Spring Bread Wheat Research Articles

Evaluation of grain yield in fifty-eight spring bread wheat genotypes grown under heat stress

Evaluation of grain yield in fifty-eight spring bread wheat genotypes grown under heat stress

Validation of Candidate Gene-Based Markers and Identification of Novel Loci for Thousand-Grain Weight in Spring Bread Wheat.

Increased thousand-grain weight (TGW) is an important breeding target for indirectly improving grain yield (GY). Fourteen reported candidate genes known to enhance TGW were evaluated in two independent and existing datasets of wheat at CIMMYT, the Elite Yield Trial (EYT) from 2015 to 2016 (EYT2015-16) and the Wheat Association Mapping Initiative (WAMI) panel, to study their allele effects on TGW and to verify their suitability for marker-assisted selection. Of these, significant associations were detected for only one gene (TaGs3-D1) in the EYT2015-16 and two genes (TaTGW6 and TaSus1) in WAMI. The reported favorable alleles of TaGs3-D1 and TaTGW6 genes decreased TGW in the datasets. A haplotype-based genome wide association study was implemented to identify the genetic determinants of TGW on a large set of CIMMYT germplasm (4,302 lines comprising five EYTs), which identified 15 haplotype blocks to be significantly associated with TGW. Four of them, identified on chromosomes 4A, 6A, and 7A, were associated with TGW in at least three EYTs. The locus on chromosome 6A (Hap-6A-13) had the largest effect on TGW and additionally GY with increases of up to 2.60 g and 258 kg/ha, respectively. Discovery of novel TGW loci described in our study expands the opportunities for developing diagnostic markers and for multi-gene pyramiding to derive new allele combinations for enhanced TGW and GY in CIMMYT wheat.

Marker-trait associations of yield related traits in bread wheat (Triticum aestivum L.) under a semi-arid climate

Identifying QTLs (quantitative trait loci) that control yield related traits under a stressed environment is very useful for marker-assisted selection (MAS). Marker-trait associations (MTA) for several agro-morphological traits were performed with 130 Tunisian and exotic spring bread wheat (Triticum aestivum L.) accessions under a semi-arid climate in El Kef, Tunisia. Grain yield and other important traits were evaluated. A population structural analysis identified two sub populations. In total, 29 MTAs were detected at –log P ≥ 3 using an MLM (mixed linear model), and only 5 MTAs with –log P ≥ 4. The locus on chromosome 4A was detected to control the heading date accounting for up to 22% of the trait variance. Two other loci located on chromosomes 3B and 7B were found to be stable during the two cropping seasons and have a pleiotropic effect on the heading date, yield, internodes length and grain per spike. These two regions are candidates for further genetic analysis.

Genetic Contribution of Synthetic Hexaploid Wheat to CIMMYT\u2019s Spring Bread Wheat Breeding Germplasm

Synthetic hexaploid (SH) wheat (AABBD’D’) is developed by artificially generating a fertile hybrid between tetraploid durum wheat (Triticum turgidum, AABB) and diploid wild goat grass (Aegilops tauschii, D’D’). Over three decades, the International Maize and Wheat Improvement Center (CIMMYT) has developed and utilized SH wheat to bridge gene transfer from Ae. tauschii and durum wheat to hexaploid bread wheat. This is a unique example of success utilizing wild relatives in mainstream breeding at large scale worldwide. Our study aimed to determine the genetic contribution of SH wheat to CIMMYT’s global spring bread wheat breeding program. We estimated the theoretical and empirical contribution of D’ to synthetic derivative lines using the ancestral pedigree and marker information using over 1,600 advanced lines and their parents. The average marker-estimated D’ contribution was 17.5% with difference in genome segments suggesting application of differential selection pressure. The pedigree-based contribution was correlated with marker-based estimates without providing chromosome segment specific variation. Results from international yield trials showed that 20% of the lines were synthetic derived with an average D’ contribution of 15.6%. Our results underline the importance of SH wheat in maintaining and enhancing genetic diversity and genetic gain over years and is important for development of a more targeted introgression strategy. The study provides retrospective view into development and utilization of SH in the CIMMYT Global Wheat Program.

