This article was downloaded by: [Á. Mesterházy]On: 09 July 2013, At: 06:51Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

Canadian Journal of Plant PathologyPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/tcjp20

Identification and validation of fusarium head blightand Fusarium-damaged kernel QTL in a Frontana/Remus DH mapping populationÁ. Szabó-Hevér a , S. Lehoczki-Krsjak a , B. Tóth a , L. Purnhauser a , H. Buerstmayr b , B.Steiner b & Á. Mesterházy aa Cereal Research Non-Profit Limited Company, P.O. Box 391, H-6701, Szeged, Hungaryb IFA-Tulln, Institute for Agrobiotechnology, Konrad Lorenz Str. 20, 3430, Tulln, AustriaAccepted author version posted online: 23 Mar 2012.Published online: 27 Jun 2012.

To cite this article: . Szab-Hevr , S. Lehoczki-Krsjak , B. Tth , L. Purnhauser , H. Buerstmayr , B. Steiner & . Mesterhzy(2012) Identification and validation of fusarium head blight and Fusarium-damaged kernel QTL in a Frontana/Remus DHmapping population, Canadian Journal of Plant Pathology, 34:2, 224-238, DOI: 10.1080/07060661.2012.676571

To link to this article: http://dx.doi.org/10.1080/07060661.2012.676571

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

Can. J. Plant Pathol. (2012), 34(2): 224–238

Genetics and resistance/Génétique et résistance

Identification and validation of fusarium head blight andFusarium-damaged kernel QTL in a Frontana/Remus DHmapping population

Á. SZABÓ-HEVÉR1, S. LEHOCZKI-KRSJAK1, B. TÓTH1, L. PURNHAUSER1, H. BUERSTMAYR2, B. STEINER2

AND Á. MESTERHÁZY1

1Cereal Research Non-Profit Limited Company, P.O. Box 391, H-6701 Szeged, Hungary2IFA-Tulln, Institute for Agrobiotechnology, Konrad Lorenz Str. 20, 3430 Tulln, Austria

(Accepted 13 March 2012)

Abstract: Fusarium head blight (FHB) is a devastating disease of wheat (Triticum aestivum L.). This study investigated a ‘Frontana/Remus’doubled haploid population (n = 210 lines) to map and validate the ‘Frontana’ resistance quantitative trait loci (QTL) focusing onFusarium-damaged kernels (FDK). The plant material was evaluated in six epidemic situations for Fusarium resistance in inoculated fieldexperiments, with either Fusarium graminearum or F. culmorum. Other studies have focused on FHB QTL, but it is important to evaluate howfar these QTL determine FDK values. The data show that the genetic regulation of FHB resistance is more complex than earlier proposed.FHB resistance QTL were identified on chromosomes 3A, 4A and 6B. Markers showed association with FDK resistance on chromosomes 3Dand at the marker Xs12m15_4. QTL on 2B, 4B, 5A and 7B chromosomes were responsible for both FHB and FDK resistance; in this case, thesame QTL influenced both traits and possibly other traits during disease development. These QTL are very important, because they can beconsidered to be real Fusarium resistance QTL. The use of markers in breeding programmes, which are associated only with FHB or FDKresistance may be questionable and require further research. Heading date QTL were detected on chromosomes 1A, 2D and 7B overlappingwith neither FHB nor FDK resistance QTL. The QTL identified in the ‘Frontana/Remus’ population were in good agreement with earlierresults from the literature.

Key words: disease resistance loci, Fusarium culmorum, Fusarium-damaged kernels, Fusarium graminearum, fusarium head blight, QTL,Triticum aestivum

Résumé: La fusariose des panicules (FP) est une maladie dévastatrice qui atteint le blé (Triticum aestivum L). Cette étude a été porté sur unepopulation haploïde doublée, le ‘Frontana/Remus’ (n = 210 lignées), afin d’organiser et valider les loci des traits qualitatifs (LTQ) derésistance du ‘Frontana’ en se focalisant sur les grains fusariés (GF). La matière végétale a été évaluée pour sa résistance à la fusariose danssix situations épidémiques au moyen d’expériences d’inoculation sur le terrain, soit avec de la Fusarium graminearum ou de la F. culmorum.D’autres études sont axées sur le FP LTQ, mais cela est important d’évaluer comment ces LTQ peuvent déterminer la quantité les GF. Lesdonnées montrent que la régulation génétique de la résistance à la FP est plus complexe qu’on a le proposé anvant. Des FP LTQ ont étéidentifiés sur les chromosomes 3A, 4A et 6B. Les marqueurs montrent un lien de résistance aux GF au niveau de chromosome 3D et de lamarqueur Xs12m15_4. Les LTQ sur les chromosomes 2B, 4B, 5A et 7B se trouvent être responsables de résistance à la FP et aux GF, dans cecas, le même LTQ influe les deux traits de la même manière et vraisemblablement les autres traits au cours de l’évolution de la maladie.A notre niveau, ces LTQ sont très importants parce que pouvant être considères comme de vrais LTQ de résistance à la fusariose. L’utilisationdes marqueurs dans les programmes d’amélioration qui sont associées uniquement de résistance à la FP ou aux GF est un procédé douteux etmérite une recherche approfondie. Les LTQ de la date d’épiaison ont été détectés au niveau des chromosomes 1A, 2D et 7B, étant à cheval ni

Correspondence to: Ákos Mesterházy. E-mail: akos.mesterhazy@gabonakutato.hu

ISSN: 0706-0661 print/ISSN 1715-2992 online © 2012 The Canadian Phytopathological Societyhttp://dx.doi.org/10.1080/07060661.2012.676571

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 225

avec les LTQ de resistance à la FP ou aux GF. Les LTQ identifiés dans la population ‘Frontana/Remus’ correspondent aux résultats enregistréspar les études antérieures.

Mots clés: fusariose des panicules, Fusarium culmorum, Fusarium graminearum, grains fusariés, loci de la résistance aux maladies, LTQ,Triticum aestivum

Introduction

Fusarium head blight (FHB) is one of the most impor-tant cereal diseases causing concerns for food and feedsafety, yield and quality. The use of resistant cultivars,together with proper crop management practices, are themost effective strategies to control FHB (Bai & Shaner,1994; McMullen et al., 1997). However, progress in dis-ease control has been much slower than initially supposed15–20 years ago (Brown-Guedira et al., 2008). Identifyingeffective resistant stocks and understanding the com-plex genetic structure of FHB resistance would enhanceeffective breeding for this trait. Buerstmayr et al. (2009)summarized 22 quantitative trait loci (QTL) for FHBresistance, mapped to all wheat chromosomes – except7D – in different mapping populations. The most impor-tant QTL have been found on chromosomes 2D, 3BS,3BSc, 4B, 5AS and 6BS (McCartney et al., 2004; Yuet al., 2006; Liu et al., 2007), and have been validated inindependent mapping populations.

The best-characterized QTL are Fhb1 on chromosome3BS and Fhb2 on chromosome 6B, both coding Type 2resistance, and both derived from the highly resistant‘Sumai 3’ or its close relatives (Waldron et al., 1999;Anderson et al., 2001; Buerstmayr et al., 2002, 2003;Somers et al., 2003; Lemmens et al., 2005; Cuthbert et al.,2006). Their intensive use in breeding did not produce theexpected results, as the wheat lines inherited many dele-terious traits from the adapted germplasm; only sporadicsuccess was recorded in variety development.

