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Tillage and cropping sequence may influence C and N sequestration, microbial activities, and N mineralization in dryland soil aggregates. We evaluated the 21‐yr effect of tillage and cropping sequence combinations on C and N fractions in aggregates of a Dooley sandy loam (fine‐loamy, mixed, superactive, frigid Typic Argiustolls) at the 0‐ to 20‐cm depth in eastern Montana. Tillage and cropping sequences were no‐tilled continuous spring wheat (NTCW) (Triticum aestivum L.), spring‐tilled continuous spring wheat (STCW), fall‐ and spring‐tilled continuous spring wheat (FSTCW), fall‐ and spring‐tilled spring wheat‐barley (Hordeum vulgare L.) (1984–1999) followed by spring wheat‐pea (Pisum sativum L.)(2000–2004)(FSTW‐B/P), and spring‐tilled spring wheat‐fallow (STW‐F). Carbon and N fractions were soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4–N, and NO3–N. Aggregate proportion was greater in NTCW than in FSTCW in the 4.75‐ to 2.00‐mm aggregate‐size class at 0 to 5 cm but was greater in STW‐F than in STCW in the 2.00‐ to 0.25‐mm size class at 5 to 20 cm. After 21 yr, STW‐F reduced SOC, STN, POC, and PON concentrations in aggregates by 34 to 42% at 0‐ to 5‐cm and by 20 to 32% at 5‐ to 20‐cm compared with NTCW and STCW. The PCM and MBC were greater in NTCW and STCW than in STW‐F in the <2.00‐mm size class at 0 to 5 cm but MBN varied with treatments, aggregate‐size classes, and soil depths. Compared with other treatments, NH4–N concentration was lower in STW‐F in the 4.75‐ to 0.25‐mm size class but PNM and NO3–N were greater in FSTW‐B/P in the <2.00‐mm size class. Long‐term reduced tillage with continuous spring wheat increased soil aggregation, C and N sequestration, and microbial biomass and activities in all aggregates but increased tillage intensity with spring wheat‐barley/pea rotation increased N mineralization and availability in small aggregates compared with the conventional STW‐F.

Opportunities exist to reduce nitrous oxide (N2O) emissions from nitrogen (N) fertilizers using enhanced efficiency fertilizers (EEFs) and managing application timing. This study examined (1) application timing (fall/spring) and (2) fertilizer N source on N2O emissions, yield, and N uptake of Canadian hard red spring wheat (Triticum aestivum L.) in Southern Manitoba. Fertilizer N sources included granular urea and four EEF products: (1) polymer‐coated urea (environmentally smart nitrogen [ESN]); (2) urea plus nitrification inhibitor (eNtrench); (3) urea plus urease inhibitor (Limus); and (4) urea plus nitrification and urease inhibitor (SuperU). Nitrification‐inhibited products most consistently reduced N2O emissions while maintaining productivity. Compared to urea alone, urea + eNtrench was most effective in reducing cumulative N2O emissions by 47%–64% at four of six site‐years. SuperU reduced N2O emissions by 37%–57% at three of six site‐years. ESN and urea + Limus did not affect emissions in most years. Wheat yield, protein, and N uptake were unaffected by N source in five of six site‐years. Compared to spring, fall application gave greater N2O emissions by 33%–67% at three of six site‐years due to spring‐thaw emissions. Fall was inferior to spring application in wetter site years with lower yield, protein, and N uptake. Overall, nitrification‐inhibited products—either alone or with a urease inhibitor—are a promising tool to reduce N2O emissions while maintaining wheat productivity in Manitoba. However, given that there were few consistent increases in yield or protein, the additional cost of the inhibitors will be a barrier to adoption. Core Ideas EEF products with nitrification and nitrification/urease inhibitors consistently reduced N2O emissions. Controlled release urea and urease‐inhibited urea did not reduce N2O emissions. Fall application of urea increased N2O emissions in three site‐years compared to spring application. The nitrification inhibitors applied with urea in fall or spring were effective to reduce N2O emissions. Overall, fall application decreased yield, grain protein, and N uptake in relatively wet years.

