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AAC Kongsore is a white-hulled spring oat ( Avena sativa L.) cultivar selected and developed under organic management. AAC Kongsore had high yields under organic and conventional production systems, compared to check cultivars (AAC Oravena, Leggett, AC Morgan and CDC Dancer). AAC Kongsore has good physical and milling quality traits.

Marker-assisted selection requires the identification of molecular markers associated with major genes and quantitative trait loci (QTLs). In this study, we used 167 doubled haploid lines derived from two unregistered spring wheat ( Triticum aestivum L.) parental lines that belong to the Canada Western Special Purpose wheat market class to map QTLs associated with five traits using inclusive composite interval mapping (ICIM). Using ICIM, the least-squares means phenotype data across three to four environments, and a genetic map of 2676 single-nucleotide polymorphisms (SNPs) out of the wheat 90K SNP array, we identified 10 QTLs associated with days to maturity (4A and 5B), plant lodging (4B, 5A, 5D, and 7D), grain yield (2D), leaf rust (4A), and stem rust (1A and 2B). Each QTL individually explained 6.0%–22.3% of the phenotypic variance and together accounted for 8.6%–38.2% of the total variance per trait. Two of the QTLs associated with rusts ( QLr.dms-4A and QSr.dms-1A) had a minor effect (6.0%–9.0%), whereas the second QTL for stem rust ( QSr.dms-2B) had a major effect (22.3%). Although chromosome 2B harbors multiple disease resistance QTLs, the physical location of QSr.dms-2B has not been reported in previous studies. Results from this study provide additional valuable information to wheat researchers; in particular, the area on chromosome 2B should be considered for future analyses.

Grain protein concentration (GPC) is considered one of the most important quality factors, and it has remained a major culling criterion in the Canadian wheat cultivar development and registration process. However, grain protein composition also plays a critical role in determining the end-use quality of cereal-based products. The objective of this study was to determine whether high-yielding, lower protein Canada Western Red Spring (CWRS) analog wheat lines can exhibit acceptable baking properties (comparable with CWRS cultivars) under contrasting soil nitrogen levels. Five CWRS-analog lines together with four CWRS and one Canada Prairie Spring Red wheat cultivar, representing wide ranges of quality and grain yield potential, were assessed for agronomic and quality traits in multi-environment trials at three locations and five nitrogen fertilizer rates. CWRS analog lines produced significantly higher grain yield and, on average, 0.9% less GPC than the CWRS cultivars. Despite the lower GPC, CWRS-analog lines such as W07786 exhibited suitable and stable baking performance across all nitrogen levels. Based on the genotype × trait biplot analysis, CWRS-analog baking properties were mainly associated with sodium dodecyl sulfate sedimentation and flour water absorption. Our findings revealed that it is possible to develop wheat cultivars with up to 15% higher grain yield than modern CWRS cultivars and comparable end-use characteristics by reducing current GPC requirements (by up to 1%) while simultaneously selecting for improved baking attributes. This would facilitate an increase in CWRS grain yield genetic gains while maintaining favorable end-use quality and improving the crop competitiveness in western Canada.

Plants exhibit differential behaviours through changes in biomass development and distribution in response to environmental cues, which may impact crops uniquely. We conducted a mesocosm experiment in pots to determine the root and shoot behavioural responses of wheat, T. aestivum. Plants were grown in homogeneous or heterogeneous and heavily or lightly fertilized soil, and alone or with a neighbour of the same or different genetic identity (cultivars: CDC Titanium, Carberry, Glenn, Go Early, and Lillian). Contrary to predictions, wheat did not alter relative reproductive effort in the presence of neighbours, more nutrients, or homogenous soil. Above and below ground, the plants’ tendency to use potentially shared space exhibited high levels of plasticity. Above ground, they generally avoided shared, central aerial space when grown with neighbours. Unexpectedly, nutrient amount and distribution also impacted shoots; plants that grew in fertile or homogenous environments increased shared space use. Below ground, plants grown with related neighbours indicated no difference in neighbour avoidance. Those in homogenous soil produced relatively even roots, and plants in heterogeneous treatments produced more roots in nutrient patches. Additionally, less fertile soil resulted in pot-level decreases in root foraging precision. Our findings illustrate that explicit coordination between above- and belowground biomass in wheat may not exist.

