Spring Bread Wheat Research Articles

Genetic Dissection of Drought Tolerance of Elite Bread Wheat (Triticum aestivum L.) Genotypes Using Genome Wide Association Study in Morocco.

Drought is one of the most important yield-limiting factors in Morocco. Identification and deployment of drought-tolerant wheat varieties are important to cope with the challenge of terminal moisture stress and increase wheat productivity. A panel composed of 200 elite spring bread wheat genotypes was phenotyped for yield and agronomic traits for 2 years (2020 and 2021) in Morocco under rainfed and irrigated environments. The panel was genotyped using 20K SNPs and, after filtration, a total of 15,735 SNP markers were used for a genome-wide association study (GWAS) using a mixed linear model (MLM) to identify marker-trait associations (MTA) and putative genes associated with grain yield and yield-related traits under rainfed and irrigated conditions. Significant differences were observed among the elite genotypes for grain yield and yield-related traits. Grain yield performance ranged from 0.97 to 6.16 t/ha under rainfed conditions at Sidi Al-Aidi station and from 3.31 to 9.38 t/h under irrigated conditions at Sidi Al-Aidi station, while Grain yield at Merchouch station ranged from 2.32 to 6.16 t/h under rainfed condition. A total of 159 MTAs (p < 0.001) and 46 genes were discovered, with 67 MTAs recorded under rainfed conditions and 37 MTAs recorded under irrigated conditions at the Sidi Al-Aidi station, while 55 MTAs were recorded under rainfed conditions at Merchouch station. The marker ‘BobWhite_c2988_493’ on chromosome 2B was significantly correlated with grain yield under rainfed conditions. Under irrigated conditions, the marker ‘AX-94653560’ on chromosome 2D was significantly correlated with grain yield at Sidi Al-Aidi station. The maker ‘RAC875_c17918_321’ located on chromosome 4A, associated with grain yield was linked with the gene TraesCS4A02G322700, which encodes for F-box domain-containing protein. The markers and candidate genes discovered in this study should be further validated for their potential use in marker-assisted selection to generate high-yielding wheat genotypes with drought tolerance.

The use of drought resistance indices in the study of the spring bread wheat collection under the conditions of Aktobe Region

Background. Due to the global climate warming trend, the breeding of new drought-resistant cultivars of spring bread wheat remains a priority task for Western Kazakhstan breeders. However, an increase in resistance is often accompanied by a decrease in genotype productivity, and searching for an optimal combination of these characteristics is a trend in contemporary plant breeding.Materials and methods. In 2017–2019, 175 spring bread wheat accessions from the collection of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) and locally developed contemporary cultivars were studied under the conditions of Aktobe Agricultural Station. The field study was carried out according to VIR’s guidelines. To assess the drought tolerance of the accessions, the following indices were used: mean productivity (MP), stress tolerance (TOL), yield stability index (YSI), drought resistance index (DI), and stress tolerance index (STI).Results and discussion. Drought tolerance indices were calculated for all accessions using yield data in the driest (2019) and more favorable (2017) year. The total score of ranks for all indices was calculated for each accession. The total score correlated most strongly with the yield in an unfavorable year. As a result, 20 cultivars with the best total scores were identified, including 11 accessions bred in Aktobe Region, the reference cultivar, and promising accessions from other countries.Conclusion. The cultivars identified according to a set of indices are promising in terms of their use in breeding for drought resistance under the conditions of Aktobe Region. The proposed index system makes it possible to combine assessments of different drought tolerance aspects.

Earliness of spring bread wheat accessions under the conditions of the Middle Volga Region

Background. Development of early-ripening high-yielding cultivars of spring bread wheat is a complicated and difficult process. Striving for higher yields has triggered a trend to prolong the growing season pf the cultivars released by the Tatar Research Institute of Agriculture (TatRIA). Our breeding efforts to produce early cultivars, based on using an early-ripening sample as one of the parents, were unsuccessful. This paper presents a search for solutions to the said problem.Materials and methods. We studied spring bread wheat accessions from the collections of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) and Baicheng Academy of Agricultural Sciences (China) as well as promising lines developed by TatRIA. The study of the material was based on conventional spring bread wheat breeding methods. Phenological phases of wheat development were identified using the Zadoks scale.Results. An ambiguous role played by the vernalization response (Vrn) and photoperiod sensitivity (Ppd) genes in wheat earliness was shown, which is consistent with the data repeatedly presented in other publications. We identified accessions with the shortest period from sprouting to heading. Under our climate conditions, the earliest cultivars were those from Novosibirsk Province, Russia, and the North-Eastern China, where wheat development from sprouting to heading lasted 36–46 days.

