AAC Camrose Canada Prairie Spring Red Wheat

AAC Perform, an awned hard red spring wheat (Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stem, and stripe rust. Based on 43 station years of registration trial data from 2017 to 2019, the grain yield of AAC Perform was about 6% higher than AAC Foray and about 12% over AAC Penhold. AAC Perform was significantly shorter than AAC Foray and had straw strength similar to AAC Penhold. It was about two days later maturing than AAC Foray. AAC Perform had similar test weight, smaller kernel size and lower protein concentration as compared with AAC Foray. AAC Perform had milling and baking quality suitable for grades of the Canada Prairie Spring Red wheat market class.

Brown, P. D., Randhawa, H. S., Mitchell Fetch, J., Fox, S. L., Humphreys, D. G., Meiklejohn, M., Green, D., Wise, I., Fetch, T., Gilbert, J., McCallum, B. and Menzies, J. 2015. AAC Foray red spring wheat. Can. J. Plant Sci. 95: 799–803. AAC Foray, an orange wheat blossom midge (Sitodiplosis mosellana Géhin) tolerant hard red spring wheat (Triticum aestivum L.), combined high grain yield and good agronomic performance with excellent resistance to leaf and stem rust, and improved resistance to Fusarium head blight. AAC Foray had maturity, straw strength, and test weight similar to the check cultivars. AAC Foray is eligible for grade of the Canada Prairie Spring Red wheat market class.

Leaf rust, caused by Puccinia triticina, is a common and widespread disease of wheat in the US. On an annual basis, over 50 races of the leaf rust fungus are detected. There are at least 5 major groups of genetically distinct P. triticina isolates in the US based on allelic variation at microsatellite loci. Distinct regional race populations of P. triticina are found in the US, due to the widespread use of race-specific leaf rust resistance (Lr) genes in different market classes of wheat. In the south-eastern States where soft red winter wheats are grown, races with virulence to Lr9, Lr11, and Lr18 are predominant. In the southern Great Plains region where hard red winter wheats are grown, races with virulence to genes Lr9, Lr17, Lr24, and Lr26 are common. In the northern Great Plains region where hard red spring wheats are grown, races with virulence to Lr2a and Lr16 are common. Due to the wide dispersal of P. triticina, some races are found in all regions of the US. Highly effective durable resistance to leaf rust has been difficult to achieve due to the high degree of virulence variation in the P. triticina population and the rapid selection of races with virulence to effective Lr genes in wheat cultivars. Hard red spring wheat cultivars with genes Lr16, Lr23, and Lr34 have been highly resistant for more than 10 years in Minnesota and the Dakotas. Stem rust, caused by P. graminis f. sp. tritici, has not been a common disease of wheat in the US since the last major epidemics in the 1950s. The low levels of stem rust infections in the US can be attributed to the increasing use of highly resistant winter and spring wheat cultivars, which has greatly reduced the overall level of stem rust urediniospores. Eradication of the alternate host, Berberis vulgaris, has reduced the number of races and slowed the emergence of new races. Resistance genes Sr2, Sr6, Sr17, Sr24, Sr31, Sr36, and SrTmp are common in the winter wheats. Genes Sr6, Sr9b, Sr11, and Sr17 are common in the spring wheats. Spring wheat cultivars may also have adult plant stem rust resistance derived from cv. Thatcher. Many of the winter and spring wheats are susceptible to the new stem rust race from East Africa; however, cultivars with resistance to this race can be found in each of the major wheat classes.

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.

BackgroundSecale strictum subsp. africanum, a self-fertile and perennial wild rye species, is endemic to the Roggeveld Mountains of the south-western Karoo, South Africa. Despite historical abundance on the Roggeveld plateau, S. strictum subsp. africanum is currently threatened with extinction. Many reasons have been given for its decline, including susceptibility to rusts. MethodsLeaves with stem, leaf and stripe rust pustules were sampled from cultivated and naturally occurring S. strictum subsp. africanum on the farm Kanariesfontein near Sutherland. Identity of the rust pathogens was determined through infection and sequencing studies. ResultsInoculation studies showed that stem and leaf rust collected from wild rye were avirulent on bread wheat, but virulent on Secale cereale. The stripe rust specimen was virulent on bread wheat and was identified as Puccinia striiformis race 6E16A−. Using ITS sequencing, the wild rye leaf rust specimen was confirmed as Puccinia recondita, and the stripe rust specimen as P. striiformis. ITS sequences did not distinguish between Puccinia graminis f. sp. tritici and Puccinia graminis f. sp. secalis, respectively the causal organisms of wheat and rye stem rust. Inoculation of wild rye plants with P. graminis f. sp. tritici proved its susceptibility to stem rust races attacking wheat and triticale. ConclusionThis study established that S. strictum subsp. africanum is a host for both rye and wheat stem rust, rye leaf rust and wheat stripe rust.