This study performed comprehensive analyses on the predictive abilities of single-trait and two multi-trait models in three populations. Our results demonstrated the superiority of multi-traits over single-trait models across seven agronomic and four to seven disease resistance traits of different genetic architecture. The predictive ability of multi-trait and single-trait prediction models has not been investigated on diverse traits evaluated under organic and conventional management systems. Here, we compared the predictive abilities of 25% of a testing set that has not been evaluated for a single trait (ST), not evaluated for multi-traits (MT1), and evaluated for some traits but not others (MT2) in three spring wheat populations genotyped either with the wheat 90K single nucleotide polymorphisms array or DArTseq. Analyses were performed on seven agronomic traits evaluated under conventional and organic management systems, four to seven disease resistance traits, and all agronomic and disease resistance traits simultaneously. The average prediction accuracies of the ST, MT1, and MT2 models varied from 0.03 to 0.78 (mean 0.41), from 0.05 to 0.82 (mean 0.47), and from 0.05 to 0.92 (mean 0.67), respectively. The predictive ability of the MT2 model was significantly greater than the ST model in all traits and populations except common bunt with the MT1 model being intermediate between them. The MT2 model increased prediction accuracies over the ST and MT1 models in all traits by 9.0-82.4% (mean 37.3%) and 2.9-82.5% (mean 25.7%), respectively, except common bunt that showed up to 7.7% smaller accuracies in two populations. A joint analysis of all agronomic and disease resistance traits further improved accuracies within the MT1 and MT2 models on average by 21.4% and 17.4%, respectively, as compared to either the agronomic or disease resistance traits, demonstrating the high potential of the multi-traits models in improving prediction accuracies.

Ultra-early wheat growing systems based on soil temperature triggers for planting instead of arbitrary calendar dates can increase grain yield and overall growing system stability of spring wheat (Triticum aestivum L.) on the northern Great Plains. We conducted field trials at three sites in western Canada from 2017 to 2019 to evaluate the suitability of Canadian spring hexaploid wheat cultivars and market classes for use within ultra-early spring wheat growing systems. All cultivars and classes exhibited improved grain yield stability (lower adjusted coefficient of variation values) and optimal grain yield when planted ultra-early at 2 °C soil temperature rather than delaying planting to 8 °C.

AAC Oravena is a white-hulled spring oat (Avena sativa L.) cultivar selected and developed under organic management. AAC Oravena yields well under organic and conventional production systems, compared with check cultivars. AAC Oravena has good milling quality. AAC Oravena was registered (Reg. No. 7561) by the Variety Registration Office, Canada Food Inspection Agency, on 3 July 2014.

Stripe rust, caused by Puccinia striiformis Westend. f.sp. tritici Erikss. (Pst), is one of the most devastating diseases of wheat (Triticum aestivum L.) globally. Exploring and utilizing new sourc...

Noor hard red spring wheat (Triticum aestivum L.) was developed using a modified bulk breeding method at the University of Alberta, Edmonton, AB Canada. Noor is an apically awnletted, hollow-stemmed line with a combination of high yield potential, good lodging tolerance, and medium maturity. During the three years (2016–2018) of evaluation in the Parkland Wheat Cooperative test, Noor yielded 12% higher than the mean of all the checks and matured similarly to Carberry and Glenn, but 3.1 and 2.6 d later than AC Splendor and Parata, respectively. Noor was 94.9 cm tall, shorter than AC Splendor (98.4 cm), similar in height to Glenn (94.0 cm) and Parata (93.5 cm), but taller than Carberry (86.0 cm). The lodging score of Noor (2.1) was lower than Parata (3.0) and AC Splendor (3.0), but similar to Carberry (2.3) and Glenn (2.1). The test weight (kg·hL−1) of Noor (80.0) was higher than AC Splendor (78.6), similar to Carberry (80.2) and Parata (80.4), but lower than Glenn (82.2). Grain weight (35 g) and NIR protein of Noor (14.1%) was lower than all the checks. Overall, Noor was rated resistant (R) to the prevalent races of leaf, stem, and stripe rusts during the three years of testing. Noor was rated intermediate (I) to common bunt and Fusarium head blight. Three years of end-use quality evaluation indicated that Noor is acceptable for the Canada Western Red Spring class, with fewer flags.

