Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects.
AAC Icefield is the first hard white winter wheat (Triticum aestivum L.) cultivar registered in western Canada. It was selected from a population of F-1-derived doubled-haploids of the cross McClintock/83W020007. Registration testing occurred from 2013 to 2017. These data, collected over 53 site -years, showed that AAC Icefield yielded significantly more grain than CDC Buteo, was similar in yield to Flourish, Moats, and CDC Falcon, and was significantly lower yielding than AAC Elevate and Sunrise. AAC Icefield expressed fair survival, intermediate maturity, short straw, and very good lodging resistance. Test weight and kernel weight were within the range of the checks. Ratings based on the prevalent disease races in western Canada were summarized as resistant to stem rust, moderately resistant to leaf and stripe rust, intermediate in resistance to Fusarium head blight, and susceptible to common bunt. The grain yield, agronomic characteristics, and disease resistance attributes of AAC Icefield provide good adaptation for all areas of western Canada. Despite lower grain protein concentration than Canada Western Red Winter wheat cultivars, AAC Icefield showed exceptional gluten strength per unit of protein. AAC Icefield is well-suited to a wide range of end-uses including white and whole-grain pan bread, French and flat breads, Asian steamed bread, and noodles. Currently designated in the Canada Western Experimental wheat class to facilitate test marketing, a decision on permanent class placement for AAC Icefield will be made by the Canadian Grain Commission following the assessment of market interest.
Pintail is an awnless hard red winter wheat ( Triticum aestivum L.) cultivar that was registered in 2012 and is eligible for grades of Canada Western General Purpose (CWGP) wheat. It was developed using wheat x maize-pollen doubled haploid techniques. Evaluated across western Canada from 2008 to 2010 relative to CDC Harrier, CDC Falcon and CDC Ptarmigan, Pintail expressed grain yield ranging from 98.6 to 105.8% of these CWGP wheat checks. Its area of greatest adaptation was in the parkland and semi-arid prairie regions of Alberta and western Saskatchewan, where cold tolerance is a primary concern. Pintail exhibited excellent winter survival, intermediate maturity, medium height and strong straw. Test weight was within the range of the checks, and kernel weight was lower than all of the checks. Pintail displayed moderate resistance to stripe rust, moderate susceptibility to stem and leaf rust, and susceptibility to common bunt and Fusarium head blight. The high yield and awnless spike of Pintail should make it particularly attractive in various livestock feed and forage applications.
AAC Goldrush is a hard red winter wheat (Triticum aestivum L.) cultivar eligible for grades of Canada Western Red Winter wheat. It was developed using a modified pedigree breeding method. AAC Goldrush was tested in replicated trials across western Canada for 6 yr: 2 yr for initial characterization followed by 4 yr of evaluation in registration trials. Based on 41 station - years of registration trial data, AAC Goldrush yielded significantly more grain than CDC Buteo and was similar to Flourish, Moats, and AAC Elevate. AAC Goldrush expressed very good winter survival, intermediate maturity, medium height straw with good lodging resistance, and average size kernels. Disease ratings at the time of registration were resistant to the prevalent races of leaf rust, moderately resistant to stem rust, intermediate in resistance to stripe rust and Fusarium head blight, and susceptible to common bunt. Leaf spot reactions were similar to the best check. The grain yield, agronomic characteristics, and disease resistance attributes of AAC Goldrush make it particularly well-suited to the eastern Prairie region of western Canada where CDC Buteo has been popular.
Background and aims Nitrogen (N) nutrition is a critical factor in zinc (Zn) acquisition and its allocation into grain of wheat (Triticum aestivum L.). Most of the information collected about this topic is, however, derived from the pot experiments. It is also not known whether optimal N management by decreasing N input could affect the Zn status in grain and plant in the field. The aim of this research is to investigate the impact of N management on grain and shoot Zn status of winter wheat. Methods Field experiments were conducted in two cropping seasons. Results Results showed applying N at optimal rate (198 kgN ha−1 in 2007–2008 and 195 kgN ha−1 in 2008–2009) maintained or resulted in significantly higher grain Zn concentration and especially grain content of Zn compared to no or lower N treatments. For example, grain Zn concentration increased from 21.5 mgkg−1 in the control to 30.9 mgkg−1 with optimized N supply in 2007–2008 and from 24.7 mg kg−1 in the control to 29.1 mgkg−1 with optimized N supply in 2008–2009. Further increasing N supply from optimal to excessive N supply resulted in non-significant increases in grain Zn concentration and content. Generally, similar trends were also found in shoot Zn. Moreover, 72 % to 100 % of the shoot Zn requirement had been accumulated at anthesis, and accordingly 67 % to 100 % of grain Zn content was provided by Zn remobilization from pre-anthesis Zn uptake with N supply. Grain Zn accumulation mainly originates from Zn remobilization and the optimal N management would ensure better shoot Zn nutrition to contribute to increasing Zn remobilization from vegetative tissues and to maintain relatively higher grain Zn for better human nutrition.
