AAC Vortex is a hard red winter wheat (Triticum aestivum L.) cultivar well-adapted to all areas of western Canada and classified for grades of Canada Western Red Winter (CWRW) wheat. It was developed using doubled-haploid methodology. AAC Vortex was evaluated for registration relative to CDC Buteo, Emerson, Moats, and AAC Elevate across Alberta, Saskatchewan and Manitoba. Based on 44 replicated trials over 4 y (2016/17–2019/20), AAC Vortex had significantly higher grain yield than CDC Buteo and Emerson, and higher grain protein concentration than all of the checks except Emerson. AAC Vortex expressed winter survival and lodging resistance equal to the best checks, medium maturity and height, and acceptable test weight. AAC Vortex was resistant to stem, leaf and stripe rust, moderately resistant to Fusarium head blight, and susceptible to common bunt. AAC Vortex produced flour of higher protein concentration than all of the checks except Emerson, had higher clean wheat flour yield and loaf volume than all of the checks, and was similar in gluten strength to Emerson.
Introduction
AAC Vortex hard red winter wheat (Triticum aestivum L.) was developed at the Agriculture and Agri-Food Canada (AAFC) Lethbridge Research and Development Centre (LeRDC) in Lethbridge, AB. Tested as LQ148 and W583, AAC Vortex was granted registration No. 9385 by the Variety Registration Office, Plant Production Division, Canadian Food Inspection Agency on 11 June 2021. Plant Breeders’ Rights application No. 21-10477 was accepted for filing on 27 Apr. 2021.
High grain yield and winter survival, desirable agronomic traits, and resistance to stem rust (Puccinia graminis Pers.: Pers. f.sp. tritici Eriks. & E. Henn.), leaf rust (Puccinia triticina Eriks.), stripe rust (Puccinia striiformis Westend.), and Fusarium head blight {caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein.) Petch]} make AAC Vortex Canada Western Red Winter (CWRW) wheat well-suited for production in all areas of western Canada. AAC Vortex replaced Emerson (Graf et al. 2013) as a CWRW wheat registration trial check in 2020/2021 based on improved agronomic performance over Emerson and similarities in disease resistance and end-use quality profile.
Residents of temperate climates are generally familiar with the effects of a polar vortex, a persistent area of low atmospheric pressure and extremely cold air above the Earth’s poles. During winter in the northern hemisphere, the polar vortex will regularly expand southward, causing temperatures to plummet over wide areas. Accordingly, AAC Vortex is a fitting name for this winter wheat cultivar as it alludes to its excellent survival in western Canada, where endurance of frigid winter conditions is essential.
Pedigree and Breeding Method
AAC Vortex is an F1-derived doubled haploid (DH) cultivar selected from the three-way cross LF1815/LD1829//Emerson completed in 2008 at the AAFC LeRDC. All of the parents were developed at AAFC LeRDC and have the following pedigrees: LF1815 (W448) = CDC Falcon/Radiant; LD1829 = Norstar*4//Elgin*2/PI178383/3/W198; Emerson = McClintock/CDC Osprey. An expanded ancestry of AAC Vortex is presented in Fig. 1.
Between 2009 and 2011, 207 F1-derived DH lines were produced from 39 plants using wheat × maize pollination techniques (Fedak et al. 1997; Knox et al. 2000). Nine DH lines were derived from the F1 plant from which AAC Vortex originated. Field evaluation of a 124 genotype subset began in 1.5 m observation rows grown under irrigation near Lethbridge in 2012, from which 29 desirable lines were selected based on winter survival, spring vigour, plant type, height, straw strength, stripe rust resistance, and general leaf health. The remaining lines began field evaluation in 2013 or 2014. The 29 selections from 2012 were rated for stem and leaf rust resistance in an artificially inoculated nursery at the University of Manitoba in Winnipeg, MB in 2013. Nine lines with acceptable resistance were then tested in a single replicate preliminary agronomic trial under irrigation in Lethbridge, as well as in inoculated nurseries for stem and leaf rust in Winnipeg, stripe rust in Lethbridge, and FHB in Carman, MB. Favourable agronomic performance, resistance to all three rusts and FHB, and acceptable end-use quality encouraged replicated testing of two lines in 2015 and one line in 2016 at sites across western Canada. Disease screening protocols were similar to those for registration testing and are described in the Performance section. Evaluation of resistance to wheat curl mite (Aceria tosichella Keifer) colonization was also conducted based on resistance expressed by parent LF1815 (Thomas and Connor 1986). Following 11 site-years of replicated agronomic trials across western Canada, up to four years of disease resistance assessment, and three years of end-use quality evaluation, LQ148 was evaluated as W583 in the Western Canadian Winter Wheat Cooperative (WWWC) registration trial for three years (2016/17–2018/19) for the purposes of registration, plus one additional year as a transitional check (2019/20).