Using 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.

QTL analyses of two bi-parental mapping populations with AC Barrie as a parent revealed numerous FHB-resistance QTL unique to each population and uncovered novel variation near Fhb1. Fusarium head blight (FHB) is a destructive disease of wheat worldwide, leading to severe yield and quality losses. The genetic basis of native FHB resistance was examined in two populations: a recombinant inbred line population from the cross Cutler/AC Barrie and a doubled haploid (DH) population from the cross AC Barrie/Reeder. Numerous QTL were detected among the two mapping populations with many being cross-specific. Photoperiod insensitivity at Ppd-D1 and dwarfing at Rht-B1 and Rht-D1 was associated with increased FHB susceptibility. Anthesis date QTL at or near the Vrn-A1 and Vrn-B1 loci co-located with major FHB-resistance QTL in the AC Barrie/Reeder population. The loci were epistatic for both traits, such that DH lines with both late alleles were considerably later to anthesis and had reduced FHB symptoms (i.e., responsible for the epistatic interaction). Interestingly, AC Barrie contributed FHB resistance near the Fhb1 locus in the Cutler population and susceptibility in the Reeder population. Analyses of the Fhb1 candidate genes PFT and TaHRC confirmed that AC Barrie, Cutler, and Reeder do not carry the Sumai-3 Fhb1 gene. Resistance QTL were also detected at the expected locations of Fhb2 and Fhb5. The native FHB-resistance QTL detected near Fhb1, Fhb2, and Fhb5 do not appear to be as effective as Fhb1, Fhb2, and Fhb5 from Sumai-3. The presence of awns segregated at the B1 awn inhibitor locus in both populations, but was only associated with FHB resistance in the Cutler/AC Barrie population suggesting linkage caused the association rather than pleiotropy.

Jake hard red spring wheat (Triticum aestivum L.) was developed using a modified bulk breeding method at the University of Alberta, Edmonton, AB. Jake is an awned, hollow-stemmed line with high yield potential, medium tall plants, and medium maturity. During the three years (2015–2017) of evaluation in the Parkland Wheat Cooperative test, Jake yielded 6% higher than the mean of all of the checks, and matured 0.7 and 1.7 d later than Parata and Splendor but 2.9 d earlier than Glenn. Jake was 91.2 cm tall, shorter than AC Splendor (95.8 cm), but similar in height to Glenn (91.8 cm) and Parata (92 cm). The lodging score of Jake (2.2) was lower than Parata (3.1) and AC Splendor (3.1), but similar to Glenn. The test weight of Jake (80.8) was higher than AC Splendor (78.3), similar to Parata (80.5), but lower than Glenn (82.5). The grain weight of Jake (35.6 g) was similar to Parata (35.6 g), but lower than Glenn (36.7 g) and AC Splendor (37.4 g), while the NIR Protein of Jake (15.9%) was higher than Glenn (15.5%) and similar to the other checks. Jake was moderately resistant to resistant to leaf, stem, and stripe rusts, and moderately resistant to common bunt during the 3 yr of testing. The reaction of Jake to Fusarium head blight was variable and ranged from moderately susceptible to moderately resistant, with DON values similar to Carberry and Glenn. Three years of end-use quality evaluation has indicated that Jake is acceptable for the CWRS class.