Stem rust [causal organism: Puccinia graminis f. sp. tritici (Pgt)], stripe rust [Puccinia striiformis f. sp. tritici (Pst)], and leaf rust [Puccinia triticina (Pt)] are important fungal diseases of wheat in Central Asia and worldwide. Therefore, identification of seedling and adult plant resistance (APR) genes is of major importance for the national wheat breeding program in many countries. The objectives of this study were to identify genes that confer seedling and APR resistances in widely grown wheat cultivars, landraces and advanced lines from Tajikistan. A total of 41 wheat accessions were inoculated with eleven races of Pgt, twelve races of Pst and nine races of Pt for postulation of Sr (stem rust), Yr (yellow or stripe rust), and Lr Lr (leaf rust) resistance genes at the seedling stage. In addition, all of the accessions were tested in field trials for the response to stem rust and stripe rust. Genes for seedling stem rust resistance (i.e. Sr5, Sr6, Sr11, Sr31, and Sr38), stripe rust resistance (Yr9, Yr17, and Y27), and leaf rust resistance (Lr16 and Lr26) were postulated in the Tajik wheat. The presence of the pleiotropic APR genes Sr2/Yr30/Lr27 (associated with pseudo-black chaff phenotype) and Lr34/Yr18/Sr57 (associated with leaf tip necrosis phenotype), and also Lr37 were assessed in the field and confirmed with linked molecular markers. In most of the wheat accessions, resistance genes could not be postulated because their infection types did not match the avirulence or virulence profile of the Pgt, Pst and Pt races tested. Six, seven, and nine accessions were identified that likely possess new genes for resistance to stem rust, stripe rust, and leaf rust, respectively, which have not been described previously. The research demonstrates the presence of effective seedling resistance and APR genes in widely grown wheat accessions that could facilitate further rust resistance breeding in the national wheat breeding program in Tajikistan.

Common or bread wheat (Triticum aestivum L.) is the most important cereal crop in the world, including Kazakhstan, where it is a major agricultural commodity. Fungal pathogens producing leaf, stem, and yellow (stripe) rusts of wheat may cause yield losses of up to 50–60%. One of the most effective methods for preventing these losses is to develop resistant cultivars with high yield potential. This goal can be achieved using complex breeding studies, including the identification of key genetic factors controlling rust disease resistance. In this study, a panel consisting of 215 common wheat cultivars and breeding lines from Kazakhstan, Russia, Europe, USA, Canada, Mexico, and Australia, with a wide range of resistance to leaf rust (LR), stem rust (SR), and yellow rust (YR) diseases, was analyzed under field conditions in Southern Kazakhstan. The collection was genotyped using the 20K Illumina iSelect DNA array, where 11,510 informative single-nucleotide polymorphism markers were selected for further genome-wide association study (GWAS). Evaluation of the phenotypic diversity over 2 years showed a mostly mixed reaction to LR, mixed reaction/moderate susceptibility to SR, and moderate resistance to YR among wheat accessions from Kazakhstan. GWAS revealed 45 marker–trait associations (MTAs), including 23 for LR, 14 for SR, and eight for YR resistances. Three MTAs for LR resistance and one for SR resistance appeared to be novel. The MTAs identified in this work can be used for marker-assisted selection of common wheat in Kazakhstan in breeding new cultivars resistant to LR, SR, and YR diseases. These findings can be helpful for pyramiding genes with favorable alleles in promising cultivars and lines.

Leaf rust, caused by Puccinia triticina Eriks., is the most common disease of wheat (Triticum aestivum L.) in the United States and worldwide. The objective of this study was to characterize seedling and adult plant leaf rust resistance in hard red spring wheat cultivars grown in Minnesota, North Dakota, and South Dakota, and postulate the identity of the seedling leaf rust resistance genes in the cultivars. Twenty-six cultivars, near-isogenic lines of Thatcher wheat that differ for single leaf rust resistance genes, and three wheat cultivars with known leaf rust resistance genes, were tested with 11 different isolates of leaf rust collected from the United States and Canada. The leaf rust infection types produced on seedling plants of the cultivars in greenhouse tests were compared with the infection types produced by the same isolates on the Thatcher near-isogenic lines to postulate which seedling leaf rust resistance genes were present. Seedling leaf rust resistance genes Lr1, Lr2a, Lr10, Lr16, Lr21, and Lr24 were postulated to be present in spring wheat cultivars. Seedling genes Lr3, Lr14a, and Lr23 likely were present in some cultivars but could not be clearly identified in this study. Most of the cultivars had some level of adult plant leaf rust resistance, most likely due to Lr34. Cultivars that had seedling resistance genes Lr1, Lr2a, Lr10, or Lr16 had poor to intermediate levels of leaf rust resistance in field plots. Cultivars with combinations of seedling resistance genes Lr16 and Lr24 with additional adult plant resistance were highly resistant to leaf rust.