The moderately resistant Brazilian spring wheatcultivar ‘Frontana’ originates from the cross of‘Fronteira/Mentana’ (Schroeder & Christensen, 1963;Van Ginkel et al., 1996). The genetic background ofits FHB resistance was analysed by several researchgroups. Singh et al. (1995) declared that the resistanceof ‘Frontana’ is controlled by the additive interactionof a minimum of three minor genes. Steiner et al.(2004) investigated the ‘Frontana/Remus’ DH population(210 lines) and found Type I Fusarium resistance QTLon chromosomes 3A, 5A, 2B, 4B and 6B in ‘Frontana’,and on chromosomes 1B, 2A and 3B in ‘Remus’. Mardiet al. (2006) confirmed the 3AL QTL of ‘Frontana’ in the‘Frontana/Falat’ population and identified two additional

QTL on chromosomes 1BL and 7AS. Srinivasacharyet al. (2008) found ‘Frontana’ FHB resistance QTL onchromosomes 1B, 2B, 3A, 6A, 6B, 7A and 7D in a RILpopulation from a cross between RL4137 (FHB-resistantline derived from ‘Frontana’) and the moderately FHB-resistant variety ‘Timgalen’. Beyond these, QTL forplant height on 2B, 4A and 5B, as well as for ‘awns’on 2B were identified. These authors (Srinivasacharyet al., 2008) analysed only FHB symptoms, while othertraits of Fusarium resistance were not considered. Themoderate resistance of ‘Frontana’ was confirmed alsoby Burlakoti et al. (2010) who compared the geneticbackground of ‘Alsen’ (developed from ‘Sumai 3’),‘Frontana’ and the susceptible W9207 line. Notably,‘Frontana’ showed the highest level of resistance to initialinfection among the three parents. ‘Alsen’ showed thehighest level of resistance with respect to FHB spread,Fusarium-damaged kernels (FDK) and deoxynivalenol(DON) content. This result may be explained by thedifferences in mechanism of Type I resistance (initialinfection) and Type II (FHB spread) resistance and thedifferent effectiveness of the QTL. Yang et al. (2006)stated that ‘Frontana’ does not have QTL in common with‘Sumai 3’ on chromosomes 3B and 6B, which confirmsthe importance of ‘Frontana’ as a source of resistance.

FHB severity is influenced by different morphologicaltraits, such as plant height and heading date (Mesterhazy,1987, 1995; Parry et al., 1995). In order to avoid falseQTL detection, it is essential to screen wheat lines in dif-ferent environments. This has been confirmed by Draegeret al. (2007) through the identification of QTL for FHBresistance in the winter wheat variety ‘Arina’ and by Luet al. (2011) through the investigation of the effect ofRht-D1b plant height allele compared with FHB resis-tance QTL in a DH population in three countries, acrosssix years. In spite of all the published studies, dur-ing phenotyping mapping populations, usually just oneF. graminearum and/or F. culmorum isolate/inoculum(when mixed) was used in 2–3 study years (Mardi et al.,2005, 2006; Chen et al., 2007; Klahr et al., 2007), mean-ing that just 2–3 epidemic situations gave the phenotypicdata, which might not be enough to detect real or mediumeffective QTL and reduce the genotype-by-environmentinteraction.

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 226

With the low number of epidemic situations –especially under field conditions – the resistance data areless reliable than with a higher number of environments,and might lead to invalid QTL analyses. This is the keyactivity since the molecular genetic work with current lab-oratory instrumentation can be easily standardized, whilethis is not the case for the phenotyping of mapping pop-ulations, especially under field conditions (Szabo-Heveret al., 2008). In this study, the number of epidemicsituations was increased by increasing the number ofdifferent aggressive isolates in order to obtain more reli-able data in resistance phenotyping and to obtain lessinteraction with the environment.

FHB resistance is a complex trait as it is controlled byseveral small, medium or large effective QTL. Marker-assisted selection (MAS) for FHB resistance alreadyexists. In recent years, screening for FHB resistance(Fhb1 and Fhb2) has become particularly important(Gupta et al., 2010). Salameh et al. (2010) and von derOhe et al. (2010) investigated the effect of Qfhs.ifa-5Acompared with the effect of Fhb1 on FHB resistance.Among others, their results showed that Qfhs.ifa-5A hasa smaller effect on FHB resistance than Fhb1 or bothQTL together. Beyond this, no systematic negative effectof the spring wheat-derived QTL on grain yield, thou-sand grain weight, hectolitre weight and protein contentwas found (Salameh et al., 2010). Wilde et al. (2007)investigated the effect of the 3B and 5A QTL fromCM82036 (‘Sumai 3/Thornbird’) and the 3A QTL from‘Frontana’. In their experiment, plants carrying 3B, 5Aand 3A QTL showed the highest level of FHB severityresistance and DON reduction compared with those car-rying only the 3B and 5A QTL; however, the phenotypicselection seemed to be the most efficient method in theresistance tests.

The QTL with small and medium effects are mostfrequently not validated which is a problem in MAS.There are no publications identifying ‘Frontana’-derivedFDK resistance QTL, which is important, because FDKhas a stronger association with toxin accumulation thanthe visual scores of incidence or severity (Mesterházy,1995).

The objectives of this study were: (i) to compare theQTL data with the Austrian results using a different inoc-ulation method from that used by Steiner et al. (2004) inTulln; (ii) to identify FDK QTL in the ‘Frontana/Remus’population and compare them with the QTL for FHBseverity; (iii) to identify QTL which are not Fusariumresistance QTL, but may influence disease development;and (iv) to estimate the practicability of MAS when‘Frontana’ is used as a donor of FHB resistance.

Materials and methods

Plant materials

The ‘Frontana/Remus’ doubled haploid (DH) populationwas generated at IFA-Tulln, Austria and was mapped forQTL by Steiner et al. (2004). The population was devel-oped from the cross of ‘Frontana’ by ‘Remus’ and consistsof 210 DH lines. ‘Frontana’ (‘Fronteira/Mentana’) is aBrazilian spring wheat cultivar known for its resistanceto FHB. ‘Remus’ is a spring wheat cultivar released bythe Bavarian State Institute for Agronomy in Freising,Germany. It is well adapted for cultivation in CentralEurope, but it is susceptible to FHB.

Field experiments for Fusarium resistance evaluation

The plant material was evaluated in the nursery of CerealResearch Ltd. in Szeged (Hungary) over four seasons:2002, 2004, 2005 and 2006, using individual F. gramin-earum and F. culmorum isolates. Seed was sown in allexperiments in mid-October, using Wintersteiger PlotSpider planter (Wintersteiger GmbH, Ried, Austria), atthe usual sowing time of winter wheat. The plots (i.e.genotypes) were planted in two replications in a random-ized complete block design to serve later as main plotsof the experiments. No winter damage was observed inthese experiments. Each replicate consisted of 1.5 m longrows. The width of the main plots was set according to thenumber of isolates used for inoculation to place one bunchinfected per row: 1-row plots were planted in trials inoc-ulated with 1 isolate, 2-row plots for 2 isolates and 4-rowplots for 4 isolates.

Inoculum production and inoculation procedure

Fungal suspensions were made in 10 L heat stableglass flasks filled with 9.4 L liquid Czapek-Dox medium(Mesterházy, 1977). They were aerated at room tem-perature for a week. Conidium concentration was deter-mined using a Bürker haemocytometer (MOM, Budapest,Hungary). The aggressiveness of the isolates was testedin Petri dishes according to the method of Mesterházy(1985). Until used, the inocula were stored at 4 ◦Cin 600 L refrigerators (‘Grönland’ from Rostock, EastGermany). Each genotype was inoculated individuallywith one to four isolates of either F. graminearum orF. culmorum. The details of the inocula of isolates usedare shown in Table 1. In the experiments altogether, eightisolates were used; however, two isolates in 2006 werenot pathogenic enough, so they were omitted from further

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 227

Table 1. Isolate names and number of conidia ml−1 used in thefield screening in each experiment and the results of the Petri dishtest (mean percentage of infected germs of five readings) accordingto the method of Mesterházy (1985).

YearExperiment

nameIsolatename

Number ofconidiaml−1

Petridish test

(%)

2002 Exp. 1. Fc. 12375 0.6∗105 13.32004 Exp. 2. Fc. 12551 8.3∗105 52.82005 Exp. 3. Fg. 12377 5.0∗105 17.7

Exp. 4. Fc. 12375 0.2∗105 26.22006 Exp. 5. Fc. 12551 3.5∗105 41.3

Exp. 6. Fg. J5A2 0a 30.5

aOnly mycelium was present.

analysis. The remaining six epidemic situations are stillfar more than the 2–3 generally applied in the literature.

At full flowering (Feekes growth stage 10.5.1), bunchesof 15–25 spikes were sprayed from all sides with ahand-held-sprayer to inoculate the spikes uniformly, usingabout 15–20 mL fungal suspension for each sample asdescribed by Mesterházy (1987, 1995). One bunch ofspikes per row of each genotype (in a randomized com-plete block design) was inoculated with a single isolate.Arrangement was combined with the use of isolates thatwere not randomized within plots, but 30–40 cm was keptbetween bunches. After inoculation, bunches were cov-ered with a transparent polyethylene bag for 48 hours.After removing the bags, the plants were loosely boundwith a label for identification at half plant height to allowthe leaves to photosynthesize freely.