Some studies have investigated the potential of genomic selection (GS) on stripe rust, leaf rust, Fusarium head blight (FHB), and leaf spot in wheat, but none of them have assessed the effect of the reaction norm model that incorporated GE interactions. In addition, the prediction accuracy on common bunt has not previously been studied. Here, we investigated within-population prediction accuracies using the baseline M1 model and two reaction norm models (M2 and M3) with three random cross-validation (CV1, CV2, and CV0) schemes. Three Canadian spring wheat populations were evaluated in up to eight field environments and genotyped with 3158, 5732, and 23,795 polymorphic markers. The M3 model that incorporated GE interactions reduced residual variance by an average of 10.2% as compared with the main effect M2 model and increased prediction accuracies on average by 2–6%. In some traits, the M3 model increased prediction accuracies up to 54% as compared with the M2 model. The average prediction accuracies of the M3 model with CV1, CV2, and CV0 schemes varied from 0.02 to 0.48, from 0.25 to 0.84, and from 0.14 to 0.87, respectively. In both CV2 and CV0 schemes, stripe rust in all three populations, common bunt and leaf rust in two populations, as well as FHB severity, FHB index, and leaf spot in one population had high to very high (0.54–0.87) prediction accuracies. This is the first comprehensive genomic selection study on five major diseases in spring wheat.

Using phenotype data of three spring wheat populations evaluated at 6-15 environments under two management systems, we found moderate to very high prediction accuracies across seven traits. The phenotype data collected under an organic management system effectively predicted the performance of lines in the conventional management and vice versa. There is growing interest in developing wheat cultivars specifically for organic agriculture, but we are not aware of the effect of organic management on the predictive ability of genomic selection (GS). Here, we evaluated within populations prediction accuracies of four GS models, four combinations of training and testing sets, three reaction norm models, and three random cross-validations (CV) schemes in three populations phenotyped under organic and conventional management systems. Our study was based on a total of 578 recombinant inbred lines and varieties from three spring wheat populations, which were evaluated for seven traits at 3-9 conventionally and 3-6 organically managed field environments and genotyped either with the wheat 90 K SNP array or DArTseq. We predicted the management systems (CV0

Using 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.

In previous studies, we reported quantitative trait loci (QTL) associated with the heading, flowering, and maturity time in four hard red spring wheat recombinant inbred line (RIL) populations but the results are scattered in population-specific genetic maps, which is challenging to exploit efficiently in breeding. Here, we mapped and characterized QTL associated with these three earliness traits using the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq v2.0 physical map. Our data consisted of (i) 6526 single nucleotide polymorphisms (SNPs) and two traits evaluated at five conventionally managed environments in the ‘Cutler’ × ‘AC Barrie’ population, (ii) 3158 SNPs and two traits evaluated across three organic and seven conventional managements in the ‘Attila’ × ‘CDC Go’ population, (iii) 5731 SilicoDArT and SNP markers and the three traits evaluated at four conventional and organic management systems in the ‘Peace’ × ‘Carberry’ population, and (iv) 1058 SNPs and two traits evaluated across two conventionally and organically managed environments in the ‘Peace’ × ‘CDC Stanley’ population. Using composite interval mapping, the phenotypic data across all environments, and the IWGSC RefSeq v2.0 physical maps, we identified a total of 44 QTL associated with days to heading (11), flowering (10), and maturity (23). Fifteen of the 44 QTL were common to both conventional and organic management systems, and the remaining QTL were specific to either the conventional (21) or organic (8) management systems. Some QTL harbor known genes, including the Vrn-A1, Vrn-B1, Rht-A1, and Rht-B1 that regulate photoperiodism, flowering time, and plant height in wheat, which lays a solid basis for cloning and further characterization.

