Common Wheat Lines Research Articles

A study of the influence of the T2DL.2DS-2SS translocation and the 5S(5D) substitution from Aegilops speltoides on breeding-valuable traits of common wheat.

The use of the gene pool of wild relatives for expanding the genetic diversity of common wheat is an important task of breeding programs. However, the practical application of common wheat lines with alien genetic material is constrained by the lack of information on chromosomal rearrangements and the negative impact of the transferred material on agronomically important traits. This research is aimed at studying 14 introgression lines with the T2DL.2DS-2SS translocation and the 5S(5D) substitution from Aegilops speltoides obtained from crossing common wheat varieties (Aurora, Krasnodarskaya 99, Nika Kubani) with the genome-substituted form Avrodes (BBAASS). Hybrid lines with different combinations of T2DL.2DS-2SS and T1BL.1RS translocations and 5S(5D) substitution were characterized by resistance to leaf and yellow rusts, productivity components and technological qualities of grain. The assessment of the varieties' resistance to rust diseases showed that Krasnodarskaya 99, Nika Kubani and the Aurora variety, which is a carrier of the T1BL.1RS translocation, are highly susceptible to diseases, while the presence of the T2DL.2DS-2SS translocation and the 5S(5D) substitution, both together and separately, provides resistance to fungal pathogens. The analysis of the lines using markers designed for known resistance genes of Ae. speltoides did not reveal the presence of the Lr28, Lr35 and Lr51 genes in the lines. The results suggest that the genetic material of Ae. speltoides transferred to chromosomes 2D and 5D contains new resistance genes. To determine the effect of the T2DL.2DS-2SS translocation and the 5S(5D) substitution on the productivity and technological qualities of grain, the lines were assessed by weight of 1000 grains, grain weight and number of ears per 1 m2, by protein and gluten content, gluten quality and general baking evaluation. A positive effect was determined upon the weight of 1000 grains, protein and gluten content. There were no significant differences in other characteristics. The T2DL.2DS-2SS translocation and the 5S(5D) substitution did not have a negative effect on the productivity and technological quality of grain, and are of interest for breeding practice.

Identification of a recessive gene RgM4G52 conferring red glume, stem, and rachis in a Triticum boeoticum mutant.

Anthocyanins are plant secondary metabolites belonging to the polyphenol class of natural water-soluble phytopigments. The accumulation of anthocyanins in different plant tissues can improve plant survival under adverse conditions. In addition, plants with the resulting colorful morphology can be utilized as landscape plants. Triticum boeoticum (syn. Triticum monococcum ssp. aegilopoides, 2n=2x=14, AbAb) serves as a valuable genetic resource for the improvement of its close relative common wheat in terms of enhancing resilience to various biotic and abiotic stresses. In our previous study, the EMS-mutagenized mutant Z2921 with a red glume, stem, and rachis was generated from T. boeoticum G52, which has a green glume, stem, and rachis. In this study, the F1, F2, and F2:3 generations of a cross between mutant-type Z2921 and wild-type G52 were developed. A single recessive gene, tentatively designated RgM4G52, was identified in Z2921 via genetic analysis. Using bulked segregant exome capture sequencing (BSE-Seq) analysis, RgM4G52 was mapped to chromosome 6AL and was flanked by the markers KASP-58 and KASP-26 within a 3.40-cM genetic interval corresponding to 1.71-Mb and 1.61-Mb physical regions in the Chinese Spring (IWGSC RefSeq v1.1) and Triticum boeoticum (TA299) reference genomes, respectively, in which seven and four genes related to anthocyanin synthesis development were annotated. Unlike previously reported color morphology-related genes, RgM4G52 is a recessive gene that can simultaneously control the color of glumes, stems, and rachis in wild einkorn. In addition, a synthetic Triticum dicoccum-T. boeoticum amphiploid Syn-ABAb-34, derived from the colchicine treatment of F1 hybrids between tetraploid wheat PI 352367 (T. dicoccum, AABB) and Z2921, expressed the red stems of Z2921. The flanking markers of RgM4G52 developed in this study could be useful for developing additional common wheat lines with red stems, laying the foundation for marker-assisted breeding and the fine mapping of RgM4G52.

Characterization of New Wheat-Thinopyrum intermedium Derivative Lines with Superior Genes for Stripe Rust and Powdery Mildew Resistance.