FHB and FDK assessment

Observations of FHB disease severity were started on the10th day after inoculation and were repeated on everyfourth day. FHB evaluations were made on a 0–100 lin-ear scale (% of spikelets infected = severity) as long asthe control heads were green; this meant four readings perseason.

The groups of inoculated heads were harvested manu-ally and stored until threshing in paper bags. The sampleswere threshed using a stationary thresher (WintersteigerLD 180, Ried, Austria) at low wind, in order to retain theshrivelled, low thousand kernel weight (TKW) Fusarium-damaged kernels. Chaff was removed using an Ets Plaut-Aubry (41290 Conan-Oucques, France) air separator.After cleaning, FDK were visually rated (visual estima-tion of scabby grains with definite tombstone, or chalky-white and rose discoloration as a percentage). Shrivelled,

but non-discolored grains were not considered Fusarium-damaged; these originated mostly from withered spikeletsabove the infection point due to wilting (Lehoczki-Krsjaket al., 2010).

Other traits

In each year, plant height was measured as the distancefrom the soil surface to the top of heads excluding awns.The date of heading and anthesis were also recorded asthe number of days from 1 January to heading or anthesis.

Genomic DNA extraction

DNA was isolated from seedling leaf tissue accord-ing to the CTAB method (Rogers & Bendich, 1985).The quality and quantity were measured with NanoDrop1000 Spectrophotometer (Thermo Scientific Company).

Molecular markers

The 583 marker data, comprising 135 microsatellite mark-ers, 416 AFLP, 32 RFLP markers and the map informationof the ‘Frontana/Remus’ population were provided bySteiner et al. (2004). Forty-five SSR markers were testedon the population at Cereal Research Ltd. (Hungary).Most of the primers used in Hungary were selected fromthe literature (Röder et al., 1998; Somers et al., 2004;Mardi et al., 2006). The PCR reaction mix for SSR mark-ers contained: 0.12 µM forward primer, 0.12 µM reverseprimer, 1× PCR Master Mix (Fermentas) and 20 ng tem-plate DNA for 10 µl reaction volume per sample. ThePCR programme for SSR primers was: 94 ◦C for 8 minand then 40 cycles of 94 ◦C for 5 s, 50–60 ◦C for 5 s, 72◦C for 8 s followed by 72 ◦C for 5 min. The PCRs wereperformed on an Eppendorf Mastercycler

®ep 96-well

thermocycler. The PCR products were separated on 5%polyacrylamide gels using a Sequi-Gen GT SequencingCell 30 cm gel apparatus (Bio-Rad) or with the Agilent2100 Bioanalyzer (Agilent Technologies).

Statistical analysis

Statistical analyses were made by SPSS 15.0 soft-ware ‘Descriptive statistics’ function to calculate means,minimum and maximum values, percentiles, standarddeviation, to test the normal distribution of the FHBseverity and FDK data. The ‘General Linear Model’(GLM) function was used to perform the two-wayANOVA, investigating the genotype-by-experiment inter-actions. The FHB severity and FDK data for each

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 228

fungal isolate from different years were analysed as sin-gle experiments (epidemic situations), because there areno races within F. graminearum and host resistance isnon-specific for different Fusarium spp. (Mesterházy,1995, 2002). Therefore the epidemics caused by eitherF. graminearum or F. culmorum could be analysedtogether. The data for all epidemic situations werechecked for normal distribution (Weber, 1972). Broad-sense heritability was estimated across experimentsaccording to Nyquist (1991) with the following formu-las: H2 across experiments = 1−(MSGxE/MSG). (MSGxE:mean square genotype × experiment; MSG: mean squaregenotype).

QTL analysis

Linkage groups were constructed using JoinMap®

3.0(Van Ooijen & Voorrips, 2001) and interval mapping wasdone using MapQTL

®5 (Van Ooijen, 2004). Linkage

groups were established by using a maximum recom-bination fraction of 0.45. The permutation tests (deter-mined by 1000 iterations) indicated minimum LOD scoresbetween 1.2 and 2.1 at a P = 0.05 significance level.Interval mapping (IM) was made with the phenotypicdata of single experiments, with the mean values ofF. graminearum and F. culmorum inoculations and over-all means for FHB severity and FDK rates of all the

selected isolates, as well as with lodging, plant height andheading date.

Results

Fusarium resistance

The means of the parental lines and the DH lines, the pop-ulation ranges and standard deviation for FHB severityand FDK rate reported by isolates and across the differ-ent environments is shown in Table 2. In the experiments,the FHB-resistant parent ‘Frontana’ and the susceptible‘Remus’ showed Fusarium infection symptoms accordingto their resistance level. Nevertheless, the isolates and thedifferent environmental conditions among years causeddifferences in FHB severity and FDK rate means betweenthe parental and the DH lines. The distribution of FHBseverity and FDK rate means of the selected experimentsis presented in Figs 1 and 2.

The large differences for FHB severity and FDK ratebetween parental genotypes accounted for significantgenetic variation in the mapping populations. ANOVAwas calculated for FHB severity and FDK rate across thesix epidemic situations (Table 3). The FDK data wereusually significantly more severe than FHB severity. Thegenotype effects differ significantly from the genotype-by-experiment interaction, indicating that the basic rank-ing is similar. The heritability estimates (0.64 for FHB

Table 2. Means, ranges and standard deviations for fusarium head blight (FHB) severity and Fusarium-damaged kernels (FDK) rate causedby isolates of Fusarium graminearum and Fusarium culmorum over six environments (experiments) in a ‘Frontana/Remus’ population.Plant height (cm) and heading date (days) are mean values from the investigated experiments.

Experiment Isolate Trait Frontana Remus Pop. mean Pop range SD

Exp. 1. Fc. 12375 FHB 13.3 75.8 47.6 3.3–86.7 18.8FDK 40.0 100.0 50.9 2.5–100.0 21.2

Exp. 2. Fc. 12551 FHB 7.1 36.3 29.4 0.0–92.0 18.1FDK 45.0 80.0 62.5 1.0–100.0 23.3

Exp. 3. Fg. 12377 FHB 0.6 66.2 27.4 0.6–73.3 17.4FDK 2.0 92.5 48.3 0.0–92.5 26.6

Exp. 4. Fc. 12375 FHB 3.2 60.8 31.5 3.2–76.7 15.8FDK 5.0 70.0 48.0 0.0–92.5 25.6

Exp. 5. Fc. 12551 FHB 35.4 44.3 47.3 6.5–82.5 18.2FDK 50.0 55.0 63.3 5.0–100.0 21.9

Exp. 6. Fg. J5A2 FHB 2.0 23.8 18.6 0.2–54.8 11.6FDK 1.3 40.0 30.4 0.5–80.0 20.7

MEAN F. culmorum FHB 14.8 54.3 38.9 6.3–66.4 11.3FDK 35.0 76.3 56.3 11.5–90.8 15.8

F. gramin-earum

FHB 1.3 45.1 23.0 1.3–63.3 11.4

FDK 1.7 66.3 39.9 1.7–90.0 20.0FHB 10.3 51.2 33.7 6.6–65.4 10.2FDK 23.9 72.9 51.0 8.3–85.0 15.7

Plant height 110 92 106 87–132 9.0Heading date 128 139 134 124–143 5.0

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 229

Fig. 1. Histogram of fusarium head blight (FHB) means of 210doubled-haploid lines in a ‘Frontana/Remus’ population over sixenvironments.

Fig. 2. Histogram of Fusarium-damaged kernels (FDK) levels of210 doubled-haploid lines in a ‘Frontana/Remus’ population oversix environments.

and 0.74 for FDK) indicate a good reproducibility of theresults among tests for both traits.

Correlations were calculated among each experimentand means for the two Fusarium species, means for FHBseverity, FDK levels, lodging, plant height and headingdate across the experiments (Table 4). The correlationswere somewhat closer for FDK values, indicating a betterreproducibility. Means, calculated for the two Fusariumspecies used in the experiments, showed good correlationwithin FHB or FDK, while only moderate correlation wasdetected among the two traits. The correlations betweenindividual experiments to the F. culmorum means werecloser than those of the F. graminearum means which

can be explained by the different number of epidemic sit-uations used for calculating means for the two species.Plant height and lodging did not seriously influence FHBdata (in dry seasons, lodging was rare); however, a laterheading date increased FHB values through the differ-ent weather conditions during the initial fungal growth.Lodging and plant height influenced FDK values at alow level; however, the later heading genotypes decreasedFDK severity. Lodging was moderately correlated withplant height, and heading date was later for taller geno-types.