Ultra-early seeding of spring wheat (Triticum aestivum L.) on the northern Great Plains can increase grain yield and grain yield stability compared to current spring wheat planting systems. Field trials were conducted in western Canada from 2015 to 2018 to evaluate the impact of optimal agronomic management on grain yield, quality, and stability in ultra-early wheat seeding systems. Four planting times initiated by soil temperature triggers were evaluated. The earliest planting was triggered when soils reached 0&ndash, 2.5 &deg, C at a 5 cm depth, with the subsequent three plantings completed at 2.5 &deg, C intervals up to soil temperatures of 10 &deg, C. Two spring wheat lines were seeded at each planting date at two seeding depths (2.5 and 5 cm), and two seeding rates (200 and 400 seeds m&minus, 2). The greatest grain yield and stability occurred from combinations of the earliest seeding dates, high seeding rate, and shallow seeding depth, wheat line did not influence grain yield. Grain protein content was greater at later seeding dates, however, the greater grain yield at earlier seeding dates resulted in more protein production per unit area. Despite extreme ambient air temperatures below 0 &deg, C after planting, plant survival was not reduced at the earliest seeding dates. Planting wheat as soon as feasible after soil temperatures reach 0 &deg, C, and prior to soils reaching 7.5&ndash, 10 &deg, C, at an optimal seeding rate and shallow seeding depth increased grain yield and stability compared to current seeding practices. Adopting ultra-early wheat seeding systems on the northern Great Plains will lead to additional grain yield benefits as climate change continues to increase annual average growing season temperatures.

Early seeding has been suggested as a method of increasing the grain yield and grain yield stability of wheat (Triticum aestivum L.) in the Northern Great Plains. The point at which early seeding results in a decrease in grain yield has not been clearly identified. Changes in climatic conditions have increased frost-free periods and increased temperatures during grain filling, which can either be taken advantage of or avoided by seeding earlier. Field trials were conducted in western Canada from 2015 to 2018 to evaluate an ultra-early wheat planting system based on soil temperature triggers as opposed to calendar dates. Planting began when soil temperatures at 5 cm depth reached 0°C and continued at 2°C intervals until 10°C, regardless of calendar date. Conventional commercial spring wheat genetics and newly identified cold tolerant spring wheat lines were evaluated to determine if ultra-early wheat seeding systems required further development of specialized varieties to maintain system stability. Ultra-early seeding resulted in no detrimental effect on grain yield. Grain yield increased at sites south of 51° latitude N, and was unaffected by ultra-early seeding at sites north of 51° latitude N. Grain protein content, kernel weight, and bulk density were not affected by ultra-early seeding. Optimal seeding time was identified between 2 and 6°C soil temperatures. A greater reduction in grain yield was observed from delaying planting until soils reached 10°C than from seeding into 0°C soils; this was despite extreme environmental conditions after initial seeding, including air temperatures as low as -10.2°C, and as many as 37 nights with air temperatures below 0°C. Wheat emergence ranged from 55 to 70%, and heads m-2 decreased with delayed seeding while heads plant-1 did not change. Cold tolerant wheat lines did not increase stability of the ultra-early wheat seeding system relative to the conventional spring wheat check, and are therefore not required for growers to adopt ultra-early seeding. The results of this study indicate that growers in western Canada can successfully begin seeding wheat earlier, with few changes to their current management practices, and endure less risk than delaying seeding until soil temperatures reach 10°C or greater.

Zealand hard red spring wheat (Triticum aestivum L.) was developed using a modified bulk breeding method at the University of Alberta in Edmonton, AB. Zealand is an apically awn-letted, hollow-stemmed cultivar with a combination of high yield potential, tall plant type, large leaves, and early maturity. In three years of testing in the Western Bread Wheat Cooperative Registration Test during 2013–2015, Zealand exhibited grain yield similar to Glenn and Carberry and 5%–6% lower than Unity and AAC Viewfield, though this difference was not significant (p > 0.05). Zealand yielded 37% greater than the highest-yielding Canada Western Red Spring (CWRS) check, CDC Osler, in A-level testing at a certified organic farm. Zealand matured 1–4 d earlier and was taller than all the check cultivars, but exhibited lodging resistance better than Unity and similar to the other checks. The test weight of Zealand (79.1 kg hL−1) was lower than Glenn and similar to the other checks, while its seed mass was in the range of the check cultivars. Overall, Zealand was rated as resistant (R) to the prevalent races of leaf rust, moderately resistant (MR) to stripe rust and loose smut, intermediate (I) to stem rust and leaf spot, and moderately susceptible (MS) to common bunt and Fusarium head blight. Three years of end-use quality evaluation indicated that Zealand is acceptable for the CWRS class, with relatively few weaknesses. The tall plant type, large leaves, and early maturity render Zealand suitable for organic/high weed environments.

