A Database for Triticeae and Avena
University of Agriculture - Vienna
Institute of Agronomy and Plant Breeding,
Gregor Mendel Str. 33, A-1180 Vienna, Austria, and the Institute
for Agrobiotechnology, Department of Plant Science, Konrad Lorenz
Str. 20, A-3430 Tulln, Austria.
Fusarium head blight on wheat.
H. Buerstmayr, M. Lemmens, H. Grausgruber, F. Moule, M. Fidesser, and P. Ruckenbauer.
Investigations on Fusarium head blight
(FHB, scab) resistance in wheat have continued in 1994. Natural
outbreaks of FHB are rare in Austria, but plant breeders and grain
marketing organizations are increasingly aware of the disease,
particularly because of the danger of mycotoxin contamination
and quality losses.
Research activities on Fusarium head
blight focus on the following topics:
1) Improvement of artificial inoculation
techniques. The severity
of Fusarium spp. attack on wheat spikes depends on the
developmental stage of the plants, the presence and nature of
inoculum, and the environmental conditions, in addition to plant
resistance.
In a resistance-breeding program, plant
resistance has to be measured as accurately as possible. Therefore,
in the case of artificial inoculation, other influences must be
controlled very carefully. The control of the developmental stage
of the plants and inoculum is rather easy -
inoculation takes place during anthesis. The inoculum used is
a spore suspension of a Fusarium isolate with known pathogenicity
and a defined concentration. More difficulties arise with environmental
conditions, e.g., temperature and humidity. In field trials,
temperature cannot be controlled. Control of humidity is possible
in several ways: 1) inoculate in the evening, 2) keep humidity
high by covering inoculated ears with plastic bags, and 3) maintain
high humidity with a mist-irrigation system.
To compare the above-mentioned ways of humidity control, a field trial was carried out in 1994. A set of 25 winter wheat genotypes of known resistance was sown in two replicates and inoculated with two Fusarium isolates. Disease development was measured by visual scoring over a period of 26 days after inoculation and, for each entry, an area under the disease progressing curve (AUDPC) was calculated. The methods were compared for repeatability and accuracy. The results have shown that the use of a mist-irrigation system for humidity control was superior to other methods.
We thank the Austrian National Bank
for their financial support, Project number 4906.
2) Resistance breeding.
To support the private Austrian plant breeders, we gave them
F2 bulks of 100 reciprocal crosses between FHB-resistant
winter wheats and well adapted Austrian wheat cultivars.
The following table shows the parents used in the crosses. Most of the lines have been tested for FHB resistance during 3 years under artificial inoculation. Disease development was assessed by visual scoring over a period of 26 days after inoculation and, for each entry, the AUDPC was calculated.
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FHB 1992 FHB 1993 FHB 1994
Line Origin (AUDPC) (AUDPC) (AUDPC)
_________________________________________________________________________________
UNG 226 Hungary 3.07 1.34 9.70
SVP 72017-17-5-10-1 The Netherlands 17.70 2.45 6.91
81 F3 79 France 15.71 1.36 6.79
Arina Switzerland 20.39 2.70 6.68
UNG 171 (Bence) Hungary 17.14 3.16 11.07
UNG 159 Hungary 38.25 0.82 8.85
Praag 8 Czech Republic 23.03 1.76 5.72
Novokrumka 0102 Russia 21.29 1.05 9.88
SVP C8718-5 The Netherlands 7.18 0.86 8.29
UNG 136.1 Hungary 0.58 0.64 7.15
Leopold Austria - 6.69 11.40
Aurus Austria 48.58 19.18 18.40
Perlo Austria 11.23 5.25 8.10
Capo Austria 25.07 5.64 8.10
Bimbo Germany 34.33 8.21 15.65
Alidos Germany - 14.57 -
Martin Austria 12.01 2.10 8.59
Justus Austria 23.92 5.68 12.85
Ikarus Austria 42.65 7.35 10.70
Hubertus Austria 36.55 7.88 20.60
Agron Austria 7.03 4.25 21.70
_________________________________________________________________________________
We thank the Ministry of Agriculture
and Forestry for financial support, Project number L687/91.
3) Germplasm screening.
A number of winter and spring wheat genotypes, foreign germplasms,
and Austrian genotypes have been evaluated for FHB resistance.