Genetic potential of quality in spring bread wheat cultivars bred at Kurgan agricultural research institute

Background. For the Trans-Urals, characterized by unstable climate over the years (alternating droughty and excessively moist years, recurrences of colds in spring, possibility of early frosts, etc.), grain quality is a prioritized genetic trait in spring bread wheat cultivars. In Kurgan Province, the share of thirdclass wheat varied since 1994 from 43% to 96%; only in the recent unfavorable years (2015 – 2017) it dropped to 11 – 27% due to rust epidemics. The aim of the study was to characterize the genetic potential of grain quality and its phenotypic implementation in promising cultivars bred at Kurgan Agricultural Research Institute and officially released for cultivation in the region.Materials and methods. The capacities of the KASIB4 – 13 (Kazakhstan–Siberia Wheat Improvement Network under the auspices of CIMMYT) represented by 17 breeding centers in Kazakhstan and Siberia were used to assess grain quality of 14 cultivars with different maturation time bred at Kurgan Agricultural Research Institute. Quality assessment was performed with due regard to the standards of Kazakhstan, CIS, and leading exporting countries, thus combining local and international levels, and employing genetic, biochemical and technological grain quality levels under different soil and climate conditions.Results and discussion. Generally, all cultivars demonstrated protein and gluten content and the level of vitreousness sufficient for strong and valuable wheat. The selected percentage was 92% for hard grain and medium hard grain wheat forms, up to 94% for high-protein and high-gluten ones, and up to 57% for genotypes without 1B/1R wheat/rye translocation. In terms of sedimentation, 86% of the genotypes were predicted to belong to the strong and valuable wheat class; according to the composition of HMW glutenin subunits, mixing quality and flour strength (W), 30 – 42% were identified as high-quality genotypes. The in-depth study of grain quality within the KASIB environmental network revealed heterogeneity among cultivars in a number of genetic and biochemical parameters and provided an opportunity to select high-quality genotypes by marker characteristics and technological properties, which is likely to improve the efficiency of intra-cultivar selection and overall quality assessment of cultivars.

Results of analyzing the passport database ‘Spring bread wheat landraces in the VIR collection’

Background. Recently, an increased interest in crop landraces has been observed among scientists working with plant genetic resources (PGR). Institutes have been organizing collecting missions to explore old varieties still cultivated locally. Attention paid to landraces is also associated with the introduction of GIS technologies into PGR studies. The N. I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) holds a unique collection of spring bread wheat landraces. One of the Institute’s top priorities is to develop and maintain a passport database, using a set of fields specifically fit for landraces.Analysis of the passport database. The passport database ‘Spring Bread Wheat Landraces in the VIR Collection’ is analyzed here. The database contains information on 5,925 accessions and has 36 fields. Statistical data are presented for the main fields: origin, collection site, botanical variety, year of registration in the collection, donor institute or expedition, and collector’s name.

Thermal Imaging Reliability for Estimating Grain Yield and Carbon Isotope Discrimination in Wheat Genotypes: Importance of the Environmental Conditions.

Canopy temperature (Tc) by thermal imaging is a useful tool to study plant water status and estimate other crop traits. This work seeks to estimate grain yield (GY) and carbon discrimination (Δ13C) from stress degree day (SDD = Tc − air temperature, Ta), considering the effect of a number of environmental variables such as the averages of the maximum vapor pressure deficit (VPDmax) and the ambient temperature (Tmax), and the soil water content (SWC). For this, a set of 384 and a subset of 16 genotypes of spring bread wheat were evaluated in two Mediterranean-climate sites under water stress (WS) and full irrigation (FI) conditions, in 2011 and 2012, and 2014 and 2015, respectively. The relationship between the GY of the 384 wheat genotypes and SDD was negative and highly significant in 2011 (r2 = 0.52 to 0.68), but not significant in 2012 (r2 = 0.03 to 0.12). Under WS, the average GY, Δ13C, and SDD of wheat genotypes growing in ten environments were more associated with changes in VPDmax and Tmax than with the SWC. Therefore, the amount of water available to the plant is not enough information to assume that a particular genotype is experiencing a stress condition.

