ABSTRACT 
 
 
 
 
Title of Document: SCAB RESISTANCE QTLS ARE 
ASSOCIATED WITH QUALITY AND 
AGRONOMIC TRAITS OF SOFT RED 
WINTER WHEAT   
  
 Lydia Ann Cardwell, Master of Science, 2011 
  
Directed By: Associate Professor, Jos? Costa, Plant Science & 
Landscape Architecture 
 
 
 
Fusarium head blight (FHB) is a devastating fungal disease affecting Triticum 
aestivum crops worldwide. While many quantitative trait loci (QTL) responsible for 
FHB resistance have been reported, some widely used sources are from exotic 
cultivars that may carry undesirable alleles linked with resistance. Ning_7840, a 
Chinese hard red spring wheat, contains a major FHB QTL on the 3BS chromosome, 
along with two minor QTL on the 5A and 2DL chromosomes. Ning_7840 was 
crossed with Pioneer_2643, a soft red winter wheat, to create 86 recombinant inbred 
lines. The effect of the Ning_7840 alleles on agronomic traits and milling and baking 
quality traits was examined over three growing seasons in Maryland. While the 3BS 
QTL was not associated negatively with other traits, the 2DL and 5A QTL were. This 
suggests the introduction of FHB resistance QTL on 5A and 2DL into soft red winter 
wheat may negatively affect agronomic and quality traits. 
  
 
 
 
 
 
 
 
 
 
 
SCAB RESISTANCE QTLS ARE ASSOCIATED WITH QUALITY AND 
AGRONOMIC TRAITS OF SOFT RED WINTER WHEAT.    
 
 
 
By 
 
 
Lydia Ann Cardwell 
 
 
 
 
 
Thesis submitted to the Faculty of the Graduate School of the  
University of Maryland, College Park, in partial fulfillment 
of the requirements for the degree of 
Master of Science 
2011 
 
 
 
 
 
 
 
 
 
 
 
 
 
Advisory Committee: 
Dr. Jos? Costa, Chair 
Dr. Robert Kratochvil 
Dr. William Kenworthy 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
? Copyright by 
Lydia Ann Cardwell 
2011 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ii 
 
Acknowledgements 
 I would like to show my gratitude toward my advisor, thesis committee, 
family, and friends. I would not have been able to complete this thesis without their 
help and support. I would like to thank my advisor, Dr. Jos? Costa, for his help and 
guidance along this entire undertaking. Without his support, this thesis would not 
have been possible. I would also like to express gratitude to Dr. William Kenworthy 
and Dr. Robert Kratochvil, my committee members for their assistance. Much 
appreciation goes to our collaborators, Dr. Gina Brown-Guedira, Dr. Yanhong Dong, 
and Ed Souza for their contributions. I would also like to thank everyone who worked 
with me in the lab and field. And last, but certainly not least, I would like to express 
my gratitude to my family and friends, who gave me their love and support 
throughout this entire process and who were there for me each step of the way.   
 
 iii 
 
Table of Contents 
 
Acknowledgements ....................................................................................................... ii 
 
Table of Contents ......................................................................................................... iii 
 
List of Tables ................................................................................................................ v 
 
Chapter 1: Literature Review ........................................................................................ 1 
Fusarium Head Blight ............................................................................................... 1 
Epidemiology of FHB in wheat ............................................................................ 2 
Symptoms ............................................................................................................. 3 
Effect ..................................................................................................................... 3 
Control .................................................................................................................. 3 
Wheat Genome.......................................................................................................... 5 
Quantitative Trait Loci (QTL) .............................................................................. 5 
Sources of Resistance ........................................................................................... 5 
Genetic Markers .................................................................................................... 6 
Simple Sequence Repeat Markers (SSRs) ............................................................ 7 
Wheat Classes ....................................................................................................... 7 
Agronomic traits ....................................................................................................... 8 
Test weight ............................................................................................................ 8 
Plant Height .......................................................................................................... 8 
Heading date ......................................................................................................... 9 
Grain Yield............................................................................................................ 9 
Milling and Baking Quality Traits ............................................................................ 9 
Flour yield ........................................................................................................... 10 
Flour protein........................................................................................................ 10 
Softness equivalent ............................................................................................. 10 
Solvent Retention Capacity................................................................................. 11 
Interclass hybridization ........................................................................................... 12 
 
Chapter 2: Scab Resistance QTL are Associated with Agronomic Traits of Soft Red 
Winter Wheat .............................................................................................................. 13 
Introduction ............................................................................................................. 13 
Materials and Methods ............................................................................................ 15 
Plant Materials .................................................................................................... 15 
Marker Analysis with SSR markers .................................................................... 16 
Statistical Analyses ............................................................................................. 17 
Results ..................................................................................................................... 21 
3BS QTL ............................................................................................................. 21 
2DL QTL ............................................................................................................ 21 
5A QTL ............................................................................................................... 21 
Discussion ............................................................................................................... 21 
 
 iv 
 
Conclusions ............................................................................................................. 23 
 
Chapter 3: Scab Resistance QTL are Associated with Quality Traits of Soft Red 
Winter Wheat .............................................................................................................. 24 
Introduction ............................................................................................................. 24 
Materials and Methods ............................................................................................ 26 
Plant Materials .................................................................................................... 26 
Marker Analysis with SSR markers .................................................................... 26 
Statistical Analyses ............................................................................................. 27 
Results ..................................................................................................................... 30 
3BS ...................................................................................................................... 30 
2DL ..................................................................................................................... 30 
5A ........................................................................................................................ 30 
Discussion ............................................................................................................... 30 
Conclusion .............................................................................................................. 32 
 
References ................................................................................................................... 33 
 
 
 
 
 v 
 
List of Tables 
Table 1. Size (in base pairs) of SSR marker fragments derived from Ning 7840 and 
Pioneer 2643. .............................................................................................................. 19 
Table 2. Mean values of agronomic traits for each FHB QTL. .................................. 20 
Table 3. Means of milling and baking quality traits measured on wheat harvested. .. 29 
 
 
 1 
 
Chapter 1: Literature Review 
 
Fusarium Head Blight 
 
 Fusarium head blight (FHB) is a devastating fungal disease which occurs in 
cereals, including wheat (Triticum aestivum), barley (Hordeum vulgare), oats (Avena 
sativa) and sorghum (Sorghum bicolor). In wheat it is also known as scab, Fusarium 
blight, ear blight, tombstone scab, pink mold, and white heads. Fusarium head blight 
occurs throughout the world wherever wheat is grown (Sutton 1982). It was first 
noted in England in 1884 by W.G. Smith, and in 1891 it was reported in the United 
States by Arthur and Chester, independently. FHB causes economic losses and grain 
contamination. Between 1991 and 1996, scab caused yield losses estimated at 378 
million bushels to wheat growers in the United States (McMullen et al. 1997). 
Fusarium Head Blight is caused by a number of species in the genus Fusarium, 
including Fusarium graminearum, teleomorph (Giberella zeae), F. acuminatum, F. 
avenaceum, (teleomorph G. avenacea), F. crookwellense, F. culmorum, F. nivale 
(syn. Michrodochium nivale; teleomorph Monographella nivalis, syn. Calonectria 
nivalis), F. equiseti, F. moniliforme, F. oxysporum, F. poae, F. proliferatum, F. 
pallidoroseum (syn. F. semitectum), F. sambucinum, F. sporotrichiodes, F. 
subglutinans, and F. tricinctum. The leading causal species in North America is 
Fusarium graminearum Schwabe (teleomorph Giberella zeae), while other 
geographic areas have reported different leading causal fungi (Sutton 1982; Parry et 
al. 1995; McMullen et al. 1997). 
 