The wild species Thinopyrum intermedium (genome JJJSJSStSt) serves as a valuable germplasm resource providing novel diseases resistance and agronomically important genes for wheat improvement. Two wheat-Th. intermedium partial amphiploids, TAI7045 (2n = 56) and 78784 (2n = 56), exhibit high resistance to stripe rust and powdery mildew, and their chromosome constitutions have been characterized. With the aim to transfer novel resistance genes from Th. intermedium, the crosses of common wheat line MY11 with TAI7045 and 78784 were produced, and their individual F2-F5 progenies were characterized using sequential non-denaturing fluorescence in situ hybridization (ND-FISH) and molecular markers. We identified a set of wheat-Th. intermedium addition lines, involving the chromosomes 1St-JS, 2St, 2St-JS, 3St, 4J, 4St, 5St, 5J.St, 6JS.J, and 7JS. Above all, the stable wheat-Th. intermedium small segmental translocation lines with chromosomes 4DS.4DL-4StL-4DL-4JL and 4DS.4DL-4StL-4DL were selected. Combining data from specific marker amplification and resistance evaluation, we mapped the gene(s) for resistance to powdery mildew and stripe rust in the 233.56-329.88 Mb region of the long arm of the 4St chromosome from the reference Th. intermedium genome. The new wheat-Th. intermedium introgressions will be used as novel germplasm for breeding purposes.

Fine-mapping of LrN3B on wheat chromosome arm 3BS, one of the two complementary genes for adult-plant leaf rust resistance.

The common wheat line 4N0461 showed adult-plant resistance to leaf rust. 4N0461 was crossed with susceptible cultivars Nongda4503 and Shi4185 to map the causal resistance gene(s). Segregation of leaf rust response in F2 populations from both crosses was 9 resistant:7 susceptible, indicative of two complementary dominant resistance genes. The genes were located on chromosome arms 3BS and 4BL and temporarily named LrN3B and LrN4B, respectively. Subpopulations from 4N0461 × Nongda4503 with LrN3B segregating as a single allele were used to fine-map LrN3B locus. LrN3B was delineated in a genetic interval of 0.07cM, corresponding to 106kb based on the Chinese Spring reference genome (IWGSC RefSeq v1.1). Four genes were annotated in this region, among which TraesCS3B02G014800 and TraesCS3B02G014900 differed between resistant and susceptible genotypes, and both were required for LrN3B resistance in virus-induced gene silencing experiments. Diagnostic markers developed for checking the polymorphism of each candidate gene, can be used for marker-assisted selection in wheat breeding programs.

Physiological and antioxidant responses of synthetic hexaploid wheat germplasm under drought

BackgroundAs a result of the world population and climate change impact increases (especially in arid environments), there is a critical need for high-yield, drought-tolerant wheat. Synthetic hexaploid wheat derived lines (SHW-DL), were created artificially by crossing different durum wheat cultivars (AABB) with accessions of Aegilops tauschii (DD), a beneficial source of new genes for common bread wheat (Triticum aestivum L). Here, we studied the response of a panel of 91 SHW-DL for drought tolerance based on physiological, antioxidant enzyme activities, and drought tolerance indices.ResultsA wide range of variation and high values of heritability observed for grain yield, physiological and antioxidant traits indicating that the SHW-DL panel constitutes a valuable gene source for drought tolerance improvement of wheat. Despite decreases in grain yield (YLD), leaf area index (LAI), and relative water content (RWC) an increase in the content of malondialdehyde (MDA) was observed. Moreover, drought streass increased the antioxidant enzyme activities of ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POD), and also photosynthetic pigments, proline (Pro), and MDA content. With higher values of grain yield, physiological and biochemical traits such as photosynthetic pigments, and RWC, and lower content of MDA, and peroxidase (H2O2) activity, SHW-DL performed better compared to common wheat lines under water stress conditions.ConclusionsDifferent responses to water stress within the germplasm and between synthetic and common wheat suggest that selection for adaptive and suitable genotypes is possible for drought tolerance in synthetic wheat germplasm. Genotypes 54, 98, 102, 105, 122, 124, 143, 159, 196, and 198 were identified to be directly used in breeding programs or indirectly by crossing them with other wheat germplasm collections.