Genetic diversity of gliadin-coding alleles in bread wheat (Triticum aestivum L.) from Northern Kazakhstan.

BackgroundSpring bread wheat (Triticum aestivum L.) represents the main cereal crop in Northern Kazakhstan. The quality of wheat grain and flour strongly depends on the structure of gluten, comprised of gliadin and glutenin proteins. Electrophoresis spectra of gliadins are not altered by environmental conditions or plant growth, are easily reproducible and very useful for wheat germplasm identification in addition to DNA markers. Genetic polymorphism of two Gli loci encoding gliadins can be used for selection of preferable genotypes of wheat with high grain quality.MethodsPolyacrylamide gel electrophoresis was used to analyse genetic diversity of gliadins in a germplasm collection of spring bread wheat from Northern Kazakhstan.ResultsThe highest frequencies of gliadin alleles were found as follows, in Gli1: -A1f (39.3%), -B1e (71.9%), and -D1a (41.0%); and in Gli-2: -A2q (17.8%), -B2t (13.5%), and -D2q (20.4%). The combination of these alleles in a single genotype may be associated with higher quality of grain as well as better adaptation to the dry environment of Northern Kazakhstan; preferable for wheat breeding in locations with similar conditions.

Molecular identification of the stem rust resistance genes in the introgression lines of spring bread wheat

A total of 57 introgression lines and 11 cultivars of spring bread wheat developed by All-Russian Institute of Plant Protection and cultivated in the Volga Region were analyzed. The lines were obtained with the participation of CIMMYT synthetics, durum wheat cultivars, direct crossing with Agropyron elongatum (CI-7-57) and have introgressions from related species of bread wheat, namely translocations from Ag. elongatum (7DS-7DL-7Ae#1L), Aegilops speltoides (2D-2S), Ae. ventricosum (2AL-2AS-2MV#1), Secale cereale (1BL-1R#1S), 6Agi (6D) substitution from Ag. intermedium and triticale Satu. Cultivars and lines were assessed for resistance to Saratov, Lysogorsk, Derbent and Omsk stem rust pathogen populations (Puccinia graminis f. sp. tritici), and analyzed for the presence of the known Sr resistance genes using molecular markers. The analysis of the cultivars’ and lines’ resistance to the Saratov pathogen population in the field, as well as to Omsk, Derbent and Lysogorsk populations at the seedling stage, showed the loss of efficiency of the Sr25 and Sr6Agi genes. The Sr31 gene remained effective. Thirty one wheat lines out of 57 (54.4 % of samples) were resistant to all pathogen populations taken into analysis. The Sr31/Lr26, Sr25/Lr19, Sr28, Sr57/Lr34 and Sr38/Lr37 genes were identified in the introgression lines. The Sr31/Lr26 gene was identified in 19 lines (33.3 % of samples). All lines carrying the 1RS.1BL translocation (Sr31/Lr26) were resistant to all pathogen populations taken into analysis. The Sr25/Lr19 gene was identified in 49 lines (86 %). The gene combination Sr31/Lr26+ Sr25/Lr19 was identified in 15 lines (26.3 %). The gene combinations Sr38/Lr37+Sr25/Lr19, Sr57/Lr34+Sr25/Lr19 and Sr31/Lr26+Sr25/Lr19+Sr28 were identified in 3 introgression lines. These three lines were characterized by resistance to the pathogen populations studied in this work. The Sr2, Sr24, Sr26, Sr32, Sr36 and Sr39 genes were not detected in the analyzed wheat lines.

