Fusarium Culmorum Strains Research Articles

Substrate Influence on Mycotoxin Production of Fusarium Species and their Analytical Detection

Several strains of Fusarium culmorum, F. graminearum, F. moniliforme, F. tricinctum, F. rosevm, F. semitectum and F. sporotrichioides were investigated on corn and rice substrate for F-2, zearalenol and T-2 toxin synthesis. Toxin production was confirmed by GLC and estimated by TCLC. Substrate didn’t influence significantly recovery of the investigated mycotoxins in case of rice and corn and was about 70%. Sensitivity of TLC method is lowest for T-2 (0,05 ng/spot), detection of F-2 and zearalenol could be improved with Sarudi reagent Toxin synthesis of individual strains showed depence on substrate.

3-Acetyl deoxynivalenol production in a strain ofFusarium culmorum insensitive to the fungicide difenoconazole

The production of the mycotoxin, 3-acetyl deoxynivalenol (3-ADON), was investigated in a strain ofFusarium culmorum insensitive to the systemic fungicide, difenoconazole. On exposure to graded concentrations of the fungicide, the insensitive strain continued to synthesise 3-ADON when difenoconazole levels of 100 and 200μg/ ml media were used. In contrast, a control (sensitive) strain ceased production of 3-ADON at difenoconazole levels of 100 μg/ml. Differences between the two strains were also observed for 3-ADON production with time. Following incubation with fungicide at 0.1 μg/ ml, 3-ADON production occurred more rapidly in CS than in IS cultures. This is the first report of increased persistence and alteration of the pattern of production of a mycotoxin following the development of fungicide insensitivity in a fungal phytopathogen.

Assessing non-specificity of resistance in wheat to head blight caused by inoculation with European strains of Fusarium culmorum, F. graminearum and F. nivale using a multiplicative model for interaction

To determine whether resistance to Fusarium head blight in winter wheat is horizontal and non-species specific, 25 genotypes from five European countries were tested at six locations across Europe in the years 1990, 1991, and 1992. The five genotypes from each country had to cover the range from resistant to susceptible. The locations involved were Wageningen, Vienna, Rennes, Hohenheim, Oberer Lindenhof, and Szeged. In total, 17 local strains of Fusarium culmorum, F. graminearum, and F. nivale were used for experimental inoculation. One strain, F. culmorum IPO 39-01, was used at all locations. Best linear unbiased predictions (BLUPs) for the head blight ratings of the genotypes were formed within each particular location for each combination of year and strain. The BLUPs over all locations were collected in a genotype-by environment table in which the genotypic dimension consisted of the 25 genotypes, while the environmental dimension was made up of 59 year-by-strain-by-location combinations. A multiplicative model was fitted to the genotype by-environment interaction in this table. The inverses of the variances of the genotype-by-environment BLUPs were used as weights. Interactions between genotypes and environments were written as sums of products between genotypic scores and environmental scores. After correction for year-by-location influence very little variation in environmental scores could be ascribed to differences between strains. This provided the basis for the conclusion that the resistance to Fusarium head blight in winter wheat was of the horizontal and non-species specific type. There was no indication for any geographical pattern in virulence genes. Any reasonable aggressive strain, a F. culmorum strain for the cool climates and a F. graminearum strain for the warmer humid areas, should be satisfactory for screening purposes.

Trichothecene Chemotypes of Three Fusarium Species

Identification of the mycotoxins produced by different species of Fusarium can serve to verify their classification or to relate the variation of toxigenic potential within a species. Strains of Fusarium graminearum (55), Fusarium crookwellense (16), and Fusarium culmorum (3) were grown in three liquid media and on rice. The toxins produced in the various media were assessed by analyzing the metabolites by gas chromatography/mass spectrometry. These data are used to propose a number of chemotypes. The metabolic profiles of Fusarium graminearum were similar, having chemotype I (deoxynivalenol) in common. In Chinese strains, chemotype IA (deoxynivalenol, 3-acetyl) predominated while the Mexican strains, as with other North American strains, were chemotype IB (deoxynivalenol, 15-acetyl). The Fusarium culmorum strains tested had a chemotype similar to that of chemotype IA of Fusarium graminearum. The Fusarium crookwellense strains, which were collected from eight countries, had a chemotype II (nivalenol, diacetyl) in common, regardless of their source. A similar chemotype II has been reported for Fusarium graminearum strains but it is rare. The Fusarium crookwellense strains also showed the presence of chemotype IA (isotrichodermin, 8-hydroxy) and chemotype IB (isotrichodermin, 7-hydroxy).