 2 
 
 
Epidemiology of FHB in wheat 
 
 Giberella zeae is a homothallic ascomycete capable of outcrossing. 
Throughout corn growing regions of the United States, corn debris provides the major 
source of inoculum (Sutton 1982). Crop residue may contain mycelia and 
perithecium, while mycelia and spores can overwinter on seed (Khonga and Sutton 
1988; Fernandez and Fernandes 1990). The primary inoculum is found in the form of  
airborne ascospores produced by perithecia and macroconidia produced by mycelia. 
Rainfall is needed for the maturation of the ascospores and conidia, but it is not 
needed for dispersal (Paulitz 1996). The ascospores are released due to hydrostatic 
pressure from increased humidity and are ejected onto the heads of wheat growing in 
the field. Maximal discharge occurs 6-9 days after the production of perithecia and 
coincides with high relative humidity. The optimal temperature for infection varies 
depending on the individual species. Optimal F. graminearum development occurs 
around 26.5?C (Anderson 1948; Tschanz et al. 1976). Most infection occurs during 
anthesis, with hyphae penetrating the ovaries, glumes, palea, and lemma (Pugh et al. 
1933; Pritsch et al. 2000; Wanyoike et al. 2002; Bushnell et al. 2003). The presence 
of anthers may prevent infection, but has also been reported to promote growth of the 
pathogen by providing more tissue for the fungus to colonize (Sutton 1982). Once 
infected, perithecia and mycelia are produced and spread up and down the head (Pugh 
et al. 1933; Parry et al. 1995). Seed which has become infected will show the 
characteristic blight symptoms of FHB. 
 
 
 3 
 
Symptoms 
 Infection of FHB occurs in the flowers and spreads throughout the head. The 
symptoms are readily apparent prior to senescence. Beginning at the base of the 
spreading upwards the spikelet becomes bleached. Pink mycelia or black perithecia 
may grow on the diseased spikelet. Severely infected heads may be short and dwarfed 
with closed spikelets. Diseased kernels become shriveled and bleached or pink, 
weighing much less than healthy kernels (Parry et al. 1995; McMullen et al. 1997).  
 
Effect 
 Fusarium head blight causes kernel damage, yield loss, and mycotoxin 
contamination. Between  1991 and 1996, FHB caused yield losses estimated at 378 
million bushels to wheat growers in the United States. Infected kernels may become 
shriveled, bleached, and contaminated with dangerous mycotoxins. These mycotoxins 
include tricothecenes (deoxynivalenol) and estrogenic mycotoxins (zearalenone) 
(Neish and Cohen 1981; Desjardins and Proctor 2007). Deoxynivalenol (DON) is a 
protein biosynthesis inhibitor. Zearalenone (ZEA) is the primary estrogenic 
mycotoxin responsible for infertility and breeding problems in swine (Forsyth et al. 
1977; Vesonder and Hesseltine 1981). 
 
Control 
 There is no single method of control which is completely effective, so a 
variety of management methods is necessary (Bai and Shaner 1994; McMullen et al. 
2008). Management methods include fungicides, resistant cultivars, and biocontrol. 
The cultural practices of tillage and avoiding crop rotations of corn (Zea mays) before 
 
 4 
 
wheat are suggested methods for controlling inoculum source and spread (Dill-Macky 
and Jones 2000). In Maryland a corn-wheat-soybean (Glycine max) rotation is 
popular, as it allows three crops, instead of two, to be grown in two years. No-till 
methods of planting these crops have become more popular in recent years, as they 
keep the soil intact and prevent erosion and run-off. Unfortunately, no-till methods 
may leave corn and wheat residue behind, providing a habitat for the fungus to 
overwinter. While research has been done which shows promise concerning 
biocontrol methods to combat FHB, no method has yet been produced commercially 
(Leonard and Bushnell 2003). 
 Triazole fungicides are effective against FHB. These fungicides work by 
inhibiting C14-demethylase, a chemical that functions in the production of sterols, 
which are necessary in the proper development of cell walls in the fungus. Triazoles 
currently approved by the Environmental Protection Agency (EPA) are 
prothioconazole, metconazole, and tebuconazole (McMullen et al. 2008). These are 
available in Proline (prothioconazole), Caramba (metconazole), Folicur 
(tebuconazole), Prosar-o (prothioconazole + tebuconazole), as well as other 
commercial forms. Fungicides must be applied just before infection or during early 
infection in order to be most effective. The recommended application time for Proline 
is at 50% flowering (Feekes growth stage 10.5.2). All of the triazoles have pre-
harvest application restrictions of 30 days. 
 
 
 
 5 
 
Wheat Genome 
 
 Wheat has a complex genome. It is comprised of over 16,000 Mb, 80% of 
which is redundant. It is a hexaploid which behaves as a diploid (2n=6x=42). Because 
of this complexity, less is known about the wheat genome as a whole when compared 
to other plant species' genomes. The wheat genome is comprised of three diploid 
genomes- designated as A, B, and D (Smith 1995). 
 
Quantitative Trait Loci (QTL) 
 Genetic resistance to FHB is one of the strongest methods of control at 
present, although no cultivar exists which is 100% resistant.  FHB resistance presents 
itself as a quantitative trait. The term quantitative trait locus refers to an area of a 
genome associated with a continuous trait- one that varies in degrees of expression, as 
opposed to Mendelian traits, which are qualitative. Zhou et al. (2003) showed the 
distribution of the percentage of scabbed spikelets of an F2 population derived from a 
cross between an FHB resistant cultivar, Ning7840, and a susceptible cultivar, 
Wheaton, showed a normal distribution. 
 
Sources of Resistance 
 A number of quantitative trait loci (QTL) have been identified which provide 
resistance to FHB. Three widely used QTL have been identified from the cultivar 
Sumai 3. They are located on the 3BS, 5A, and 2DL chromosomes (Gupta et al. 2000; 
Mardi et al. 2005). Anderson et al. (2001) found that the QTL located on 3BS was 
responsible for 41.6% of the FHB resistance in Sumai 3. They also showed that the 
 
 6 
 
3BS QTL was responsible for resistance to fungal spread, while the 5A QTL 
controlled initial fungal infection. Sumai 3 is a widely used source of resistance with 
many derived lines being used in wheat breeding programs (Liu 1984; Wilcoxson 
1993). One of those derived lines is Ning 7840, a Chinese hard red spring wheat. 
Ning 7840 contains all three of the FHB resistance QTL from Sumai 3 (Buerstmayr et 
al. 2009). 
 
Genetic Markers 
 Genetic markers have been extremely useful in wheat breeding. Using 
traditional breeding methods to select traits in wheat breeding requires a lot of time 
and resources. Wheat goes through one growth cycle each year. It is costly to grow 
many different breeding lines only to select a few to advance to the next generation. 
Using markers, it is possible to screen many lines quickly. This is done by sowing 
many seeds (obtained from different breeding lines) in trays and performing DNA 
testing on the leaves to select which lines to advance. Markers make it possible to 
detect differences in DNA between cultivars that otherwise may or may not be 
visible. Phenotypic markers are physical differences in the organism that correspond 
to the underlying responsible DNA. Molecular markers, on the other hand, have the 
ability to detect DNA differences between organisms which are not phenotypically 
expressed or easily identifiable. Phenotypic evaluation requires time and resources 
that could be conserved using genetic marker assessment techniques (Bai and Shaner 
1994, Rudd et al. 2001). There are a number of different marker associated techniques 
available in wheat breeding, including single nucleotide polymorphisms (SNPs), 
 
 7 
 
restriction fragment length polymorphism (RFLPs), simple sequence repeats (SSRs), 
and diversity arrays technology (DArTs).  
 
Simple Sequence Repeat Markers (SSRs) 
 Simple sequence repeats (SSRs), or microsatellites, are a type of genetic 
marker comprised of sequences of repeating DNA base pairs. The number of times 
the sequence is repeated may vary between alleles. This characteristic makes it 
possible to determine which parent supplied the SSR. Using SSRs located near the 
significant QTL makes it possible to determine whether or not the QTL has been 
passed on to the progeny. SSR markers developed for wheat (Song et al. 2005, Kolb 
et al. 2001) have previously been used successfully for FHB resistance breeding. 
 