Grain quality of spring wheat (&lt;i&gt;Triticum aestivum&lt;/i&gt; L.) cultivars developed in Western Siberia under the conditions of Northern Kazakhstan

Background. Environmental testing is the first stage of wheat breeding, the purpose of which is to identify wheat samples suitable for local environments and capable of forming a fairly stable yield and high-quality grain. The proposed study presents the test results for spring bread wheat cultivars of Russian breeding grown in arid environments of Northern Kazakhstan in order to preserve their yield and baking qualities.Materials and methods. The material of the study included 15 spring bread wheat cultivars. Protein and gluten content and the quality of gluten were determined using an infrared analyzer; the physical properties of the test were assessed using a Chopin alveograph and Brabender farinograph.Results. As a result of biochemical assessment, increased protein and gluten content and grain weight were observed in cvs. ‘Tyumenskaya 30’, ‘Aviada’, ‘Lutescens 585’, ‘Serebrina’, and ‘Tyumenets 2’. Dough deformation energy (W) characteristic of high-quality wheat and the balance in the P/L ratio (elasticity/elongation) were shown by cvs. ‘Tyumenskaya 33’ (290 a.u.; 1.15 P/L), ‘SKENT-3’ (307 a.u.; 0.89 P/L), and ‘Lutescens 585’ (374 a.u., 1.10 P/L). In laboratory baking, the volume of bread ranged from 620 ml (‘Tyumenskaya 27’) to 768 ml (‘Tyumenskaya 29’) with an average value of 707 ml. A baking quality analysis of the cultivars grown in the Northern Trans-Urals and Northern Kazakhstan demonstrated that the conditions in Northern Kazakhstan were more favorable for obtaining bread with an increased volume. On the basis of environmental tests and an assessment of a set of biochemical and technological indicators, cvs. ‘SKENT-3’ and ‘Tyumenskaya 29’ were selected. It makes sense to continue studying wheat cultivars that can be sources and donors of high-quality grain for the development of cultivars for the arid steppe of Northern Kazakhstan.

The effect of the 7DL-7Ae#1L·7Ae#1S translocation on the productivity and quality of spring bread wheat grain.

The 7DL-7Ae#1L·7Ae#1S translocation with the Lr29 gene attracts the attention of bread wheat breeders by its effectiveness against Puccinia triticina. However, its impact on useful agronomic traits has been little studied. In this report, the prebreeding value of 7DL-7Ae#1L·7Ae#1S was studied in analogue lines (ALs) of spring bread wheat cultivars Saratovskaya 68 and Saratovskaya 70 during 2019–2021. The presence of the Lr29 gene was conf irmed by using molecular marker Lr29F24. The ALs with the Lr29 gene were highly resistant to P. triticina against a natural epiphytotics background and in laboratory conditions. 7DL-7Ae#1L·7Ae#1S in Saratovskaya 68 ALs reduced grain productivity in all years of research. On average, the decrease was 35 and 42 %, or in absolute f igures 1163 and 1039 against 1802 kg/ha in the cultivar-recipient. In Saratovskaya 70 ALs, there was a decrease in grain yield in 2019 and 2020, and there were no differences in 2021. On average, the decrease was 18 and 32 %, or in absolute f igures 1101 and 912 against 1342 kg/ha in the cultivar-recipient. The analogues of both cultivars showed a signif icant decrease in the weight of 1000 grains, which ranged from 14 to 20 % for Saratovskaya 68 and 17–18 % for Saratovskaya 70. An increase in the period of germination-earing was noted only in Saratovskaya 68 lines, which averaged 1.3 days. ALs of Saratovskaya 70 had no differences in this trait. 7DL-7Ae#1L·7Ae#1S did not affect plant height and lodging resistance in all ALs. Studies of the bread-making quality in lines with 7DL-7Ae#1L·7Ae#1S revealed a signif icant increase in grain protein and gluten content. As for the effect on the alveograph indicators, there were differences between ALs of both cultivars. While Saratovskaya 68 ALs had a decrease in elasticity and in the ratio of dough tenacity to the extensibility, Saratovskaya 70 lines had an increase in these indicators. All lines increased the f lour strength and the loaves volume, but while Saratovskaya 68 ALs had an increased porosity rating, Saratovskaya 70 ALs had the same rating as the recipient.

