scholarly journals Two oat genotypes with different field resistance to Fusarium head blight respond similarly to the infection at spikelet level

Author(s):  
Juho Hautsalo ◽  
Satu Latvala ◽  
Outi Manninen ◽  
Minna Haapalainen ◽  
Asko Hannukkala ◽  
...  

Abstract Cultivar resistance is essential for the management of Fusarium head blight (FHB) disease in oat production. However, the breeders lack methods suitable for phenotyping disease resistance and resistance sources. In this paper we compared two oat genotypes, a rejected variety BOR31 and a landrace VIR7766, with four different traits that could reflect resistance to FHB in a greenhouse environment. Spray and point inoculations were used to inoculate Fusarium graminearum into flowering oat plants. When spray-inoculated, VIR7766 was significantly more resistant against the initial infection than BOR31, measured by the number of Fusarium-infected kernels and by DON accumulation. In the point-inoculated oats, the loss of fresh weight in the inoculated spikelet correlated well with the increasing F. graminearum biomass in the spikelet, measured six days after inoculation. However, no difference in the growth of the fungus was observed between the tested oat genotypes by point inoculation. We speculate that once the infection is established, the ability of the oat plant to resist the spread of the infection within a spikelet is low in the genotypes studied, although oat, in general, due to its panicle structure, is considered to have a high resistance against Fusarium infection.

Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 167-174 ◽  
Author(s):  
B. D. McCallum ◽  
A. Tekauz ◽  
J. Gilbert

Fusarium head blight (FHB) is currently the primary disease of concern in barley in Canada and sources of FHB resistance need to be identified. A diverse collection of 77 two-rowed and 81 six-rowed barley lines was screened for resistance to FHB in inoculated, irrigated nurseries from 1995 to 1998. Barley spikes were spray inoculated with conidia of Fusarium graminearum and visual symptoms of FHB were scored to determine an FHB index. Deoxynivalenol (DON) content was determined from harvested seed samples during 1997 and 1998. Although there was variation in the average FHB index and DON content among the different years of testing, the rankings of the lines generally were correlated among the years of testing and the two measures of FHB. Based on the FHB index from 1995 and 1996, a subset of 18 lines with low FHB and 12 lines with high FHB were compared with 20 FHB resistance sources and 7 Canadian lines or cultivars during 1997 and 1998 in both inoculated and noninoculated nurseries. Lines Nepolegajuscij, Krasnojarskij, Nordic, Murakaki-mochi, Golozernyj 1, Maris Mink, Symko, Ussurijskij 8, Suvenir, and Canadian cultivars AC Sterling and Morrison were similar to the best resistance sources (Zhedar1, Seijo II, and Chevron) and had consistently low DON content.


2020 ◽  
Vol 11 ◽  
Author(s):  
Guixia Hao ◽  
Susan McCormick ◽  
Thomas Usgaard ◽  
Helene Tiley ◽  
Martha M. Vaughan

Fusarium graminearum causes Fusarium head blight (FHB) on wheat, barley, and other grains. During infection, F. graminearum produces deoxynivalenol (DON), which contaminates grain and functions as a virulence factor to promote FHB spread throughout the wheat head. F. graminearum secretes hundreds of putative effectors, which can interfere with plant immunity to promote disease development. However, the function of most of these putative effectors remains unknown. In this study, we investigated the expression profiles of 23 F. graminearum effector-coding genes during the early stage of wheat head infection. Gene expression analyses revealed that three effectors, FGSG_01831, FGSG_03599, and FGSG_12160, respectively, were highly induced in both a FHB susceptible and a moderately resistant variety. We generated deletion mutants for these effector genes and performed FHB virulence assays on wheat head using point and dip inoculations to evaluate FHB spread and initial infection. No statistically significant difference in FHB spread was observed in the deletion mutants. However, deletion mutants Δ01831 displayed a significant reduction in initial infection, and thus resulted in less DON contamination. To investigate the potential mechanisms involved, these three effectors were transiently expressed in Nicotiana benthamiana leaves. N. benthamiana leaves expressing these individual effectors had significantly reduced production of reactive oxygen species induced by chitin, but not by flg22. Furthermore, FGSG_01831 and FGSG_03599 markedly suppressed Bax-induced cell death when co-expressed with Bax in N. benthamiana leaves. Our study provides new insights into the functions of these effectors and suggests they play collective or redundant roles that likely ensure the successful plant infection.