No complete resistance was found, but considerable genetic variation
was detected. Spring durums tend to be most susceptible. Some
Chinese Spring wheat lines are most resistant.
4) Studies on the genetic basis of
FHB resistance. A backcross,
reciprocal monosomic analysis was done with the monosomics of
the very susceptible cultivar, Hobbit-sib, from IPSR Norwich,
England. The Hobbit-sib monosomics were crossed with two resistant
wheat lines from CRI Szeged, Hungary. The resistant Hungarian
lines have resistance from Nobeokabozu-komugi and/or Sumai #3
in their pedigree.
In addition, existing single chromosome
substitution lines, which we obtained from Mr. A.J. Worland (IPSR
Norwich), were investigated. The analysis of substitution lines
included the Hobbit-sib (Triticum macha), Chinese
Spring (Cheyenne), Chinese Spring (Triticum spelta),
Chinese Spring (Hope), and Chinese Spring (Lutescens) substitution
series. Fusarium head blight was induced by artificial inoculation
with Fusarium graminearum and F. culmorum
isolates. Visual scoring of diseased spikelets was done over
a period of 26 days after inoculation, and the AUDPC calculated.
Furthermore, the harvest reduction of diseased ears was determined.
The results of the 1994 data of the
Hobbit-sib (Triticum macha) substitution line indicate
possible resistance genes on chromosomes II (2A), IX (5A), and
X (6B), estimated for AUDPC. QTLs for FHB resistance may be located
on these chromosomes.
Markers for FHB resistance would be
of great value for resistance breeding. The development of test
stocks for the identification of markers is underway.
5) In vitro selection for FHB resistance.
In order to decrease the amount of artificial field inoculation
required in a FHB resistance breeding program, a study was carried
out to develop a simple laboratory method to predict FHB resistance
of wheat. In the literature, several methods are described to
select plants with increased level of disease resistance using
the toxic metabolites produced by the fungus as selection agents.
Fusarium spp. produce several toxins on wheat, the most
important of which are the trichothecenes (e.g., deoxynivalenol
(DON)). These toxins probably play a role in the aggressiveness
of the pathogen and promote disease development and colonization.
They inhibit eukaryotic protein synthesis by blocking the peptidyl
transferase step. It has been reported that plants tolerant to
these toxins have an increased resistance to FHB. In this study,
the germination of seeds from 25 winter wheat genotypes was examined
in the presence of Fusarium toxins. Germination of seeds
requires abundant protein synthesis. The results were compared
with accurate data of the field resistance of the above-mentioned
wheat nursery to FHB.
Fusarium
graminearum isolates were grown on maize agar (containing
maize powder, 75 g/l; agar, 10 g/l) and incubated in the dark
at 25 C
for 6 to 8 weeks. Toxin analyses (Dr. Mesterhazy, Szeged, Hungary)
showed that the DON content varied from less than 1 to 18.5 ppm.
Toxic Fusarium medium (TFM) was diluted 1:2, 1:5, and
1:10 (w:w), and buffered at pH 6.5 with phosphate buffer. Agar
was added to a final amount of 6 g/l. The media were autoclaved
and poured into Petri dishes (15 cm diameter). One hundred disinfected
seeds were put horizontally, with the embryo directed upwards,
on the agar and slightly pressed into the medium. Water agar
(pH 6.5) was used as a control. The dishes were incubated in
the dark at 5 C.
The cumulative number of germinated seeds was counted daily.
The data were plotted against days after imbibition and were
fitted to a Gompertz function. The number of germinated seeds
in TFM was calculated when the control medium contained 80 germinated
seeds (NGTC80).
Germination was retarded in TFM. Significant
differences were found in toxicity of the TFM and in tolerance
of the genotypes. Correlation coefficients between data of NGTC80
and field resistance data ranged from 0.60 to 0.75. The TFM also
contained other toxins (e.g., zearalenon). Whether DON alone
or in combination with other toxic Fusarium agent(s) in
the TFM is responsible for the selective toxic effect is currently
under investigation.
We greatly acknowledge the financial
support by the Austrian Science Foundation (FWF), Project number
P09190-BIO.
