Registration of ‘Lang‐MN’ hard red spring wheat

Kharouf, Sh., Sh. Hamzeh and M.F. Azmeh. 2021. Races Identification of Wheat Rusts in Syria during the 2019 Growing Season. Arab Journal of Plant Protection, 39(1): 1-13. Wheat rust diseases, caused by Puccinia striiformis f. sp. tritici (stripe or yellow rust), P. triticina f. sp. tritici (leaf or brown rust) and P. graminis f. sp. tritici (stem or black rust) are important factors affecting both durum and bread wheat production in Syria. Considerable losses were caused by these diseases, especially stripe rust, estimated at more than one million metric tons, in the 2010 season, out of 5 million anticipated production. Therefore, it is essential to monitor and follow the movement of these three rust physiological races. In the 2019 growing season, 165 wheat fields were surveyed, and 312 samples were collected and characterized. Ten races of stripe rust were identified in ten locations, of which, four represent new record in Syria, namely the races 16E154, 69E150, 264E46 and 258E64. In addition, four races of leaf rust were identified in four locations, one of which (BKLP) is a new record in Syria. In addition, three previously recorded stem rust races were identified from three different locations. It should be mentioned that the newly recorded races of stripe rust are able to overcome resistance genes Yr1 and Yr5, on which the resistance of durum wheat cultivars such as "Cham3" depended, with a disease severity of 40S recorded in the same locations. It is also worth noting that the stripe rust race 462E128 (warrior) was not detected in the isolates studied. Likewise, the stem rust race Ug99 was also not identified, and because of the aggressiveness of this race, continuous inspection through field surveys accompanied with pathogenicity tests is essential during the coming seasons. Keywords: Stripe (yellow) rust, Leaf (brown) rust, stem (black) rust, race identification, wheat, Syria

Leaf rust, stem rust, and stripe rust are among the most important diseases of wheat and barley worldwide and are best controlled using genetic resistance. To increase the diversity of rust resistance in wheat and barley, a project was initiated to identify and characterise rust resistance genes from the wild species of Aegilops sharonensis (Sharon goatgrass) and Hordeum vulgare ssp. spontaneum (wild barley), respectively. One hundred and two accessions of Sharon goatgrass from Israel and 318 Wild Barley Diversity Collection (WBDC) accessions from the Fertile Crescent, Central Asia, North Africa, and the Caucasus region were evaluated for resistance to leaf rust, stem rust, and/or stripe rust. Sharon goatgrass exhibited a wide range of infection types (ITs) in response to leaf rust, stem rust, and stripe rust. The percentage of resistant accessions in Sharon goatgrass was 58.8–78.4% for leaf rust, 11.8–69.6% for stem rust, and 46.1% for stripe rust, depending on the race used and the plant growth stage. Genetic studies with Sharon goatgrass revealed oligogenic resistance to leaf rust and stem rust. Wild barley also exhibited a wide range of ITs to leaf rust and stem rust; however, the overall frequency of resistance was lower than for Sharon goatgrass. The percentage of resistant accessions in wild barley was 25.8% for leaf rust and 5.7–20.1% for stem rust, depending on the race used. Resistance to the new virulent stem rust race TTKS (i.e. Ug99), present in eastern Africa, was found in both Sharon goatgrass (70% of accessions) and wild barley (25% of 20 accessions tested). Association mapping for stem rust resistance was applied in the WBDC using Diversity Arrays Technology (DArT) markers. Using the highly conservative P value threshold of 0.001, 14 and 15 significant marker associations were detected when the number of subpopulations (K value) was set for 10 and 8, respectively. These significant associations were in 9 and 8 unique chromosome bins, respectively. Two significant marker associations were detected for resistance to the wheat stem rust race MCCF in the same bin as the rpg4/Rpg5 complex on chromosome 7(5H). The presence of a major stem rust resistance gene in this bin on chromosome 7(5H) was validated in a bi-parental mapping population (WBDC accession Damon × cv. Harrington) constructed with DArT markers. The results from this study indicate that Sharon goatgrass and wild barley are rich sources of rust resistance genes for cultivated wheat and barley improvement, respectively, and that association mapping may be useful for positioning disease resistance genes in wild barley.