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.


2008 ◽  
Vol 88 (6) ◽  
pp. 1087-1089 ◽  
Author(s):  
Stephen N Wegulo ◽  
Floyd E Dowell

Fusarium head blight (scab) of wheat, caused by Fusarium graminearum, often results in shriveled and/or discolored kernels, which are referred to as Fusarium-damaged kernels (FDK). FDK is a major grain grading factor and therefore is routinely determined for purposes of quality assurance. Measurement of FDK is usually done visually. Visual sorting can be laborious and is subject to inconsistencies resulting from variability in intra-rater repeatability and/or inter-rater reliability. The ability of a single-kernel near-infrared (SKNIR) system to detect FDK was evaluated by comparing FDK sorted by the system to FDK sorted visually. Visual sorting was strongly correlated with sorting by the SKNIR system (0.89 ≤ r ≤ 0.91); however, the SKNIR system had a wider range of FDK detection and was more consistent. Compared with the SKNIR system, visual raters overestimated FDK in samples with a low percentage of Fusarium-damaged grain and underestimated FDK in samples with a high percentage of Fusarium-damaged grain. Key words: Wheat, Fusarium head blight, Fusarium-damaged kernels, single-kernel near-infrared


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.


2002 ◽  
Vol 106 (6) ◽  
pp. 961-970 ◽  
Author(s):  
L. Gervais ◽  
F. Dedryver ◽  
J.-Y. Morlais ◽  
V. Bodusseau ◽  
S. Negre ◽  
...  

2012 ◽  
Vol 33 (1) ◽  
pp. 97-111 ◽  
Author(s):  
Johann Leplat ◽  
Hanna Friberg ◽  
Muhammad Abid ◽  
Christian Steinberg

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.


Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 554-560 ◽  
Author(s):  
Stephen N. Wegulo ◽  
William W. Bockus ◽  
John Hernandez Nopsa ◽  
Erick D. De Wolf ◽  
Kent M. Eskridge ◽  
...  

Fusarium head blight (FHB) or scab, incited by Fusarium graminearum, can cause significant economic losses in small grain production. Five field experiments were conducted from 2007 to 2009 to determine the effects on FHB and the associated mycotoxin deoxynivalenol (DON) of integrating winter wheat cultivar resistance and fungicide application. Other variables measured were yield and the percentage of Fusarium-damaged kernels (FDK). The fungicides prothioconazole + tebuconazole (formulated as Prosaro 421 SC) were applied at the rate of 0.475 liters/ha, or not applied, to three cultivars (experiments 1 to 3) or six cultivars (experiments 4 and 5) differing in their levels of resistance to FHB and DON accumulation. The effect of cultivar on FHB index was highly significant (P < 0.0001) in all five experiments. Under the highest FHB intensity and no fungicide application, the moderately resistant cultivars Harry, Heyne, Roane, and Truman had less severe FHB than the susceptible cultivars 2137, Jagalene, Overley, and Tomahawk (indices of 30 to 46% and 78 to 99%, respectively). Percent fungicide efficacy in reducing index and DON was greater in moderately resistant than in susceptible cultivars. Yield was negatively correlated with index, with FDK, and with DON, whereas index was positively correlated with FDK and with DON, and FDK and DON were positively correlated. Correlation between index and DON, index and FDK, and FDK and DON was stronger in susceptible than in moderately resistant cultivars, whereas the negative correlation between yield and FDK and yield and DON was stronger in moderately resistant than in susceptible cultivars. Overall, the strongest correlation was between index and DON (0.74 ≤ R ≤ 0.88, P ≤ 0.05). The results from this study indicate that fungicide efficacy in reducing FHB and DON was greater in moderately resistant cultivars than in susceptible ones. This shows that integrating cultivar resistance with fungicide application can be an effective strategy for management of FHB and DON in winter wheat.


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