Performance
Grain yield and agronomics
AAC Vortex was assessed in the WWWC registration trials relative to CDC Buteo (Fowler 2010), Emerson (Graf et al. 2013), Moats (Fowler 2012), and AAC Elevate (Graf et al. 2015). Agronomic test sites across western Canada were in Alberta (Beaverlodge, Lacombe, Lethbridge, Olds, Warner), Saskatchewan (Indian Head, Melfort, Saskatoon, Swift Current), and Manitoba (Brandon, Carman, Portage la Prairie, Winnipeg), through the collaborative efforts of AAFC, Alberta Agriculture and Forestry, and the University of Manitoba. Analyses of variance were conducted using a combined mixed effects model where environments were considered random and genotypes were fixed. The least significant difference (LSD) test was used to identify significant differences from the check cultivars.
Data from across western Canada collected from 44 sites over 4 yr provided a detailed synopsis of the grain yield and agronomic performance of AAC Vortex. Data for CDC Falcon, a previously popular cultivar in the eastern prairies and currently a Canada Western Special Purpose wheat check, are also reported. The mean grain yield of AAC Vortex was 5% higher than the CWRW check mean (P ≤ 0.05) across all sites. Relative to specific checks, AAC Vortex had significantly higher grain yield than CDC Buteo (+7%), Emerson (+10%), and CDC Falcon (+5%), but was similar to Moats (+2%) and AAC Elevate (+1%). On a regional basis, AAC Vortex was particularly well-adapted to the more northerly parkland area (Zone 2) where it yielded 11% more than the CWRW check mean and 8% more than Moats, the highest yielding check in the zone (P ≤ 0.05). Notably, AAC Vortex was 10% higher yielding than Emerson in Saskatchewan (P ≤ 0.05), and although the difference in yield (+5%) was not significant in Manitoba, the similarities in disease resistance suggest that it could be a suitable replacement for Emerson in these areas where it has been popular (see Canadian Grain Commission, Grain varieties by acreage insured) (Table 1).
Table 1.
Mean grain yield (t·ha−1) of AAC Vortex and the check cultivars, Western Canadian Winter Wheat Cooperative registration trials (2017–2020).
AAC Vortex exhibited winter survival that was similar to the CWRW check cultivars and higher than CDC Falcon (P ≤ 0.05). The heading date was similar to CDC Buteo, Emerson and AAC Elevate, one day earlier than Moats, and a day later than CDC Falcon (P ≤ 0.05). Physiological maturity was reached at the same time as CDC Buteo, Moats, and AAC Elevate. AAC Vortex was similar in height to AAC Elevate, 2–4 cm shorter than the remaining CWRW checks, and 9 cm taller than CDC Falcon (P ≤ 0.05). Lodging resistance was similar to Emerson, AAC Elevate and CDC Falcon, and significantly better than CDC Buteo and Moats (P ≤ 0.05). The test weight and seed weight of AAC Vortex were within the range of the CWRW checks. AAC Vortex had higher grain protein concentration than all of the checks except Emerson (P ≤ 0.05), and greater grain protein yield per hectare than all of the checks (P ≤ 0.05) (Table 2).
Table 2.
Mean agronomic and seed characteristics of AAC Vortex and the check cultivars, Western Canadian Winter Wheat Cooperative registration trials (2017–2020).