Early maturing spring wheat in Nordic wildtype NAM-B1 germplasm for short-duration alternative wheat-producing regions

AbstractIn the USA, western Washington (WWA) and the Alaska (AK) Interior are two regions where maritime and continental climates, high latitude and cropping systems necessitate early maturing spring wheat (Triticum aestivum L.). Both regions aim to increase the production of hard spring bread wheat for human consumption to support regional agriculture and food systems. The Nordic region of Europe has a history of breeding for early maturing spring wheat and also experiences long daylengths with mixed maritime and continental climates. Nordic wheat also carries wildtype (wt) NAM-B1, an allele associated with accelerated senescence and increased grain protein and micronutrient content, at a higher frequency than global germplasm. Time to senescence, yield, protein and mineral content were evaluated on 42 accessions of Nordic hard red spring wheat containing wt NAM-B1 over 2 years on experimental stations in WWA and the AK Interior. Significant variation was found by location and accession for time to senescence, suggesting potential parental lines for breeding programmes targeting early maturity. Additionally, multiple regression analysis showed that decreased time to senescence correlated negatively with grain yield and positively with grain protein, iron and zinc content. Breeding for early maturity in these regions will need to account for this potential trade-off in yield. Nordic wt NAM-B1 accessions with early senescence yet with yields similar to regional checks are reported. Collaboration among alternative wheat regions can aid in germplasm exchange and varietal development as shown here for the early maturing trait.

Genetic polymorphism of glutenin subunits with high molecular weight and their role in grain and dough qualities of spring bread wheat (Triticum aestivum L.) from Northern Kazakhstan

High-molecular weight glutenin (HMWG) subunits are an important component of the gluten protein complex in cereal grains and can influence the baking properties of wheat. The study of polymorphism of glutenin makes it possible to isolate preferred genotypes with higher grain quality. To determine the allelic state of the Glu-1 loci controlling HMWG in 122 spring bread wheat varieties from Northern Kazakhstan, an SDS-based analysis was performed. The highest frequencies (in percentage) were detected in the alleles Glu-A1b (56.1), Glu-A1c (42.4), Glu-B1c (85.0), Glu-D1a (50.6) and Glu-D1d (46.9). A technological and baking evaluation of 33 varieties and 40 prospective selection lines on samples of bread wheat with known allelic compositions at the Glu-1 loci was carried out. Associations between HMWG and several technological traits were established: component 2* (allele Glu-A1b) with gluten content and P/L ratio; 7 + 9 components (allele Glu-B1c) with valorimetric index; and components 2 + 12 (allele Glu-D1a) with the ratio P/L. In some cases, discrepancies between the predicted baking qualities based on HMWG subunits and the results of traditional technological and baking evaluations have been revealed.

Assessment of bread spring wheat varieties for resistance to leaf fungal diseases in various climatic zones of Ukraine

The article highlights the results of researches of bread spring wheat varieties for resistance to leaf fungal diseases in two ecological zones Forest-Steppe and Polissia of Ukraine. For the zone of the Forest-Steppe, varieties with complex resistance to pathogens have been identified — MIP Zlata, Leguan; for resistance to Erysiphe graminis and Puccinia recondita — Heroinia, Panianka, Simkoda myronivska, Yasna; for resistance to Erysiphe graminis and Septoria tritici — Koksa variety. For the zone of Polissia MIP Zlata, Panianka have been identified for complex resistance to pathogens anmd Simkoda myronivska –f or resistance to Erysiphe graminis and Puccinia recondita. It was revealed that the most valuable there are varieties, which are characterized by a combination of high index of complex resistance with individual resistance to individual leaf fungal diseases.