Wheat stripe rust is a fungal disease caused by Puccinia striiformis f. sp. tritici . The outbreak of wheat stripe rust will have a great impact on wheat production in Xinjiang, China. In order to identify resistance to wheat stripe rust and the distribution of resistance genes in 82 wheat cultivars (41 spring wheat and 41 winter wheat), wheat seedling resistance was evaluated using CYR32, CYR33 and CYR34, and wheat adult plant stage resistance was identified using a combination of 3 races. Six molecular markers were used to identify Yr29 , Yr39 , Yr46 , Yr69 and YrTr1 in 82 wheat cultivars. The results showed that 3 of 82 wheat cultivars (Xinchun No.14, Xinchun No.22, and Xindong No.22) were immune to stripe rust at the adult plant stage. Xinchun No.29, Xinchun No.32, Xindong No.5 and Xindong No.29 were resistant at all stage. The highest detection rates were for Yr69 and YrTr1 , at 78.05% and 76.83%. However, the detection rates for Yr39 and Yr46 were only 0 and 2.44%, respectively. The Xindong No.22 were detected with the most resistance genes, which included 4 Yr genes. Furthermore, Xindong No.22 were immune to the disease at adult plant stage. The results confirmed the resistance gene distribution of the wheat cultivars in Xinjiang were heterogeneously, and the number of Yr genes was significantly and positively correlated with wheat cultivars resistant to stripe rust.

Recent outbreaks traced to contaminated flour have created a need in the milling industry for a process that reduces pathogens in wheat while maintaining its functional properties. Vacuum steam treatment is a promising technology for treatment of low-moisture foods. Traditional thermal treatment methods can compromise wheat functionality due to high temperatures; thus, maintaining the functional quality of the wheat protein was critical for this research. The objective of this study was to evaluate the effect of vacuum steam treatment of hard red spring (HRS) wheat kernels on final flour quality and the overall efficacy of vacuum stream treatment for reducing pathogens on HRS wheat kernels. HRS wheat samples were treated with steam under vacuum at 65, 70, 75, and 85°C for 4 and 8 min. Significant changes in dough and baked product functionality were observed for treatments at ≥70°C. Treatment time had no significant effect on the qualities evaluated. After determining that vacuum steam treatment at 65°C best preserved product quality, HRS wheat was inoculated with Escherichia coli O121 and Salmonella Enteritidis PT 30 and processed at 65°C for 0, 2, 4, 6, or 8 min. The treatments achieved a maximum average reduction of 3.57 ± 0.33 log CFU/g for E. coli O121 and 3.21 ± 0.27 log CFU/g for Salmonella. Vacuum steam treatment could be an effective pathogen inactivation method for the flour milling industry.

Key messageUsing phenotypic data of four biparental spring wheat populations evaluated at multiple environments under two management systems, we discovered 152 QTL and 22 QTL hotspots, of which two QTL accounted for up to 37% and 58% of the phenotypic variance, consistently detected in all environments, and fell within genomic regions harboring known genes.Identification of the physical positions of quantitative trait loci (QTL) would be highly useful for developing functional markers and comparing QTL results across multiple independent studies. The objectives of the present study were to map and characterize QTL associated with nine agronomic and end-use quality traits (tillering ability, plant height, lodging, grain yield, grain protein content, thousand kernel weight, test weight, sedimentation volume, and falling number) in hard red spring wheat recombinant inbred lines (RILs) using the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq v2.0 physical map. We evaluated a total of 698 RILs from four populations derived from crosses involving seven parents at 3–8 conventionally (high N) and organically (low N) managed field environments. Using the phenotypic data combined across all environments per management, and the physical map between 1058 and 6526 markers per population, we identified 152 QTL associated with the nine traits, of which 29 had moderate and 2 with major effects. Forty-nine of the 152 QTL mapped across 22 QTL hotspot regions with each region coincident to 2–6 traits. Some of the QTL hotspots were physically located close to known genes. QSv.dms-1A and QPht.dms-4B.1 individually explained up to 37% and 58% of the variation in sedimentation volume and plant height, respectively, and had very large LOD scores that varied from 19.0 to 35.7 and from 16.7 to 55.9, respectively. We consistently detected both QTL in the combined and all individual environments, laying solid ground for further characterization and possibly for cloning.

