The use of wheatgrass (Thinopyrum intermedium) in breeding.

Wheatgrass (Th. intermedium) has been traditionally used in wheat breeding for obtaining wheat-wheatgrass hybrids and varieties with introgressions of new genes for economically valuable traits. However, in the 1980s in the United States wheatgrass was selected from among perennial plant species as having promise for domestication and the development of dual-purpose varieties for grain (as an alternative to perennial wheat) and hay. The result of this work was the creation of the wheatgrass varieties Kernza (The Land Institute, Kansas) and MN-Clearwater (University of Minnesota, Minnesota). In Omsk State Agrarian University, the variety Sova was developed by mass selection of the most winter-hardy biotypes with their subsequent combination from the population of wheatgrass obtained from The Land Institute. The average grain yield of the variety Sova is 9.2 dt/ha, green mass is 210.0 dt/ ha, and hay is 71.0 dt/ha. Wheatgrass is a crop with a large production potential, benef icial environmental properties, and valuable grain for functional food. Many publications show the advantages of growing the Kernza variety compared to annual crops in reducing groundwater nitrate contamination, increasing soil carbon sequestration, and reducing energy and economic costs. However, breeding programs for domestication of perennial crops are very limited in Russia. This paper presents an overview of main tasks faced by breeders, aimed at enhancing the yield and cultivating wheatgrass eff iciency as a perennial grain and fodder crop. To address them, both traditional and modern biotechnological and molecular cytogenetic approaches are used. The most important task is to transfer target genes of Th. intermedium to modern wheat varieties and decrease the level of chromatin carrying undesirable genes of the wild relative. The f irst consensus map of wheatgrass containing 10,029 markers was obtained, which is important for searching for genes and their introgressions to the wheat genome. The results of research on the nutritional and technological properties of wheatgrass grain for the development of food products as well as the differences in the quality of wheatgrass grain and wheat grain are presented.

Puccinia graminis f. sp. tritici Population Causing Recent Wheat Stem Rust Epidemics in Kazakhstan Is Highly Diverse and Includes Novel Virulence Pathotypes.

Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a reemerging disease that caused severe epidemics in northern Kazakhstan and western Siberia in the period of 2015 to 2019. We analyzed 51 stem rust samples collected between 2015 and 2017 in five provinces in Kazakhstan. A total of 112 Pgt races were identified from 208 single-pustule isolates. These races are phenotypically and genotypically diverse, and most of them are likely of sexual origin. No differentiation of phenotypes and single-nucleotide polymorphism genotypes was observed between isolates from Akmola and North Kazakhstan provinces, supporting the idea of a wide dispersal of inoculum in the northern regions of the country. Similarities in virulence profiles with Pgt races previously reported in Siberia, Russia, suggest that northern Kazakhstan and western Siberia constitute a single stem rust epidemiological region. In addition to the races of sexual origin, six races reported in Europe, the Caucasus, and East Africa were detected in Kazakhstan, indicating that this epidemiological region is not isolated, and spore inflow from the west occurs. Virulence alone or in combination to several genes effective against the Ug99 race group was detected, including novel virulence on Sr32 + Sr40 and Sr47. The occurrence of a highly diverse Pgt population with virulence to an important group of Sr genes demonstrated the importance of the pathogen's sexual cycle in generating new and potentially damaging virulence combinations.

Genotypic and ecological variability of zinc content in the grain of spring bread wheat varieties in the international nursery KASIB.

