Several quantitative trait loci (QTL) have been identified for Fusarium head blight (FHB) resistance in the cultivar Sumai 3. Wheat breeders need to know which Sumai 3 loci are present in derived lines used as parents for effective marker-assisted selection for genetic improvement. This study was conducted to identify the loci in Sumai 3 derived parents that contribute FHB resistance in breeding populations. Three doubled haploid (DH) populations utilizing Sumai 3 derived parents, ND3085, ND744, and Alsen, were evaluated during 2007 and 2008 in FHB nurseries near Carman, MB, Ottawa, ON and Charlottetown, PE. The percentage of incidence, severity, Fusarium-damaged kernels (FDK), and deoxynivalenol (DON) accumulation were measured, and FHB index calculated. DNA markers at six FHB resistance loci detected in Sumai 3 were evaluated on the populations. For each trait, a t test was applied to means of observations pooled by parental type of each marker to determine which loci contributed to resistance. The alleles at 3BS and 5AS most frequently contributed to Type I and Type II FHB resistance, as well as to reduced FDK and DON in all three populations. Markers revealed resistance on 3BS and 5AS in Alsen, ND3085, and ND744, on 3BSc, 4D, and 6BS in ND744, on 4D in ND3085, and on 6BS in Alsen. In some environments, the susceptible parent Infinity contributed minor QTL on 2D, 3BSc, and 6BS. Likewise, Helios contributed minor QTL on 5AS and 6BS.

Fusarium head blight (FHB) is a devastating disease of wheat because of direct detrimental effects on grain yield, quality, and marketability and production of mycotoxins (e.g. deoxynivalenol or DON). Conditions most favourable for the development of FHB are high humidity, frequent rainfall and relatively warm night temperatures at heading, especially in regions where host crop residues are present. These risk factors have resulted in a significant westward expansion of FHB in the Canadian prairies, while favouring continued development in Ontario, Quebec and the Maritimes. Since cultivar selection is a key integrated pest management (IPM) strategy, a systems approach that couples genetic resistance with management tactics is required. Thus, successful FHB mitigation is an ideal case study in Genotype (G) x Environment (E) x Management (M) interactions where more resistant cultivars (G) are grown in at-risk regions (E), and unique approaches to management (M) for sustainable wheat production are required. Since no cultivar is completely resistant to FHB, greater attention to management strategies is needed. The over-arching principle for FHB management is the manipulation of agronomic factors that facilitate completion of critical crop developmental phases, such as flowering, while doing so rapidly and uniformly, as a consequence of early sowing and increased seeding rates. These strategies and the adoption of practices involving proper fungicide selection, and optimal application timings and methods will lead to improved yield stability and quality in high-risk environments. This paper explores the potential synergies that exist for FHB mitigation when appropriate genetics are combined with an array of key agronomic strategies.

Field trials were conducted under natural infection and artificial inoculation from 2012 to 2014 at seven sites across the Canadian prairies to determine genetic and management effects on Fusarium head blight (FHB) in wheat production systems. A system of management, which consisted of (1) a control of no fungicide was compared with (2) the seed treatment (ST) thiamethoxam + difenoconazole + metalaxyl-M + S-isomer, (3) an in-crop foliar fungicide (tebuconazole + prothioconazole), or (4) ST + foliar fungicide, was integrated with four wheat cultivars of contrasting growth habits and levels of FHB resistance. Results indicated the cultivars expressing improved FHB resistance, Carberry (spring wheat) and Emerson (winter wheat), were superior over susceptible cultivars, Harvest (spring wheat) and CDC Falcon (winter wheat), in reducing Fusarium-damaged kernel (FDK) and deoxynivalenol (DON) levels, and displayed higher yield under high Fusarium pressure. Winter wheat displayed higher overall yield, with Emerson producing the highest and most stable yields across environments. Application of foliar fungicide, with or without the ST, increased grain yield, seed mass, and test weight; and lowered FDK and DON. Seed treatment alone increased test weight, spring plant density of both winter wheat varieties, and kernel weight in Emerson. A management strategy of foliar fungicide and (or) ST + foliar fungicide generally produced higher yields with greater stability, particularly for susceptible cultivars in high FHB environments. The results of this study reinforce that integration of FHB-resistant cultivars with appropriate cultural practices is required to reduce the risk of FHB and optimize grain yield, and is further enhanced with a winter vs. spring growth habit.