Hulled wheat species are often used as whole grains in processing, and have been attracting attention in the last 20 years in the food industry. Whole wheat flour of hulled wheat can be used in the food industry for value addition. This study was conducted to evaluate the kernel quality and chemical composition of the whole grain flour of hulled wheats as a preliminary approach to use these species for value addition. The experimental design was separate, randomized complete block designs for einkorn, emmer, and spelt, with four field replicates. According to the results, significant differences (p < 0.05) were observed in kernel quality traits, such as test weight, 1000 kernel weight, and kernel hardness, compared to hard red spring wheat. The results of the chemical composition revealed that hulled wheats were characterized by significantly lower (p < 0.05) protein and higher (p < 0.05) crude fat contents compared to whole wheat flour of hard red spring wheat. Among hulled wheats, total dietary fiber content was highest in emmer, followed by einkorn and spelt. In conclusion, the whole wheat flour of einkorn, emmer, and spelt used in this study differ from hard red spring wheat in their kernel quality and chemical composition.

Discount payments associated with low grain protein concentration in hard red spring wheat (HRSW, Triticum aestivum L.) in recent years has increased interest for using controlled‐release N fertilizers to increase protein concentration while maintaining optimal grain yields. Field experiments were conducted during 6 site‐years in Minnesota from 2007 to 2009 to examine effects of a polymer‐coated urea (PCU, Environmentally Smart Nitrogen [ESN], Agrium Inc., Calgary, AB, Canada) and non‐coated urea on grain yields and protein concentrations of two HRSW cultivars, Alsen and Knudson, that vary in grain yield and protein concentration potentials. Polymer‐coated urea and urea were applied in spring at six rates that supplied 0 to 110 kg N ha−1 in 2007 and 0 to 168 kg N ha−1 in 2008 and 2009. Because of genetic differences, Knudson produced greater grain yield than Alsen in environments (site‐years), which were cooler and drier early in the growing season and the yield differences between the two cultivars increased with increasing N rates. In the same environment, PCU decreased grain yield compared with urea, which could be related to a reduced N release early in the growing season. Compared with urea, higher N (at Zadoks scale 85) and protein concentrations (at Zadoks scale 92) with PCU were observed due to increased N availability later during the growing season. To increase wheat protein concentrations from using PCU, future studies should evaluate different mixtures of PCU and urea.