Wheat Classes 
 The USDA recognizes six distinct classes of wheat: durum, soft white, hard 
white winter, hard red winter, hard red spring, and soft red winter (Wheat Foods 
Council 2010). Wheat from each class is suited to a different end use or uses. Hard 
red spring wheat, named for its hard endosperm, red bran color, and its growing 
season, is used primarily for bread, due to its high protein and strong gluten. On the 
other hand, soft red winter wheat, which has a soft endosperm, red bran, and requisite 
vernalization in order to express its reproductive growth stages, is used for making 
products that require low protein content, such as cookies, pretzels, and crackers. The 
end uses for the flour from different classes of wheat often result in the different 
classes of wheat having very different ideal traits. Even within a class, two cultivars 
 
 8 
 
may have different end uses. For example, gluten quality is a determinant in whether 
a particular soft red winter wheat may be used for pastries or crackers. Crackers need 
strong gluten, while pastries use flour with weak gluten. (Wheat Foods Council 2010) 
 
Agronomic traits 
Test weight 
 Test weight is correlated with milling quality (Schuler et al. 1995). It is 
measured in pounds per bushel in the United States. Lower test weight may indicate 
shriveled or sprouted kernels. However, according to the US grading system for 
wheat, hard red spring wheat must be at least 58 pounds per bushel to meet grade 1, 
while soft red spring must be at least 60 lbs per bushel. This is because hard red 
spring wheat tends to have lower test weight than most of the other classes.  
 
Plant Height 
 Some traits are advantageous to all classes. For instance, height is a very 
important trait for wheat breeders. Shorter plants typically results in less lodging. 
Lodging, or the plants falling over, can be the result of either plants that are too tall or 
as frequently is the case, it can occur when too much nitrogen is supplied to the crop 
It is often exacerbated when heavy rains or winds occur. It ultimately results in 
lowered yield because it is much hard to harvest wheat with a combine when its heads 
are inches off the ground. Wheat cultivars used to be much taller than they are today. 
This is because Norman Borlaug, during the mid-twentieth century, developed semi-
dwarf wheat cultivars. Because of the increased yield from his research and its global 
 
 9 
 
impact, Dr. Borlaug is credited with saving over a billion lives worldwide 
(Easterbrook 1997). 
 
Heading date 
 Heading date is another important trait, which may vary widely between 
classes of wheat. Flowering is controlled by vernalization, photoperiod, and earliness 
per se genes (Lewis et al. 2008).  Spring wheat usually heads much earlier from the 
date of planting, because it does not undergo vernalization. Winter wheat must be 
planted before the winter, but is not harvested until the late spring. Earlier harvesting 
in winter wheat is a helpful trait, however, since many farmers follow winter wheat 
with soybeans. 
 
Grain Yield 
 Grain yield may vary greatly depending upon genetics and environment. 
Environmental conditions which may affect yield include local conditions where the 
wheat was planted, due soil and water conditions (Major et al. 1988, Vaughan et al. 
1990). Yield may be reduced due to pathogens, lodging, or even pests in the field, 
such as birds and deer.  
 
Milling and Baking Quality Traits 
 
 Specific quality traits used to determine the quality of soft red winter wheat 
include softness equivalent, flour yield, flour protein, water retention capacity, lactic 
acid absorption, and sucrose solvent retention capacity (SRC). 
 
 10 
 
 
Flour yield 
 Flour yield is the measurement of how much endosperm there is in the kernel 
which can be separated from the bran. It is measured as the percentage of flour per 
weight of grain milled. Larger flour yield is desired by the milling and baking 
industry and has been correlated with larger starch granules and more total starch 
(Gaines et al. 2000). 
 
Flour protein 
 Flour protein relates to the rheological properties of dough (Uthayakumaran et 
al. 1999). Soft red winter wheat has low flour protein, allowing dough to absorb less 
water. This creates a softer dough more suitable for cookies or pastries. Hard wheat, 
on the other hand, has higher amounts of protein in the flour, which lends itself to 
bread making (Smith 1995). There are four different types of protein found in kernels 
of the Triticeae tribe. They are albumins, globulins, prolamins, and glutelins (Eliasson 
and Larsson 1993). Prolamins and glutelins form glutens. In wheat, gliadin is the 
prolamin, while the glutelin is glutenin. Together, gliadin and glutenin make up the 
gluten found in wheat flour. 
 
Softness equivalent 
 Softness equivalent is determined by break-flour yield. Break-flour yield is 
the proportion of flour produced by the first break roll in the mill to the total amount 
of flour produced. It is an appropriate method for softness equivalent because it is an 
 
 11 
 
indicator of the hardness of the wheat being milled. Softer wheat produces more 
break flour. This is because harder kernels have a stronger adhesion between starch 
and protein, causing resistance to fracture (Anjum and Walker 1991). Soft kernel 
texture is associated with larger starch granules, which form a more loosely 
compacted endosperm than in harder wheat, which has less surface area for bonding 
with other endosperm components (Gaines et al. 2000). 
 
Solvent Retention Capacity 
 Solvent Retention Capacity is an influential trait with regards to the baking 
quality of flour. Higher solvent retention capacity causes flour to hold onto water 
more strongly, causing a longer baking time and a tougher end product (Guttieri et al. 
2004). Low water-holding capacity is desirable in soft wheat flour (Faridi et al. 1994). 
Solvent retention capacity is measured in water retention capacity, lactic acid SRC, 
sucrose SRC, and sodium carbonate SRC (Bettge et al. 2002). Water retention 
capacity is a measure of the overall solvent retention capacity. Sodium carbonate 
SRC is determined by the amount of damaged starch created during the milling 
process. Good quality soft red winter wheat is low in damaged starch. Sucrose SRC is 
determined by the amount of gliadin and pentosan in the flour. Lactic acid absorption 
is a predictor of soft wheat flour gluten strength. Lactic acid absorption is important 
to know in order to determine the proper end use of the flour, as it is associated with 
glutenin characteristics (Slade and Levine 1994, Gaines 2000). Both cookies and 
crackers are made from soft wheat, but crackers require a strong gluten, while the best 
cookies are made from flour with weaker gluten. 
 
 12 
 
Interclass hybridization 
 
 Many FHB resistance breeding programs rely on interclass hybridization. The 
new genetic combinations available may improve resistance to FHB, but the vastly 
different traits between two classes may have a negative effect on quality. In addition, 
Sumai 3 derived lines, which are commonly used, are exotic cultivars suited to a 
different environment. Agronomic as well as milling and baking quality traits may be 
affected by the introduction of FHB resistance. This could be due to the source of 
FHB resistance, linkage drag, or a combination of both. Linkage drag occurs during 
breeding when two genes are linked, but only one of them is desired. By selecting the 
desired gene in a cross, closely linked but undesired genes may also be selected 
(Brinkman and Frey 1977). 
 Campbell et al. (1999; 2001) studied milling and baking quality in a soft x 
hard wheat cross and found that only softness equivalence and damaged starch were 
affected by a single locus. Flour yield, flour protein, and water absorption were all 
quantitative traits, suggesting a more complex inheritance. Marza et al. (2006) 
evaluated agronomic traits in a cross between Ning7840 and Clark, a soft red winter 
wheat. They found QTL associated with grain yield on chromosomes 5A and 4B. 
They also discovered QTL associated with other traits which may affect grain yield, 
such as lodging, leaf rust reaction, and shattering on chromosomes 1B, 5A, and 7A. 
 