Genetic control of resistance to Fusarium head blight (FHB) is quantitative, making phenotypic selection difficult. Genetic markers to resistance are helpful to select favorable genotypes. This study was conducted to determine if Fhb1 and Fhb5 present in the Sumai 3 source of FHB resistance occur in Sumai 3-derived North American spring wheat cultivars and to understand the appropriateness of using markers to select for the favorable alleles at these loci in breeding. Sumai 3-derived parents Alsen, ND3085, ND744, Carberry, and Glenn were used in crosses to generate 14 doubled haploid breeding populations. The parents and progeny were genotyped with five Fhb1 and three Fhb5 microsatellite markers. Progeny were selected based on performance relative to parents and other control cultivars in FHB nurseries near Portage la Prairie and Carman, MB. χ2 and t test analyses were performed on marker and FHB data. The χ2 test frequently determined the proportion of lines carrying molecular variants associated with FHB resistance increased following nursery selection for FHB. Similarly, the t test regularly demonstrated that selection for FHB resistance lowered the mean level of disease associated with resistant marker haplotypes. The study affirmed FHB resistance sources Alsen, Carberry, ND3085, and ND744 have Fhb1 and Fhb5 loci like Sumai 3, but no evidence was found that Glenn carries Fhb1 and Fhb5 resistance alleles. The results justified use of Fhb1 and Fhb5 markers for marker assisted selection in populations derived from Alsen, Carberry, ND3085, and ND744, but not Glenn. Combined or individual application of Xgwm493 and Xgwm533 in selection of genotypes carrying Fhb1, and Xgwm150, Xgwm304, and Xgwm595 for Fhb5 will enhance FHB resistance in wheat.

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is one of the most destructive diseases of wheat especially in humid and semi-humid wheat growing areas of the world. Agronomic traits such as plant height, flowering date, and presence/ absence of awns play important roles in wheat life cycle and grain yield. In the present study, characterization of agronomic traits and their association with Fusarium head blight were investigated in a population of recombinant inbred lines (RILs) derived from the cross of Canadian bread wheat cultivar 'AC Brio' to Triticum timopheevii-derived line 'TC 67'. The population was grown under both greenhouse (Winnipeg, MB, Canada) and field (Carman and Glenlea, MB, Canada) conditions and measurements were made for agronomic traits including plant height, flowering date, presence/absence of awns, and glume threshability. The wheat genotypes were also assessed in the greenhouse for disease severity (type II resistance) and in field plots for disease incidence (type I resistance), disease severity (indicating a combination of type I and type II resistance), deoxynivalenol (DON) content (type III resistance), and Fusarium-damaged kernels (FDK) which is an indicator of type IV resistance. Results showed that there was significant variation in plant height, flowering date, and FHB resistance among the genotypes, and the frequency distributions of these traits were continuous, indicating the quantitative inheritance of the traits. While both plant height and flowering date showed negative correlations with disease incidence, severity, and DON content, they both were positively correlated with FDK under field conditions. In the greenhouse, both plant height and flowering date were positively correlated with disease severity. Awnedness and seed threshability were also significantly associated to all FHB-related traits. While the presence of awns was associated with a significant decrease in FHB, the genotypes that were easy to thresh were more susceptible to the disease. The line 'TC 67' with novel FHB resistance derived from T. timopheevii may be useful in wheat breeding, but the positive association of disease resistance with undesirable agronomic traits such as plant height may delay cultivar development efforts.