Publication.
van Eeuwijk FA, Mesterhazy A, Kling
CI, Ruckenbauer P, Saur L, Buerstmayr H, Lemmens M, Keizer LCP,
Maurin N, and Snijders CHA. 1994. Assessing non-specificity
of resistance of wheat to head blight caused by inoculation with
European strains of Fusarium culmorum, F.
graminearum, and F. nivale using a multiplicative
model for interaction. Theor Appl Genet (In press).
Breeding for bread making quality of wheat using protein electrophoresis.
S. Greger, H. Bistrich, B. Charvat, and T. Lelley.
In a research project financially supported
by the Austrian Science Foundation (P10300-CH), crosses between
Austrian and Hungarian wheat breeding lines and cultivars have
been made. Using the DH and SSD techniques, recombinant inbreed
lines are being produced representing specific combinations between
different HMW-glutenin, LMW-glutenin, and gliadin alleles. These
lines will be investigated for their qualitative and their quantitative
protein combinations and for different baking quality parameters.
The relationship between the occurrence of certain proteins and
the bread making quality will be analysed. Because some of the
Hungarian lines used as crossing parents contain the 1BL-1RS
translocation, we also want to analyse the effect of the translocation
on quality.
We investigated 91 Austrian and 72
Hungarian winter wheat varieties and breeding lines, which were
tested in the respective national trials in 1992 for their high
molecular weight (HMW) glutenin subunits and for the presence
or absence of the 1BL-1RS
translocation using SDS-PAGE. In the Austrian material, 19 different
allele compositions were found; in the Hungarian material, 18
different allele compositions were found. In the Austrian and
Hungarian material, the prevailing allele compositions were 0,
7Y+9, 5+10 (28.6 %) and 2*, 7Y+9, 5+10 (31.5 %), respectively.
Two Hungarian varieties were found to contain a new Glu-B1
allele, 14+19, which seems to be a recombination between the alleles
13+19 and 14+15. We also detected differences in the mobility
of the HMW glutenin subunit 7 in several varieties. The 1BL-1RS
translocation occurred in only 11.5 % of the Austrian, but in
51 % of the Hungarian material. The Austrian variety Ferdinand
was found to contain a complete 1B/1R substitution. Significant
correlations between the presence of different HMW glutenin subunits
and the Zeleny sedimentation volume were detected. The highest
positive correlations were found with the subunits 2*, 7Y+9, and
5+10, and the highest negative correlation with 2+12.
Producing wheat double haploids using `wheat x maize' hybridisation.
S. Greger, Ch. Bitsch, B. Charvat, and T. Lelley.
For our studies concerning bread making
quality in wheat, we introduced the method of `wheat
x maize'
hybridisation to produce wheat DHs. We received an average number
of 3.7 embryos/ear and 3 green haploid plants/ear. During this
work, different techniques to make the method more practical and
less time consuming are being tested; e.g., for the colchicine
treatment, after excision the embryos will be put on a medium
containing colchicine for 1 day. Thereafter, the embryos will
be replanted on a colchicine-free medium.
We are also investigating the effect
of the 1BL-1RS
translocation and the 1B/1R substitution on the efficiency of
haploid production, by the above method, using near isogenic lines.
The first experiments have been done to produce DHs from triticale
through hybridisation with maize.
Introducing bread making quality into triticale.
J. Lafferty and T. Lelley.
To improve bread making quality of triticale, chromosome 1D, with HMW glutenin subunits 5+10, is being introduced into different improved hexaploid triticale genotypes. This chromosome substitution was possible after the production of 1D/1A, 1D/1B, and 1D/1R chromosomal substitution lines in hexaploid triticale (Kazman E and Lelley T. 1994. Plant Breed 113:89-98). The procedure first involved the production of primary octoploid triticale, using hexaploid wheats with high bread-making quality having the HMW glutenin subunits 5+10 in the Glu-D1 locus. These
octoploid triticales then were crossed
with selected hexaploid triticale varieties. In this winter season,
we successfully backcrossed the pentaploid F1 with
their respective triticale varieties. Seeds produced through
backcrosses will be tested with SDS-PAGE for the presence of the
5+10 subunits. Plants showing these subunits will be backcrossed
again to their respective triticale parents. After another backcross,
isogenic lines, with or without substitution of chromosome 1D
for its respective homoeologous group one chromosome, will be
selected and tested for bread making quality.