Molecular linkage map

In the linkage analysis, 583 markers were mappedto 44 linkage groups, covering a genetic distance of1643 cM. Partial maps were obtained for all wheatchromosomes. The QTL analyses were made with themeans across epidemic situations (experiments) and witheach situation separately. The latter is not shown, as theuse of means across experiments did not significantlychange the results. All the QTL regions detected on thedifferent chromosomes in the different experiments areshown in Table 5. There was no case where a QTL wouldbe significant in all epidemic situations. However, theQTL analyses gave significantly better results with meandata (Table 6). With some exceptions, the F. culmorumgave higher LOD values than F. graminearum, which canbe explained by the lower number of epidemic situationswith this latter Fusarium species. The genetic map ofchromosomes containing marker intervals linked to FHBand/or FDK resistance is shown in Fig. 3.

FDK: Chromosome regions on 2B (Xgwm120-Xs12m19_9 and Xgwm526), 3D (Xs12m19_5-Xgwm341),4B (Xs13m26_7-Xs13m18_9), 5A (Xgwm293-Xs24m19_5), 7B (Xs12m25_2) and one unassignedlinkage group (Xs12m15_4) were significant for FDKas a measure for resistance. A QTL on chromosome7B (Xs12m25_2) showed the highest LOD value (4.05),accounted for 10.9% of the phenotypic variance (r2 orVE) and was found in the same position as the QTLfor FHB severity. Other QTL coincidental with FHB

Table 3. Analysis of variance for fusarium head blight (FHB) severity and levels of Fusarium-damaged kernels (FDK).

FHB FDK

df MS F-value P df MS F-value P

Experiment (E) 5 53 440.32 1966.46 <0.0001 5 56 842.84 431.19 <0.0001Genotype (G) 209 1218.24 44.83 <0.0001 209 2777.58 21.07 <0.0001E x G 998 433.19 15.94 <0.0001 998 733.13 5.56 <0.0001Error 1213 27.18 1213 131.83

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 230

Tabl

e4.

Cor

rela

tions

betw

een

fusa

rium

head

blig

ht(F

HB

)se

veri

ty,F

usar

ium

-dam

aged

kern

els

(FD

K)

leve

lsin

each

expe

rim

ent(

1–6)

,with

mea

nva

lues

,lod

ging

,pla

nthe

ight

and

head

ing

date

(n=

210)

.(∗∗

=co

rrel

atio

nis

sign

ifica

ntat

the

0.01

leve

l;∗=

corr

elat

ion

issi

gnifi

cant

atth

e0.

05le

vel)

.

FHB

FDK

Plan

tE

xp.1

.E

xp.2

.E

xp.3

.E

xp.4

.E

xp.5

.E

xp.6

.Fc

mea

nFg

mea

nM

ean

Exp

.1.

Exp

.2.

Exp

.3.

Exp

.4.

Exp

.5.

Exp

.6.

Fcm

ean

Fgm

ean

Mea

nL

oadi

ngH

eigh

t

FHB

Exp

.2.

0.20

∗∗E

xp.3

.0.

18∗

0.31

∗∗E

xp.4

.0.

20∗∗

0.32

∗∗0.

84∗∗

Exp

.5.

0.28

∗∗0.

15∗

Exp

.6.

0.17

∗0.

22∗∗

0.62

∗∗Fc

mea

n0.

69∗∗

0.66

∗∗0.

50∗∗

0.60

∗∗0.

60∗∗

0.42

∗∗Fg

mea

n0.

20∗∗

0.28

∗∗0.

87∗∗

0.76

∗∗0.

33∗∗

0.65

∗∗0.

58∗∗

Mea

n0.

58∗∗

0.60

∗∗0.

68∗∗

0.72

∗∗0.

55∗∗

0.55

∗∗0.

96∗∗

0.79

∗∗FD

KE

xp.1

.0.

54∗∗

0.17

∗0.

37∗∗

0.31

∗∗E

xp.2

.0.

17∗

0.37

∗∗0.

18∗

0.21

∗∗0.

16∗

0.34

∗∗0.

20∗∗

0.32

∗∗0.

43∗∗

Exp

.3.

0.19

∗∗0.

50∗∗

0.49

∗∗0.

16∗

0.30

∗∗0.

48∗∗

0.40

∗∗0.

22∗∗

0.29

∗∗E

xp.4

.0.

15∗

0.17

∗0.

36∗∗

0.50

∗∗0.

18∗

0.33

∗∗0.

38∗∗

0.39

∗∗0.

22∗∗

0.29

∗∗0.

70∗∗

Exp

.5.

0.15

∗0.

55∗∗

0.29

∗∗0.

34∗∗

0.29

∗∗0.

25∗∗

0.35

∗∗0.

18∗

0.18

∗E

xp.6

.0.

22∗∗

0.17

∗0.

17∗

0.46

∗∗0.

51∗∗

0.40

∗∗0.

34∗∗

0.42

∗∗0.

31∗∗

0.35

∗∗0.

28∗∗

0.33

∗∗0.

50∗∗

Fcm

ean

0.37

∗∗0.

28∗∗

0.19

∗∗0.

31∗∗

0.37

∗∗0.

28∗∗

0.50

∗∗0.

31∗∗

0.48

∗∗0.

68∗∗

0.76

∗∗0.

53∗∗

0.66

∗∗0.

64∗∗

0.54

∗∗Fg

mea

n0.

17∗

0.19

∗∗0.

38∗∗

0.41

∗∗0.

29∗∗

0.40

∗∗0.

38∗∗

0.51

∗∗0.

46∗∗

0.32

∗∗0.

40∗∗

0.86

∗∗0.

66∗∗

0.40

∗∗0.

75∗∗

0.65

∗∗M

ean

0.32

∗∗0.

27∗∗

0.29

∗∗0.

38∗∗

0.37

∗∗0.

35∗∗

0.49

∗∗0.

42∗∗

0.52

∗∗0.

60∗∗

0.68

∗∗0.

71∗∗

0.72

∗∗0.

60∗∗

0.68

∗∗0.

95∗∗

0.86

∗∗L

odgi

ng−0

.18∗∗

−0.1

6∗−0

.18∗∗

−0.1

8∗∗Pl

anth

eigh

t0.

19∗∗

−0.2

2∗∗−0

.28∗∗

−0.3

0∗∗−0

.19∗∗

−0.2

1∗∗−0

.26∗∗

−0.3

4∗∗−0

.32∗∗

0.53

∗∗H

eadi

ngda

te0.

20∗∗

0.29

∗∗0.

45∗∗

0.31

∗∗−0

.15∗

0.26

∗∗0.

32∗∗

0.32

∗∗−0

.25∗∗

−0.3

2∗∗−0

.42∗∗

−0.2

5∗∗−0

.33∗∗

−0.1

4∗−0

.28∗∗

0.18

∗∗0.

34∗∗

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 231

Tabl

e5.

Loc

atio

nsof

the

QT

Lde

tect

edan

dch

rom

osom

ere

gion

sw

ithL

OD

valu

esfo

rfu

sari

umhe

adbl

ight

(FH

B)

seve

rity

and

Fus

ariu

m-d

amag

edke

rnel

s(F

DK

)le

vels

inea

chex

peri

men

t.T

hehi

ghlig

hted

valu

esar

esi

gnifi

cant

acco

rdin

gto

the

geno

me-

wid

epe

rmut

atio

nte

sts.

FHB

FDK

Exp

.1.

Exp

.2.

Exp

.3.

Exp

.4.

Exp

.5.

Exp

.6.

Exp

.1.

Exp

.2.

Exp

.3.

Exp

.4.

Exp

.5.

Exp

.6.

Mar

ker;

map

inte

rval

Chr

omos

ome

LO

DL

OD

LO

DL

OD

LO

DL

OD

LO

DL

OD

LO

DL

OD

LO

DL

OD

Xgw

m12

0-X

s12m

19_9

2B2.

031.

831.

010.

351.

070.

893.

411.

691.

381.

211.

201.

18X

gwm

526

2B0.

850.

210.

950.

750.

562.

001.

551.

461.

212.

260.

841.