Purpose. To analyze variety samples from winter wheat collection nursery for resistance to Fusarium head blight and group of pathogens and to identify sources of resistance. Methods. The experiments were conducted at the Myronivka Institute of Wheat under conditions of artificial infection with pathogens in field infectious nurseries. Common techniques have been used to create artificial infectious backgrounds and to assess damage level of winter bread wheat plants with the pathogens. Results. During 2016-2019, were assessed 170 collection samples of winter wheat of different ecological and geographical origin were assessed among which effective sources of resistance against causal agents of the main diseases (Fusarium head blight, common bunt, root rot, powdery mildew, Septoria leaf blotch, brown rust) have been identified. Depending on weather conditions, the disease progress varied through the years with the most level in optimal 2018 and the least in drought 2017. On artificial infectious backgrounds of the pathogens among the samples assessed there were identified 13 ones being highly resistant against the causative agent of Fusarium head blight and two samples of them were immune (i.e. no damage) against common bunt during the years of the research. The damage of the collection samples with pathogen Fusarium graminearum was from 1.0 % to 3.2 %, whereas the susceptible variety Natula was damaged up to 18.0 %. The rest of these winter wheat samples were resistant to two, three, four, and five diseases in various combinations. The variety samples Ray, Rada, Warwik SRW were distinguished by their resistance to five diseases (Fusarium head blight, common bunt, root rot, powdery mildew, and brown rust); the variety samples Famulus, Zlatina 2, Catalus were resistant to four diseases (Fusarium head blight, common bunt, root rot, powdery mildew) as well as the variety sample ТХ9801170 / Doskonala was resistant to four diseases (Fusarium head blight, common bunt, root rot, brown rust). Resistance to three diseases was detected in the varieties Fermerka (Fusarium head blight, root rot, brown rust), MV-VERBUNKOS (Fusarium head blight, common bunt, root rot), and Dromos (Fusarium head blight, root rot, powdery mildew). Conclusions. The sources of group resistance to Fusarium head blight five major pathogens in various combinations have been identified and they are recommended for use in wheat breeding for immunity.

Fusarium head blight continues to be a threat to spring wheat (Triticum aestivum L.) production in the north‐central region of the United States. ‘Lang‐MN’ (Reg. no. CV‐1182, PI 687038) hard red spring wheat was released by the University of Minnesota Agricultural Experiment Station in 2017 because it combines the best available Fusarium head blight resistance with high grain yield, grain protein concentration, and good end‐use quality characteristics. Lang‐MN is a mid‐late maturity cultivar that also has acceptable lodging resistance despite its above average plant height owing to its lack of the semi‐dwarfing genes Rht‐B1 or Rht‐D1 but presence of Rht24. Lang‐MN has good resistance to the prevalent races of leaf rust, stripe rust, and stem rust and is well adapted to the north‐central United States.

CDC Dynamic durum wheat is adapted to the durum production area of the Canadian prairies. This conventional height durum wheat cultivar combines high grain yield potential and protein concentration with high grain pigment and low grain cadmium. CDC Dynamic is resistant to prevalent races of leaf, stem, and stripe rust, and common bunt and expresses end-use quality suitable for the Canada Western Amber Durum (CWAD) class.

Graf, R. J., Thomas, J. B., Beres, B. L., Gaudet, D. A., Laroche, A. and Eudes, F. 2012. Flourish hard red winter wheat. Can. J. Plant Sci. 92: 183–189. Flourish is a hard red winter wheat (Triticum aestivum L.) eligible for all grades of the Canada Western Red Winter wheat class. Compared with the check cultivars in the Western Winter Wheat Cooperative registration trials (CDC Osprey, AC Bellatrix, Radiant, CDC Buteo), Flourish produced similar grain yield with earlier maturity, shorter straw, improved lodging resistance and higher grain protein content. Flourish displayed winter survival similar to the checks. In the eastern prairie rust hazard region of Manitoba and eastern Saskatchewan, Flourish yielded about 5% more grain than CDC Buteo and CDC Falcon, cultivars that are well-adapted and widely grown in the region. Flourish exhibited intermediate resistance to stem and leaf rust combined with moderate resistance to stripe rust and common bunt, a unique combination of disease resistance traits for a western Canadian winter wheat cultivar.