Visual diagnosis of plant disease following a visually evident epidemic results in untimely and excessive application of pesticide. Conventional nondestructive testing methods are difficult for early recognition before the onset of symptoms. In this study, tomato mosaic disease and wheat leaf rust were taken as examples. Infrared thermal imaging technology was used to continuously detect the temperature information of the two crops during the incubation period following the introduction of inoculum. Diseases of tomato and wheat were induced by rubbing inoculation and spray inoculation, respectively. Maximum temperature difference (MTD) was calculated to characterize the continuous temperature change during the incubation period. The results showed that the MTD of tomato mosaic disease ranged from 0.2°C ~ 1.7°C, and that of wheat leaf rust 0.4°C ~ 2°C. As the disease progresses, the MTD of both plants showed an increasing trend while the average temperature decreased. The time to observe the symptoms earlier than the naked eye for tomato mosaic and wheat leaf rust is 5d and 7d respectively. Studies showed that it is feasible to realize the early determination of disease through the combination of infrared thermal imaging and MTD calculation. It provides the theoretical basis and method basis for the early and accurate application of spraying.

Better management of synthetic nitrogen (N) fertilizers in conventional agricultural systems laid the foundation for feeding the increasing world's population since the Green Revolution. However, excessive reliance on inorganic fertilizer has resulted in environmental degradation issues. Difficulties in soil nutrition management in organic cropping systems often results in lower and variable yields, also raising questions of sustainability. Improving nitrogen use efficiency (NUE) is thus of key importance to overcome environmental concerns in conventional systems and production limitations in organic systems. The differences in the two farming systems have impacts on crop traits and N cycles, making it difficult to enhance NUE with a single strategy. Different approaches need to be adopted to improve NUE in each system. Extensive efforts have been made to better understand mechanisms to potentially improve NUE in cereal crops under both systems. This review suggests that NUE may be improved through a combination of management practices and breeding strategies specific to the management system. Diversified crop rotations with legumes are effective practices to optimize the N cycle in both conventional and organic systems. Best Management Practices coupled with nitrification inhibitors, controlled release products and split-application practices can reduce N loss in conventional systems. In organic systems, we need to take advantage of available N sources and adapt practices such as no-tillage, cover crops, and catch crops. Utilization of beneficial soil microorganisms is fundamental to optimizing availability of soil N. Estimation of soil organic matter mineralization using prediction models may be useful to enhance NUE if models are calibrated for target environments. Cereal crops are often bred under optimum N conditions and may not perform well under low N conditions. Thus, breeders can integrate genetic and phenotypic information to develop cultivars adapted to specific environments and cultivation practices. The proper choice and integration of strategies can synchronize N demand and supply within a system, resulting in reduced risk of N loss while improving NUE in both conventional and organic systems.

