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1.
Overexpression of defense response genes in transgenic wheat enhances resistance to Fusarium head blight 总被引:2,自引:0,他引:2
Mackintosh CA Lewis J Radmer LE Shin S Heinen SJ Smith LA Wyckoff MN Dill-Macky R Evans CK Kravchenko S Baldridge GD Zeyen RJ Muehlbauer GJ 《Plant cell reports》2007,26(4):479-488
Fusarium head blight (FHB) of wheat, caused by Fusarium graminearum and other Fusarium species, is a major disease problem for wheat production worldwide. To combat this problem, large-scale
breeding efforts have been established. Although progress has been made through standard breeding approaches, the level of
resistance attained is insufficient to withstand epidemic conditions. Genetic engineering provides an alternative approach
to enhance the level of resistance. Many defense response genes are induced in wheat during F. graminearum infection and may play a role in reducing FHB. The objectives of this study were (1) to develop transgenic wheat overexpressing
the defense response genes α-1-purothionin, thaumatin-like protein 1 (tlp-1), and β-1,3-glucanase; and (2) to test the resultant
transgenic wheat lines against F. graminearum infection under greenhouse and field conditions. Using the wheat cultivar Bobwhite, we developed one, two, and four lines
carrying the α-1-purothionin, tlp-1, and β-1,3-glucanase transgenes, respectively, that had statistically significant reductions
in FHB severity in greenhouse evaluations. We tested these seven transgenic lines under field conditions for percent FHB disease
severity, deoxynivalenol (DON) mycotoxin accumulation, and percent visually scabby kernels (VSK). Six of the seven lines differed
from the nontransgenic parental Bobwhite line for at least one of the disease traits. A β-1,3-glucanase transgenic line had
enhanced resistance, showing lower FHB severity, DON concentration, and percent VSK compared to Bobwhite. Taken together,
the results showed that overexpression of defense response genes in wheat could enhance the FHB resistance in both greenhouse
and field conditions. 相似文献
2.
Susanne Vogelgsang Andreas Hecker Tomke Musa Brigitte Dorn Hans-Rudolf Forrer 《Mycotoxin Research》2011,27(2):81-96
Over the course of 5 years, different maize residue treatments were conducted on 14 zero tillage on-farm sites in Switzerland
to evaluate their effect on the development of Fusarium head blight (FHB) and the contamination with the mycotoxin deoxynivalenol
(DON) in winter wheat grains and wheat straw following grain maize. Two experimental series with three and five different
treatments were carried out, respectively. Fusarium graminearum (Schwabe) was the predominant FHB-causing species with an overall incidence of 15% infected wheat grains. A significant correlation
between symptoms in the field, F. graminearum incidence and DON content in wheat grains and wheat straw was observed. The average DON content in both wheat grains and
wheat straw was approximately 5,000 μg/kg and thus several times higher than the European maximum limit of 1,250 μg/kg for
unprocessed small-grain cereals for human consumption. Of all grain samples, 74% were above the maximum limit. Pooled over
both experimental series, the average reduction of DON in grains through treatments of the maize residue compared with a control
treatment ranged between 21 and 38%. The effect of various other factors, including the year, the wheat variety, the site,
the maize hybrid and the production system was evaluated as well. The year and the wheat variety were the most important FHB
influencing factors. Over all treatments, the variety Levis showed a fivefold higher average DON content compared with the
variety Titlis. From different categories of maize residue particles, intact pieces of 5–15 cm length were strongly correlated
with F. graminearum incidence and DON content in grains. During the time course of this study, the recommendation from a preliminary version
of the internet-based DON forecasting system FusaProg to apply or to omit a fungicide treatment was correct in 32 out of 42
cases. The results are currently being used to optimise the FusaProg models. This study has shown that in a grain maize/winter
wheat rotation, the DON content in wheat grains frequently exceeded the European maximum limit, even with a thorough treatment
of maize residues and less susceptible wheat varieties. Hence, in order to reduce the contamination risk in a zero tillage
system, the crop rotation needs to be modified. 相似文献
3.