Spring bread wheat is the staple crop in Western Siberia and Kazakhstan, a signif icant portion of which goes for export. Wheat breeding with a high level of zinc in wheat grain is the most cost-effective and environmentally friendly way to address zinc def iciency in the diet. The purpose of this work was to evaluate the contribution of the factors 'location' and 'genotype' in the variability of zinc content in wheat grain, and to identify the best varieties as sources of this trait for breeding. The research on screening zinc content in the wheat grain of 49 spring bread wheat varieties from the Kazakhstan- Siberia Spring Wheat Trial (KASIB) nursery was carried out at 4 sites in Russia (Chelyabinsk, Omsk, Tyumen, Novosibirsk) and 2 sites in Kazakhstan (Karabalyk and Shortandy) in 2017-2018. The content of zinc in wheat grain was evaluated at the Ionomic Facility of University of Nottingham in the framework of the EU project European Plant Phenotyping Network-2020. The analysis of variance showed that the main contribution into the general phenotypic variation of the studied trait, 38.7 %, was made by the factor 'location' due to different contents of zinc and moisture in the soil of trial sites; the effect of the factor 'year' was 13.5 %, and the effect of the factor 'genotype' was 8.0 %. The most favorable environmental conditions for accumulation of zinc in wheat grain were observed in the Omsk region. In Omsk, the average zinc content in all studied varieties was 50.4 mg/kg, with 63.7 mg/ kg in the best variety 'OmGAU 100'. These values are higher than the target values of the international program Harvest Plus. 'Novosibirskaya 16' (49.4 mg/kg), 'Silach' (48.4 mg/kg), 'Line 4-10-16' (47.2 mg/ kg), 'Element 22' (46.3 mg/kg) and 'Lutescens 248/01' (46.0 mg/kg) were identif ied as being the best varieties. Signif icant possibilities for the production of wheat grain with high zinc content, which is in demand for the production of bread and pastry products with functional properties, were identif ied in the Western Siberian region.

Root and canopy traits and adaptability genes explain drought tolerance responses in winter wheat.

Bread wheat (Triticum aestivum L) is one of the three main staple crops worldwide contributing 20% calories in the human diet. Drought stress is the main factor limiting yields and threatening food security, with climate change resulting in more frequent and intense drought. Developing drought-tolerant wheat cultivars is a promising way forward. The use of holistic approaches that include high-throughput phenotyping and genetic markers in selection could help in accelerating genetic gains. Fifty advanced breeding lines were selected from the CIMMYT Turkey winter wheat breeding program and studied under irrigated and semiarid conditions in two years. High-throughput phenotyping was done for wheat crown root traits and canopy senescence dynamics using vegetation indices (green area using RGB images and Normalized Difference Vegetation Index using spectral reflectance). In addition, genotyping by KASP markers for adaptability genes was done. Overall, under semiarid conditions yield reduced by 3.09 t ha-1 (-46.8%) compared to irrigated conditions. Genotypes responded differently under drought stress and genotypes 39 (VORONA/HD24-12//GUN/7/VEE#8//…/8/ALTAY), 18 (BiII98) and 29 (NIKIFOR//KROSHKA) were the most drought tolerant. Root traits including shallow nodal root angle under irrigated conditions and root number per shoot under semiarid conditions were correlated with increased grain yield. RGB based vegetation index measuring canopy green area at anthesis was better correlated with GY than NDVI was with GY under drought. The markers for five established functional genes (PRR73.A1 -flowering time, TEF-7A -grain size and weight, TaCwi.4A - yield under drought, Dreb1- drought tolerance, and ISBW11.GY.QTL.CANDIDATE- grain yield) were associated with different drought-tolerance traits in this experiment. We conclude that-genotypes 39, 18 and 29 could be used for drought tolerance breeding. The trait combinations of canopy green area at anthesis, and root number per shoot along with key drought adaptability makers (TaCwi.4A and Dreb1) could be used in screening drought tolerance wheat breeding lines.

Stem rust in Western Siberia - race composition and effective resistance genes.