Phytopathological screening of common winter wheat lines for resistance to Puccinia triticina

Abstract. Leaf rust on wheat caused by P. triticina is the most widespread fungal disease worldwide and in Bulgaria. The development of wheat genotypes resistant to leaf rust is related to the different types of resistance and ways of gene inheritance. The different varieties have different susceptibility during the different stages of their ontogenetic development. The study of the initial material is an important step in the breeding for resistance and it is an ongoing process. Two hundred and forty-six breeding lines were tested against the local population of P. triticina during 2015-2017, under conditions of infection field and in a greenhouse at Dobrudzha Agricultural Institute – General Toshevo, Bulgaria. Twenty lines were selected, which demonstrated different degrees of resistance under infection field conditions and which showed resistance to some of the seven pathotypes used in the study. The identification of the pathotypes was based on the type of reaction of 20 monogenic lines. The reaction of isogenic lines was compared with the reaction of the selection lines and the results showed that the reaction of line 165/05-46 corresponded to isogenic lines carrying genes Lr 9, Lr 19 and Lr 25. The response of the other 3 lines (245/03-72, 13/04-97, 14/06-110) partially coincided with the response of the above mentioned genes. The reaction of the other 3 lines (169/05-69, 14/06-81, 8/08-25) partially coincided with the reaction of isogenic lines carrying genes Lr 2a, Lr 28 and Lr 29. It was determined that seven of the lines were carriers of a race-specific gene and that it was necessary to subject these lines to further breeding and genetic studies to determine presence of race-specific resistance. Five of the lines (72/05-53, 61/03-75, 106/04-189, 268/03-151, 79/04-131) combined incomplete resistance at young stage with resistance at adult stage. Four of the tested lines (68/06-78, 29/02-133-38, 79/04-125-28, 197/05-33) exhibited typical race non-specific resistance or APR. Four lines (13/04-165, 14/05-119, 19/06-79 and 61/03-81) demonstrated “slow rusting” type of resistance. Twenty of the studied lines were carriers of effective resistance and can be included in the breeding programs as donors of resistance to P. triticina.

Development of Winter Common Wheat Lines with the Stem Rust Resistance Gene Sr33

Development of Winter Common Wheat Lines with the Stem Rust Resistance Gene Sr33

Molecular cytological analysis of alien introgressions in common wheat lines created by crossing of Triticum aestivum with T. dicoccoides and T. dicoccum.

Wild and domesticated emmer (ВВАА, 2n = 28) are of significant interest for expanding the genetic diversity of common wheat as sources of a high protein and microelement grain content, resistance to many biotic and abiotic factors. Particular interest in these species is also determined by their close relationship with Triticum aestivum L., which facilitates interspecific hybridization. The objective of this work was to analyze the nature of alien introgressions in hybrid lines from crossing common wheat varieties with T. dicoccoides and T. dicoccum, and to assess the effect of their genome fragments on the cytological stability of introgression lines. A C-banding technique and genotyping with SNP and SSR markers were used to determine localization and length of introgression fragments. Assessment of cytological stability was carried out on the basis of chromosome behavior in microsporogenesis. A molecular cytogenetic analysis of introgression wheat lines indicated that the inclusion of the genetic material of wild and domesticated emmer was carried out mainly in the form of whole arms or large fragments in the chromosomes of the B genome and less extended inserts in the A genome. At the same time, the highest frequency of introgressions of the emmer genome was observed in chromosomes 1A, 1B, 2B, and 3B. The analysis of the final stage of meiosis showed a high level of cytological stability in the vast majority of introgression wheat lines (meiotic index was 83.0-99.0 %), which ensures the formation of functional gametes in an amount sufficient for successful reproduction. These lines are of interest for the selection of promising material with agronomically valuable traits and their subsequent inclusion in the breeding process.

Technological evaluation and determination of the traits stability in breeding materials in the early generations