01X

gwm

1121

-Xgw

m77

93A

1.39

0.25

0.29

0.40

4.93

1.57

1.75

0.97

0.34

0.28

2.04

1.36

Xs1

2m19

_5-X

gwm

341

3D0.

971.

800.

060.

330.

430.

390.

872.

400.

802.

031.

270.

65X

wg2

324A

1.85

1.09

0.89

1.22

0.63

0.59

1.01

0.11

0.02

0.04

0.00

0.08

Xs1

3m26

_7-X

s13m

18_9

4B3.

390.

431.

872.

441.

060.

741.

690.

232.

530.

740.

590.

84X

gwm

293-

Xs2

4m19

_55A

1.33

1.78

0.83

1.13

0.12

0.90

2.18

2.73

1.62

1.49

0.26

0.68

Xs1

3m14

_10-

Xs2

3m14

_46B

0.44

1.65

1.29

1.15

0.63

1.30

0.09

0.14

0.01

0.14

0.01

0.22

Xs1

2m25

_27B

1.22

1.78

2.21

2.10

0.92

1.04

1.17

1.13

2.41

3.78

2.04

1.01

Xs1

2m15

_4N

D1.

060.

110.

171.

010.

130.

111.

670.

821.

072.

160.

570.

92

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 232

Tabl

e6.

Loc

atio

nsof

the

QT

Lde

tect

edan

dch

rom

osom

ere

gion

sw

ithL

OD

valu

es,p

erce

ntag

eof

expl

aine

dph

enot

ypic

vari

ance

(VE

)fo

rfu

sari

umhe

adbl

ight

(FH

B)

seve

r-ity

,F

usar

ium

-dam

aged

kern

els

(FD

K)

leve

ls(A

)an

dhe

adin

gda

te(H

D)

(B).

The

high

light

edva

lues

mea

nL

OD

>2.

0,ot

hers

are

sign

ifica

ntac

cord

ing

toth

ege

nom

e-w

ide

perm

utat

ion

test

s.

FHB

FDK

AF.

culm

orum

F.gr

amin

earu

mM

ean

F.cu

lmor

umF.

gram

inea

rum

Mea

n

Mar

ker;

map

inte

rval

Chr

omos

ome

LO

DV

EL

OD

VE

LO

DV

EL

OD

VE

LO

DV

EL

OD

VE

Xgw

m12

0-X

s12m

19_9

2B2.

277.

2n.

s.n.

s2.

497.

83.

209.

6n.

s.n.

s3.

109.

2X

gwm

526

2Bn.

s.n.

s.1.

966.

31.

815.

62.

758.

51.

495.

02.

748.

6X

gwm

1121

-Xgw

m77

93A

2.67

8.2

n.s.

n.s.

2.50

7.6

n.s.

n.s.

n.s.

n.s.

n.s.

n.s.

Xs1

2m19

_5-X

gwm

341

3Dn.

s.n.

s.n.

s.n.

s.n.

s.n.

s.3.

249.

7n.

s.n.

s.2.

888.

7X

wg2

324A

2.69

9.5

n.s.

n.s.

2.60

9.0

n.s.

n.s.

n.s.

n.s.

n.s.

n.s.

Xs1

3m26

_7-X

s13m

18_9

4B3.

308.

82.

165.

93.

499.

41.

403.

82.

827.

62.

266.

1X

gwm

293-

Xs2

4m19

_55A

1.82

5.2

1.57

4.3

1.62

4.7

2.50

7.2

1.87

5.4

2.43

7.0

Xs1

3m14

_10-

Xs2

3m14

_46B

2.05

6.1

1.89

5.4

2.33

6.8

n.s.

n.s.

n.s.

n.s.

n.s.

n.s.

Xs1

2m25

_27B

3.46

9.4

2.43

6.8

3.88

10.6

4.19

11.1

2.11

6.1

4.05

10.9

Xs1

2m15

_4N

Dn.

s.n.

s.n.

s.n.

s.n.

s.n.

s.2.

617.

31.

303.

72.

577.

2

BH

D

Mar

ker;

map

inte

rval

Chr

omos

ome

LO

DV

E

Xs1

3m14

_5a-

Xw

g983

1A3.

1210

.1X

s25m

19_1

6-X

gwm

608

2D2.

578.

7X

gwm

467B

2.87

9.5

n.s.

:not

sign

ifica

nt.

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 233

Fig. 3. Genetic map of QTL associated with fusarium head blight severity (FHB, dashed lines) and/or Fusarium-damaged kernels levels (FDK,dotted lines) over six experiments. Solid lines are the significant LOD level of a given linkage group.

resistance were identified on 2B (Xgwm120-Xs12m19and Xgwm526), 4B (Xs13m26_7-Xs13m18_9) and 5A(Xgwm293-Xs24m19_5).

FHB severity: Interval mapping analysis with MapQTLrevealed Fusarium resistance QTL on chromosomes 2B(Xgwm120-Xs12m19_9 and Xgwm526), 3A (Xgwm1121-Xgwm779), 4A (Xwg232), 4B (Xs13m26_7-Xs13m18_9),5A (Xgwm293-Xs24m19_5), 6B (Xs13m14_10-Xs23m14_4) and 7B (Xs12m25_2), all originatedfrom ‘Frontana’. The highest LOD value (3.88) wasmeasured on chromosome 7B explaining 10.6% ofthe phenotypic variance (r2 or VE). The chromosomeregion Xgwm293-Xs24m19_5 on 5A had the smallest,although still significant, effect. Markers did not show

the same association with both traits. Five of the 10 QTLinfluenced significantly both traits (FHB severity andFDK) simultaneously. Three had an effect only on FHB,and another two determined only FDK resistance.

Other traits: Among the other phenotypic traitsexamined, QTL for heading date were identifiedon chromosomes 1A (Xs13m14_5a-Xwg983) and 2D(Xs25m19_16-Xgwm608), as well as on 7B (Xgwm46);none overlapped with FHB severity or FDK QTL.

Discussion

The moderately resistant genotypes might have manyQTL with small or medium effects. This group has an

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 234

Fig. 3. (Continued).

increasing significance for breeding, because they aremostly adapted and FHB resistance can be improved withtheir use. The genetic regulation of FHB resistance ismore complicated than previously thought. QTL werefound that regulated either FHB or FDK and also QTLwere found which conferred resistance to both traits. Thismeans that QTL determining only FHB severity do notprovide sufficiently reliable information about potential

resistance using MAS. Additionally, we do not knowhow these QTL determining FHB severity will influ-ence DON contamination. The function of the QTL arealso not known, and the genes that are behind themare unknown. Since many traits can influence diseasedevelopment, many of which are not defence-related traitscan be identified as FHB QTL that may have nothing to dowith the genetic resistance. We think that the more reliable

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 235

markers are those which determine more resistance-basedtraits, because in that case, the probability of having realFusarium resistance QTL is much higher than in the caseof markers which link to QTL determining either FHBor FDK. On the other hand, we should develop mappingpopulations that are morphologically more homogeneous:plant height and heading date differences are smaller, alllines are awned or awnless, the structure of the headis similar, the plant materials where compact and otherhead types occur are better exposed to unwanted changesand influences. These many uncertainties lead us to con-clude that more epidemic situations are necessary to detectreal resistance QTL. Better phenotyping is also important.We found that securing humidity with polyethylene bagsinstead of misting is more neutral to plant height influ-ence. In the artificially inoculated nursery, the differentplant height groups had nearly the same FHB values, buttheir natural infection severities showed large differencesaccording to plant height classes (Mesterházy, 1987).

The situation we report in ‘Frontana’ is not unique.Three mapping populations of the Swiss winter wheat‘Arina’ were analysed with different susceptible parents(Paillard et al., 2004; Draeger et al., 2007; Semagn et al.,2007). Of the many QTL and markers described in thesepapers, only one was common in the three tests, theRht-D1 marker on the chromosome 4DS. Draeger et al.(2007) published eight QTL associated with AUDPC,and only one locus (Qfhs.jic 7a) influenced FDK. DONwas, however, influenced by two marker regions whichalso influenced AUDPC (Qfhs.jic-4d and Qfhs.jic.6b).These observations are similar to the results in the‘Frontana/Remus’ population.