H. Buerstmayr M. Lemmens G. Fedak P. Ruckenbauer Communicated B. S. Gill 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(1):76-85
Fusarium head blight (FHB or scab) caused by Fusarium spp. is a widespread disease of cereals causing yield and quality losses and contaminating cereal products with mycotoxins. The
breeding of resistant varieties is the method of choice for controlling the disease. Unfortunately, the genetic basis of scab
resistance is still poorly understood. We present the results of a back-cross reciprocal monosomic analysis of FHB resistance
using the highly resistant Hungarian winter wheat line ‘U-136.1’ and the highly susceptible cultivar ‘Hobbit-sib’. Resistance
testing was performed in a field trial artificially inoculated with a Fusarium culmorum conidial suspension. Five hemizygous families containing ‘U-136.1’ chromosomes 6B, 5A, 6D, 1B, and 4B had a visually reduced
spread of infection compared to lines having the ‘Hobbit-sib’ chromosome. Chromosome 2B from ‘U-136.1’ had an increased spread
of infection. The critical chromosomes controlling seed weight were 6D, 3B, 5A, and 6B while those controlling deoxynivalenol
(DON) content were homoeologous groups 2 and 6, although the latter effects were not significant due to a high coefficient
of variation. Results from this and other studies show that chromosomes 6D, 6B, 5A, 4D, and 7A have frequently been associated
with scab resistance in a number of wheat cultivars. Research groups now attempting to map scab resistance in wheat using
markers should pay special attention to the above-mentioned chromosomes.
Received: 31 March 1998 / Accepted: 14 July 1998 相似文献
4.
Transgenic wheat expressing a barley class II chitinase gene has enhanced resistance against Fusarium graminearum 总被引:1,自引:0,他引:1
Shin S Mackintosh CA Lewis J Heinen SJ Radmer L Dill-Macky R Baldridge GD Zeyen RJ Muehlbauer GJ 《Journal of experimental botany》2008,59(9):2371-2378
Fusarium head blight (FHB; scab), primarily caused by Fusarium graminearum, is a devastating disease of wheat worldwide. FHB causes yield reductions and contamination of grains with trichothecene mycotoxins such as deoxynivalenol (DON). The genetic variation in existing wheat germplasm pools for FHB resistance is low and may not provide sufficient resistance to develop cultivars through traditional breeding approaches. Thus, genetic engineering provides an additional approach to enhance FHB resistance. The objectives of this study were to develop transgenic wheat expressing a barley class II chitinase and to test the transgenic lines against F. graminearum infection under greenhouse and field conditions. A barley class II chitinase gene was introduced into the spring wheat cultivar, Bobwhite, by biolistic bombardment. Seven transgenic lines were identified that expressed the chitinase transgene and exhibited enhanced Type II resistance in the greenhouse evaluations. These seven transgenic lines were tested under field conditions for percentage FHB severity, percentage visually scabby kernels (VSK), and DON accumulation. Two lines (C8 and C17) that exhibited high chitinase protein levels also showed reduced FHB severity and VSK compared to Bobwhite. One of the lines (C8) also exhibited reduced DON concentration compared with Bobwhite. These results showed that transgenic wheat expressing a barley class II chitinase exhibited enhanced resistance against F. graminearum in greenhouse and field conditions. 相似文献
5.
6.