The experiment was carried out on an experimental field of Institute of Plant Genetic Resources “K. Malkov”, Sadovo during the period 2016 - 2018. Nineteen common winter wheat lines and variety Sadovo 1 were studied, under the controlled trial conditions. The purpose of the research is technological evaluation and determination of the stability of traits in breeding materials in the early generations. The analyzes were carried out in a laboratory to assess the technological qualities of the grain. For the characterization of the studied lines, the following traits were taken into account: sedimentation value (SV) - using a 2% solution of glacial acetic acid (Pumpyanskiy, 1971); fermentation number FN - Pelshenke test (PT) by mixing a sample with live yeast in two repetitions (Pelshenke et al., 1953). The traits stability of breeding material was evaluated by the stability variances σi2 and Si2 according to Shukla (1972), the equivalency Wi according to Wricke (1962) and the criterion of phenotypic stability (Ysi) according to Kang (1993). The program product IPCSSVKYSI (Interactive program for calculating Shukla’s stability index (Ysi), developed by Kang & Magari (1995) was used to determine the stability index. The highest value for the trait sedimentation value was reported for line RU 32/2072.73.74, followed by line RU 47/3504. With a high value of the trait fermentation number are the lines RU 32/2072.73.74, RU 91/1729; RU 93/1895 and RU 128/2900. The influence of the factors genotype, environment and their interaction on the phenotypic appearance of the studied traits has been significant. The following lines can be highlighted as valuable breeding materials: RU 32/2072,73,74 and RU 47/3504 (high value and stability of the traits of sedimentation value and fermentation number). RU 49/2300 (high value and stability of the trait sedimentation value). RU 91/1729 (high value and stability of the trait fermentation number) The listed genotypes can be successfully used in breeding and improvement work to create new and high-quality common winter wheat varieties.

Breeding estimation of the winter wheat varieties in the conditions of the southern forest-steppe of Western Siberia

The expansion of winter wheat sowing areas is one of the reserves for increasing grain production in the Siberian region, since the areas under winter wheat is 15–20 % larger than under spring wheat according to productivity and has great potential in using bioclimatic resources of the region. the availability of sources of economically valuable traits and the development of various initial material on their basis is of decisive importance for breeding of new winter wheat varieties and their successful introduction into production. The purpose of the current paper was to find sources of economically valuable traits from the collection of winter wheat varieties of Russian breeding in the conditions of Western Siberia. There has been studied a collection of varieties and lines of winter common wheat of Russian breeding from the institutions of the Rostov region, Stavropol, and Krasnodar Areas. Field and laboratory trials were carried out on the experimental field of the Omsk SAU in the conditions of the southern forest-steppe of Western Siberia in 2020–2022. Sowing was laid in fallow at the generally accepted sowing dates. According to the breeding estimation of the studied samples in the field seasons of 2020–2022 there was a significant correlation between winter resistance of plants and winter wheat productivity (r = 0.59), as well as an inverse correlation between productivity and gluten percentage (r = –0.36), grain ash content (r = –0.73) and sedimentation (r = –0.38). The varieties ‘Barynya’ (North Caucasian FNAC), ‘Gubernator Dona’, ‘Donna’ (Rostov ARC), ‘Don 107’, ‘Nakhodka’ (ARC “Donskoy”) and the line ‘K18918’ (RCG named after P.P. Lukyanenko), characterized by increased winter resistance (6.5–8 points) and productivity (351–384 g/m2) have been recommended as sources in breeding to improve productivity level and stability of winter wheat varieties in the conditions of Western Siberia. The varieties ‘Etnos’, ‘Anka’, ‘Gurt’, ‘Antonina’, ‘Alekseich’ and ‘Duplet’ of Krasnodar breeding with a high protein and gluten percentage (16.1–17.9 % and 35.5–39.3 %), large grain ash content and sedimentation (1.59–1.92 % and 58.0–67.0 ml) can be used as an initial material in breeding to improve the quality of winter wheat grain.

Seedling and adult plant resistance to leaf rust in some Bulgarian common wheat lines.

The response of 250 common winter wheat breeding lines was investigated for resistance to the causative agent of Puccinia triticina under conditions of an infected field on the territory of Dobrudzha Agricultural Institute - General Toshevo, Bulgaria, during three successive seasons. Twenty lines with different degrees of resistance under field conditions were selected. Multi-pathotype testing was used to study the response of these lines at seedling stage under greenhouse conditions to individual pathotypes of P. triticina. Based on the response of the lines at seedling and adult stages, we found out that 20 % of them carried race-specific resistance. One of the lines (99/08-52) reacted with full resistance to the pathotypes used under greenhouse conditions. The reaction demonstrated by this line coincided with the response of isogenic lines carrying the genes Lr9, Lr19, Lr22a, Lr22b and Lr25. The other three lines (19/06- 108, 82/08-43 and 82/08-35) showed a resistant reaction to 6 or 5 of the pathotypes used in the study. Their response partially coincided with the reaction of 5 isogenic lines, and the presence of some of these genes in the above lines is quite possible. Lines carrying this type of resistance are to be subjected to further genetic and breeding investigations to prove the presence of a race-specific gene. Twenty-five percent of the lines combined partial race-specific resistance at seedling stage with the resistance of race non-specific nature at adult stage. Forty percent of all studied lines carried race non-specific resistance, and 15 % of the lines possessed resistance of the "slow rusting" type. As a result of the study we carried out, the lines that demonstrated stable resistance to leaf rust can provide sufficient protection of the host and can be included in the breeding programs for developing varieties resistant to P. triticina.