Stem rust in recent years has acquired an epiphytotic character, causing significant economic damage for wheat production in some parts of Western Siberia. On the basis of a race composition study of the stem rust populations collected in 2016-2017 in Omsk region and Altai Krai, 13 pathotypes in Omsk population and 10 in Altai population were identified. The race differentiation of stem rust using a tester set of 20 North American Sr genes differentiator lines was carried out. The genes of stem rust pathotypes of the Omsk population are avirulent only to the resistance gene Sr31, Altai isolates are avirulent not only to Sr31, but also to Sr24, and Sr30. A low frequency of virulence (10-25 %) of the Omsk population pathotypes was found for Sr11, Sr24, Sr30, and for Altai population - Sr7b, Sr9b, Sr11, SrTmp, which are ineffective in Omsk region. Field evaluations of resistance to stem rust were made in 2016-2018 in Omsk region in the varieties and spring wheat lines from three different sources. The first set included 58 lines and spring bread wheat varieties with identified Sr genes - the so-called trap nursery (ISRTN - International Stem Rust Trap Nursery). The second set included spring wheat lines from the Arsenal collection, that were previously selected according to a complex of economically valuable traits, with genes for resistance to stem rust, including genes introgressed into the common wheat genome from wild cereal species. The third set included spring bread wheat varieties created in the Omsk State Agrarian University within the framework of a shuttle breeding program, with a synthetic wheat with the Ae. tauschii genome in their pedigrees. It was established that the resistance genes Sr31, Sr40, Sr2 complex are effective against stem rust in the conditions of Western Siberia. The following sources with effective Sr genes were selected: (Benno)/6*LMPG-6 DK42, Seri 82, Cham 10, Bacanora (Sr31), RL 6087 Dyck (Sr40), Amigo (Sr24, 1RS-Am), Siouxland (Sr24, Sr31), Roughrider (Sr6, Sr36), Sisson (Sr6, Sr31, Sr36), and Fleming (Sr6, Sr24, Sr36, 1RS-Am), Pavon 76 (Sr2 complex) from the ISRTN nursery; No. 1 BC1F2 (96 × 113) × 145 × 113 (Sr2, Sr36, Sr44), No. 14а F3 (96 × 113) × 145 (Sr36, Sr44), No. 19 BC2F3 (96 × 113) × 113 (Sr2, Sr36, Sr44), and No. 20 F3 (96 × 113) × 145 (Sr2, Sr36, Sr40, Sr44) from the Arsenal collection; and the Omsk State Agrarian University varieties Element 22 (Sr31, Sr35), Lutescens 27-12, Lutescens 87-12 (Sr23, Sr36), Lutescens 70-13, and Lutescens 87-13 (Sr23, Sr31, Sr36). These sources are recommended for inclusion in the breeding process for developing stem rust resistant varieties in the region.

Endemic and panglobal genetic groups, and divergence of host-associated forms in worldwide collections of the wheat leaf rust fungus Puccinia triticina as determined by genotyping by sequencing.

The wheat leaf rust fungus, Puccinia triticina, is found in the major wheat growing regions of the world and is a leading cause of yield loss in wheat. Populations of P. triticina are highly variable for virulence to resistance genes in wheat and adapt quickly to resistance genes in wheat cultivars. The objectives of this study were to determine the genetic relatedness of worldwide collections of P. triticina using restriction site associated genotyping by sequencing. A total of 558 isolates of P. triticina from wheat producing regions in North America, South America, Europe, the Middle East, Ethiopia, Russia, Pakistan, Central Asia, China, New Zealand, and South Africa were characterized at 6745 single nucleotide loci. Isolates were also tested for virulence to 20 near-isogenic lines that differ for leaf rust resistance genes. Populations that were geographically proximal were also more closely related for genotypes. In addition, groups of isolates within regions that varied for genotype were similar to groups from other regions, which indicated past and recent migration across regions. Isolates from tetraploid durum wheat in five different regions were highly related with distinct genotypes compared to isolates from hexaploid common wheat. Based on a molecular clock, isolates from durum wheat found only in Ethiopia were the first to diverge from a common ancestor form of P. triticina that is found on the wild wheat relative Aegilops speltoides, followed by the divergence of isolates found worldwide that are virulent to durum wheat, and then by isolates found on common wheat.

Multilocus Genotypes of the Wheat Leaf Rust Fungus Puccinia triticina in Worldwide Regions Indicate Past and Current Long-Distance Migration.

Many plant pathogenic fungi have a global distribution across diverse ecological zones and agricultural production systems. Puccinia triticina, the wheat leaf rust fungus, is a major pathogen in many wheat production areas of the world. The objective of this research was to determine the genetic relatedness of P. triticina in different worldwide regions. A total of 831 single-uredinial isolates collected from 11 regions were characterized for multilocus genotype at 23 simple sequence repeat loci and for virulence to 20 lines of wheat with single genes for leaf rust resistance. A total of 424 multilocus genotypes and 497 virulence phenotypes were found. All populations had high heterozygosity and significant correlation between virulence and molecular variation, which indicated clonal reproduction. The populations from North America and South America, Central Asia and Russia, and the Middle East and Europe were closely related for multilocus genotypes and many individual isolates from other continental regions were closely related. Twenty-seven multilocus genotypes were found in more than one continental region, and 13 of these had isolates with identical virulence phenotypes. The wide geographic distribution of identical and highly related multilocus genotypes of P. triticina indicated past and more recent migration events facilitated by the spread of clonally produced urediniospores.