Zhang G Mergoum M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(6):757-766
Kernel shattering (KS) can cause severe grain yield loss in wheat (Triticum aestivum L.). The introduction of genotypes with Fusarium head blight (FHB) resistance has elevated the KS importance. ‘Sumai3,’ the
most commonly used FHB-resistant germplasm worldwide, is reported to be KS susceptible. The objectives of this study were
to detect quantitative trait loci (QTLs) for KS and to determine the relationship between KS and FHB. A recombinant inbred
line population derived from a cross between Sumai3 and ‘Stoa’ was evaluated for KS in five environments and FHB in two field
trials, separately. Four genomic regions on chromosomes 2B, 3B, and 7A were associated with KS. Of them, two major KS QTLs
were detected consistently over three environments and each located proximal to the centromere on chromosomes 3B and 7A. The
resistant alleles at these two QTLs together can reduce KS by 66.1% relative to the reciprocal alleles and by 41.1% compared
to the population mean. The field FHB data revealed four QTLs on chromosomes 2B, 3B, and 7A. Three of these FHB QTLs coincided
with and/or linked to the KS QTLs with opposite allele effects in the corresponding genomic regions, which may explain the
negative correlation (r = −0.29 and P < 0.01) between the KS and FHB infection found in this study. The results in this study indicate that KS and FHB in Sumai3
are, in part, inherited dependently. However, the correlation between KS and FHB is not strong, and the major FHB resistance
QTL on chromosome arm 3BS was not linked to any KS QTL. Our results showed that pyramiding of the two major KS-resistant alleles
and the unlinked major FHB-resistant allele could produce lines with both low values of KS and FHB infection. 相似文献
7.
Identification of QTLs for resistance to Fusarium head blight, DON accumulation and associated traits in the winter wheat variety Arina 总被引:3,自引:0,他引:3
Draeger R Gosman N Steed A Chandler E Thomsett M Srinivasachary Schondelmaier J Buerstmayr H Lemmens M Schmolke M Mesterhazy A Nicholson P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(5):617-625
Fusarium head blight (FHB) of wheat has become a serious threat to wheat crops in numerous countries. In addition to loss
of yield and quality, this disease is of primary importance because of the contamination of grain with mycotoxins such as
deoxynivalenol (DON). The Swiss winter cultivar Arina possesses significant resistance to FHB. The objective of this study
was to map quantitative trait loci (QTL) for resistance to FHB, DON accumulation and associated traits in grain in a double
haploid (DH) population from a cross between Arina and the FHB susceptible UK variety Riband. FHB resistance was assessed
in five trials across different years and locations. Ten QTL for resistance to FHB or associated traits were detected across
the trials, with QTL derived from both parents. Very few of the QTL detected in this study were coincident with those reported
by authors of two other studies of FHB resistance in Arina. It is concluded that the FHB resistance of Arina, like that of
the other European winter wheat varieties studied to date, is conferred by several genes of moderate effect making it difficult
to exploit in marker-assisted selection breeding programmes. The most significant and stable QTL for FHB resistance was on
chromosome 4D and co-localised with the Rht–D1 locus for height. This association appears to be due to linkage of deleterious genes to the Rht-D1b (Rht2) semi-dwarfing allele rather than differences in height per se. This association may compromise efforts to enhance FHB resistance
in breeding programmes using germplasm containing this allele. 相似文献
8.
Identification and molecular mapping of two QTLs with major effects for resistance to Fusarium head blight in wheat 总被引:1,自引:0,他引:1
Chu C Niu Z Zhong S Chao S Friesen TL Halley S Elias EM Dong Y Faris JD Xu SS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(7):1107-1119
Fusarium head blight (FHB) is a devastating disease of wheat worldwide. Novel sources of resistance are critical for improving
FHB resistance levels in wheat. From a large-scale evaluation of germplasm for reactions to FHB, we identified one wheat accession
(PI 277012) that consistently showed a high level of resistance in both greenhouse and field experiments. To characterize
the FHB resistance in this accession, we developed a doubled haploid (DH) mapping population consisting of 130 lines from
the cross between PI 277012 and the hard red spring wheat cultivar ‘Grandin’. The DH population was then evaluated for reactions
to FHB in three greenhouse seasons and five field environments. Based on a linkage map that consisted of 340 SSR markers spanning
2,703 cM of genetic distance, two major quantitative trait loci (QTLs) for FHB resistance were identified on chromosome arms
5AS and 5AL, with each explaining up to 20 and 32% of the variation in FHB severity, respectively. The two QTLs also showed
major effects on reducing the percentage of Fusarium damaged kernels (FDK) and deoxynivalenol (DON) accumulation in seeds.