Genetic analysis of stripe rust resistance in the common wheat line Kfa/2*Kachu under a Chinese rust environment.

We mapped a new race-specific seedling stripe rust resistance gene on wheat chromosome 5BL and a new APR locus QYr.hazu-2BS from CIMMYT wheat line Kfa/2*Kachu. Breeding resistant wheat (Triticum aestivum) varieties is the most economical and efficient way to manage wheat stripe rust, but requires the prior identification of new resistance genes and development of associated molecular markers for marker-assisted selection. To map stripe rust resistance loci in wheat, we used a recombinant inbred line population generated by crossing the stripe rust-resistant parent 'Kfa/2*Kachu' and the susceptible parent 'Apav#1'. We employed genotyping-by-sequencing and bulked segregant RNA sequencing to map a new race-specific seedling stripe rust resistance gene, which we designated YrK, to wheat chromosome arm 5BL. TraesCS5B02G330700 encodes a receptor-like kinase and is a high-confidence candidate gene for YrK based on virus-induced gene silencing results and the significant induction of its expression 24h after inoculation with wheat stripe rust. To assist breeding, we developed functional molecular markers based on the polymorphic single nucleotide polymorphisms in the coding sequence region of YrK. We also mapped four adult plant resistance (APR) loci to wheat chromosome arms 1BL, 2AS, 2BS and 4AL. Among these APR loci, we determined that QYr.hazu-1BL and QYr.hazu-2AS are allelic to the known pleiotropic resistance gene Lr46/Yr29/Pm39 and the race-specific gene Yr17, respectively. However, QYr.hazu-2BS is likely a new APR locus, for which we converted closely linked SNP polymorphisms into breeder-friendly Kompetitive allele-specific PCR (KASP) markers. In the present study, we provided new stripe rust resistance locus/gene and molecular markers for wheat breeder to develop rust-resistant wheat variety.

The Use of the Genetic Resources of Tetraploid Wheat <i>Triticum aethiopicum</i> on the Developing of Purple-Grain Common Wheat with a High Content of Anthocyanins

The article considers the results on the developing of purple-grain common wheat and the study of its genetic diversity. Triticum aethiopicum Jakubz. 2n = 28 is the only source of genes for the purple grains color among the wheat species. The trait of purple grain is accompanied by an increase in the content of anthocyanins and micronutrients in the grain. To develop common wheat lines with purple grain, T. aethiopicum k-19068 was first hybridized with the Iranian landrace T. aestivum k-14333. The resulting hybrids were then crossed with the highly productive common wheat cultivar Liza. The developing lines F6 (2n = 42) characterize low diversity on multiple alleles of gliading-coding loci (H = 0.410). They were dominated by alleles inherited from the parent variety Liza. No gliadin alleles that could belong to T. aethiopicum have been identified. Comparison of groups of lines with purple and white grains made it possible to show that they do not significantly differ from each other in terms of yield and elements of its structure. As a result, we have not found a negative correlation between the high content of anthocyanins in grain and grain productivity. This allows us to hope for the possibility of developing high-yielding lines of common wheat with purple grain enriched with anthocyanins.

Drought resistance of introgressive spring common wheat lines with genetic material of tall wheatgrass