 
 13 
 
Chapter 2: Scab Resistance QTL are Associated with Agronomic 
Traits of Soft Red Winter Wheat 
 
  
Introduction 
 
 Fusarium head blight (FHB), or scab, is a widely documented and studied 
disease caused by species in the fungal genus Fusarium. FHB causes mycotoxin 
contamination, kernel damage, and yield loss. Methods of control include the use of 
fungicide, tillage, and host resistance. Sources of resistance to FHB have been 
reported from a number of wheat cultivars, including Sumai 3 (Gupta et al. 2000; 
Mardi et al. 2005). Lines derived from Sumai 3, such as Ning 7840, are widely used 
in breeding for resistance to FHB. Ning 7840 is a Chinese hard red spring wheat 
containing three FHB resistance QTL (Buerstmayr et al. 2009). These QTL are 
located on the 3BS, 2DL, and 5A chromosomes. 
 Because it carries these three QTL, Ning 7840 is often used in crosses with 
other wheat classes, such as soft red winter wheat. Soft red winter wheat is grown in 
the Eastern United States. It is characterized by its soft endosperm, red bran, and may 
require a vernalization period for onset of reproduction growth. Ning 7840 is a 
Chinese hard red spring wheat, not locally adapted to the Eastern United States, has a 
hard endosperm, and does not require vernalization. Agronomic traits also differ 
between Ning 7840 and soft red winter wheat cultivars. Ning 7840 has increased 
lodging, height, susceptibility to powdery mildew, lower test weight, and grain yield 
compared to soft red winter wheat cultivars.  
 
 14 
 
 Ohe et al. (2010) studied whether agronomic and quality traits were associated 
with the 3BS or 5A QTL in crosses of Ning 7840 with two European winter wheat 
cultivars. While they found both QTL to have positive effects on FHB resistance, 
there were only very small negative associations with yield, and no association was 
found between the FHB QTL with heading date or with plant height.  
 McCartney et al. (2007) generated three backcross populations from different 
FHB resistant parents in order to assess FHB QTL in Canadian spring wheat. One of 
the backcross populations was used to look at the three QTL derived from Sumai 3. 
While all three QTL affected FHB resistance, none of them were associated with 
plant height or anthesis date. 
 Both of these studies that found similar results evaluated FHB resistance and 
agronomic traits. However, Ohe et al. (2010) assessed hard winter wheat adapted to 
Europe, while McCartney et al. (2007) looked at hard spring wheat from Canada. 
Since the backgrounds of these cultivars differ from soft red winter wheat, FHB 
resistance and agronomic traits may also be different. 
 The purpose of this study was to assess differences in agronomic traits 
between recombinant inbred lines (RILs) with and without resistance QTL to 
determine whether the 3FHB resistance QTL from Ning 7840 had negative trait 
associations in soft red winter wheat. Traits tested were test weight, moisture content, 
height, heading, yield, powdery mildew, and lodging. Traits relating to FHB 
resistance were also measured, including scab incidence, scab severity, percentage of 
FDK, scab index, DON content, and one thousand kernel weight. The presence of the 
 
 15 
 
FHB QTL was detected using simple sequence repeat (SSR) markers on either side of 
each QTL (Song et al. 2005). 
Materials and Methods 
 
Plant Materials 
 A population of 86 wheat recombinant inbred lines was derived from a cross 
between ?Ning 7840? and ?Pioneer 2643?. Ning 7840 is a Chinese hard red spring 
wheat cultivar derived from an Aurora/Anhui 11//Sumai 3 cross. Pioneer 2643 
(Experimental Pioneer line XW522)  is a soft red winter wheat cultivar. Recombinant 
inbred lines were created by selfing each of the 86 F2 lines resulting from the cross 
by single seed descent until the F7 generation. 
 The 86 recombinant inbred lines and the parental cultivars, Ning 7840 and 
Pioneer 2643, were planted at the University of Maryland's Lower Eastern Shore 
Research and Education Center (LESREC) in Salisbury, MD in the fall of 2007, 
2008, and 2009 in 1.2 m long rows in a block design with two replications. The 
nursery was inoculated with corn infested with FHB in the early spring of each year 
and misted (Paulitz et al, 1996). In the Spring of 2008 in Salisbury, frost damage 
occurred, so the study was not used in this evaluation. In both 2009 and 2010 in 
Salisbury, height, incidence, severity, percentage of Fusarium damaged kernels 
(FDK), DON content and 1000 kernel weight (1000 W) were measured. In 2010 
powdery mildew was observed in the field, and was also scored using a 0-9 scale. 
Scab incidence was visually estimated by percentage as the amount of plants infected 
with scab. Scab severity was estimated visually by percentage by how scabby the 
heads of the infected plants were. Plant height was measured, from the soil to the top 
 
 16 
 
of the spike excluding awns, at plant maturity. Approximately ten random heads were 
selected from each row and threshed. From each sample, 200 seeds were randomly 
selected by hand, and the percent of Fusarium damaged kernels (FDK) was 
determined. The 200 seeds were then weighed and the weight was multiplied by 5 to 
convert to 1000 kernel weight. All of the threshed seeds were then sent to Yanhong 
Dong at the University of Minnesota where the DON content was determined in parts 
per million (ppm). 
  The Ning 7840 by Pioneer 2643 population was also planted at the Wye 
Research and Education Center (WREC)  in Queenstown, MD in the fall of 2007, 
2008, and 2009 in 4 m long, 7 row plots with 0.15 m spacing between rows. In 2008 
in Queenstown, moisture content, test weight, height, grain yield, lodging and 
powdery mildew were measured. Lodging and powdery mildew did not occur in 2009 
or 2010 so was not recorded in those years. In 2009, moisture content, test weight, 
height, and heading days in Julian (days from January 1) were recorded. Natural FHB 
occurred in 2009, so a sample of each RIL was harvested and tested for DON content, 
percentage of FDK, and 1000 kernel weight (as described above). In 2010, moisture 
content, test weight, and grain yield were recorded. 
 
Marker Analysis with SSR markers 
 Simple sequence repeat markers were obtained from the population, and the 
two parental lines. Seeds were germinated in the lab in trays, and 2.5cm long cuttings 
were taken from the first leaf of each plant. The leaves were then desiccated to be 
evaluated for SSR markers. The SSR marker evaluation was done by Gina Brown 
 
 17 
 
Guedira at the Raleigh (NC) USDA Genotyping Lab. A total of six SSR markers (two 
markers corresponding to each QTL) were scored on the RIL population. The 
markers used for the QTL on the 3BS chromosome were umn10 (Liu et al, 2008) and 
gwm533; for the QTL on the 2DL chromosome, cfd233 and gwm 539 were used; and 
the markers used to detect the QTL on the 5A chromosome were gwm304 and 
wmc705 (Somers et al. 2004). The distance between the markers cfd233 and gwm539 
is 12cM, while the distance between gwm304 and wmc705 is 4cM (Somers et al. 
2004). The allele size of  the SSR marker relating to each parent is shown in Table 1. 
 
Statistical Analyses 
 For each QTL, the RILs were scored according to which SSR markers were 
present. If both markers were derived from Ning 7840, the QTL was scored as A 
(QTL present). If both markers coincided with Pioneer 2643, the QTL was scored as 
B (QTL absent). If the two markers were not derived from the same parent the QTL 
was scored as either C or D (QTL presence unknown), depending on which marker 
was derived from each parent. Means for each trait were then analyzed by pairwise 
comparison between the presence or lack of the QTL. The means of the RILs with an 
unknown QTL were disregarded for the purpose of comparison. The number of RILs 
included for the pairwise comparisons of each QTL are shown in Table 1. Because it 
was expected that the presence of the FHB QTLs derived from Ning 7840 would have 
a negative impact on the RILs, a one-tailed probability was used. Pairwise 
comparisons were obtained using the LSMeans and pdiff statements in Proc GLM in 
SAS version 9.1 (SAS Institute Inc., Cary, NC). 
 
