreage per county, and environmental conditions on the EBLUP for each county were not significant in the majority of years.


Sign in / Sign up

Export Citation Format

Share Document