Background. To breed drought-resistant cultivars of common wheat1 (Triticum aestivum L.), it is important to use the gene pools of its relatives, including tall wheatgrass Thinopyrum ponticum (Podpěra) Z.-W. Liu & R.- C. Wang (= Agropyron elongatum (Host) Beauv.). Materials and methods. The introgressive lines of spring common wheat with T. ponticum genetic material and standard cultivars were studied in the field in the southern forest-steppe of Western Siberia using generally recognized methods. The ecological plasticity of cultivars and introgressive lines by grain yield and yield components was calculated according to the method of S. A. Eberhart and W. A. Russell. During the research period, there was a prolonged drought in 2012, and irregular short severe droughts occurred in 2013, 2014, and 2017. Results. An analysis of the ecological plasticity of standard cultivars adapted to the regional conditions showed that cv. ‘Pamyati Azieva’ corresponded to the extensive type, and cvs. ‘Duet’, and ‘Erythrospermum 59’ corresponded to the intensive type. Under drought conditions, the grain yield of cv. ‘Pamyati Azieva’ was determined by the stable development of productive tiller number, seed number and grain yield per main ear, but plasticity in 1000 grain weight was observed. Cvs. ‘Duet’ and ‘Erythrospermum 59’ showed ecological plasticity due to the adaptive development of two or three yield components. Introgressive lines exceeded the standard cultivars in grain yield (1.1–2.2 times) in dry seasons. Five lines were similar to cv. ‘Pamyati Azieva’ in plasticity and stability, and under drought conditions they demonstrated high and stable development of three or four yield components. The intensive lines formed their yield due to the compensatory development of three yield components in different combinations. Conclusion. Introgressive lines with T. ponticum genetic material are valuable for breeding spring common wheat cultivars with various drought-adaptation mechanisms.

Competitive Variety Testing of winter common wheat in the conditions of the Penza region

The current paper has presented the results of winter common wheat, studied in the nursery of the Competitive Variety Testing in the forest-steppe zone of the Penza region for 2016–2020. The purpose of the study was to estimate breeding lines of winter common wheat of the Competitive Variety Testing according to the main economic and biological traits and to identify samples with a complex of economically valuable traits and properties, in which the productivity level is stably maintained. The objects of the study were 35 winter common wheat lines developed by the FSBSI “Federal Research Center of Fiber Crops”. The zoned variety of winter common wheat ‘Fotinya’ was used as a standard one. The productivity of winter common wheat lines in the competitive variety testing ranged from 4.31 t/ha (the line ‘Erythrospermum 17/01-1-08’) to 4.85 t/ha (the line ‘Erythrospermum 12/00-16-04’). According to productivity, the standard variety ‘Fotinya’ significantly exceeded 13 lines, the increase of which ranged from 0.37 to 0.92 t/ha, НСР05 = 0.24 t/ha. During the study period, there was carried out a comprehensive estimation of winter common wheat lines to identify the best of them as carriers of economically valuable traits, which can promote developing new highly productive varieties with a high level of adaptability to the conditions of the forest-steppe of the Middle Volga region. The lines ‘Erythrospermum 12/00-16-04’, ‘Erythrospermum 29/03-2-06’, ‘Erythrospermum 21/00-3-08’, ‘Erythrospermum 18/04-3-08’, ‘Erythrospermum 17/01-7-08’ are of great interest for breeding, since they have been distinguished by a set of indicators (with a mean yield of 4.38–4.85 t/ha, more than 90 % of winter resistance, early maturity, 9 points of resistance to lodging, natural grain weight of 767–780 g/l, 86–90 % of kernel hardiness, 28.2–32.2 % of gluten in grain, 14.8–17.1 % of protein in grain). The selected lines have been recommended for inclusion in breeding programs for the development of highly productive winter common wheat genotypes.

Phytohormonal balance in leaves of the soft wheat lines isogenic for VRN genes

The paper presents results of the study of the phytohormonal balance in mature, formed leaves of the lines of common wheat (Triticum aestivum L.) of the winter variety Olvia during the transition from vegetative to generative development. Near isogenic for the VRN genes lines (NILs) created in the gene pool of the Olvia variety and plants of the vernalized and non-vernalized winter variety were used. The experiments were carried out under the conditions of a vegetation experiment in the factorial chamber of the Department of Physiology and Biochemistry of Plants and Microorganisms of the V.N. Karazin KhNU. During the experiment, we conducted physiological observations and analyzed the development rate of experimental plants. Phytohormone analysis was carried out in fixed plant material by a chromatographic distribution of phytohormone mixture with thin-layer chromatography. The phytohormones were identified by the reference standards irradiating the chromatograms with ultraviolet UV (254 nm), and the content was determined by biotesting methods. The level of main classes of classical growth-stimulating phytohormones (auxins (IAA), cytokinins (CK), and gibberellins (GA), and growth-inhibiting hormones (abscisins (ABA)) was analyzed. The indicators of phytohormonal balance were calculated as the ratio of growth-stimulating and growth-inhibiting hormones. The results of the experiments showed that phytohormones in mature, formed leaves of the experimental plants are represented by auxins – 64.9-70.7 μg/g, cytokinins – 26.6-30.5 μg/g, gibberellins – 179.47-228.68 μg/g, and abscisins – 54.06-89.76 μg/g of dry weight. Among the phytohormone classes studied, the minimal was the cytokinins’ content, while the phytohormones of terpenoid nature (gibberellins and abscisins) were represented best. It has been established that the phytohormonal balance viz. the ratio of growth-stimulating and growth-inhibiting phytohormones reflects the development rate of experimental plants. Rapidly developing plants of isolines VRN 1 and VRN 3, and the plants of vernalized variety were characterized by the maximum phytohormone balance (especially GA/ABA), while the slowly developing plants of the isoline VRN 2 and the non-vernalized variety Olvia had the minimum balance. Since the plant organism is an integrated system of organs and functions, we assume that this indicator – phytohormonal balance in plant leaves, can be used as a marker of the ontogenetic state of the entire plant organism. The identified changes in the phytohormonal status of mature, formed leaves and the development rates of experimental plants have the same regularities in all the models used in our research: the model of isogenic lines and the model of vernalized and non-vernalized plants of the winter variety. This fact makes it possible to assume that changes in the phytohormone balance of mature leaves, which reflect the ontogenetic state of the entire plant organism, are determined by the genotypic and phenotypic (epigenetic) influence.