Disease resistance
During registration testing, resistance to the major diseases of economic importance to winter wheat in both the eastern and western prairies was assessed by AAFC and the University of Manitoba using methodologies described in the Operating Procedures (Appendix E) of the Prairie Recommending Committee for Wheat, Rye and Triticale (www.pgdc.ca). Supplementary checks were included in the various nurseries to aid in making accurate assessments. The adult plant reactions to stem and leaf rust were determined in artificially inoculated field nurseries conducted by the University of Manitoba in Winnipeg using race composites supplied by the AAFC Morden Research and Development Centre (MRDC), and reported using the modified Cobb scale (Peterson et al. 1948). The stem rust races used for one or more years included: MCC (P0001), QTH (P0005), RHT (P0002), RKQ (P0003), RTH (P0007), TMR (P0006), and TPM (P0004) (Fetch et al. 2021). The leaf rust races were a representative mixture collected in western Canada during the previous field season (McCallum et al. 2021). Seedling reactions to individual races of stem and leaf rust prevalent in Canada were also determined under controlled-environment conditions by personnel at AAFC, MRDC. The races of stem rust were the same as those used in the field nurseries whereas the leaf rust races used for one or more years included MBDS (12-3), MBRJ (128-1), MGBJ (74-2), TDBG (06-1-1), TDBG (11-180-1) and TJBJ (77-2). Stripe rust ratings were determined in irrigated, inoculated nurseries at AAFC, LeRDC (Puchalski and Gaudet 2011). The reaction to common bunt [Tilletia tritici (Bjerk.) G. Wint. in Rabenh. and T. laevis Kühn in Rabenh.] was also estimated in nurseries conducted at AAFC, LeRDC by planting into cold soil at two locations in mid-October. All seed was inoculated with a composite of races that included L1, L16, T1, T6, T13, and T19 (Hoffman and Metzger 1976; Gaudet and Puchalski 1989). FHB response was determined by staff at the University of Manitoba using a mist-irrigated field nursery with three replicates in Carman. Spray-inoculation of each line occurred at 50% anthesis and again three to four days later using a suspension of F. graminearum macroconidia that contained equal quantities of two 3-acetyldeoxynivalenol (3-ADON) and two 15-acetyldeoxynivalenol (15-ADON) producing chemotypes at a final concentration of 50 000 macroconidia ml−1. Visual index (% incidence × % severity/100) rating typically occurred 18 to 21 d after anthesis or when symptoms were well developed (Gilbert and Woods 2006; Cuthbert et al. 2007). At maturity, a 50 g sample was harvested from each row to determine the percentage of fusarium damaged kernels (FDK) and to quantify the deoxynivalenol (DON) content using enzyme-linked immunosorbent assays (ELISA). The response to WCM infestation was conducted each year using non-viruliferous mites under controlled-environment conditions at AAFC LeRDC. Several replicates of 10 to 15 plants were rated for the typical symptoms of leaf rolling and trapping of new leaves following 2 to 3 wk of mite exposure.
Following three years of data collection, the Prairie Recommending Committee for Wheat, Rye and Triticale (PRCWRT) Disease Evaluation Team summarized the disease ratings for AAC Vortex as resistant to the prevalent races of stem rust, leaf rust and stripe rust, moderately resistant to FHB, and susceptible to common bunt. Data from a fourth year of disease testing is also presented (Tables 3 and 4, Fig. 2). As a cultivar with moderate resistance to FHB, AAC Vortex is an important component in management strategies directed towards mitigating the effects of this disease (Ye et al. 2017, Beres et al. 2018). To prevent potential losses from common bunt, seed of AAC Vortex and all similarly susceptible cultivars should be treated with an effective fungicide prior to planting (Gaudet et al. 2013, Aboukhaddour et al. 2020). AAC Vortex did not express resistance to the wheat curl mite (data not presented).
Table 3.
Disease reactions of AAC Vortex and the check cultivars, Western Canadian Winter Wheat Cooperative registration trials (2017–2020).
Table 4.
Fusarium head blight (FHB) reaction of AAC Vortex, check cultivars and supplementary checks, Western Canadian Winter Wheat Cooperative registration trials (2017–2020).
Fig. 2.
Biplot of the mean standardized values [(observed value – mean)/standard deviation] for Visual Rating Index (8 sites) versus deoxynivalinol concentration (5 sites) for AAC Vortex and the check cultivars, Western Canadian Winter Wheat Cooperative registration trials (2017–2020). Data reported in Table 4. Values in parentheses are long-term ratings provided by the PRCWRT Disease Evaluation Team.