The importance of type I resistance is increasinglyrecognized, and the testing methodology has slowly devel-oped to investigate it more precisely. It seems also that thecombination of Type I and Type II resistance is highlyeffective. Cultivar ‘Sumai 3’ proves this clearly wherethe 3BS and 5A QTL come from two different vari-eties (‘Funo’ and ‘Taiwanxiaomai’). In China, Mexico(CIMMYT), USA and Canada, breeding has focused onType II resistance. Nowadays, they consider also TypeI resistance and there is a general conviction that sprayinoculation is suitable to test the total resistance, whilethe point inoculation tests only Type II; therefore, sprayinoculation can be more suitable for breeding purposes(Mesterházy, 1995; Miedaner et al., 2003). Applyingthe best Fusarium testing method is very important forQTL mapping and MAS, as effective Fusarium resis-tance breeding needs both phenotypic selection and MAS(Wilde et al., 2007; Kosová et al., 2009; Löffler et al.,2009). Our observations suggest that the spraying inoc-ulation covers overall FHB resistance and the original

description of Type I (response to spraying inoculation)and Type II (response to point inoculation) is not correct.Variants of the spraying inoculation cover all resistancetypes, not only these two; as well as kernel resistance,DON resistance and tolerance can be tested with thesemethodological approaches (Mesterházy, 1995).

Plant morphological and developmental traits, such asplant height, spike morphology, and early or late flower-ing, influence FHB infection. Accordingly, it is possiblethat some of the putative FHB resistance QTL corre-spond to genes modulating morphological or develop-mental traits (disease escape) rather than physiologicalresistance. Therefore, in QTL mapping studies, other planttraits in addition to FHB severity, such as plant height andflowering date, should be measured in order to check forco-location with FHB resistance QTL (Buerstmayr et al.,2009).

In spite of the differences in field testing method-ology, the inoculation methods and location, the QTLfrom the experiment in Szeged showed very goodagreement with the results of Steiner et al. (2004).They used both spray inoculation and mist irri-gation for testing field resistance and single-floretinoculation testing for resistance to fungal spreadalong the ear. They identified chromosome regionson the 2B (Xs13m25_8-Xs24m15_6), 3A (Xdupw227-Xgwm720), 4B (Xs13m25_9), 5A (Xgwm129-Xbarc197),6B (Xs23m14_4) chromosomes for FHB severity and/orFHB incidence, plus another region on 2B (Xs25m15_2-Xs24m19_11) for FHB spread, in agreement with ourmapping results for FHB severity. The FHB QTL of‘Remus’ (on chromosomes 1B, 2A and 3B) could not besupported with the Hungarian data as we detected neitherFHB nor FDK resistance QTL deriving from ‘Remus’.A comparison of the QTL regions we identified with thoseof Steiner et al. (2004) is shown in Table 7. Occasionally,the flanking markers of certain validated QTL are differ-ent, although these QTL regions are essentially the samein both studies.

We confirmed the existence of two Fusarium resistancerelated QTL on the 2B chromosome: one in the regionof the Xgwm526, which was also identified by Schmolkeet al. (2005), and another at Xgwm120-Xs12m19_9 thatwere reported by Steiner et al. (2004) and Srinivasacharyet al. (2008) too as a ‘Frontana’ FHB severity and plantheight QTL.

A homologous region was identified associatingwith FHB resistance on chromosome 3A (Xgwm1121-Xgwm779) in Hungary as it was in Austria with the samepopulation by Steiner et al. (2004). In other ‘Frontana’-crossed populations, Mardi et al. (2006), Berzonsky et al.(2007), Wilde et al. (2007) and Srinivasachary et al.

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 236

Table 7. Chromosomes and markers linked to fusarium headblight (FHB) resistance identified in Szeged and Tulln (severityand/or incidence) in the ‘Frontana/Remus’ DH mapping popula-tion based on the general means across years.

Presence in

Marker; map interval Chromosome Cultivar Szeged Tulln∗

Xs12m25_14–Xs24m17_2 1B Remus − +Xs13m26_4 2A Remus − +Xs23m15_3 3B Remus − +Xgwm120-Xs12m19_9 2B Frontana + +Xgwm526 2B Frontana + −Xgwm1121-Xgwm779 3A Frontana + +Xwg232 4A Frontana + −Xs13m26_7-Xs13m18_9 4B Frontana + +Xgwm293-Xs24m19_5 5A Frontana + +Xs13m14_10-Xs23m14_4 6B Frontana + +Xs12m25_2 7B Frontana + −∗Steiner et al. (2004)

(2008) also detected the same chromosome region respon-sible for Fusarium resistance.

For FHB severity and FDK, we detected a QTL on4B between the markers Xs13m26_7 and Xs13m18_9as did Steiner et al. (2004), but they found this regionwas associated also with plant height. FHB resistanceQTL at 5A and 6B were also in agreement betweenthe two studies. We found the 5A chromosome region(Xgwm293-Xs24m19_5) responsible for FHB severity andFDK resistance. This region also was identified in the‘Frontana/Remus’ population by Steiner et al. (2004),who found this region also related to plant height. Gervaiset al. (2003) observed that the FHB resistance QTL on the5A chromosome is independent from the QTL on the 5Afor plant height. We could not verify this last assumptionin ‘Frontana’ with the Hungarian testing method, as wedid not detect any plant height QTL during the analysis.

The 6B QTL between the markers Xs13m14_10-Xs23m14_4 was detected as a FHB severity QTL. Thischromosome region was described by several researchgroups in Asian wheat lines (Waldron et al., 1999;Anderson et al., 2001; Shen et al., 2003; Yang et al., 2003;Somers et al., 2006). The QTL we identified does notseem to be related to fhb2 on the 6B chromosome. Thisview was supported by Yang et al. (2006) who stated that‘Frontana’ does not have homologous QTL with ‘Sumai3’ on the 6B chromosome.

In the Szeged analysis, the QTL at the markerXs12m25_2 on the 7B chromosome had the highest effecton FHB severity and FDK levels. This is the first reportof this chromosome region as a ‘Frontana’-derived resis-tance QTL. Schmolke et al. (2005) identified this regionas associated not only with FHB resistance, but also with

heading date, a result which may have originated fromthe heterogeneity problems of a RIL population derivedfrom the cross of the Fusarium-resistant ‘Dream’ and theFHB-susceptible dwarf type ‘Lynx’.

FDK QTL in the ‘Frontana/Remus’ population

In the literature, ‘Frontana’-derived FDK QTL havenot yet been reported. In addition to the four FHBresistance QTL on the 3A (Xgwm1121-Xgwm779), 4A(Xwg232) and 6B (Xs13m14_10-Xs23m14_4) regions,four QTL were mapped for FHB severity and also forFDK levels on chromosomes: 2B (Xgwm120-Xs12m19_9and Xgwm526), 4B (Xs13m26_7-Xs13m18_9), 5A(Xgwm293-Xs24m19_5), 7B (Xs12m25_2) and two addi-tional chromosome regions were identified influencingonly FDK rates on 3D (Xs12m19_5-Xgwm341) andone at the marker Xs12m15_4 without chromosomedetermination.

It might be easier to understand the results of the QTLanalysis by following the correlations among the differ-ent experiments and different traits. The visual scores areevaluated 3–4 weeks after inoculation, but for harvest2–3 additional weeks elapse. Heavy rains in this periodenhance further disease development that is reflected onlyin the FDK value. Lodging influences FHB data throughplant height as tall genotypes tend to lodge more probably.The effect of lodging on FDK is more frequent because ofthe time slippage between the evaluations of the two traits.Researchers should be aware, however, that there may beas yet unidentified traits that influence results. Traits thatdetermine physiological resistance should not be identi-fied as FHB QTL. This can be verified only by furtherresearch. Difficulties can be eliminated from the analy-sis of small and medium effective QTL via testing theplant material during at least four or more experimentalepidemic situations. It is shown well in our study, wherethe QTL effects were dissimilar between single (statisti-cally selected) experiments. This can be explained withthe different aggressiveness of the isolates and with thephenomena that the phenotypic difference of genotypes inthe experiments can be variable, which variation can bebalanced by using mean values of different good qualitydatasets with normal distribution.

QTL linked to heading date

For date of anthesis, Steiner et al. (2004) identified aQTL on 2D, in the same region we detected a QTLfor heading date (Xs25m19_16-Xgwm608). This regionwas mentioned by other research groups as a FHB resis-tance coding interval of ‘Frontana’ (Mardi et al., 2005;

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Fusarium head blight resistance in wheat 237

Yang et al., 2005), but our data do not support this view.However, when the population has a long flowering time(10–14 days), changing weather conditions can cause dif-ferences between FHB levels of early or late genotypesand may result in phenotyping errors.