FHB resistance has not previously been reported to be associated with this particular genomic region of chromosome arm 5AL,
thus indicating the novelty of FHB resistance in PI 277012. Plant maturity was not associated with FHB resistance and the
effects of plant height on FHB resistance were minor. Therefore, these results suggest that PI 277012 is an excellent source
for improving FHB resistance in wheat. The markers identified in this research are being used for marker-assisted introgression
of the QTLs into adapted durum and hard red spring wheat cultivars. 相似文献
9.
Miedaner T Wilde F Steiner B Buerstmayr H Korzun V Ebmeyer E 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(3):562-569
Fusarium head blight (FHB) is a devastating disease in wheat that reduces grain yield, grain quality and contaminates the harvest
with deoxynivalenol (DON). As potent resistance sources Sumai 3 and its descendants from China and Frontana from Brazil had
been analysed by quantitative trait loci (QTL) mapping. We introgressed and stacked two donor QTL from CM82036 (Sumai 3/Thornbird)
located on chromosomes 3B and 5A and one donor QTL from Frontana on chromosome 3A in elite European spring wheat and estimated
the effects of the three individual donor QTL and their four combinations on DON, Fusarium exoantigen content, and FHB rating adjusted to heading date. One class with the susceptible QTL alleles served as control.
Each of the eight QTL classes was represented by 12–15 F3-derived lines tested in F5 generation as bulked progeny possessing the respective marker alleles homozygously. Traits were evaluated in a field experiment
across four locations with spray inoculation of Fusarium culmorum. All three individual donor-QTL alleles significantly reduced DON content and FHB severity compared to the marker class with
no donor QTL. The only exception was the donor-QTL allele 3A that had a low, but non-significant effect on FHB severity. The
highest effect had the stacked donor-QTL alleles 3B and 5A for both traits. They jointly reduced DON content by 78% and FHB
rating by 55% compared to the susceptible QTL class. Analysis of Fusarium exoantigen content illustrates that lower disease severity is associated with less mycelium content in the grain. In conclusion,
QTL from non-adapted sources could be verified in a genetic background of German elite spring wheat. Within the QTL classes
significant (P<0.05) genotypic differences were found among the individual genotypes. An additional phenotypic selection would, therefore,
be advantageous after performing a marker-based selection. 相似文献
10.
Martin Löffler Chris-Carolin Schön Thomas Miedaner 《Molecular breeding : new strategies in plant improvement》2009,23(3):473-488
Fusarium head blight (FHB) in wheat results in reduced yield and quality and in accumulation of mycotoxins. The objective of this
study was to identify genomic regions in wheat involved in the control of FHB resistance applying a QTL meta-analysis approach
by combining QTL of 30 mapping populations to propose independent meta-QTL (MQTL). A consensus map was created on which initial
QTL were projected. Nineteen MQTL comprising 2–13 initial QTL with widely varying confidence intervals were found on 12 chromosomes.
Some of them coincided with genomic regions previously identified (e.g. chromosomes 3BS, 6B), however, some MQTL were newly
detected by this study. Separate analysis of populations with the same resistant parent showed a rather high consistency for
the Chinese spring wheat donor ‘Sumai 3’, but little consistency for the Chinese donor ‘Wangshuibai’ and the Swiss donor ‘Arina’.
According to our results breeders can in future (1) choose parents for crossing not comprising the same resistance loci or
QTL intervals, (2) exploit new MQTL, and (3) select markers of some of these MQTL to be used in marker-assisted selection.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
Fusarium head blight (FHB) is one of the most devastating wheat diseases, causing both yield loss and quality reduction. To detect
quantitative trait loci (QTL) responsible for FHB resistance, plants of the F
2:3 population derived from a ‘Wangshui-bai’ × ‘Sy95-7’ cross were artificially inoculated. Of 396 simple sequence repeats (SSRs),
125 amplified fragment length polymorphisms were used for FHB resistance QTL analysis. Five QTLs for FHB resistance were detected
on chromosomes 3B, 6B, 7A, 1B and 2D. The effect of the QTL located on chromosome 3B on phenotypic variation was 31.69%, while
that of the QTL found on 2D was the smallest and only accounted for 4.98% of the variation. The resistance alleles originated
from ‘Wangshibai’ and association of the QTLs using these SSR markers may facilitate marker-assisted selection to improve
FHB resistance in the wheat breeding programs of southwest China. 相似文献
12.
