No abstract

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat (Triticum aestivum L.). Deployment of resistant wheat cultivars is one of the best strategies to mitigate disease-associated risks. The genotype P2711 possesses effective stripe rust resistance under field conditions in western Canada, however, the genetic basis of this resistance is unknown. To identify resistance, a recombinant inbred line (RIL) population comprised of 252 RILs was developed from the cross AAC Cameron/P2711. This population was evaluated for stripe rust severity at the adult plant stage in Creston, BC (in 2018, 2019, and 2020) and Lethbridge, AB (in 2018 and 2020), and was genotyped using the wheat 90K iSelect single nucleotide polymorphism (SNP) assay. A high-density genetic map comprised of 8,915 markers was constructed covering all the wheat chromosomes. Four resistance quantitative trait loci (QTLs) were contributed by P2711 and three from AAC Cameron. QYr.lrdc-2A.1, corresponding to the Yr17 gene, was the most stable QTL and detected in four out of five environments, whereas QYr.lrdc-2B was the second most stable QTL. These two QTL along with QYr.lrdc-5A showed a significant reduction in stripe rust severity when present together. Where most of the QTLs detected in both locations, QYr.lrdc-1A.1 and QYr.lrdc-1A.2, both were detected only in Creston, BC. Stable QTLs on chromosome 2A, 2B, and 5A, and their closely associated markers identified in this study could be utilized in marker-assisted selection for stripe rust resistant cultivar development.

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 0–2.5 °C at a 5 cm depth, with the subsequent three plantings completed at 2.5 °C intervals up to soil temperatures of 10 °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−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 °C after planting, plant survival was not reduced at the earliest seeding dates. Planting wheat as soon as feasible after soil temperatures reach 0 °C, and prior to soils reaching 7.5–10 °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.

A random sample of 3258 adult household residents of Edmonton, Alberta, Canada, were interviewed by trained lay interviewers, using the Diagnostic Interview Schedule (DIS), which generated DSM‐III diagnosis data. This paper reports results for major depressive disorder (MDD). MDD was found to affect women more than men by a ratio of nearly 2 to 1. The lifetime prevalence rate for both sexes combined was 8.6%. The period prevalence rates for both sexes combined were 3.2% and 4.6%, for six month and one year, respectively. The presence of a recurrent Major Depressive Disorder was associated with an increased risk of substance abuse, panic disorder and dysthymia, whereas a single major depressive episode was not associated with increased comorbidity.