Pyrenophora tritici-repentis (Ptr), the cause of tan spot of wheat, is a foliar pathogen of economic importance worldwide. Tan spot development is associated with the production of necrotrophic effectors (Ptr ToxA, Ptr ToxB and Ptr ToxC) that serve as fungal pathogenicity and/or virulence factors. The objective of this study was to investigate the sensitivity to each of these effectors in a collection of 100 Canadian wheat cultivars representing all wheat classes and developed over a century by various Canadian breeding programmes. Heterologously expressed, His-tagged Ptr ToxA and Ptr ToxB, and spore germination fluids possessing putative Ptr ToxC activity, were produced and used to screen the cultivars for sensitivity. Of the 100 wheat cultivars tested, 92 were sensitive to at least one effector, 68 were sensitive to Ptr ToxA, 63 were sensitive to Ptr ToxC and 24 were sensitive to Ptr ToxB. Only eight cultivars were insensitive to all three effectors. These results reflect the widespread sensitiv...

Growing resistant wheat (Triticum aestivum L) varieties is an important strategy for the control of leaf rust, caused by Puccinia triticina Eriks. This study sought to identify the chromosomal location and effects of leaf rust resistance loci in five Canadian spring wheat cultivars. The parents and doubled haploid lines of crosses Carberry/AC Cadillac, Carberry/Vesper, Vesper/Lillian, Vesper/Stettler and Stettler/Red Fife were assessed for leaf rust severity and infection response in field nurseries in Canada near Swift Current, SK from 2013 to 2015, Morden, MB from 2015 to 2017 and Brandon, MB in 2016, and in New Zealand near Lincoln in 2014. The populations were genotyped with the 90K Infinium iSelect assay and quantitative trait loci (QTL) analysis was performed. A high density consensus map generated based on 14 doubled haploid populations and integrating SNP and SSR markers was used to compare QTL identified in different populations. AC Cadillac contributed QTL on chromosomes 2A, 3B and 7B (2 loci), Carberry on 1A, 2B (2 loci), 2D, 4B (2 loci), 5A, 6A, 7A and 7D, Lillian on 4A and 7D, Stettler on 2D and 6B, Vesper on 1B, 1D, 2A, 6B and 7B (2 loci), and Red Fife on 7A and 7B. Lillian contributed to a novel locus QLr.spa-4A, and similarly Carberry at QLr.spa-5A. The discovery of novel leaf rust resistance QTL QLr.spa-4A and QLr.spa-5A, and several others in contemporary Canada Western Red Spring wheat varieties is a tremendous addition to our present knowledge of resistance gene deployment in breeding. Carberry demonstrated substantial stacking of genes which could be supplemented with the genes identified in other cultivars with the expectation of increasing efficacy of resistance to leaf rust and longevity with little risk of linkage drag.

Parata is a hard red spring wheat developed at the University of Alberta. In three years of testing in the Parkland Cooperative Registration Test, Parata was higher yielding (P −1, while seed mass was within the range of the check cultivars. Parata was rated resistant to the prevalent races of stem and stripe rust in three years of testing. It was rated R/MR in two years and MS in one year for leaf rust; and was I in two years and S in one year for common bunt. The FHB disease indices for Parata ranged from MS (1 rating) to MR in six station years. Three years of end-use quality evaluation has indicated that Parata is acceptable for the CWRS class, with improvements especially in flour yield and flour ash.

Genetic variation is prerequisite for wheat improvement. High grain yield and protein content and early maturity are some of the major objectives in global as well as Canadian wheat breeding programs. We investigated genetic diversity for earliness related and plant height reducing (Rht) genes in 82 spring wheat cultivars, registered in western Canada, through eight diagnostic DNA markers. Allelic variation was observed at the Vrn-A1, Vrn-B1, Vrn-D1 and Ppd-D1 loci but not at Ppd-A1 and Ppd-B1 loci in the 82 cultivars. Spring type allele of Vrn-A1 was present in 94 % cultivars, whereas only two cultivars carried spring allele of Vrn-D1. Among the four earliness related genes, the most frequent combination was Vrn-A1a, Vrn-B1, vrn-D1 and Ppd-D1b, which was found in 32 cultivars. As for the Rht genes, eight cultivars had Rht-B1b and 13 cultivars had Rht-D1b. All cultivars carrying dominant allele of Vrn-B1, photoperiod-insensitive allele of Ppd-D1 and height reducing allele of Rht-1 had shorter plants and higher grain yield but lower grain protein content. Days to heading and maturity showed positive genetic (rg = 0.65) and phenotypic (rp = 0.44) correlation, and were also positively correlated with grain yield and kernel weight but negatively correlated with test weight and protein content. Plant height was positively correlated with grain protein content (rg = 0.53; rp = 0.42), but negatively correlated with grain yield (rg = −0.47; rp = −0.14). Grain yield and protein content showed negative genetic correlation (rg = −0.57). Among the sixty cultivars from Canada Western Red Spring Class released over 100 years, the newest cultivar yielded 23 % more grain and had 15 % higher grain protein than the oldest cultivar ‘Red Fife’. Breeders in western Canada have incorporated vernalization and photoperiod insensitive and Rht genes in modern cultivars to promote early maturity, to make use of off-season nurseries abroad, and to improve lodging tolerance.