Toxin B — trichothecene deoxynivalenol (DON) is the most frequent Fusarium mycotoxin in Fusarium head blight (FHB) disease produced by Fusarium fungi. Thirty-one samples of naturally cultivated winter wheat were collected from different localities in Slovakia and evaluated
for DON content, and after an artificial inoculation twelve of winter wheat cultivars were evaluated for FHB, fusarium damaged
kernels (FDK) and DON content (resistance Type I and II) during two years. Plants were inoculated at anthesis with a conidial
suspension of Fusarium culmorum (W. G. Smith) Sacc. The highest mean contents of DON 1.641 ppm were found in produced potato region (PPR) and 1.654 ppm in
produced sugar beet region (PSBR). A positive correlation was found between DON content and rainfall, and a negative correlation
was found between content of DON and temperature. Lower positive correlations were found between the contents of DON in 2003
and 2004 in the resistance Type I and Type II in twelve artificially infected cultivars. The significant positive correlations
in content of DON were found between resistance Type I and Type II in the years 2003 and 2004. The lowest content of DON was
found in the cultivars Alka, Malyska and the highest one in the cultivars Vanda and Boka. The positive correlation between
the content of DON and FDK (in %) in head (average 2003 and 2004 years) from artificially infected and analysed cultivars
was statistically significant in both resistances Type I and Type II. 相似文献
13.
The Effect of Nitrogen Fertilization on Fusarium Head Blight Development and Deoxynivalenol Contamination in Wheat 总被引:1,自引:0,他引:1
The impact of nitrogen (N) fertilization on the development of Fusarium head blight (FHB) in wheat and the resulting deoxynivalenol (DON) contamination in the kernels was studied. In a first experiment, the disease was assessed on two locations under natural infection pressure. Five different types of nitrogen fertilizer (both organic and mineral) were investigated, each applied at five input rates from 0 to 160 kg N/ha. With all fertilizers, a significant increase of disease intensity was observed with increasing N input, while the type of N fertilizer had poor or no effects on FHB. Depending on the fertilizer used, the percentage of diseased spikelets increased from 2.2% at zero N rate up to 6.6% at 160 kg N input per hectare. In a second series of trials, three spring wheat varieties including one Durum wheat line were artificially inoculated with a Fusarium graminearum and a F. culmorum strain, known producers of DON. A mineral N fertilizer was applied at five input levels from 0 to 160 kg N/ha. A significant increase in FHB intensity and DON contamination in the grain was observed with increasing N from 0 to 80 kg/ha. At higher input rates, relevant in contemporary crop husbandry, disease intensity and toxin contamination remained at constant levels. It is concluded that adaptation of N fertilization represents no relevant tool in managing FHB in practical wheat cultivation. 相似文献
14.
Donald M Gardiner Kemal Kazan Sebastien Praud Francois J Torney Anca Rusu John M Manners 《BMC plant biology》2010,10(1):289
Background
The fungal pathogen Fusarium graminearum causes Fusarium Head Blight (FHB) disease on wheat which can lead to trichothecene mycotoxin (e.g. deoxynivalenol, DON) contamination of grain, harmful to mammalian health. DON is produced at low levels under standard culture conditions when compared to plant infection but specific polyamines (e.g. putrescine and agmatine) and amino acids (e.g. arginine and ornithine) are potent inducers of DON by F. graminearum in axenic culture. Currently, host factors that promote mycotoxin synthesis during FHB are unknown, but plant derived polyamines could contribute to DON induction in infected heads. However, the temporal and spatial accumulation of polyamines and amino acids in relation to that of DON has not been studied. 相似文献15.