Yielding capacity and flour-milling properties of spring bread wheat varieties depending on growing environmental conditions

Purpose. To determine the dependence of yield and flour-milling properties of new spring bread wheat varie­ties of Myronivka breeding on different growing season conditions. Methods. During 2017–2019, twelve spring bread wheat varieties were studied in the conditions of the V. M. Remeslo Myronivka Institute of Wheat of NAAS. Grain and flour qua­lity indicators were determined according to conventional methods. Results. It was found that weather conditions in 2019 were more favorable for realizing the yield potential of spring wheat varieties, but they had a nega­tive impact on quality indicators. By exceeding on 30–40% the standard ‘Elehiia myronivska’, the varieties – ‘Bozhena’ (4.23 t/ha), ‘Oksamyt myronivskyi’ (4.28 t/ha), ‘MIP Svitlana’ (4.31 t/ha), and ‘Dubravka’ (4.62 t/ha) were selected in terms of yield. The varieties ‘Simkoda myronivska’, ‘MIP Zlata’, ‘Bozhena’, ‘MIP Vizerunok’, and ‘MIP Oleksandra’ were singled out by the combination of high physical indicators of grain quality. The varieties ‘Simkoda myronivska’, ‘Oksamyt myronivskyi’, and ‘Panianka’ were distinguished by complex of the highest flour quality indicators. The varieties being the most stable in terms of individual characters were identified. These were ‘Simkoda myronivska’, ‘MIP Zlata’, ‘Bozhena’, ‘Oksamyt myronivskyi’, ‘MIP Svitlana’, and ‘MIP Oleksandra’ by yiel­ding capacity. According to quality indicators, in particular, by 1000 kernel weight, varieties ‘Simkoda myronivska’, ‘MIP Vizerunok’ were distinguished; high scores for grain vitreousness were in most varieties, except for ‘Elehiia myroniv­ska’, ‘Simkoda myronivska’, and ‘MIP Oleksandra’; according to test weight and flour yield, all varieties had high rates; according to the protein content, the variety ‘Oksamyt myronivskyi’ was distinguished; varieties ‘Dubravka’ and ‘MIP Oleksandra’ by wet gluten content. The ANOVA established that the most dependence on weather conditions was revealed for such parameters as 1000 kernel weight (part of influence 83.7%), protein content (76.7%), sedimentation value (66.7%), flour yield (52.6%), gluten deformation index (46.0%), and wet gluten content (42.6%); the most dependence on the interaction of factors year  variety was revealed for yielding capacity (52.3%), the grain vitreousness (50.5%), and the test weight (36.5%). A reliable effect of the factor variety on yield (34.9%) and all investigated quality indicators (5.1–35.1%) was revealed. Conclusions. It is expedient to use the varieties listed above as sources of certain traits for the creation of new high-yielding and high-quality varieties for different areas of use.

Estimation results of the spring bread wheat varieties on disease resistance in the Kazan Research Center