Seven families of soft red winter wheat (Triticum aestivum L.) lines were compared for yield, kernel weight, and test weight. Each family consisted of two lines, nearly isogenic, except for awns vs. awnlets. The families of lines (F3BC6 sibs) were developed by backcrosslng to ‘Vermillion’ and by selection. Treatments consisting of flag leaf removal at anthesis, leaf rust, and leaf rust plus stem rust were imposed on the lines.Leaf rust, leaf rust plus stem rust, and removal of the flag leaf, each greatly reduced yield, test weight, and kernel weight within a given year and had a much greater effect on these characteristics than did the presence or absence of awns. However, due to the large year × leaf‐removal interaction effect, the leaf‐removal treatment was not statistically significant when analyzed over yearsAwnedli nes yielded as well as or higher than their awnleted isolines in each of the experiments. Awns appeared to have a more consistent advantage for kernel weight than for yield but compensated little for removal of the flag leaf or its impaired function by rust as compared with the awnless condition. Awned types showed the greatest advantage under severe rust conditions.

Several tests were done in bread wheat (Triticum aestivum L.) to demonstrate the occurrence of genes on D-genome chromosomes that suppress resistance to leaf rust (Puccinia recondita f. sp. tritici Rob. ex Desm.) and stem rust (Puccinia graminis f. sp. tritici Eriks. &Henn.). Ten rust-resistant wild tetraploid wheats (T. turgidum var. dicoccoides) were crossed with both durum (T. turgidum var. durum) and bread wheats. In all cases, resistance to leaf rust and stem rust was expressed in the hybrids with durum wheats but suppressed in the hybrids with bread wheats. Crosses were made between five diverse durum wheats and four diverse bread wheats. The pentaploid hybrid seedlings of 12 crosses were tested with leaf rust race 15 and in all cases the resistance of the durum parents was suppressed. Fourteen D-genome disomic chromosome substitution lines in the durum wheat 'Langdon' were tested with stem rust race 15B-1 and leaf rust race 15. Chromosomes 1B, 2B, and 7B were found to carry genes for resistance to stem rust but no suppressors were detected. Chromosomes 2B and 4B carried genes for resistance to leaf rust, and 1D and 3D carried suppressors. Crosses between seven D-genome monosomies of 'Chinese Spring' and three dicoccoides accessions showed that 'Chinese Spring' possesses genes on 1D, 2D, and 4D, which suppress the stem rust resistance of all three dicoccoides accessions. All three chromosomes must be present to suppress resistance, indicating that some form of complementary gene interaction is involved. In addition, 'Chinese Spring' carries a gene or genes on 3D that suppresses the leaf rust resistance of all three dicoccoides accessions, plus a gene or genes on 1D that suppresses the leaf rust resistance of only one of them. The data raise some interesting questions about the specificity of the suppressors. The high frequency of occurrence of suppressors in the bread wheat population suggests that they must have a selective advantage.Key words: Triticum aestivum, stem rust, leaf rust, rust resistance, suppressor.

AAC Craven (BW1127) is a hollow-stemmed, awned, and high yielding Canada Western Red Spring (CWRS) wheat cultivar suited to the growing conditions of western Canada. AAC Craven yielded 4916 kg ha −1 (8% higher than AAC Brandon and 17% higher yielding than Carberry) in the Central Bread Wheat Cooperative registration trials (2021–2023). AAC Craven matured 89 days after seeding and reached a height of 74 cm, similar to AAC Brandon. The lodging score of AAC Craven was 1.9 (1–9 scale), which is better than AAC Brandon (2.3). The test weight of AAC Craven was 80 kg hL −1 and 1000-kernel weight was 33 mg kernel −1 . The grain protein content of AAC Craven was 14.2%, 0.8 units lower than AAC Brandon. AAC Craven expressed moderately resistant reaction to Fusarium head blight (FHB; Fusarium spp.). AAC Craven was resistant to prevalent races of leaf rust ( Puccinia triticina Erikss.), stem rust ( Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn), and stripe rust ( Puccinia striiformis Westend) in western Canada. AAC Craven had intermediate to moderately susceptible reaction to common bunt ( Tilletia caries (DC) Tul. & C. Tul. and T. laevis J.G. Kühn). AAC Craven was resistant to orange wheat blossom midge ( Sitodiplosis mosellana Géhin). AAC Craven was deemed to fit the CWRS wheat class by the Canadian Grain Commission and registered with Canadian Food Inspection Agency.