A. Salameh M. Buerstmayr B. Steiner A. Neumayer M. Lemmens H. Buerstmayr 《Molecular breeding : new strategies in plant improvement》2011,28(4):485-494
Breeding for fusarium head blight (FHB) resistance of wheat is a continuous challenge for plant breeders. Resistance to FHB
is a quantitative trait, governed by several to many genes and modulated by environmental conditions. The presented study
was undertaken to assess the effect on improving FHB resistance and on possible unwanted side effects (‘linkage drag’) of
two resistance QTL, namely Fhb1 and Qfhs.ifa-5A, from the spring wheat line CM-82036 when transferred by marker-assisted backcrossing into several European winter wheat
lines. To achieve these goals, we developed and evaluated fifteen backcross-two–derived families based on nine European winter
wheat varieties as recipients and the FHB resistant variety CM-82036 as resistance donor. The QTL Qfhs.ifa-5A had a relatively small impact on increasing FHB resistance. On average lines with Fhb1 plus Qfhs.ifa-5A combined were only slightly more resistant compared to lines with Fhb1 alone. The obtained results suggest that the effect of the spring wheat–derived QTL on improving FHB resistance increases
in the order Qfhs.ifa-5A < Fhb1 ≤ Qfhs.ifa-5A plus Fhb1 combined. The genetic background of the recipient line had a large impact on the resistance level of the obtained lines.
No systematic negative effect of the spring wheat–derived QTL on grain yield, thousand grain weight, hectoliter weight and
protein content was found. The use of spring wheat–derived FHB resistance QTL for breeding high yielding cultivars with improved
FHB resistance appears therefore highly promising. 相似文献
16.
Fusarium graminearum Schwabe is the primary cause of Fusarium head blight (FHB) in North America. Chemically distinct F. graminearum sub-populations can be identified based on the type or composition of deoxynivalenol (DON) mycotoxin derivatives, including
3-acetyl (3-ADON) and 15-acetyl (15-ADON). The evaluation of randomly selected 3-ADON and 15-ADON isolates, collected from
spring wheat throughout Canada, was performed using thin layer chromatography (TLC), high-performance liquid chromatography
(HPLC), ice-nucleation activity (INA), and heat and cold tolerance tests conducted within a temperature range of −70°C to
65°C. The results indicated that the 3-ADON sub-population, which is responsible for the highest disease severity and has
rapidly displaced the 15-ADON sub-population, produces more DON and zearalenone (ZEA) than the 15-ADON sub-population when
exposed to heat and cold. Following exposures (1 and 2 h) to extremely high or low temperatures, 3-ADON isolates exhibited
faster mycelial growth than 15-ADON isolates. In addition, the warmest temperature at which INA activity occurred was in 3-ADON
(−3.6°C) vs. 15-ADON (−5.1°C). Taken together, these features suggest that the newly emerging 3-ADON sub-population is more
resilient than the resident 15-ADON sub-population. Overall, the differences between the two sub-populations could provide
new insights into FHB epidemiology and if validated under field conditions, may provide important information for predicting
future FHB epidemics. 相似文献
17.
Wheat for human consumption (140 samples) was collected after harvest from all regions of Bulgaria. The 1995 crop year was characterized by heavy rainfall in the spring and summer months. The internal mycoflora of wheat samples was dominated by Fusarium spp. and Alternaria spp., and storage fungi were rarely present. The samples were analysed for contamination with Fusarium mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), using enzyme immunoassay methods. DON and ZEA were the predominant toxins, with a contamination frequency of 67% and 69%, respectively. The average levels of these toxins in positive samples were 180 g/kg (DON) and 17 g/kg (ZEA), maximum concentrations were 1800 g kg–1 and 120 g kg–1, respectively. Acetyl derivatives of DON, namely 3-AcDON and 15-AcDON, were found in 2.1 % and 0.7% of the samples, at at maximum level of about 100 g kg–1. Only one sample was positive for T-2 (55 g/kg), DAS was not detected. This is the first report about the natural occurrence of a range of Fusarium mycotoxins in wheat for human consumption in Bulgaria.Abbreviations 3-AcDON
3-acetyldeoxynivalenol
- 15-AcDON
15-acetyldeoxynivalenol
- DAS
diacetoxyscirpenol
- DON
deoxynivalenol
- EIA
enzyme immunoassay
- T-2
T-2 toxin
- ZEA
zearalenone 相似文献
18.