AAC Brandon hard red spring wheat (Triticum aestivum L.) has grain yield and time to maturity within the range of the check cultivars: Katepwa, Laura, Lillian, Carberry, and CDC Kernen. AAC Brandon has an awned spike, a low lodging score indicative of strong straw, and a short plant stature typical of a semidwarf. AAC Brandon expressed resistance to prevalent races of leaf, stem, and stripe rust, and moderate resistance to fusarium head blight and loose smut. Compared with the five Canada Western Red Spring check cultivars, AAC Brandon has improved flour yield and lower flower ash. AAC Brandon is eligible for grades of Canada Western Red Spring.

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.

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.

ABSTRACTVarious whole‐kernel, milling, flour, dough, and breadmaking quality parameters were compared between hard red winter (HRW) and hard red spring (HRS) wheat. From the 50 quality parameters evaluated, values of only nine quality characteristics were found to be similar for both classes. These were test weight, grain moisture content, kernel size, polyphenol oxidase content, average gluten index, insoluble polymeric protein (%), free nonpolar lipids, loaf volume potential, and mixograph tolerance. Some of the quality characteristics that had significantly higher levels in HRS than in HRW wheat samples included grain protein content, grain hardness, most milling and flour quality measurements, most dough physicochemical properties, and most baking characteristics. When HRW and HRS wheat samples were grouped to be within the same wheat protein content range (11.4–15.8%), the average value of many grain and breadmaking quality characteristics were similar for both wheat classes but significant differences still existed. Values that were higher for HRW wheat flour were color b*, free polar lipids content, falling number, and farinograph tolerance. Values that were higher for HRS wheat flour were geometric mean diameter, quantity of insoluble polymeric proteins and gliadins, mixograph mix time, alveograph configuration ratio, dough weight, crumb grain score, and SDS sedimentation volume. This research showed that the grain and flour quality of HRS wheat generally exceeds that of HRW wheat whether or not samples are grouped to include a similar protein content range.

Stripe rust (Puccinia striiformis f. sp. tritici) and leaf rust (Puccinia triticina) can cause significant yield reductions to hard red spring wheat (HRSW) in North Dakota (ND). The use of host resistance and fungicides can successfully manage this disease. However, the combination of them may not be appropriate every year. From 2016 to 2018, fungicide timing by cultivar experiments were conducted to update recommendations for rust management. Experiments were designed in a randomized complete block with a split-plot arrangement. Main plots included three HRSW cultivars that were moderately resistant, moderately susceptible, and susceptible. Subplots included the fungicide timings of Feekes 9, Feekes 10.5.1, a sequential application, and a nontreated control. Field experiments were categorized into three environments depending on rust onset and disease progress. When rust was detected at early heading, the susceptible cultivar benefited from all fungicide application timings. The detection of rust at tillering leaf stages suggested that fungicide treatments statistically lowered disease and in most cases had statistically higher yield, regardless of host resistance. These results suggest that the benefit from a fungicide application to manage leaf rust and stripe rust is highly influenced by the timing of disease onset and level of host resistance. Results will improve fungicide suggestions for HRSW producers in ND.

CDC Precision durum wheat is adapted to the durum production area of the Canadian prairies. This conventional height durum wheat cultivar combines high grain yield potential with high grain pigment and low grain cadmium. CDC Precision 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.

Inheritance of partial leaf rust and stripe rust resistance of a Thatcher wheat 90RN2491, earlier reported to carry two doses of the gene pair Lr34-Yr18 and the reference line RL6058 (6*Thatcher/PI58548) for the Lr34-Yr18 gene pair was studied against predominant and highly virulent Indian races. Thatcher derivatives 90RN2491 and RL6058 were intercrossed as well as crossed with the leaf rust and stripe rust susceptible Indian cultivar WL711. The F1, F2 and F3 generations from these crosses were assessed for rust severity against leaf rust race 77-5 and stripe rust race 46S119. The F2 and F3 generations from the crosses of RL6058 and 90RN2491 with WL711, segregated 15 resistant : 1 susceptible (F2) and 7 homozygous resistant : 8 segregating : 1 homozygous susceptible (F3) ratios, respectively, both for leaf rust and stripe rust severity. Therefore, partial resistance against each of the leaf rust and stripe rust races in both RL6058 and 90RN2491 is ascribed to two independently inherited dominant genes. One of the two genes for leaf rust and stripe rust resistance in 90RN2491 and RL6058 is Lr34 and the linked gene Yr18, respectively. The second leaf rust resistance gene in both the Thatcher lines segregated independently of stripe rust resistance. Therefore, it is not Lr34 and it remains unidentified.

Identification of a pleiotropic QTL cluster for Fusarium head blight resistance, spikelet compactness, grain number per spike and thousand-grain weight in common wheat

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.