 18 
 
 
 
 
 
 
 19 
 
 
 
Table 1. Size (in base pairs) of SSR marker fragments derived from Ning 7840 and Pioneer 2643.  
 The number (n) of recombinant inbred lines of each genotype is also shown. 
 3BS  5A  2DL  
Origin of QTL umn10 gwm533 n gwm304 wmc705 n cfd233 gwm539 n 
Ning 7840 (A) 239 145 33 217 168 45 276 126 35 
Pioneer 2643 (B) 236 129 38 199 162 35 273 137 35 
Unknown (C) 239 129 0 217 162 0 276 137 8 
Unknown (D) 236 145 9 199 168 0 273 126 3 
 
 
 
 
 20 
 
 
 
Table 2. Mean values of agronomic traits for each FHB QTL.  
Scab incidence and scab severity were measured in Salisbury in 2009 and 2010. FDK, DON, and 1000 kernel weight were 
measured in Salisbury in 2009 and 2010, as well as in Queenstown in 2009. Height was measured in Salisbury in 2009 and 
2010 and in Queenstown in 2008 and 2009. Moisture content and test weight were measured in Queenstown in 2008, 2009, 
and 2010. Grain yield was measured in Queenstown in 2008 and 2010. Powdery mildew was measured in Salisbury in 2010 
and Queenstown in 2008. Lodging was recorded in Queenstown in 2008. 
QTL Inc1 Sev1 FDK1 Index1 DON 1000 W1 Height MC1 TW1 Yield1 Heading PM1 Lodging 
(+/-) (%) (%) (%)  (ppm) (g) (cm) (%) (kg/hL) (g) (Julian) (0-9) (0-9) 
3BS + 14.2 24.4* 3.2* 12.6* 1.26* 30.8 82.0 12.6 72.4 1973 122 3.6 4.2 
3BS- 16.2 31.0* 4.7* 15.9* 2.16* 30.7 86.4 12.6 72.0 1934 122 3.2 4.9 
2DL + 13.7 24.1 3.1 12.4 1.36* 29.2* 88.7 12.6 72.7 1836* 124 3.4 4.6 
2DL - 16.7 26.6 3.9 14.4 2.05* 32.1* 88.1 12.7 72.3 2090* 124 2.9 5.1 
5A + 13.7 26.5 3.6 13.11 1.69 30.0* 86.9 12.6 72.2 1833* 123 3.4 5.6* 
5A - 15.6 28.2 4.1 14.6 1.89 31.9* 86.1 12.6 72.6 1982* 122 3.9 4.2* 
Ning  
7840 7.4* 19.2* 1.1* 8.4* 0.27* 27.4* 81.8* 12.6 73.6 1576* 119 5.1* 8.0 
Pioneer  
2643 26.5* 32.7* 5.8* 20.0* 2.32* 34.9* 73.6* 13.1 74.1 2635* 122 2.7* 3.0 
 *Mean values significantly different at p=0.05 
 1. Inc= percentage of scab incidence, Sev= percentage of scab severity, FDK= percentage of fusarium damaged kernels, 1000W = weight 
 of one thousand kernels, MC= moisture content, TW= test weight, Yield= grain yield per plot, PM = powdery mildew 
 
 21 
 
Results 
 
3BS QTL 
 The presence of the 3BS QTL was associated positively with most of the FHB 
resistance traits (Table 2). Scab severity, percentage of FDK, index, and DON content 
were significantly lower in the RILs containing the 3BS QTL compared to the RILs 
without the 3BS QTL. None of the other traits were associated with the 3BS QTL. 
2DL QTL 
 The presence of the 2DL QTL was not positively associated with scab 
incidence, scab severity, FDK, or index, but it was associated with a decrease in DON 
content. The 2DL QTL was negatively associated with one thousand kernel weight 
and grain yield. No associations were observed for height, moisture content, test 
weight, heading, powdery mildew, or lodging for the 2DL QTL. 
5A QTL 
 The 5A QTL was not positively associated with any of the FHB resistance 
traits in this study. However, it was negatively associated with thousand kernel 
weight, grain yield, and lodging. 
 
Discussion 
 
 Ning 7840 was lower than Pioneer 2643 for scab incidence, scab severity 
percentage of fusarium damaged kernels, index, and DON content. Ning 7840 also 
had lower one thousand kernel weight and grain yield, and higher height and powdery 
mildew score. There was no significant difference between Ning 7840 and Pioneer 
 
 22 
 
2643 for moisture content, test weight, and heading date. However, Ning 7840 had 
higher lodging than Pioneer 2643. 
 Of the FHB resistance traits which Ning 7840 was expected to positively 
influence, scab severity, fusarium damaged kernels, index and DON content, 
decreased by the presence of the 3BS QTL, while only DON content was lowered by 
the presence of the 2DL QTL. None of the FHB resistance traits were significantly 
different between the lines with or without the 5A FHB QTL. 
 The 3BS FHB QTL was not associated with any negative agronomic traits. 
Both the 2DL FHB QTL and the 5A FHB QTL were associated with significantly 
lower one thousand kernel weight, as well as lowered grain yield, while the 5A FHB 
QTL was also associated with an increase in lodging. 
 These results indicate that the 3BS FHB QTL, while being the most effective 
for FHB resistance, was not negatively associated with any of the traits evaluated. 
The 2DL QTL showed some effectiveness in scab resistance, but was also associated 
with kernel weight and grain yield. The 5A FHB QTL showed no effect on FHB 
resistance in this study and was negatively associated with three agronomic traits. 
 Ohe et al. (2010) studied the influence of Ning 7840 in two European winter 
wheat germplasm. They found neither heading date nor height were associated with 
the 3BS or 5A FHB QTL, which is consistent with the findings in this study. 
 McCartney et al. (2007) previously reported the 3BS, 2DL, and 5A FHB QTL 
each had an effect on the percentage of fusarium damaged kernels and DON content, 
while both the 3BS and 2DL FHB QTL lowered index in three backcross spring 
wheat populations derived from Sumai 3. Their findings on the 3BS FHB QTL is 
 
 23 
 
similar to this study, however I did not find the 2DL or 5A FHB QTL to be associated 
with the percentage of FDK, or the 2DL FHB QTL to be associated with scab index. 
This may be due to a difference in background in the parental populations or perhaps 
an environmental difference. McCartney et al. (2007) also found no effect on height 
by any of the FHB QTL, which corresponded to my study. 
 
Conclusions 
 The 3BS FHB QTL was successful at providing FHB resistance without 
negatively affecting agronomic traits. The 2DL FHB QTL provided some FHB 
resistance, but also influenced some agronomic traits. The 5A FHB QTL was the least 
successful; it did not provide any improved scab resistance but negatively affected 
agronomic traits. 
 
 24 
 
Chapter 3: Scab Resistance QTL are Associated with Quality Traits 
of Soft Red Winter Wheat 
 
Introduction 
 Fusarium head blight (FHB), or scab, is a widely documented and studied 
disease caused by species in the genus Fusarium. FHB causes mycotoxin 
contamination, kernel damage, and yield loss. Methods of control include the use of 
fungicide, tillage, and host resistance. Sources of resistance to FHB have been 
reported from a number of wheat cultivars, including Sumai 3 (Gupta et al. 2000; 
Mardi et al. 2005). Lines derived from Sumai 3, such as Ning 7840, are widely used 
in breeding for resistance to FHB. Ning 7840 is a Chinese hard red spring wheat 
containing three FHB resistance QTL (Buerstmayr et al. 2009). These QTL are 
located on the 3BS, 2DL, and 5A chromosomes. 
 Because it carries these three QTL, Ning 7840 is often used in crosses with 
other wheat classes, such as soft red winter wheat. Soft red winter wheat is 
characterized by its soft endosperm, red bran, and requirements of a vernalization 
period to initiate reproductive growth. While Ning 7840 also has red bran, it has a 
hard endosperm, and does not require vernalization. Endosperm hardness is an 
important quality trait determining end use in wheat. Wheat with hard endosperm is 
typically used in bread making, while wheat with soft endosperm is used in the 
production of cookies, cakes, and pastries (Smith 1995). The milling and baking 
qualities desired in soft red winter wheat differ greatly from those for hard red spring 
wheat. Among the quality characteristics desired for soft red winter wheat are higher 
flour yield, lower flour protein, and lower solvent retention capacity than hard wheat. 
 