Kubota, H., Quideau, S. A., Hucl, P. J. and Spaner, D. M. 2015. The effect of weeds on soil arbuscular mycorrhizal fungi and agronomic traits in spring wheat (Triticum aestivum L.) under organic management in Canada. Can. J. Plant Sci. 95: 615–627. Understanding the influence of weeds in agroecosystems may aid in developing efficient and sustainable organic wheat production systems. We examined the effect of weeds on soil microbial communities and the performance of spring wheat (Triticum aestivum L.) under organic management in Edmonton, AB, Canada. We grew 13 Canadian spring wheat cultivars in organically managed hand-weeded less-weedy and weedy treatments in 2010 and 2011. The less-weedy treatment exhibited greater grain yield and tillers per square meter, while kernel weight, test weight, days to maturity, plant height, grain P and protein content were not altered by weed treatment. Canada Western Red Spring (CWRS) wheat cultivars CDC Go and CDC Kernen were the most yield-stable because they minimized fertile tiller reduction in response to weed pressure (10 and 13% reduction, respectively, compared with the average reduction of 20%). Other cultivars exhibited yield stability through increased kernel weight. The contribution of arbuscular mycorrhizal fungi (AMF) to the total phospholipid fatty acid increased in both treatments; however, the rate of this increase was greater in the weedy treatment than the less-weedy treatment (from 2.9 to 3.9%, from 2.8 to 3.1%, respectively). Weed dry biomass was positively correlated with AMF% in the less-weedy treatment only. Organic systems tend to be weedier than conventional systems. We found that weeds are important determinants of AMF proliferation in soil. In addition, choosing wheat cultivars that maintain important yield components under severe weed stress is one strategy to maximize yields in organic systems.

A randomly derived recombinant inbred line (RIL) population (n = 163) from a cross between CIMMYT spring wheat ‘Attila’ and the Canadian ‘CDC Go’ was used to map quantitative trait loci (QTL) affecting various agronomic and quality traits. The experiment was also designed to investigate the feasibility of organic wheat breeding by determining selection differentials and the effect of Rht-B1 in paired organic and conventional management systems. Heritability estimates differed between systems for five of nine traits measured; including grain yield, number of tillers, plant height, kernel weight, and grain protein content. Direct selection in each management system resulted in 50% or fewer selected individuals in common between the two systems, for eight of the nine (except for flowering time) studied traits. Most QTL were specific to either the organic or the conventional management system. However, consistent QTL for grain yield, grain volume weight, kernel weight, and days to flowering were mapped in both systems on chromosomes 6A, 1B, 3A, and 5B, respectively. The effect of Rht-B1 was more pronounced in organic systems, where RILs carrying the wild-type allele were taller, produced more grain yield with higher grain protein content, and suppressed weed biomass to a greater extent than those carrying dwarfing alleles. Results of the present study suggest that differences exist between the two management systems for QTL effects. Indirect selection of superior genotypes from one system to another will not result in the advancement of the best possible genotypes. Therefore, selection of spring wheat cultivars for organic systems should be conducted on organically managed lands.