Influence of Growth Stage on Fusarium Head Blight and Deoxynivalenol Production in Wheat 总被引:2,自引:0,他引:2
Fusarium head blight is a major concern for wheat production worldwide. The fungi that cause the disease may infect head tissues from flowering to late stages of kernel development, but a better understanding of the influence of the time of infection on grain weight reduction and mycotoxin accumulation resulting from the infection process is needed. We investigated the influence of wheat reproductive stage at the time of inoculation on disease and grain quality parameters, especially production of deoxynivalenol (DON) in mature grains. Heads of Norm wheat were spray inoculated with a macroconidial suspension of a DON‐producing isolate of Fusarium graminearum at each of six reproductive stages from flowering to hard dough. Plants were incubated in a mist chamber for 48 h and then moved to the greenhouse until maturity. Norm wheat was susceptible at all stages inoculated but the highest grain weight reduction and DON accumulation occurred in plants inoculated past flowering to late milk stages. However, high incidences of kernel infection and significant levels of DON accumulation resulted from inoculations as late as the hard dough stage, even though there was no corresponding reduction in grain weight compared to non‐inoculated plants. The occurrence of commercially significant levels of DON in plump, high‐yielding wheat may result from infections that occur during favourable environments well after the flowering stages. Late infection and DON production should therefore be a future research focus for wheat breeding and integrated management of FHB and an important consideration for grading systems that employ the presence of visibly damaged kernels as a means of estimating DON content of wheat. 相似文献
19.
In field tests replicated in 2004 and 2005, 32 cultivars of spring barley were assessed for resistance to Fusarium head blight
(FHB) by single floret inoculation and spray inoculation with Fusarium culmorum (W. G. Smith) Sacc. It was found that the weather conditions in individual years affect to a large extent the progression
of FHB and production of mycotoxin deoxynivalenol (DON). At the same time, in both years the cultivars reacted to F. culmorum infection similarly with respect to areas under disease progress curve (AUDPC) values and content of mycotoxin DON. Spraying
inoculation led to stronger infection. The biggest differences in AUDPC values were observed between the cultivars Brise and
Celinka, and weak reaction was found in the cultivars Kompakt and Madonna. The cultivars Kompakt and Tolar were most resistant
towards FHB. In both monitored years the variety Ludan contained the lowest amounts of mycotoxin DON. Cultivars with high
infection and low DON content (r = 0.78) showed weak positive relationship between resistance to FBH and accumulation of DON (concentration 70–200 mg/kg).
This is the first information on FHB and in vivo concentrations of DON in certificated barley cultivars in Slovakia. 相似文献
20.
Fusarium culmorum can cause Fusarium head blight (FHB) disease of cereals, resulting in yield loss and contamination of grain with the trichothecene mycotoxin, deoxynivalenol (DON). In this study, we compared the efficacy of a biological control agent (Pseudomonas fluorescens strain MKB 158) with the biochemical chitosan (the deacetylated derivative of chitin) in controlling FHB disease of wheat and barley. Both agents were equally effective in reducing DON contamination of grain caused by F. culmorum. Under both glasshouse and field conditions, treatment with commercially available crabshell-derived chitosan reduced the severity of FHB symptom development on wheat and barley by ?74% (P ? 0.050). While treatment with P. fluorescens reduced the severity of FHB symptom development on these cereals by ?48% (P ? 0.050). Chitosan and P. fluorescens respectively prevented ?58 and ?35% of the FHB-associated reductions in 1000-grain weight in wheat and barley (P ? 0.050). Both agents significantly reduced the DON content of wheat and barley under both glasshouse and field conditions (P ? 0.050) and were equally efficacious in doing so (?74 and ?79% reductions due to chitosan and P. fluorescens, respectively). Crude chitin extracts from crabshells and crude chitosan-based formulations prepared from crabshells and eggshells were also tested under field conditions, but were not as effective as the commercial crabshell-derived preparation in controlling FHB disease. This is the first report on the use of chitosan for the control of Fusarium head blight disease and DON contamination of grain. 相似文献