Lillian, hard red spring wheat (Triticum aestivum L.), exhibited reduced cutting by the wheat stem sawfly (Cephus cinctus Nort.) and is adapted to the Canadian prairies. Lillian produced significantly more grain yield than AC Abbey and Neepawa and its grain yield and protein concentration were similar to AC Barrie. It matured significantly earlier than Superb and Laura, and had improved resistance to leaf rust and leaf spotting diseases compared to AC Abbey. Lillian is eligible for all grades of the Canada Western Red Spring (CWRS) wheat class. Key words: Triticum aestivum L., cultivar description, grain yield and protein, resistance wheat stem sawfly, leaf and stem rust

New races of wheat stem rust, namely TTKSK (Ug99) and its variants, pose a threat to wheat production in the regions where they are found. The accession of the wheat cultivar Webster (RL6201) maintained at the Cereal Research Centre in Winnipeg, Canada, shows resistance to TTKSK and other races of stem rust. The purpose of this study was to study the inheritance of seedling resistance to stem rust in RL6201 and genetically map the resistance genes using microsatellite (SSR) markers. A population was produced by crossing the stem rust susceptible line RL6071 with Webster. The F(2) and F(3) were tested with TPMK, a stem rust race native to North America. The F(3) was also tested with TTKSK. Two independently assorting genes were identified in RL6201. Resistance to TPMK was conferred by Sr30, which was mapped with microsatellites on chromosome 5DL. The second gene, temporarily designated SrWeb, conferred resistance to TTKSK. SrWeb was mapped to chromosome 2BL using SSR markers. Comparison with previous genetic maps showed that SrWeb occupies a locus near Sr9. Further analysis will be required to determine if SrWeb is a new gene or an allele of a previously identified gene.

Stem rust, caused by Puccinia graminis, is a catastrophic disease that has and continues to cause yield losses in barley, oat, and wheat crops worldwide. Use of host resistance genes is the most economic, efficient, and environmentally best method to control the disease. Resistance genes have been incorporated into most commercial cultivars and have been effective, for races in the North American populations of P. graminis. However, new races of stem rust are constantly emerging and therefore it is imperative to monitor the virulence structure in the populations to detect new races with increased virulence. Stem rust samples were collected in 2013 and 2014 in Manitoba, Ontario, Quebec, and Saskatchewan to determine the incidence and severity of stem rust in barley (Hordeum vulgare), oat (Avena sativa), and wheat (Triticum aestivum) fields and to characterize the virulence dynamics in the pathogen populations. No stem rust was found in cultivated wheat, and incidence was at trace (<1%) levels in barley fields and very low (0–5%) levels in oat fields in 2013 and 2014. In wheat trap plots and collections from barley, race QFCSC of P. graminis f. sp. tritici was dominant in 2013 (85.9%) and was the only race found in 2014. Races MCCFC, QTHJF, RFCSC, RKQSC, and TMRTF were at low (<5%) levels in 2013. From collections in oat fields and stands of wild barley, nine races of P. graminis f. sp. avenae were found in 2013, with TJS (56.9%) and TJJ (23.5%) the most frequent. In 2014, we found only six races and TJS (74.5%) and TJJ (19.1%) were the most frequent. No new races of stem rust were detected in Canada in 2013 or 2014.

An in vitro spike culture method was optimized to evaluate Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) and used to screen a population of ethyl methane sulfonate treated spike culture-derived variants (SCDV). Of the 134 SCDV evaluated, the disease severity score of 47 of the variants was ≤30%. Single nucleotide polymorphisms (SNP) in the UDP-glucosyltransferase (UGT) genes, TaUGT-2B, TaUGT-3B, and TaUGT-EST, differed between AC Nanda (an FHB-susceptible wheat variety) and Sumai-3 (an FHB-resistant wheat cultivar). SNP at 450 and 1,558 bp from the translation initiation site in TaUGT-2B and TaUGT-3B, respectively were negatively correlated with FHB severity in the SCDV population, whereas the SNP in TaUGT-EST was not associated with FHB severity. Fusarium graminearum strain M7-07-1 induced early expression of TaUGT-2B and TaUGT-3B in FHB-resistant SCDV lines, which were associated with deoxynivalenol accumulation and reduced FHB disease progression. At 8 days after inoculation, deoxynivalenol concentration varied from 767 ppm in FHB-resistant variants to 2,576 ppm in FHB-susceptible variants. The FHB-resistant SCDV identified can be used as new sources of FHB resistance in wheat improvement programs.