Fusarium head blight (FHB) of wheat, caused principally by Fusarium graminearum in Canada, results in accumulation of mycotoxins in the grain. The fungus produces deoxynivalenol (DON) and its acetylated forms 3-ADON or 15-ADON. Increasing numbers of F. graminearum isolates collected in Manitoba between 1998 and 2004 were of the 3-ADON chemotype, whereas prior to 1998, the 15-ADON chemotype was considered the only significant cause of FHB in North America. Between 2008 and 2012, a series of studies were conducted at Carman (2008, 2009) and Glenlea, Manitoba (2008-2012) to monitor the ratio of 3-ADON to 15-ADON chemotypes recovered after wheat plots were artificially inoculated, usually in a 1:1 ratio of 3-ADON:15-ADON isolates of F. graminearum. Additional studies were conducted under controlled conditions. In 2008, the majority of isolates recovered from both Carman and Glenlea were of the 3-ADON chemotype. In subsequent years, however, the ratio was closer to 1:1 or sometimes with a slight predominance of 15-ADON isolates. Under controlled conditions, recovery of 15-ADON isolates predominated at lower incubation temperatures (18-22 degrees C) whereas at 28 degrees C, 3-ADON isolates were more prevalent. At moderate temperature (24 degrees C), results were mixed - seven samples had a 1:1 ratio, three had higher recovery of 3-ADON isolates, and two had higher recovery of 15-ADON. However, an examination of weather variables over the 5-year period of the field studies showed no correlation between recovery of chemotype and temperature or precipitation. ResumeLa brulure de l'epi (FHB) du ble, causee principalement au Canada par Fusarium graminearum, engendre des accumulations de mycotoxines dans les grains. Le champignon produit du deoxynivalenol (DON) et ses formes acetylees 3-ADON ou 15-ADON. De plus en plus d'isolats de F. graminearum collectes au Manitoba de 1998 a 2004 appartenaient au chimiotype du 3-ADON alors que, avant 1998, le chimiotype du 15-ADON etait considere comme la seule cause importante de FHB en Amerique du Nord. De 2008 a 2012, une serie d'etudes ont ete menees a Carman (2008, 2009) et Glenlea (2008-2012), au Manitoba, pour surveiller la proportion recuperee des chimiotypes du 3-ADON et du 15-ADON apres que les parcelles de ble avaient ete inoculees artificiellement, le rapport des isolats de F. graminearum produisant du 3-ADON et du 15-ADON etant habituellement de 1:1. Des etudes supplementaires ont ete menees dans des conditions controlees. En 2008, la majorite des isolats recuperes a Carman et a Glenlea appartenaient au chimiotype du 3-ADON. Toutefois, au cours des annees suivantes, le rapport etait plus pres de 1:1 ou parfois affichait une legere predominance des isolats produisant du 15-ADON. Dans des conditions controlees, les isolats recuperes appartenant au chimiotype du 15-ADON predominaient a des temperatures d'incubation plus basses (18 a 22 degrees C) tandis que, a 28 degrees C, les isolats appartenant au chimiotype du 3-ADON etaient plus nombreux. 24 degrees C, temperature consideree comme moderee, les resultats variaientsept echantillons affichaient un rapport de1:1, trois affichaient un rapport plus eleve de recuperation des isolats produisant du 3-ADON et deux, un rapport plus eleve d'isolats produisant du 15-ADON. Toutefois, un examen des variables meteorologiques des cinq annees qu'ont dure les etudes en champ a montre qu'il n'y avait aucune correlation entre la recuperation des chimiotypes et la temperature ou les precipitations.

Preharvest sprouting (PHS) can greatly affect the consistent production of high-quality spring wheat (Triticum aestivum L.) in many regions worldwide including Western Canada. A worldwide collection of red- and white-seeded spring wheat genotypes with different levels of sprouting response were characterized for three PHS traits: falling number, germination index and sprouting index in three different environments in Manitoba, Canada. The data sets were analysed by the genotype and genotype x environment interaction model. Variance components were estimated, genotypic and their interaction effects with environments were predicted by using one of mixed linear model approaches: minimum norm quadratic unbiased estimation approach. Genotypic variance expressed as proportion to the phenotypic variance was higher compared to genotype x environment (G x E) interaction effects for all three PHS traits, suggesting that these genotypes can be used to develop high level of PHS-resistant cultivars regardless of environment. Strong correlations between PHS traits across environments suggest that all three traits are repeatable and reliable methods to determine PHS response in spring wheat depending on sample types (spike, grain or flour). Predicted genotypic effects, G x E interaction effects and the linear discriminant analysis revealed that white-seeded genotypes AUS1408, SC8019-R1 and Kanata, and red-seeded genotypes AC Domain, AC Majestic and Red RL4137 would be useful PHS-resistant donors in spring wheat cultivar development programmes.

Fusarium head blight (FHB) is a serious problem in many wheat-growing areas worldwide. The breeding and cultivation of resistant wheat cultivars is the most promising strategy to reduce the risk of FHB. We report on the comparison of 20 Canadian and 20 European genotypes for FHB response and associated traits (deoxynivalenol content, Fusarium damaged kernels, plant height, heading date) in multi-environmental field trials in Canada and Germany after artificial inoculation with Fusarium culmorum (Germany) / F. graminearum (Canada). Our study revealed Canadian and European wheat lines that were stable in performance across countries and which therefore appear as valuable FHB resistance donors in Canadian as well as in German wheat breeding programs to further improve the resistance level of wheat cultivars against FHB.