The QTL associated with heading date onchromosomes 1A, 2D and 7B did not overlap withany Fusarium resistance QTL in spite of the significantcorrelation between the resistance data and the headingdate. This confirms the accuracy of the phenotypingmethod used, as it did not cause false QTL detection.

Regarding the Fusarium resistance QTL originatingfrom ‘Frontana’, the data mostly supported the findings ofSteiner et al. (2004). However, with the Hungarian pheno-typic data, the presence of QTL on 1B, 2A and 3B derivedfrom ‘Remus’ could not be detected. We concluded there-fore that those QTL appeared less stable, and could not bevalidated from the same population under different envi-ronmental conditions. The presence of the 1A and 7AFusarium resistance QTL of Mardi et al. (2006) could notbe confirmed in our mapping population either.

The comparison of the two phenotyping systems ofthe ‘Frontana/Remus’ population resulted in small differ-ences in the QTL estimates, indicating that both method-ologies (used in Tulln or in Szeged) appear to be usefulfor Fusarium resistance testing and QTL mapping.

Our results indicate the importance of selection not onlyfor FHB, but also for FDK resistance, as we found differ-ent genetic backgrounds responsible for the two traits insome cases. It is clear that Fusarium resistance is reg-ulated not only by one or two genes but also by theinteraction of several small and moderately effective QTL,which can be associated with other plant morphologicaltraits or environmental factors. It is also important thatthe phenotypic screening that works well is more effec-tive than MAS alone (Wilde et al., 2007) and it will beso in the foreseeable future. The recommended way forFusarium resistance breeding is to identify and build upthe necessary QTL in the parent lines and identify them inthe phenotypically selected advanced progenies.

Acknowledgements

This work was supported by the DEAK Co. Ltd.,EU-funded FP5 Project FUCOMYR and FP7 projectMYCORED.

References

ANDERSON, J.A., STACK, R.W., LIU, S., WALDRON, B.L., FJELD, A.D.,COYNE, C., et al. (2001). DNA markers for fusarium head blightresistance QTLs in two wheat populations. Theor. Appl. Genet., 102,1164–1168.

BAI, G.H., & SHANER, G.E. (1994). Scab of wheat: prospects for control.Plant Dis., 78, 760–766.

BERZONSKY, W.A., GEBHARD, B.L., GAMOTIN, E., LEACH, G.D., &ALI, S. (2007). A reciprocal backcross monosomic analysis of the scabresistant spring wheat (Triticum aestivum L.) cultivar, ‘Frontana’. PlantBreed., 126, 234–239.

BROWN-GUEDIRA, G., GRIFFEY, C., KOLB, F., MCKENDRY, A.,MURPHY, J.P., & VAN SANFORD, D. (2008). Breeding Fhb-resistantsoft winter wheat: progress and prospects. Cereal Res. Commun., 36,Supplementum B, 31–35.

BUERSTMAYR, H., LEMMENS, M., HARTL, L., DOLDI, L., STEINER, B.,STIERSCHNEIDER, M., & RUCKENBAUER, P. (2002). Molecular map-ping of QTLs for fusarium head blight resistance in spring wheat. I.Resistance to fungal spread (type II resistance). Theor. Appl. Genet., 104,84–91.

BUERSTMAYR, H., STEINER, B., HARTL, L., GRIESSER, M., ANGERER,N., LENGAUER, D., et al. (2003). Molecular mapping of QTLs forfusarium head blight resistance in spring wheat. II. Resistance to fungalpenetration and spread. Theor. Appl. Genet., 107, 503–508.

BUERSTMAYR, H., BAN, T., & ANDERSON, J.A. (2009). QTL mapping andmarker-assisted selection for fusarium head blight resistance in wheat: areview. Plant Breed., 128, 1–26.

BURLAKOTI, R.R., MERGOUM, M., KIANIAN, S.F., & ADHIKARI, T.B.(2010). Combining different resistance components enhances resistanceto fusarium head blight in spring wheat. Euphytica, 172, 197–205.

CHEN, X.F., FARIS, J.D., HU, J.G., STACK, R.W., ADHIKARI, T., ELIAS,E.M., et al. (2007). Saturation and comparative mapping of a majorfusarium head blight resistance QTL in tetraploid wheat. Mol. Breed., 19,113–124.

CUTHBERT, P.A., SOMERS, D.J., THOMAS, J., CLOUTIER, S., & BRULE-BABEL, A. (2006). Fine mapping Fhb1, a major gene controlling fusariumhead blight resistance in bread wheat (Triticum aestivum L.). Theor. Appl.Genet., 112, 1465–1472.

DRAEGER, R., GOSMAN, N., STEED, A., CHANDLER, E., THOMSETT,M., SRINIVASACHARY, et al. (2007). Identification of QTLs for resis-tance to fusarium head blight, DON accumulation and associatedtraits in the winter wheat variety Arina. Theor. Appl. Genet., 115,617–625.

GERVAIS, L., DEDRYVER, F., MORLAIS, J.Y., BODUSSEAU, V., NEGRE,S., BILOUS, M., et al. (2003). Mapping of quantitative trait loci for fieldresistance to fusarium head blight in a European winter wheat. Theor.Appl. Genet., 106, 961–970.

GUPTA, P.K., LANGRIDGE, P., & MIR, R.R. (2010). Marker-assistedwheat breeding: present status and future possibilities. Mol. Breed., 26,145–161.

KLAHR, A., ZIMMERMANN, G., WENZEL, G., & MOHLER, V. (2007).Effects of environment, disease progress, plant height and heading date onthe detection of QTLs for resistance to fusarium head blight in a Europeanwinter wheat cross. Euphytica, 154, 17–28.

KOSOVÁ, K., CHRPOVÁ, J., & ŠÍP, V. (2009). Cereal resistance to fusariumhead blight and possibilities of its improvement through breeding. CzechJ. Genet Plant Breed.,45, 87–105.

LEHOCZKI-KRSJAK, S., SZABO-HEVER, A., TOTH, B., KOTAI, C.,BARTOK, T., VARGA, M., et al. (2010). Prevention of Fusarium myco-toxin contamination by breeding and fungicide application to wheat.Food Addit. Contam. Part a-Chemistry Analysis Control Exposure & RiskAssessment, 27, 616–628.

LEMMENS, M., SCHOLZ, U., BERTHILLER, F., DALL’ASTA, C., KOUTNIK,A., SCHUHMACHER, R., et al. (2005). The ability to detoxify the myco-toxin deoxynivalenol colocalizes with a major quantitative trait locus forfusarium head blight resistance in wheat. Mol. Plant-Microbe Inter., 18,1318–1324.

LIU, S., ABATE, Z.A., LU, H., MUSKET, T., DAVIS, G.L., & MCKENDRY,A.L. (2007). QTL associated with fusarium head blight resistance in thesoft red winter wheat Ernie. Theor. Appl. Genet., 115, 417–427.

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013

Á. Szabó-Hevér et al. 238

LÖFFLER, M., SCHON, C.C., & MIEDANER, T. (2009). Revealing thegenetic architecture of FHB resistance in hexaploid wheat (Triticumaestivum L.) by QTL meta-analysis. Mol. Breed., 23, 473–488.

LU, Q.X., SZABO-HEVER, A., BJØRNSTAD, Å., LILLEMO, M., SEMAGN,K., MESTERHAZY, A., et al. (2011). Two major resistance QTL arerequired to counteract the increased susceptibility to Fusarium head blightat the Rht-D1b gene in wheat. Crop Sci., 51, 2430–2438.

MARDI, M., BUERSTMAYR, H., GHAREYAZIE, B., LEMMENS, M.,MOHAMMADI, S.A., NOLZ, R., & RUCKENBAUER, P. (2005). QTL anal-ysis of resistance to fusarium head blight in wheat using a ‘Wangshuibai’-derived population. Plant Breed., 124, 329–333.

MARDI, M., PAZOUKI, L., DELAVAR, H., KAZEMI, M.B., GHAREYAZIE,B., STEINER, B., et al. (2006). QTL analysis of resistance to fusariumhead blight in wheat using a ‘Frontana’-derived population. Plant Breed.,125, 313–317.