 25 
 
 The objective of this study was to determine whether these quality traits are 
associated with the three FHB resistance QTL in Ning 7840. In order to accomplish 
this, simple sequence repeat (SSR) markers were used. SSRs are a type of genetic 
marker capable of detecting short, repeating DNA sequences. By determining how 
large the repeat sequence is, it was possible to determine from which parent a 
progeny has inherited its DNA. Similarly, using SSRs on either side of each QTL of 
interest demonstrated whether the FHB resistance QTL was present in the progeny.  
 Similar studies have been performed on other wheat types. Ohe et al. (2010) 
evaluated the association of agronomic and quality traits with the 3BS or 5A QTL in 
two European hard winter wheat cultivars. They found no association with protein 
content, and a positive association between the 3BS QTL and test weight. This 
relationship may or may not carry over to soft red winter wheat because of the 
inherent difference between hard and soft wheat for test weight. 
 McCartney et al. (2007) generated three backcross populations from different 
FHB resistant parents to assess FHB QTL in Canadian spring wheat. These 
populations included one population derived from Sumai 3 which contained the three 
FHB QTL. The quality traits evaluated in their study included test weight, protein 
content, and flour yield. They found an increase in both test weight and flour protein 
was associated to the presence of the 2DL QTL, while flour yield was not significant. 
McCartney et al. (2007) focused on hard spring wheat, so the relationship they 
observed with test weight may or may not translate into soft red winter wheat.
 The purpose of this research was to determine whether the 3 FHB resistance 
QTL introduced into a soft red winter wheat cultivar from Ning 7840 were negatively 
 
 26 
 
associated with quality traits. The ultimate aim is to be able to develop FHB resistant 
soft red winter wheat without reducing milling and baking quality. 
 
Materials and Methods 
Plant Materials 
 A population of 86 wheat recombinant inbred lines was created from a cross 
between ?Ning 7840? and ?Pioneer 2643?. Ning 7840 is a Chinese hard red spring 
wheat cultivar derived from an Aurora/Anhui 11//Sumai 3 cross. Pioneer 2643 
(Experimental Pioneer line XW522) is a soft red winter wheat cultivar. Recombinant 
inbred lines were created by selfing each F2 genotype resulting from the initial cross 
by single seed descent until the F7 generation. 
 The 86 RILs, Ning 7840, Pioneer 2643, and two checks, Sisson and Renwood 
3260, were planted at the Wye Research and Education Center (WREC) in 
Queenstown, MD in the fall of 2007 and 2008 in 4 m long, 7 row plots with 0.15 m 
spacing between rows. In 2008 one replication was harvested for quality analysis, 
while in 2009 both replications were harvested. Samples of grain for each RIL were 
sent to Dr. Edward Souza at the USDA Soft Wheat Quality Lab, Wooster, OH for 
milling and baking quality analysis. Milling score, baking score, softness equivalence 
score, test weight, adjusted flour yield, flour protein percent, lactic acid SRC, sucrose 
SRC, sodium carbonate SRC, and water RC were measured on each sample. 
 
Marker Analysis with SSR markers 
 Simple sequence repeat markers were obtained from the population, and the 
two parental lines. Seeds were germinated in a soil-less mix at room temperature, and 
 
 27 
 
cuttings were taken from the first leaf of each plant. The leaves were then desiccated 
to be evaluated for DNA extraction SSR markers. The SSR marker evaluation was 
done by Dr. Gina Brown Guedira at the Raleigh (NC) USDA Genotyping Lab. A total 
of six SSR markers (two markers corresponding to each QTL) were scored on the 
RIL population. The markers used for the QTL on the 3BS chromosome were umn10 
(Liu et al, 2008) and gwm533; for the QTL on the 2DL chromosome, cfd233 and 
gwm 539 were used; and the markers used to detect the QTL on the 5A chromosome 
were gwm304 and wmc705 (Somers et al. 2004). The distance between the markers 
cfd233 and gwm539 is 12cM, while the distance between gwm304 and wmc705 is 
4cM (Somers et al. 2004). The size of the SSR marker relating to each parent is 
shown in Table 1. 
 
Statistical Analyses 
 For each QTL, the RILs were scored according to which SSR markers were 
present. If both markers were derived from Ning 7840 the QTL was scored as A 
(QTL present), if both markers coincided with Pioneer 2643 the QTL was scored as B 
(QTL absent). If the two markers were not derived from the same parent the QTL was 
scored as either C or D (QTL presence unknown), depending on which marker was 
derived from each parent. Means for each trait were then analyzed by pairwise 
comparison between the presence or lack of the QTL. The means of the RILs with an 
unknown QTL were disregarded for the purpose of comparison. The number of RILs 
included for the pairwise comparisons of each QTL are shown in Table 1. Because it 
was expected that the presence of the FHB QTLs derived from Ning 7840 would have 
 
 28 
 
a negative impact on the RILs, one-tailed probability was used. Pairwise comparisons 
were obtained using the LSMeans and pdiff statements in Proc GLM in SAS version 
9.1 (SAS Institute Inc., Cary, NC). 
 
 
 
 
 29 
 
 
 
Table 3. Means of milling and baking quality traits measured on wheat harvested. 
QTL Milling 
Score 
Baking 
Score 
Soft. Eq. 
Score 
TW1 Flour 
Yield 
Flour 
Protein 
Lactic 
Acid SRC 
Sucrose 
SRC 
Water 
RC 
Sodium 
Carb SRC 
(+/-) (%) (%) (%) (kg/hL) (%) (%) (%) (%) (%) (%) 
3BS + 53.3 33.6 55.4 74.6 67.1 9.5 87.1 86.7 55.2 67.9 
3BS - 51.9 30.9 54.3 74.8 66.8 9.6 87.5 87.4 55.3 68.2 
2DL + 49.0* 30.1* 49.6* 75.4 66.2* 9.9* 84.1 85.9 55.4 67.3 
2DL - 56.9* 34.5* 55.9* 75.2 67.8* 9.4* 86.3 86.7 55.2 67.8 
5A + 49.3* 29.1* 49.0* 74.3* 66.3* 9.8* 83.4* 86.5 56.0* 68.6* 
5A - 55.2* 33.5* 59.3* 74.5* 67.5* 9.4* 91.1* 87.9 54.8* 67.6* 
Ning 7840 58.8 13.0* 22.7* 74.0 68.2 11.0* 70.1* 84.5 61.9* 74.3* 
Pioneer 2643 65.8 55.3* 65.6* 75.6 69.6 7.8* 101.0* 83.5 54.7* 66.3* 
 *Mean values significantly different at p=0.05 
 1. TW= test weight 
 
 
 
 
 
 30 
 
Results 
3BS 
 There were no negative effect on milling or baking quality traits associated 
with the presence of the 3BS FHB QTL from Ning 7840 (Table 3). 
2DL 
 Significant differences were observed for milling score, baking quality score, 
softness equivalent score, flour yield, and flour protein for the lines carrying the 2DL 
QTL. The milling, baking, and softness equivalent scores, as well as the flour yield 
were lowered in the RILs containing the 2DL FHB QTL, while flour protein was 
increased in the RILs with the 2DL QTL (Table 3). 
5A 
 The milling and baking quality traits were all negatively associated with the 
presence of the 5A QTL from Ning 7840, except for sucrose SRC, which did not 
differ significantly between the two groups of RILs. The means for milling score, 
baking score, softness equivalent score, test weight, flour yield, and lactic acid SRC 
were all lower in the RILs carrying the 5A QTL, while means of flour protein, water 
retention capacity, and sodium carbonate SRC were higher in the RILs containing the 
5A FHB QTL than the RILs without the 5A FHB QTL (Table 3). 
 