Effect of NAM-1 genes on the protein content in grain and productivity indices in common wheat lines with foreign genetic material introgressions in the conditions of Belarus.

Modern varieties of common wheat (Triticum aestivum L.) bred mainly for high productivity are often of low grain quality. The identification of NAM-1 alleles associated with high grain protein content in wheat relatives has enhanced the significance of distant hybridization for the nutritional value of T. aestivum L. grain. In this work we aimed to study the allelic polymorphism of the NAM-A1 and NAM-B1 genes in wheat introgression lines and their parental forms and evaluate the effects of various NAM-1 variants on the grain protein content and productivity traits in the field conditions of Belarus. We studied parental varieties of spring common wheat, the accessions of tetraploid and hexaploid species of the genus Triticum and 22 introgression lines obtained using them (2017-2021 vegetation periods). Full-length NAM-A1 nucleotide sequences of T. dicoccoides k-5199, T. dicoccum k-45926, T. kiharae, and T. spelta k-1731 accessions were established and registered with the international molecular database GenBank. Six combinations of NAM-A1/B1 alleles were identified in the accessions studied and their frequency of occurrence varied from 40 to 3 %. The cumulative contribution of NAM-A1 and NAM-B1 genes to the variability of economically important wheat traits ranged from 8-10 % (grain weight per plant and thousand kernel weight) to up to 72 % (grain protein content). For most of the traits studied, the proportion of variability determined by weather conditions was small (1.57-18.48 %). It was shown that, regardless of weather conditions, the presence of a functional NAM-B1 allele ensures a high level of grain protein content; at the same time, it does not significantly decrease thousand kernel weight. The genotypes combining the NAM- A1d haplotype and a functional NAM-B1 allele demonstrated high levels of productivity and grain protein content. The results obtained demonstrate the effective introgression of a functional NAM-В1 allele of related species increasing the nutritional value of common wheat.

Breeding evaluation and precise mapping of Fhb8 for Fusarium head blight resistance in wheat (Triticum aestivum)

AbstractThe percentage of Fusarium‐damaged kernels (FDK) was proposed as a type of Fusarium head blight (FHB) resistance displayed in matured wheat kernels. In this study, Qfdk.nau‐7D, a QTL identified in the Wangshuibai genome for its association with FDK, was introduced into FHB‐susceptible common wheat line PH691 through marker‐assisted selection and backcrossing. Evaluation of two resulted near‐isogenic lines (NILs) showed that the contribution of Qfdk.nau‐7D interval to lower FDK resulted from its effects on resistance to pathogen infection and to disease spread within the spike. Of a few major agronomic traits evaluated, head length was the only one that made difference between PH691 and the NILs. To reduce the QTL interval, a high‐density marker map was constructed using a BC3F2 population of 97 plants. Through resistance evaluation of the homozygous recombinant lines in repeated field trials, Qfdk.nau‐7D, designated as Fhb8, was placed in a 1.0‐cM Xwgrb1500‐Xwgrb1559 interval (from 93.9–96.5 Mb in CS) and showed co‐segregation with Xwgrb1587. Moreover, it was found that the association of Fhb8 with head length was due to close linkage with spike length QTL HL2.