Creation of bread spring wheat breeding material with wheat-rye translocations

Purpose. Creation of bread spring wheat varieties using domestic and foreign varieties as carriers of wheat-rye translocation. Меthods. Field, laboratory, statistical. Results. The creation of varieties with wheat-rye translocation 1AL.1RS is the perspective direction of breeding, which allows to significantly improve the gene pool of bread spring wheat. The paper covers outputs of long-term breeding studies conducted at the V. M. Remeslo Myronivka Institute of Wheat of the National Academy of Agrarian Sciences of Ukraine (MIW) for obtaining bread wheat varieties with wheat-rye translocation 1AL.1RS. As the initial breeding material varieties and lines of domestic and foreign breeding were used, in particular, the ‘TAM 107’ variety (USA) with wheat-rye translocation 1AL.1RS. During realization of the scientific breeding program, the bread winter wheat variety ‘Ekspromt’ (1AL.1RS), as well as the bread spring wheat varieties ‘Struna myronivska’ (1AL.1RS) and ‘MІP Solomіia’ (1AL.1RS) have been created. As evidenced by the analysis of the spectrum of storage proteins, the varieties ‘Struna myronivska’ and ‘MIP Solomiіa’ contain wheat-rye translocation 1AL.1RS in their genomes. The variety ‘MIP Solomiіa’ inherited it from the variety of bread spring wheat ‘Struna myronivska’. The bread spring wheat new variety ‘MІP Solomiia’ is characterized by high yielding capacity, adaptability, resistance to powdery mildew, fusarium head blight, common bunt and high indices of grain quality. Conclusions. By long-term single crossing foreign varieties and domestic breeding material when using the pedigree method, bread wheat varieties with wheat-rye translocation 1AL.1RS have been created. The bread spring wheat variety ‘MІP Solomiia’ submitted for the State Variety Testing in 2017, is characterized by high yielding capa­city, lodging resistance, low incidence of fungal diseases, resistance to common bunt, adaptability. The presence of wheat-rye translocation in spring wheats varieties of Myronivka breeding ‘Struna myronivska’ and ‘MІP Solomіia’ has been confirmed by analyzing the spectrum of storage proteins during polyacrylamide gel electrophoresis.

Optimization of Agrobacterium-mediated transformation in spring bread wheat using mature and immature embryos.

Wheat is the most widely grown staple food crop in the world and accounts fordietary needs of more than 35% of the human population. Current status of transgenic wheat development is slow all over the world due to the lack of a suitable transformation system. In the present study, an efficient and reproducible Agrobacterium-mediated transformation system in bread wheat (Triticum aestivum L.) is established. The mature and immature embryos of six recently released high yielding spring bread wheat genotypes were used to standardize various parameters using Agrobacterium tumefaciens strain EHA105 harbouring binary vector pCAMBIA3301 having gus and bar as marker genes. The optimum duration for embryo pre-culture, inoculation time and co-cultivation were 2days, 30min and 48h, respectively. The bacterial inoculum concentration of OD of1at 600 nm showed 67.25% transient GUS expression in the histochemical GUS assay. The filter paper based co-cultivation limits the Agrobacterium overgrowth and had 82.3% explants survival rate whereas medium based strategy had 22.7% explants survival only. The medium having picloram 4mg/l along with antibiotics (cefotaxime 500mg/l and timentin 300mg/l) was found best suitable for initial week callus induction. The standardized procedure gave overall 14.9% transformation efficiency in immature embryos and 9.8% in mature embryos and confirmed by gene-specific and promoter-specific PCR and southern analysis. These results indicate that the developed Agrobacterium-mediated transformation system is suitable for diverse wheat genotypes. The major obstacle for the implication of the CRISPR-based genome editing techniques is the non-availability of a suitable transformation system. Thus, the present system can be exploited to deliver the T-DNA into the wheat genome for CRISPR-based target modifications and transgene insertions.

The Effect of Terminal Heat Stress on Grain Growth and Quantitative and Qualitative Yield of Spring Bread Wheat in Ahwaz

The Effect of Terminal Heat Stress on Grain Growth and Quantitative and Qualitative Yield of Spring Bread Wheat in Ahwaz

Grain quality in bread wheat lines T. aestivum with introgression of genetic material T. dicoccoides and T. dicoccum

Related wild and cultural wheat species are regularly involved for expanding T. aestivum genetic diversity because they contain many valuable genes. We evaluated the effect of the genetic material of tetraploid species of the genus Triticum (T. dicoccoides, T. dicoccum) on the grain quality of introgression lines of spring bread wheat. The composition of the high molecular weight glutenin subunits which play an essential role in the formation of wheat baking properties was identified in the introgression lines of bread wheat and their parental forms. The traits of grain quality (hardness, protein and gluten content, gluten quality) were also evaluated. The lines with Glu-1 loci alleles from wheat relatives T. dicoccoides and Т. dicoccum were selected. It was found that the introgression of alien genetic material into the common wheat genome had a positive effect on the parameters of grain quality such as hardness, protein and gluten content. The lines with Glu-A1 loci alleles from T. dicoccoides and Glu-B1 from T. dicoccum were at the level of a parent wheat variety or of a higher gluten quality. As a result of the research, the new lines of bread soft wheat with high grain quality were found and can be used in the crop breeding.