Background Fusarium head blight resistance genes, Fhb1 (for Type-II resistance), Fhb2 (Type-II), and Fhb5 (Type-I plus some Type-II), which originate from Sumai 3, are among the most important that confer resistance in hexaploid wheat. Near-isogenic lines (NILs), in the CDC Alsask (susceptible; n  = 32) and CDC Go (moderately susceptible; n  = 38) backgrounds, carrying these genes in all possible combinations were developed using flanking microsatellite markers and evaluated for their response to FHB and deoxynivalenol (DON) accumulation in eight environments. NILs were haplotyped with wheat 90 K iSelect assay to elucidate the genomic composition and confirm alleles’ presence. Other than evaluating the effects of three major genes in common genetic background, the study elucidated the epistatic gene interactions as they influence FHB measurements; identified loci other than Fhb1 , Fhb2 , and Fhb5 , in both recurrent and donor parents and examined annotated proteins in gene intervals. Results Genotyping using 81,857 single nucleotide polymorphism (SNP) markers revealed polymorphism on all chromosomes and that the NILs carried < 3% of alleles from the resistant donor. Significant improvement in field resistance (Type-I + Type-II) resulted only among the CDC Alsask NILs, not the CDC Go NILs. The phenotypic response of NILs carrying combinations of Sumai 3 derived genes suggested non-additive responses and Fhb5 was as good as Fhb1 in conferring field resistance in both populations. In addition to Fhb1 , Fhb2 , and Fhb5, four to five resistance improving alleles in both populations were identified and three of five in CDC Go were contributed by the susceptible parent. The introgressed chromosome regions carried genes encoding disease resistance proteins, protein kinases, nucleotide-binding and leucine rich repeats’ domains. Complex epistatic gene-gene interactions among marker loci (including Fhb1 , Fhb2 , Fhb5 ) explained > 20% of the phenotypic variation in FHB measurements. Conclusions Immediate Sumai 3 derivatives carry a number of resistance improving minor effect alleles, other than Fhb1 , Fhb2 , Fhb5 . Results verified that marker-assisted selection is possible for the introgression of exotic FHB resistance genes, however, the genetic background of the recipient line and epistatic interactions can have a strong influence on expression and penetrance of any given gene.

head blight (FHB) is one of the most destructive diseases in wheat worldwide. Breeding for FHB resistance is hampered by its complex genetic architecture, large genotype by environment interaction, and high cost of phenotype screening. Genomic selection (GS) is a powerful tool to enhance improvement of complex traits such as FHB resistance. The objectives of this study were to (1) investigate the genetic architecture of FHB resistance in a North Dakota State University (NDSU) hard red spring wheat breeding population, (2) test if the major QTL and play an important role in this breeding population; and (3) assess the potential of GS to enhance breeding efficiency of FHB resistance. A total of 439 elite spring wheat breeding lines from six breeding cycles were genotyped using genotyping-by-sequencing (GBS) and 102,147 SNP markers were obtained. Evaluation of FHB severity was conducted in 10 unbalanced field trials across multiple years and locations. One QTL for FHB resistance was identified and located on chromosome arm 1AL, explaining 5.3% of total phenotypic variation. The major type II resistance QTL only explained 3.1% of total phenotypic variation and the QTL was not significantly associated with FHB resistance in this breeding population. Our results suggest that integration of many genes with medium/minor effects in this breeding population should provide stable FHB resistance. Genomic prediction accuracies of 0.22-0.44 were obtained when predicting over breeding cycles in this study, indicating the potential of GS to enhance the improvement of FHB resistance.

There is growing interest in the application of natural ingredients to replace chemical dough improvers in bread formulations in order to meet consumer demands of clean label products. The goal of this study was to evaluate the dough quality and baking quality of hard red spring (HRS) wheat flour blends to replace commercial dough improvers. Hard red winter (HRW) wheat flour is commonly used in bread and diner roll formulations. In this study, doughs were prepared by adding 10%, 20%, 30%, and 40% of HRS wheat flour to HRW wheat base-flour to compare the dough quality and baking quality relative to different levels of commercial improvers. Additional to commercial HRS flour, two commonly grown HRS wheat varieties (Glenn and Linkert) were included in the study. All of the HRS wheat flour blends had significantly (p < 0.05) higher farinograph stability and extensograph resistance at 135 min than doughs containing most of the commercial additives. Bread flour with 40% Glenn and 40% Linkert showed the highest loaf volumes of 920 cm3 and 950 cm3, respectively with the firmness of 1553.50 and 1525.50 mN, respectively. Baking quality of HRS wheat flour blends also showed significant (p < 0.05) correlation with dough rheology but commercial additives did not have the correlations. Therefore, HRS wheat flour may be used as a replacement for dough improvers, as it had better dough and bread properties compared to commercial additives and provides a great alternative for “clean-label” bread products.