Nonhost Resistance of Thinopyrum ponticum to Puccinia graminis f. sp. tritici and the Effects of the Sr24, Sr25, and Sr26 Genes Introgressed to Wheat

The damage to wheat crops by stem rust poses a threat to the food security of the world’s population. The species Thinopyrum ponticum (Podpěra, 1902) (Z.-W. Liu and R.-C. Wang, 1993) is a non-host for the stem rust fungus Puccinia graminis f. sp. tritici Eriks. and Henn. (Pgt). The Sr24, Sr25, and Sr26 genes, transferred from the Th. ponticum to the wheat gene pool, protect cultivars from the disease in different regions of the world. The study of the non-host resistance (NHR) of Th. ponticum and the effects of the introgressed Sr24, Sr25, and Sr26 genes in wheat is important for breeding cultivars with durable resistance to stem rust. The aim of the research is to study the interaction of Pgt with Th. ponticum and common wheat lines with the Sr24, Sr25, and Sr26 genes, in addition to determining the role of ROS in resistance. Wheat lines with Sr24, Sr25, and Sr26 were resistant to the West Siberian Pgt population. Using cytological methods, it was found that the NHR of Th. ponticum and Sr24, Sr25, and Sr26 led to inhibition of the most inoculumdevelopment on the plant surface. This was mainly due to the suppression of the appressoria development and their death at the stage of penetration into the stomata. Upon contact of Pgt appressoria with stomatal guard cells, the generation of the superoxide anion O2•− was revealed. This interaction is similar to the stomatal immunity of Arabidopsis thaliana to non-pathogenic bacteria. The results of our studies show that the Sr24, Sr25, and Sr26 genes reproduce the action of some NHR mechanisms in wheat.

Donors of ultra-earliness for spring common wheat breeding

Knowledge of productivity and genetic control of the rate of ultra-early lines development will facilitate their use in breeding of common wheat Tritium aestivum L. for high adaptive capacity. The research focused on ultra-early lines Rico (k-65588), Rimax (k-67257) (progeny of F3 Rico × ‘Max’, k-57181), Fori 1-8 line series (progeny of F4 ‘Photon’ × Rico) and Rifor 1-13 (progeny of F7-8 Rico × ‘Forlani Roberto’), as well as on the accessions ‘Photon’ (k-55696) and ‘Forlani Roberto’ (k-42641). The varieties ‘Leningradskaya 6’ (k-64900) and ‘Leningradskaya 97’ (k-62935) were used as standards in VIR, and ‘Chelyaba 2’ (k-64379) was used in Сhelyabinsk ARI. The alleles of Vrn and Ppd genes were identified by PCR using the published allele-specific primers. Responses to vernalization (30 days at 3°C) and to a short 12-hour day were determined according to the VIR guidelines. The ultra-earliness of common wheat lines is associated with the presence of dominant alleles Vrn-A1, Vrn-B1, Vrn-D1, Ppd-B1, Ppd-D1, and possibly Eps. The shortest emergence-to-heading period at two experimental locations was noted for Rico (39.9 ± 1.49 days), which is 14.8 ± 1.22 days earlier than the development of region-adapted varieties. The Rico genotype contains Vrn-A1, Vrn-B1, Vrn-D1, Ppd-B1 and Ppd-D1. In the Rimax genotype, different alleles of the Ppd-D1 and Vrn-B1 genes were found, possibly being a result of recombination processes in Rico × ‘Max’ hybrids. Under a short photoperiod (12 hours), the Rico and Rimax genes can interact in a cumulative polymeric mode, which is not the case in long-day environments. Unlike other Rifor lines, Rifor 4 and Rifor 5, as well as ‘Forlani Roberto’, have a recessive vrn-A1a allele. However, Rifor 4 and Rifor 5 do not respond to vernalization, while ‘Forlani Roberto’ is responsive to this factor. The absence of response to vernalization in Rifor 4 and Rifor 5 possessing the recessive vrn-A1a allele is possibly provided by a complex of modifier genes along with the dominant Vrn-D1 gene, which was formed during recombination in F7-8 Rico × ‘Forlani Roberto’ hybrids. Recombinants of spring common wheat, combining ultra-earliness and relatively high ear productivity, have been identified. Grain yield per 1 m2 of new ultra-early lines in some years can reach 90% of that of the ‘Leningradskaya 97’. It is expedient to use ultra-early lines as donors of high-rate development in common wheat breeding, considering genetic peculiarities of the source lines.