MCCARTNEY, C.A., SOMERS, D.J., FEDAK, G., & CAO, W. (2004).Haplotype diversity at fusarium head blight resistance QTLs in wheat.Theor. Appl. Genet., 109, 261–271.

MCMULLEN, M., JONES, R., & GALLENBERG, D. (1997). Scab of wheatand barley: a re-emerging disease of devastating impact. Plant Dis., 81,1340–1348.

MESTERHÁZY, Á. (1977). Reaction of winter wheat varieties to fourFusarium species. Phytopathol. Z., 90, 104–112.

MESTERHÁZY, A. (1985). Effect of seed production area on the seedlingresistance of wheat to fusarium seedling blight. Agronomie, 5, 491–497.

MESTERHÁZY, A. (1987). Selection of head blight resistant wheats throughimproved seedling resistance. Plant Breed., 98, 25–36.

MESTERHÁZY, A. (1995). Types and components of resistance to fusariumhead blight of wheat. Plant Breed., 114, 377–386.

MESTERHÁZY, A. (2002). Role of deoxynivalenol in aggressiveness ofFusarium graminearum and F. culmorum and in resistance to fusariumhead blight. Eur. J. Plant Pathol., 108, 675–684.

MIEDANER, T., MOLDOVAN, M., & ITTU, M. (2003). Comparison of sprayand point inoculation to assess resistance to fusarium head blight in amultienvironment wheat trial. Phytopathology, 93, 1068–1072.

NYQUIST, W.E. (1991). Estimation of heritability and prediction ofselection response in plant-populations. Crit. Rev. Plant Sci., 10,235–322.

PAILLARD, S., SCHNURBUSCH, T., TIWARI, R., MESSMER, M.,WINZELER, M., KELLER, B., & SCHACHERMAYR, G. (2004). QTL anal-ysis of resistance to fusarium head blight in Swiss winter wheat (Triticumaestivum L.). Theor. Appl. Genet., 109, 323–332.

PARRY, D.W., JENKINSON, P., & MCLEOD, L. (1995). Fusarium ear blight(scab) in small grain cereals – a review. Plant Pathol., 44, 207–238.

RÖDER, M.S., KORZUN, V., WENDEHAKE, K., PLASCHKE, J., TIXIER,M.H., LEROY, P., & GANAL, M.W. (1998). A microsatellite map ofwheat. Genetics, 149, 2007–2023.

ROGERS, S.O., & BENDICH, A.J. (1985). Extraction of DNA from mil-ligram amounts of fresh, herbarium and mummified plant-tissues. PlantMol. Biol., 5, 69–76.

SALAMEH, A., BUERSTMAYR, M., STEINER, B., NEUMAYER, A.,LEMMENS, M., & BUERSTMAYR, H. (2010). Effects of introgressionof two QTL for fusarium head blight resistance from Asian springwheat by marker-assisted backcrossing into European winter wheat onfusarium head blight resistance, yield and quality traits. Mol. Breed., 28,485–494.

SCHMOLKE, M., ZIMMERMANN, G., BUERSTMAYR, H., SCHWEIZER, G.,MIEDANER, T., KORZUN, V., & HARTL, L. (2005). Molecular map-ping of fusarium head blight resistance in the winter wheat populationDream/Lynx. Theor. Appl. Genet., 111, 747–756.

SCHROEDER, H.W., & CHRISTENSEN, J.J. (1963). Factors affecting resis-tance of wheat to scab caused by Gibberella zeae. Phytopathology, 53,831–838.

SEMAGN, K., SKINNES, H., BJORNSTAD, A., MAROY, A.G., &TARKEGNE, Y. (2007). Quantitative trait loci controlling fusarium head

blight resistance and low deoxynivalenol content in hexaploid wheatpopulation from ‘Arina’ and NK93604. Crop Sci., 47, 294–303.

SHEN, X., ZHOU, M., LU, W., & OHM, H. (2003). Detection of fusariumhead blight resistance QTL in a wheat population using bulked segregantanalysis. Theor. Appl. Genet., 106, 1041–1047.

SINGH, R.P., MA, H., & RAJARAM, S. (1995). Genetic-analysis ofresistance to scab in spring wheat cultivar Frontana. Plant Dis., 79,238–240.

SOMERS, D.J., FEDAK, G., & SAVARD, M. (2003). Molecular mappingof novel genes controlling fusarium head blight resistance and deoxyni-valenol accumulation in spring wheat. Genome, 46, 555–564.

SOMERS, D.J., ISAAC, P., & EDWARDS, K. (2004). A high-densitymicrosatellite consensus map for bread wheat (Triticum aestivum L.).Theor. Appl. Genet., 109, 1105–1114.

SOMERS, D.J., FEDAK, G., CLARKE, J., & CAO, W.G. (2006). Mapping ofFHB resistance QTLs in tetraploid wheat. Genome, 49, 1586–1593.

SRINIVASACHARY, GOSMAN, N., STEED, A., FAURE, S., BAYLES, R.,JENNINGS, P., & NICHOLSON, P. (2008). Mapping of QTL associatedwith fusarium head blight in spring wheat RL4137. Czech J. Genet. Plant,44, 147–159.

STEINER, B., LEMMENS, M., GRIESSER, M., SCHOLZ, U.,SCHONDELMAIER, J., & BUERSTMAYR, H. (2004). Molecular map-ping of resistance to fusarium head blight in the spring wheat cultivarFrontana. Theor. Appl. Genet., 109, 215–224.

SZABO-HEVER, A., TOTH, B., LEHOCZKI-KRSJAK, S., & MESTERHAZY,A. (2008). Mapping of FHB resistance QTLs in the Mini Mano/Frontanaand Frontana/Remus DH populations. Cereal Res. Commun., 36,Supplement. B, 271–275.

VAN GINKEL, M., VANDERSCHAAR, W., YANG, Z.P., & RAJARAM, S.(1996). Inheritance of resistance to scab in two wheat cultivars fromBrazil and China. Plant Dis., 80, 863–867.

VAN OOIJEN, J.W. (2004). MapQTL Version 5: Software for the mappingof quantitative trait loci in experimental populations. Wageningen: PlantResearch International. 57 pages.

VAN OOIJEN, J.W., & VOORRIPS, R.E. (2001). JoinMap Version 3.0:Software for the calculation of genetic linkage maps. Wageningen: PlantResearch International. 51 pages.

VON DER OHE, C., EBMEYER, E., KORZUN, V., & MIEDANER, T. (2010).Agronomic and quality performance of winter wheat backcross popula-tions carrying non-adapted fusarium head blight resistance QTL. CropSci., 50, 2283–2290.

WALDRON, B.L., MORENO-SEVILLA, B., ANDERSON, J.A., STACK, R.W.,& FROHBERG, R.C. (1999). RFLP mapping of QTL for fusarium headblight resistance in wheat. Crop Sci., 39, 805–811.

WEBER, E. (1972). Grundriss der biologischen Statistik. Jena: VEB GustavFischer Verlag. 706 pages.

WILDE, F., KORZUN, V., EBMEYER, E., GEIGER, H.H., & MIEDANER,T. (2007). Comparison of phenotypic and marker-based selection forfusarium head blight resistance and DON content in spring wheat. Mol.Breed., 19, 357–370.

YANG, Z.P., GILBERT, J., SOMERS, D.J., FEDAK, G., PROCUNIER, J.D.,& MCKENZIE, I.H. (2003). Marker assisted selection of fusarium headblight resistance genes in two doubled haploid populations of wheat. Mol.Breed., 12, 309–317.

YANG, Z.P., GILBERT, J., FEDAK, G., & SOMERS, D.J. (2005). Geneticcharacterization of QTL associated with resistance to fusarium headblight in a doubled-haploid spring wheat population. Genome, 48,187–196.

YANG, Z.P., GILBERT, J., & PROCUNIER, J.D. (2006). Genetic diversity ofresistance genes controlling fusarium head blight with simple sequencerepeat markers in thirty-six wheat accessions from east Asian origin.Euphytica, 148, 345–352.

YU, J.B., BAI, G.H., CAI, S.B., & BAN, T. (2006). Marker-assisted char-acterization of Asian wheat lines for resistance to fusarium head blight.Theor. Appl. Genet., 113, 308–320.

Dow

nloa

ded

by [

Á. M

este

rház

y] a

t 06:

51 0

9 Ju

ly 2

013