Hybrid wheat breeding is gaining prominence worldwide because it ensures higher and more static yield than conventionally bred varieties. The cleistogamous floral architecture of wheat (Triticum aestivurn L.) impedes anthers inside the floret, making it largely an inbreeder. For hybrid seed production, high anther extrusion is needed to promote cross pollination and to ensure a high level of pollen availability for the seed plant. This study, therefore, aimed at the genetic dissection of anther extrusion (AE) in panels of spring (SP), and winter wheat (WP) accessions by genome wide association studies (GWAS). We performed GWAS to identify the SNP markers potentially linked with AE in each panel separately. Phenotypic data were collected for 3 years for each panel. The average levels of Pearson's correlation (r) among all years and their best linear unbiased estimates (BLUEs) within both panels were high (r(SP) = 0.75, P 3.0) marker trait associations (MIAs) were detected (SP = 11; WP = 12). Anther extrusion behaved as a complex trait with significant markers having either favorable or unfavorable additive effects and imparting minor to moderate levels of phenotypic variance (R-2 (SP) = 9.75 - 14.24%; R-2 (WP) = 9.44 - 16.98%). All mapped significant markers as well as the markers within their significant linkage disequilibrium (r(2) >= 0.30) regions were blasted against wheat genome assembly (IWGSC1+popseq) to find the corresponding genes and their high confidence descriptions were retrieved. These genes and their orthologs in Hordeum vulgare, Brachypodium distachyon, Oryza sativa. and Sorghum bicolor revealed syntenic genomic regions potentially involved in flowering related traits. Moreover, the expression data of these genes suggested potential candidates for AE. Our results suggest that the use of significant markers can help to introduce AE in high yielding varieties to increase cross fertilization rates and improve hybrid-seed production in wheat.
AAC Wildfire is a hard red winter wheat (Triticum aestivum L.) cultivar eligible for grades of Canada Western Red Winter (CWRW) wheat. It was developed using a modified pedigree breeding method. AAC Wildfire was evaluated across western Canada for four years in the Western Winter Wheat Cooperative registration trials, where it yielded significantly more grain than all of the checks (Radiant, CDC Buteo, Flourish, Moats) and expressed very good winter survival, relatively late maturity, medium height straw with very good lodging resistance, large kernels, acceptable end-use quality, and disease resistance appropriate for the western region of the Canadian prairies. AAC Wildfire was resistant to the prevalent races of stripe rust, moderately resistant to Fusarium head blight and common bunt, showed improved leaf spot reaction, and tolerance to the original biotype of Russian wheat aphid (Diuraphis noxia Mordvilko) in North America. In the absence of effective fungicides, production of AAC Wildfire in the eastern Prairies is not recommended due to stem rust susceptibility.
O-GlcNAcylation and phosphorylation are two posttranslational modifications that antagonistically regulate protein function. However, the regulation of and the cross talk between these two protein modifications are poorly understood in plants. Here we investigated the role of O-GlcNAcylation during vernalization, a process whereby prolonged cold exposure promotes flowering in winter wheat (Triticum aestivum), and analyzed the dynamic profile of O-GlcNAcylated and phosphorylated proteins in response to vernalization. Altering O-GlcNAc signaling by chemical inhibitors affected the vernalization response, modifying the expression of VRN genes and subsequently affecting flowering transition. Over a vernalization time-course, O-GlcNAcylated and phosphorylated peptides were enriched from winter wheat plumules by Lectin weak affinity chromatography and iTRAQ-TiO2, respectively. Subsequent mass spectrometry and gene ontology term enrichment analysis identified 168 O-GlcNAcylated proteins that are mainly involved in responses to abiotic stimulus and hormones, metabolic processing, and gene expression; and 124 differentially expressed phosphorylated proteins that participate in translation, transcription, and metabolic processing. Of note, 31 vernalization-associated proteins were identified that carried both phosphorylation and O-GlcNAcylation modifications, of which the majority (97%) exhibited the coexisting module and the remainder exhibited the potential competitive module. Among these, TaGRP2 was decorated with dynamic O-GlcNAcylation (S87) and phosphorylation (S152) modifications, and the mutation of S87 and S152 affected the binding of TaGRP2 to the RIP3 motif of TaVRN1 in vitro. Our data suggest that a dynamic network of O-GlcNAcylation and phosphorylation at key pathway nodes regulate the vernalization response and mediate flowering in wheat.