Heat‐Tolerant QTLs Associated with Grain Yield and Its Components in Spring Bread Wheat under Heat‐Stressed Environments of Sudan and Egypt

Heat stress decreases photosynthesis, pollen viability, and grain number and weight and hence lowers yield and quality of wheat (Triticum aestivumL.) by variable amounts among different cultivars and genotypes. The present study was performed to determine genetic variability of spring bread wheat genotypes for yield and other agronomic traits under heat‐stressed (Wad Medani, Sudan) and high‐yielding (Sids, Egypt) environments and to identify linked single nucleotide polymorphism (SNP) markers through association mapping. A heat association panel of 197 spring wheat genotypes from ICARDA was evaluated for yield and agronomic traits at Wad Medani and Sids stations for 2 yr (2014–2015). A total of 111 significant marker‐trait associations were detected. The wsnp_Ex_c12812_20324622 marker on chromosome 4A was significantly correlated with yield at both locations. At Wad Medani, wsnp_Ex_c2526_4715978 on chromosome 5A was significantly correlated with grain yield. Wheat genotypes carrying the cytosine base at the wsnp_Ex_c12812_20324622 and wsnp_Ex_c2526_4715978 markers outyielded the ones carrying the alternative bases by 15%, whereas genotypes carrying the cytosine base at only one of the two markers increased their yield by 7.9 to 10%, suggesting the importance of using these markers for marker‐assisted selection in breeding programs to increase yield under heat stress. The top 20 high‐yielding and heat‐tolerant genotypes identified in this study have been distributed to the national research systems of Central and West Asia and North Africa (CWANA) and sub‐Saharan Africa (SSA) for potential direct release and/or use as parents after local adaptation trials.

Identifikacija gena za otpornost na lisnu rđu u jarom oplemenjivačkom materijalu hlebne pšenice u Poljoprivrednom istraživačkom institutu za jugoistočne oblasti u Rusiji

Leaf rust caused by Puccinia triticina is a common bread wheat disease in the Volga Region of Russia and breeding for this disease resistance is a priority for the Agricultural Research Institute for South-East Regions wheat program. Knowledge of the effective resistance genes present in the germplasm is relevant when selecting for effective and more durable resistance. P. triticina races with virulence to Lr9, Lr19, Lr26 and with other different virulence combinations and molecular markers of L r genes were used to determine which seedling resistance genes might be present in the 68 bread wheat lines and cultivars. Studies have shown that the effective protection against leaf rust widespread in the Volga Region spring bread wheat cultivars is controlled by Lr6Ag and Lr6Agi+Lr19 genes. In addition, cultivars carry Lr10, Lr19, Lr10+Lr26 genes. It was found that in the studied set of lines the leaf rust resistance is determined by the following Lr-genes and its combinations: 9, 10, 19, 26, 34, 37, 41, Satu, 6Ag. Moreover, usage frequency of Lr19 is 89.5%, Lr10 -40.4%, Lr26 -31.6%, Lr6Ag -21%, Lr28 -3.5%, Lr41 -3.5%, Lr9 - 1.8%, Lr34 -1.8%, Lr37 -1.8%, LrSatu -1.8%. The frequency of two L r-genes combinations is 45.7%, three - 21% and four Lr-genes - 5.3%. Mainly are used such Lr-genes combinations as: Lr19+Lr26 and Lr10+Lr19+Lr26 - 22.8%; Lr19+Lr6Ag -7%. The four Lr-genes combinations has been included Lr10+Lr26+Lr28?+Lr6Ag -1.8%, Lr1+Lr10+Lr26+Lr6Ag -1.8% and Lr10+Lr19+Lr28?+Lr6Ag -1.8%. In addition, the effective Lr19 with nonidentified Lr-genes from cultivar Saratovskaya 57 (L164) and a. elongatum (CI-7-57) combinations has been identified.