Discussion 
 
 Ning 7840 had a lower baking score and softness equivalence score than 
Pioneer 2643. Ning 7840 also had lower lactic acid solvent retention capacity, and 
higher flour protein, water retention capacity, and sodium carbonate solvent retention 
 
 31 
 
capacity. Ning 7840 did not differ from Pioneer 2643 for milling score, test weight, 
flour yield, or sucrose solvent retention capacity. 
 Milling score, baking score, and softness equivalence score were each 
decreased by the presence of both the 2DL FHB QTL and the 5A FHB QTL. The 
2DL FHB QTL was also associated with a decrease in flour yield and an increase in 
flour protein, while the 5A QTL was negatively associated with every quality trait 
tested, with the exception of sucrose SRC. 
 Ohe et al. (2010) studied the effect of the 3BS and 5A QTL on test weight and 
protein content. They found an increase in test weight associated with the 3BS QTL. 
In this evaluation the 3BS QTL did not increase test weight In the study by Ohe et al. 
(2010) there was no change in protein content associated with either the 3BS or 5A 
FHB QTL. While the 3BS QTL was not associated with an increase in flour protein in 
this study, the 5A QTL was. This may have been because the cultivars Ohe et al. 
(2010)used had higher protein content than those used in this study. The parental soft 
red winter wheat Pioneer 2643 had much lower protein content than Ning 7840. 
 McCartney et al. (2007) evaluated the influence of the 3BS, 2DL, and 5A 
FHB QTL on test weight, protein content, and flour yield in hard spring wheat. They 
found no significant differences in flour yield associated with any of the three QTL. 
Because flour yield is generally higher in soft wheat than hard wheat, it was expected 
that there would be overall decrease in flour yield associated with the FHB QTL that 
was not observed by McCartney et al. (2007).I did not observe a decrease in flour 
yield in the 2DL and 5A FHB lines containing Ning 7840 alleles. McCartney et al. 
(2007) also found an increase in test weight associated with the 2DL FHB QTL, 
 
 32 
 
while this study I found no decrease in test weight between the RILs with and without 
the 2DL QTL. McCartney et al. (2007) also reported an increase in flour protein 
associated with the 2DL FHB QTL similar to the results of this study. 
 
Conclusion 
 
 The presence of the 3BS QTL from Ning 7840 was not negatively associated 
with end-use quality traits in soft red winter wheat. Both the 2DL QTL and the 5A 
QTL, however, were associated with negative trends on quality traits. Overall, the 5A 
QTL was more consistently negatively associated with quality traits than the 2DL 
QTL. This may be due to how each QTL functions, or it may be caused by linkage 
drag (Brinkman and Frey 1977). Reducing the size of the QTL may reduce linkage 
drag. Further research could be done to test this by measuring the sizes of the QTL on 
each chromosome. If QTL size is an important factor, alternate breeding methods 
may be used to decrease linkage drag. For instance, backcrossing may lead to less of 
the genome from the resistant parent being passed on. Researching the effects of other 
sources of FHB resistance to combine them with the 3BS QTL may also be a 
successful strategy to avoid negative consequences of breeding for FHB resistance.  
 
 33 
 
References 
 
Andersen, A. L. 1948. The Development of Gibberella zeae headblight of wheat. 
Phytopathology 38:595-611. 
Anderson, J.A., R.W. Stack, S. Liu, B.L. Waldron, A.D. Fjeld, C. Coyne, B. Moreno- 
Sevilla, J.M. Fetch, Q.J. Song, P.B. Cregan, and R.C. Frohberg. 2001. DNA 
markers for Fusarium head blight resistance QTLs in two wheat populations. 
Theoretical and Applied Genetics 102:1164-1168. 
Anjum, F.M., and C.E. Walker. 1991. Review on the significance of starch and 
protein to wheat kernel hardness. Journal of the Science of Food and 
Agriculture 56:1-13. 
Bai, G., and G. Shaner. 1994. Scab of wheat: Prospects for control. Plant Disease 
78:760- 766. 
Bai, G.H., G. Shaner, and H. Ohm. 2000. Inheritance of resistance to Fusarium 
graminearum in wheat. Theoretical and Applied Genetics 100:1-8. 
Brinkman, M.A., and K.J. Frey. 1977. Yield component analysis of oat & lines that 
produce different grain yields. Crop Science 17:165-168. 
Buerstmayr, H., B. Steiner, M. Lemmens, and P. Ruckenbauer. 2000. Resistance to  
Fusarium Head Blight in Winter Wheat: Heritability and Trait Associations. 
Crop Science 40: 1012-1018. 
Buerstmayr, H., Ban, T. and Anderson, J. A. 2009. QTL mapping and marker-assisted 
selection for Fusarium head blight resistance in wheat: a review. Plant 
Breeding 128: 1?26. 
Bushnell W.R., B.E. Hazen, and C. Pritsch. 2003. Histology and physiology of  
Fusarium  head blight. In: Leonard K, Bushnell, WR, eds. Fusarium head 
blight of wheat and barley. St. Paul, Minnesota: APS Press. 44 p. 
Campbell, K.G., and P.E. Lipps. 1998. Allocation of Resources: Sources of Variation  
in Fusarium Head Blight Screening Nurseries. Phytopathology 88:1078-1086. 
Campbell, K.G., C.J. Bergman, D.G. Gualberto, J.A. Anderson, M.J. Giroux, G. 
Hareland, R.G Fulcher, M. E. Sorrells, and P.L. Finney. 1999. Quantitative 
Trait Loci Associated with Kernel Traits in a Soft ? Hard Wheat Cross. Crop 
Science 39: 1184-1195. 
Desjardins, A.E., and R.H. Proctor. 2007. Molecular biology of Fusarium  
mycotoxins. International Journal of Food Microbiology 119:47-50. 
Dill-Macky, R., and R.K. Jones. 2000. The Effect of Previous Crop Residues and  
Tillage on Fusarium Head Blight of Wheat. Plant Disease 84:71-76. 
Easterbrook, G. 1997. Forgotten benefactor of humanity. The Atlantic Monthly 279: 
75?82. 
Faridi, H., C. Gaines, and P. Finney. 1994. Soft wheat quality in production of  
cookies and crackers. Pages 154-168 in: Wheat Production Properties and 
Quality. W. Bushuk and V. F. Rasper, eds. Blackie Academic and 
Professional: Glasgow. 
 
 
 