The aim of this study was to determine ileal AA and fiber digestibility in new-generation dried distillers grains with solubles (DDGS) derived from wheat (wDDGS), a wheat-corn blend [wcDDGS, wheat and corn were fermented in a 7:3 wt/wt ratio], or corn (cDDGS) and to determine the effects of diets containing DDGS on gut bacteria and bacterial and digestive enzyme activities. Experimental diets contained one of the DDGS samples as the sole source of protein, and a low protein diet (5% casein) was included to estimate basal endogenous ileal CP and AA losses. Chromic oxide (0.3%) was added as an indigestible marker to all diets. Twelve cannulated barrows with an initial BW of 20.2 +/- 1.3 kg were allotted to the 4 experimental diets in a 2-period crossover design, which provided 6 observations per diet. Pigs were acclimatized to their diets for 5 d followed by a continuous 12-h digesta collection on d 6 and 7. Diet had no effect on the apparent ileal digestibility (AID) of CP (P = 0.58). The wDDGS diet generally had decreased (P < 0.05) AID of AA compared with the wcDDGS or cDDGS diet. Similarly, the values for standardized ileal digestibility of CP and most AA were smaller (P < 0.05) for the wDDGS diet compared with the other 2 DDGS diets. The Lys and Thr were the least digestible AA among the indispensable AA across the 3 DDGS samples. The digestibilities of nonstarch polysaccharides and NDF were not affected by diet (P = 0.80 and 0.40, respectively); however, the ileal digesta viscosity was greater (P < 0.05) for the wcDDGS diet than the wDDGS and cDDGS diets. The counts of Lactobacillus (P = 0.09) and Enterobacteriaceae (P = 0.05) were greater for the cDDGS diet compared with the other 2 diets. Accordingly, the cDDGS diet elicited a greater (P < 0.05) lactic acid concentration in digesta than the wDDGS diet. The activities of bacterial (P = 0.86 to 0.91) and digestive enzymes (P = 0.31 to 0.80) did not differ among the diets. The results indicate that the wDDGS had generally less protein and AA ileal digestibilities compared with the wcDDGS and cDDGS samples and that nonstarch polysaccharides and NDF digestibilities were similar among diets. Although diet influenced digesta bacterial counts, no effects were observed on the activities of bacterial and digestive enzymes.

Hard white wheat (Triticum aestivum L.) is a value-added product because of its processing advantages over red wheat; however, white wheat tends to be more susceptible to pre-harvest sprouting (PHS). To identify quantitative trait loci (QTLs) associated with PHS tolerance, we developed a doubled haploid (DH) mapping population from the cross AC Domain (red seeded) × White-RL4137 (white seeded). A genetic map was constructed using microsatellite markers located on chromosome groups 3, 4, 5 and 6. A population of 174 DH lines was characterized for important aspects of PHS including sprouting index, germination index, Hagberg falling number and seed coat colour. A total of 11 QTLs were identified on group 3 chromosomes and on chromosome 5D. Seven QTLs associated with the PHS traits were found to be co-incident with seed coat colour on chromosomes 3A, 3B and 3D. The 5D PHS QTL was notable because it is independent of seed coat colour.

Pre-harvest sprouting (PHS) in spring wheat (Triticum aestivum L.) is a major downgrading factors for grain producers and can significantly reduce end-use quality. PHS resistance is a complex trait influenced by genotype, environment and plant morphological factors. A population of 185 doubled haploid (DH) lines from the spring wheat cross 'RL4452/AC Domain' were used as the mapping population to detect quantitative trait loci (QTLs) associated with three PHS traits, germination index (GI), sprouting index (SI) and falling number (FN). Six major QTLs linked with PHS traits were mapped on bread wheat chromosomes 3A, 3D, 4A (2 loci), 4B and 7D. 'AC Domain' alleles contributed to PHS resistance on 3A, 4A (locus-2) and 4B, and 'RL4452' alleles contributed resistance on 3D, 4A (locus-1) and 7D. QTLs detected on chromosome 4B controlling FN (QFN.crc-4B), GI (QGI.crc-4B) and SI (QSI.crc-4B) were coincident, and explained the largest amount of phenotypic variation in FN (22%), GI (67%) and SI (26%), respectively.