Virulence Characterization of International Collections of the Wheat Stripe Rust Pathogen, Puccinia striiformis f. sp. tritici.

Wheat stripe rust (yellow rust [Yr]), caused by Puccinia striiformis f. sp. tritici, is an economically important disease of wheat worldwide. Virulence information on P. striiformis f. sp. tritici populations is important to implement effective disease control with resistant cultivars. In total, 235 P. striiformis f. sp. tritici isolates from Algeria, Australia, Canada, Chile, China, Hungary, Kenya, Nepal, Pakistan, Russia, Spain, Turkey, and Uzbekistan were tested on 20 single Yr-gene lines and the 20 wheat genotypes that are used to differentiate P. striiformis f. sp. tritici races in the United States. The 235 isolates were identified as 129 virulence patterns on the single-gene lines and 169 virulence patterns on the U.S. differentials. Virulences to YrA, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, YrUkn, Yr28, Yr31, YrExp2, Lemhi (Yr21), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), Fielder (Yr6, Yr20), Tyee (YrTye), Tres (YrTr1, YrTr2), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were detected in all countries. At least 80% of the isolates were virulent on YrA, Yr2, Yr6, Yr7, Yr8, Yr17, YrUkn, Yr31, YrExp2, Yr21, Stephens (Yr3a, YrS, YrSte), Lee (Yr7, Yr22, Yr23), and Fielder (Yr6, Yr20). Virulences to Yr1, Yr9, Yr25, Yr27, Yr28, Heines VII (Yr2, YrHVII), Paha (YrPa1, YrPa2, YrPa3), Druchamp (Yr3a, YrD, YrDru), Produra (YrPr1, YrPr2), Yamhill (Yr2, Yr4a, YrYam), Tyee (YrTye), Tres (YrTr1, YrTr2), Hyak (Yr17, YrTye), Express (YrExp1, YrExp2), Clement (Yr9, YrCle), and Compair (Yr8, Yr19) were moderately frequent (>20 to <80%). Virulence to Yr10, Yr24, Yr32, YrSP, and Moro (Yr10, YrMor) was low (≤20%). Virulence to Moro was absent in Algeria, Australia, Canada, Kenya, Russia, Spain, Turkey, and China, but 5% of the Chinese isolates were virulent to Yr10. None of the isolates from Algeria, Canada, China, Kenya, Russia, and Spain was virulent to Yr24; none of the isolates from Algeria, Australia, Canada, Nepal, Russia, and Spain was virulent to Yr32; none of the isolates from Australia, Canada, Chile, Hungary, Kenya, Kenya, Nepal, Pakistan, Russia, and Spain was virulent to YrSP; and none of the isolates from any country was virulent to Yr5 and Yr15. Although the frequencies of virulence factors were different, most of the P. striiformis f. sp. tritici isolates from these countries shared common virulence factors. The virulences and their frequencies and distributions should be useful in breeding stripe-rust-resistant wheat cultivars and understanding the pathogen migration and evolution.

RFLP mapping of the vernalization (Vrn1) and frost resistance (Fr1) genes on chromosome 5A of wheat.

A population of single chromosome recombinant lines was developed from the cross between a frost-sensitive, vernalization-insensitive substitution line, 'Chinese Spring' (Triticum spelta 5A) and a frost-tolerant, vernalization-sensitive line, 'Chinese Spring' ('Cheyenne' 5A), and used to map the genes Vrn1 and Fr1 controlling vernalization requirement and frost tolerance, respectively, relative to RFLP markers located on this chromosome. The Vrn1 and Fr1 loci were located closely linked on the distal portion of the long arm of 5AL, but contrary to previous observations, recombination between them was found. Three RFLP markers, Xpsr426, Xcdo504 and Xwg644 were tightly linked to both. The location of Vrn1 suggests that it is homoeologous to other spring habit genes in related species, particularly the Sh2 locus on chromosome 7 (5H) of barley and the Sp1 locus on chromosome 5R of rye.