In the Republic of Tatarstan, due to favorable soil-climatic and market conditions, spring wheat production is developed, but wheat grain yields are limited by a number of unfavorable factors, one of which is a spread of fungal diseases. At the same time, the pressure of pathogenic fungi makes it possible to carry out fruitful breeding work in Tatarstan on resistance to diseases, which is on of the main activity of the Kazan Research Center of the RAS. The purpose of the current study was to estimate ten new varieties for resistance to major fungal diseases. The study on resistance to leafy diseases, such as powdery mildew, stem rust, brown leaf rust, dark brown leaf blotch was carried out at a natural infectious background, to kernel smut on an artificial infectious background inoculating seeds with spores of kernel smut. The study was carried out between the years of 2017 and 2021. The analysis for the possible presence of stem rust resistance genes was performed by a PCR analysis. As a result of the study, there was found out that the varieties ‘Sto let TASSR’, ‘Balkysh’, ‘Khazine’, ‘Chistopolskaya’, ‘Bulyak’ had a complex resistance to all studied diseases. The variety ‘Sitara’ had a strong field resistance to powdery mildew and kernel smut. The variety ‘Barakat’ had a strong field resistance to powdery mildew and leaf rust. The variety ‘Nadira’ was moderately resistant to powdery mildew and dark brown leaf spot. The varieties ‘Ekada 265’ and ‘Ekada 282’ were highly resistant to local stem rust populations. The molecular genetic estimation of the stem rust resistant varieties of spring bread wheat ‘Chistopolskaya’, ‘Sto let TASSR’, ‘Balkysh’, ‘Ekada 282’ for the identification of effective Sr-genes has shown that their resistance is apparently regulated by the Sr31 gene.

Breeding increases grain yield, zinc, and iron, supporting enhanced wheat biofortification

AbstractEstimation of the rate of genetic gain over time allows quantification of breeding progress. Here we report on the rate of grain yield and zinc (Zn) concentration increase over 11 yr of targeted wheat (Triticum aestivum L.) biofortification breeding at the International Maize and Wheat Improvement Center (CIMMYT). Data from yield trials evaluated across multiple locations in South Asia and beyond showed that average annual increases in grain yield potential of ∼1.5% and 0.9% per year gains for grain Zn and Fe concentrations. Across locations in all countries, mean yields of the five highest‐yielding entries showed an annual gain of 109 kg ha−1 yr−1 in yield and 0.3 mg kg−1 for grain Fe and Zn as well as 0.66 g for the yield component thousand‐grain weight. There was a strong positive correlation between Fe and Zn (r = .42) across locations, whereas no genetic correlation was observed between grain yield and Zn (r = .05) across locations. Despite the slight negative relationship between yield and Zn, through targeted crossing and development of large segregating populations we were able to identify transgressive segregants combining increased yield and Zn concentrations. Significant differences between lines for grain micronutrient concentrations were detected, and significant location effects on grain Zn and Fe concentrations were observed. These results demonstrate that continuous and simultaneous genetic gain for grain yield and concentrations of Fe and Zn is possible in elite spring bread wheat lines with potential to deliver global impact through identification of superior parents for use by national breeding programs and the release of biofortified wheat cultivars.

Dissecting the Genetic Architecture of Phenology Affecting Adaptation of Spring Bread Wheat Genotypes to the Major Wheat-Producing Zones in India.

Spring bread wheat adaptation to diverse environments is supported by various traits such as phenology and plant architecture. A large-scale genome-wide association study (GWAS) was designed to investigate and dissect the genetic architecture of phenology affecting adaptation. It used 48 datasets from 4,680 spring wheat lines. For 8 years (2014–2021), these lines were evaluated for days to heading (DH) and maturity (DM) at three sites: Jabalpur, Ludhiana, and Samastipur (Pusa), which represent the three major Indian wheat-producing zones: the Central Zone (CZ), North-Western Plain Zone (NWPZ), and North-Eastern Plain Zone (NEPZ), respectively. Ludhiana had the highest mean DH of 103.8 days and DM of 148.6 days, whereas Jabalpur had the lowest mean DH of 77.7 days and DM of 121.6 days. We identified 119 markers significantly associated with DH and DM on chromosomes 5B (76), 2B (18), 7D (10), 4D (8), 5A (1), 6B (4), 7B (1), and 3D (1). Our results clearly indicated the importance of the photoperiod-associated gene (Ppd-B1) for adaptation to the NWPZ and the Vrn-B1 gene for adaptation to the NEPZ and CZ. A maximum variation of 21.1 and 14% was explained by markers 2B_56134146 and 5B_574145576 linked to the Ppd-B1 and Vrn-B1 genes, respectively, indicating their significant role in regulating DH and DM. The results provide important insights into the genomic regions associated with the two phenological traits that influence adaptation to the major wheat-producing zones in India.