 34 
 
Fernandez, M.R., and J.M.C. Fernandes. 1990. Survival of wheat pathogens in wheat  
and soybean residues under conservation tillage systems in southern and 
central Brazil. Canadian Journal of Plant Pathology 12: 289?294. 
Forsyth, D. M., T. Yoshizawa, N. Morooka, and J. Tuite. 1977. Emetic and refusal  
activity of deoxynivalenol to swine. Applied and Environmental Microbiology 
34:547-552. 
Gaines, C. S., M.O. Raeker, M. Tilley, P.L. Finney, J.D. Wilson, D.B. Bechtel, R.J.  
Martin, P.A. Seib, G.L. Lookhart, and T. Donelson. 2000. Associations of 
starch gel hardness, granule size, waxy allelic expression, thermal pasting, 
milling quality, and kernel texture of 12 soft wheat cultivars. Cereal 
Chemistry 77:163-168. 
Gupta, R. B., I.L. Batey, and F. MacRitchie. 1992. Relationships between 
protein composition and functional properties of wheat flours. Cereal 
Chemistry 69:125-131. 
Gupta, A., P.E. Lipps, and K.G. Campbell. 2000. Finding quantitative trait locus 
associated with Fusarium head blight of wheat using simple sequence repeat 
markers, p. 28-32. 2000 National Fusarium Head Blight Forum Proceedings, 
Erlanger, KY. 
Guttieri, M.J., C. Becker, and E.J. Souza. 2004. Application of wheat meal solvent  
retention capacity tests within soft wheat breeding programs. Cereal 
Chemistry 81: 261-266 
Khonga, E. B., and J.C. Sutton. 1988. Inoculum production and survival of  
Gibberella zeae in maize and wheat residues. Canadian Journal of Plant 
Pathology 10:232-239. 
Kolb, F.L., G.H. Bai, G.J. Muehlbauer, J.A. Anderson, K.P. Smith, and G. Fedak.  
2001. Host plant resistance genes for fusarium head blight: Mapping and 
manipulation with molecular markers. Crop Science 41:611-619. 
Leonard K.J., W.R. Bushnell, eds. 2003. Fusarium Head Blight of Wheat and Barley.  
St Paul, MN: APS Press. 512 pp. 
Lewis S., M.E. Faricelli, M.L. Appendino, M. Valarik, and J. Dubcovsky. 2008. The 
chromosome region including the earliness per se locus Eps-Am1 affects the 
duration of early developmental phases and spikelet number in diploid wheat. 
Journal of Experimental Botany 59: 3595-3607. 
Liu, Z.Z., 1984. Recent advances in research on wheat scab in China. p. 174?181.  
In: Wheats for more tropical environments. CIMMYT, Mexico, D.F., Mexico. 
Liu, S., M.O. Pumphrey, B.S. Gill, H.N. Trick, J.X. Zhang, J. Dolezel, B. Chalhoub,  
and J.A. Anderson. 2008. Toward positional cloning of Fhb1, a major QTL 
for Fusarium head blight resistance in wheat. Cereal Research 
Communications 36:195-201. 
Major, D.J., B.L. Blad, A. Bauer, J.L. Hatfield, K.G. Hubbard, E.T. Kanemasu, R.J.  
Reginato. 1988. Winter wheat grain yield response to water and nitroen on the 
North American Great Plains. Agricultural and Forest Meteorology 44: 141-
149. 
Mardi, M., H. Buerstmayr, B. Ghareyazie, M. Lemmens, S.A. Mohammadi, R. Nolz, 
 
 35 
 
and P. Ruckenbauer. 2005. QTL analysis of resistance to Fusarium head blight 
in wheat using a 'Wangshuibai'-derived population. Plant Breeding 124:329-
333. 
Marza, F.G., H. Bai, B.F. Carver, and W.C. Zhou. 2006 Quantitative trait loci for  
yield and related traits in the wheat population Ning 7840 x Clark. Theoretical 
and Applied Genetics 112:688-698 
McCartney, C.A., D.J. Somers, G. Fedak, R.M. DePauw, J. Thomas, S.L. Fox, D.G. 
Humphreys, O. Lukow, M.E. Savard, B.D. McCallum, J. Gilbert, and W. Cao. 
2007. The evaluation of FHB resistance QTLs introgressed into elite Canadian 
spring wheat germplasm. Molecular Breeding 20:209-221. 
McMullen, M., R. Jones, and D. Gallenberg. 1997. Scab of wheat and barley: A 
reemerging disease of devastating impact. Plant Disease 81:1340-1348. 
McMullen, M., S. Halley, B. Schatz, S. Meyer, J. Jordahl, and J. Ransom. 2008. 
Integrated strategies for Fusarium head blight management in the United 
States. 
Cereal Research Communications 36:563-568. 
Neish, G.A., and H. Cohen. 1981. Vomitoxin and zearalenone production by  
Fusarium graminearum from winter wheat and barley in Ontario. Canadian 
Journal of Plant Science 61: 811-815. 
Ohe, C., E. Ebmeyer, V. Korzun, and T. Miedaner. 2010. Agronomic and quality  
performance of winter wheat backcross populations carrying non-adapted 
Fusarium head blight resistance QTL. Crop Science 50:2283-2290. 
Parry, D.W., P. Jenkinson, and L. McLeod. 1995. Fusarium ear blight (scab) in small 
grain cereals-a review. Plant Pathology (Oxford) 44:207-238. 
Paulitz, T.C. 1996. Diurnal release of ascospores by Giberella zeae in inoculated  
wheat plots. Plant Disease. 80: 674-678. 
Pritsch, C., G.J. Muehlbauer, W.R. Bushnell, D.A. Somers, and C.P. Vance. 2000. 
Fungal development and induction of defense response genes during early 
infection of wheat spikes by Fusarium graminearum. Molecular Plant-
Microbe Interactions 13:159-169. 
Pugh, G.W., H. Johann, and J.G. Dickson. 1933. Factors affecting infection of wheat  
heads by Gibberella saubinetti. Journal of Agricultural Research 46: 771-797. 
Rudd, J.C., R.D. Horsley, A.L. McKendry, and E.M. Elias. 2001. Host plant  
resistance genes for Fusarium head blight. Crop Science 41: 620-627. 
Schuler, S. F., R. Bacon, P.L. Finney, and E. Gbur. 1995. Relationship of test weight  
and kernel properties to milling and baking quality in soft red winter wheat. 
Crop Science 35:949-953. 
Slade, L., and H. Levine. 1994. Structure-function relationships of cookie and cracker  
ingredients. Pages 23-141 in: The Science of Cookie and Cracker Production. 
H. Faridi, ed. Chapman and Hall: New York. 
Somers, D.J., P. Isaac, and K. Edwards. 2004. A high-density microsatellite  
consensus map for bread wheat (Triticum aestivum L.). Theoretical and 
Applied Genetics. 109:1105-1114. 
Song, Q.J., J.R. Shi, S. Singh, E.W. Fickus, J.M. Costa, J. Lewis, B.S. Gill, R. Ward, 
and P.B. Cregan. 2005. Development and mapping of microsatellite (SSR) 
markers in wheat. Theoretical and Applied Genetics 110:550-560. 
 
 36 
 
Sutton, J.C. 1982. Epidemiology of wheat head blight and maize ear rot cause by  
Fusarium graminearum. Canadian Journal of Plant Pathology 4: 195-209. 
Tshanz, A.T., R.K. Horst, and P.A. Nelson. 1976. The effect of environment on  
sexual reproduction of Giberella zeae. Mycologia 68: 327-340. 
Uthayakumaran, S., P.W. Gras, F.L. Stoddard, and F. Bekes. 1999. Effect of varying  
protein content and glutenin-to-gliadin ratio on the functional properties of 
wheat dough. Cereal Chemistry 76: 389-394. 
Van Ginkel, M., W. Van Der Schaar, and Z. Yang. 1996. Inheritance of resistance to  
scab in two wheat cultivars from Brazil and China. Plant Disease 80:863-867. 
Vaughan, B., D.G. Westfall, and K.A. Barbarick. 1990. Nitrogen and timing effects  
on winter wheat grain yield, grain protein, and economics. Journal of 
Production Agriculture 3: 324-328. 
Vesonder, R.F., and C.W. Hesseltine. 1981. Vomitoxin: natural occurrence on cereal  
grains and significance as a refusal and emetic factor to swine. Process 
Biochemistry 81:12-15. 
Wanyoike, M.W., K. Zhensheng, and H. Buchenauer. 2002. Importance of cell wall  
degrading enzymes produced by Fusarium graminearum during the infection 
of wheat heads. European Journal of Plant Pathology 108: 803-810. 
Wheat Foods Council. updated 2010. Grains of truth about wheat production and  
consumption. 
http://www.wheatfoods.org/_FileLibrary/Product/43/Wheat%20Prod.%20&%
20Consumption.pdf 
Wilcoxson, R.D. 1993. Historical overview of scab research, p. 1?5. In Proc. (1st)  
Regional Scab Forum, Moorhead, MN. Publ. Minn. Wheat Res. & 
PromCouncil, Red Lake Falls, MN. 
Zhou, W.C., F.L. Kolb, G.H. Bai, L.L. Domier, L.K. Boze, and N.J. Smith. 2003.  
Validation of a major QTL for scab resistance with SSR markers and use of 
marker-assisted selection in wheat. Plant Breeding 122: 40-46.