ИСПОЛЬЗОВАНИЕ ЭЛЕКТРОФОРЕЗА БЕЛКОВ ЗЕРНА ДЛЯ КОНТРОЛЯ ГЕНЕТИЧЕСКОЙ ЦЕЛОСТНОСТИ ОБРАЗЦОВ ЯРОВОЙ МЯГКОЙ ПШЕНИЦЫ ИЗ КОЛЛЕКЦИИ ГЕНЕТИЧЕСКИХ РЕСУРСОВ РАСТЕНИЙ ВИР

Background. VIR's Department of Wheat holds the collections of viable accessions and its originals. The process of reproduction and restoration of germination ability in wheat collections requires monitoring of varietal purity and integrity. For this purpose, botanical varieties that describe sets of morphological characteristics of the spike and grain are used. However, sometimes it is necessary to check the conformity of a variety with its original accession. In this case, the gliadin electrophoretic banding patterns are reliable markers in identifying cultivars and biotypes of wheat. Materials and methods . The study included 7 accessions of spring bread wheat: 3 for the cultivar 'Rubin' and 4 for the cultivar 'Novinka'. Identification of accessions by electrophoresis of gliadin storage protein was carried out according to the generally accepted method. Results and conclusions . Comparison of gliadin electrophoretic banding patterns of the varieties from the VIR collection of plant genetic resources with analogous accessions from other genebanks of the world resulted in the recovery of the lost varieties 'Rubin' (Sweden) and 'Novinka' (Russia).

ОЦЕНКА ЯРОВОЙ МЯГКОЙ ПШЕНИЦЫ ИЗ НОВЫХ ПОСТУПЛЕНИЙ В КОЛЛЕКЦИЮ ВИР ПО УСТОЙЧИВОСТИ К ПЫЛЬНОЙ ГОЛОВНЕ

Background. Loose smut caused by Ustilago tritici (Pers.) Rostr. is one of the major diseases of wheat widespread in all areas of its cultivation. Breeding centers in Russia constantly need new sources of resistance to this disease. Screening of spring wheat accessions for resistance to loose smut has been carried out since 2016 in the Genetics Department of the N. I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) in collaboration with the Wheat Genetic Resources Department. Materials and methods . In the 2016-2018 growing seasons, new 139 accessions of spring bread wheat were screened for resistance to loose smut against a severe infection background according to the well-known method (Krivchenko, 1984). During wheat's flowering phase, from 7 to 10 ears of each accession were inoculated with a fungal infection collected on VIR's experimental field. The severity of the infection was determined by the disease symptoms on the susceptible reference cultivars: 'Reward', 'Diamant' and 'Scala'. Assessment of the infection lesions was carried out in the next year after inoculation by counting the diseased and healthy ears in each accession. Results and conclusion . The ears of eleven accessions were resistant to loose smut during two years of evaluation. During three years of evaluation the disease symptoms were not detected on the plants of eight accessions: 'Salavat Yulaev' (k-65560, Bashkortostan), 'Fori 4' (k-65592, Leningrad Province); 'Diablon' (k- 65444, Germany), 'Ke Feng 10' (k-65472, China), k-65479 (Algeria), k- 65482 (Turkey), 'Alikat' (k-65586, Canada) and 'Selection 1403' (k- 65828, USA). Three years of evaluation showed that 10 varieties were moderately resistant (no more than 5% affected ears): 4 from Russia, 2 from Canada, and single accessions from Spain, China, Pakistan and Tajikistan. The mentioned accessions are of interest for the development of spring bread wheat cultivars with resistance to loose smut for cultivation in the North-Western region of Russia.