Genotype x strain interactions for resistance to Fusarium head blight caused by Fusarium culmorum in winter wheat

In 3 consecutive years, a set of 17 winter wheat genotypes, representing a wide range of Fusarium head blight resistance, was inoculated with four strains of Fusarium culmorum. Fusarium head blight ratings were analyzed. The interaction between genotypes, strains, and years was described using a Finlay-Wilkinson model and an Additive Main effects and Multiplicative Interaction effects (AMMI) model. The interaction consisted primarily of a divergence of genotypical responses with increasing disease pressure, modified by genotype specific reactions in certain years. The divergence was mainly caused by one very pathogenic strain. The Fusarium head blight resistance in this study can be described as horizontal resistance in terms of Vanderplank, with the exception of three genotypes selected from one particular cross that showed a 'strain-year combination' dependent resistance which was ineffective in 1 year.

The inheritance of resistance to head blight caused by Fusarium culmorum in winter wheat

Crosses were made among ten winter wheat genotypes representing different levels of resistance to Fusarium head blight to obtain F1 and F2 generations. Parents, F1 and F2 were inoculated with one strain of Fusarium culmorum. Data on incidence of head blight 21 days after first inoculation were analyzed. Broad-sense heritabilities averaged 0.39 and ranged from 0.05 to 0.89 in the individual F2 families. The joint-scaling test indicated that the inheritance of Fusarium head blight resistance was adequately described by the additive-dominance model, with additive gene action being the most important factor of resistance. With respect to the non-additive effects, dominance of resistance predominated over recessiveness. The number of segregating genes governing resistance in the studied populations was estimated to vary between one and six. It was demonstrated that resistance genes differed between parents and affected resistance differently.

Diallel analysis of resistance to head blight caused by Fusarium culmorum in winter wheat

Ten homozygous winter wheat genotypes representing different levels of resistance to Fusarium head blight were crossed in all possible combinations excluding reciprocals. Parents, F1 and F2 were inoculated with one pathogenic strain of Fusarium culmorum. Data for head blight, observed 21 days after first inoculation (OBS-2), and for the area under the disease progress curve, based on observations 14, 21 and 28 days after first inoculation (AUDPC), were analyzed. The contrast between parents and F1 crosses indicated dommance effects of the resistance genes. Diallel analysis according to Griffing's Method 4, Model 1 showed significant general combining ability (GCA) effects for both F1 and F2; specific combining ability effects were not significant. With the exception of one genotype for which general performance for Fusarium resistance was not in agreement with its GCA, the resistance to F. culmorum was uniformly transmitted to all offspring, and the parents can be described in terms of GCA. It is suggested that in the progenies with one of the awned lines as parent, one resistance gene was linked with the gene coding for presence of awns, located on chromosome 4B. A single observation date, taken at the right time, was as effective in assessing resistance as the AUDPC.

Genetic variation for resistance to Fusarium head blight in bread wheat

During a four year period, a total of 258 winter and spring wheat genotypes were evaluated for resistance to head blight after inoculation with Fusarium culmorum strain IPO 39-01. It was concluded that genetic variation for resistance is very large. Spring wheat genotypes which had been reported to be resistant to head blight caused by Fusarium graminearum were also resistant to F. culmorum. The resistant germplasm was divided into three gene pools: winter wheats from Eastern Europe, spring wheats from China/Japan and spring wheats from Brazil. In 32 winter wheat genotypes in 1987, and 54 winter wheat genotypes in 1989, the percentage yield reduction depended on the square root of percentage head blight with an average regression coefficient of 6.6. Heritability estimates indicated that for selection for Fusarium head blight resistance, visually assessed head blight was a better selection criterion than yield reduction.

Effects of Head Blight Caused byFusarium culmorumon Toxin Content and Weight of Wheat Kernels

Ten winter wheat genotypes were inoculated with three Dutch strains of Fusarium culmorum (IPO 39-01, IPO 348-01 and IPO 436-01). Seed samples were anlyzed for several trichothecene mycotoxins and zearalenone. Deoxynivalenol was detected in concentrations ranging from 0 to 48 mg/kg. Interactions between strains and genotypes were observed for head blight and kernel deoxynivalenol content. Path anlysis suggested a relation between deoxynivalenol and kernel weight reduction

Toxic strain of Fusarium culmorum (WG Sm) Sacc. from Zea mays L., associated with sickness in dairy cattle.

IN 1928 there was an extensive North American outbreak of “scab” in barley, caused by the fungus Gibberella zea (Schw.) Petch syn. G. saubinetti (conidial stage Fusarium graminearum Schw.). This was followed by the publication of a number of papers on the effect of feeding infected grain to domestic animals.

Rotting of Galtonia bulbs caused by Fusarium culmorum (W.G.Sm.) Sacc. and Penicillium corymbiferum Westling

Summary 1 A strain of Fusarium culmorum (W. G. Sm.) Sacc. and Penicillium corymbiferum Westling, which were isolated from rotting Galtonia bulbs, were found to be actively pathogenic to the bulbs under a variety of storage conditions. 2 The Fusarium is the more active parasite at rather high temperatures (28° C.). 3 Up to the present only the Penicillium and a similar form isolated from lily bulbs have been found to cause rotting of bulbs planted in soil in the open.