End-use quality
End-use quality analyses were conducted annually at the Grain Research Laboratory (GRL) of the Canadian Grain Commission (CGC), following protocols of the American Association of Cereal Chemists (2000). Following CGC determination of grain grade and protein concentration for the check cultivars at all of the agronomic test locations, a common site blending formula for the checks and all experimental lines was provided to produce composite samples where the mean protein concentration of the checks was approximately 12.5%. Grain from test sites with serious down-grading factors was not included in the quality composites.
Following three years of end-use suitability testing, the PRCWRT Quality Evaluation Team considered AAC Vortex eligible for all grades of the CWRW wheat market class. Four years of available data (2017–2020) showed that AAC Vortex produced grain and flour of higher protein concentration than all of the checks except Emerson, had higher clean wheat flour yield and loaf volume than all of the checks, and was similar in gluten strength to Emerson. (Table 5).
Table 5.
Mean end-use quality characteristics of AAC Vortex and the check cultivars, Western Canadian Winter Wheat Cooperative registration trials (2017–2020).
Other Characteristics
Seedling: leaf sheath and blade glabrous.
Plant: juvenile growth habit semi-prostrate to prostrate; flag leaf blade glabrous, medium glaucosity, mid-long, mid-wide, medium to highly recurved; flag leaf sheath glabrous, strong glaucosity; auricle anthocyanin colouration very weak to weak, glabrous margins; culm neck straight to weakly curved, hollow, anthocyanin intensity at maturity absent or very weak.
Spike: awned, tapering, medium density, medium length, medium weak glaucosity, light yellow, inclined, awns white to light brown, spreading; lower glume mid-wide, mid-long, glabrous; glume shoulders primarily strongly sloping, width absent or very narrow; glume beak mid-long, straight; rachis margins slight pubescence; resistant to shattering.
Kernel: medium red, texture medium hard, medium size.
Maintenance and Distribution of Pedigreed Seed
A standard head-row derivation approach was used to produce Breeder Seed of AAC Vortex to preserve its inherent DH purity. Head rows were grown under isolation at an irrigated site near Lethbridge in 2019, each derived from a single random spike taken from rogued increase plots grown at Lethbridge in 2018. Following elimination of rows that appeared to express minor morphological differences or contamination, seed from 61 head rows was transferred to the AAFC Seed Increase Unit where they were grown individually as several 20 m long rows in 2020. Following the removal of 5 lines, 56 breeder lines were inspected, harvested in bulk and cleaned to form 604 kg of Breeder Seed, which was released to pedigreed seed growers in fall 2020. Bulking of the Breeder Seed occurred 10 generations after the creation of the original DH plant. Breeder Seed of AAC Vortex will be maintained by the AAFC Seed Increase Unit. All other pedigreed seed classes will be multiplied and distributed by Alliance Seed, 24th Floor, 333 Main Street, Winnipeg, MB, Canada R3C 4E2. Tel: 1-877-270-2890; www.allianceseed.com.
Acknowledgements
Sincere appreciation is expressed to the dedicated technical staff at the AAFC LeRDC who contributed to the development of AAC Vortex winter wheat, in particular: D. Quinn, B. Postman, J. Prus, M. Fast, L. Kneeshaw, D. Pearson, E. Amundsen, T. Despins, C. Parent and S. Pahl. The authors also acknowledge the technical support provided by numerous AAFC personnel working at research sites in Lethbridge, Beaverlodge, Swift Current, Saskatoon, Indian Head, Melfort, Brandon, Portage la Prairie, Winnipeg, and Ottawa; the provision of an inoculated stem and leaf rust selection nursery by A. Brûlé-Babel and M. Meleshko at the University of Manitoba; and all contributors to the Western Canadian Winter Wheat Cooperative registration trials. Thanks are also extended to H. Naeem and the staff of the AAFC Seed Increase Unit at Indian Head for their meticulous care and attention in producing and maintaining the Breeder Seed of AAC Vortex. In addition to funding from AAFC, financial assistance from the following producer and industry groups is gratefully recognized: the Western Grains Research Foundation producer check-off on wheat, the Ducks Unlimited Canada administered Western Winter Wheat Initiative, the Alberta Wheat Commission, the Saskatchewan Winter Cereals Development Commission, Winter Cereals Manitoba, the Alberta Crop Industry Development Fund, and the Canadian Wheat Research Coalition.