EXOTIC WHEAT GENOTYPES RESPONSE TO WATER-STRESS CONDITIONS

Drought is the most devastating abiotic stress which has significantly threatened global wheat production. The recent study was designed to evaluate the performance of eight exotic wheat lines through the Drought Spring Bread Wheat Yield Trial (DSBWYT), along with a local drought-tolerant check cultivar, Khirman, under water-stressed conditions based on agronomic and yield-related traits. The experiment was conducted during cropping season 2019–2020 in a randomized complete block design with three replications at the Nuclear Institute of Agriculture (NIA), Tando Jam, Pakistan. The analysis of variance revealed that there was a significant difference among the genotypes for all studied traits. The genotype DSBWYT-8 possessed better agronomic traits and growth features like early growth vigor and early ground cover. On the other hand, the genotype DSBWYT-4 performed better in yield and yield-related traits like main spike yield, grains per spike, and 1000-grains weight. Both genotype revealed excellent plot grain yield and harvest index and were not significantly different from each other. The cluster analysis grouped all the genotypes into three clades. The drought-tolerant local check cultivar Khirman clustered with genotypes DSBWYT-2, DSBWYT-4, and DSBWYT-8 thus, this clade can be regarded as drought tolerant. The second cluster comprised of two genotypes, i.e., DSBWYT-1 and DSBWYT-5, which performed relatively low as compared to genotypes present in the drought-tolerant cluster, whereas the genotypes DSBWYT-3, DSBWYT-6, and DSBWYT-7 clustered together to represent low yielding genotypes under drought condition as compared with the check cultivar Khirman. Based on these results, the genotypes DSBWYT-2, DSBWYT-4, and DSBWYT-8 can be recommended as the drought-tolerant genotypes.

Anthesis and Booting: Two Critical Stages Vulnerable to Water Stress in Wheat (Triticum aestivum L.) With Respect to Yield Production

Six spring bread wheat varieties (AAS-11, BARS-09, Dharabi-11, Faisalabad-08, Chakwal-50 and Fatehjang-2016) and 4 elite lines of wheat (10FJ01, 12FJ26, 12FJ01 and 11FJS309) were analyzed with respect to water stress by providing them two types of treatments i.e., control (no stress) and strained treatment (20 days of stoppage of irrigation at booting and further 20 days of drought after anthesis) at Barani Agricultural Research Station, Fatehjang during 2017-18. Results of this study exhibited highly significant variations prevailed in all the wheat genotypes by viewing their mean performance with respect of all physiological and yield traits. AAS-11, Fatehjang-2016 and Dharabi-11 exhibited their best performance and pointed out elevated mean productivity (MP), stress tolerance index (STI), relative water content (RWC) and geometric mean productivity (GMP). Moreover, stress susceptibility index (SSI) and tolerance (TOL) was anticipated at lowest among the above-mentioned wheat varieties and lines. Based multivariate analysis (biplot) and dendrogram studies; AAS-11, Fatehjang-2016 and Dharabi-11 are most suitable wheat cultivars for drought tolerance at booting and anthesis stage. MP, STI, RWC, GMP, SSI and TOL are renowned to be favourable gauges for identification of drought tolerance wheat ideotype. Likewise, same wheat varieties also exhibited higher grain yield per plant that put them in higher ranked genotypes for making selections and recombination while improving wheat through breeding for drought resistant.

Organ-specific expression of genes involved in iron homeostasis in wheat mutant lines with increased grain iron and zinc content.

BackgroundIron deficiency is a well-known nutritional disorder, and the imbalance of trace-elements, specifically iron, is the most common nutrient deficiency of foods across the world, including in Kazakhstan. Wheat has significant nutritional relevance, especially in the provision of iron, however many bread wheat varieties have low iron despite the need for human nourishment. In this study, the expression profiles of wheat homologous genes related to iron homeostasis were investigated. The work resulted in the development of two new M5 mutant lines of spring bread wheat through gamma-irradiation (200 Gy) with higher grain iron and zinc content, lower phytic acid content, and enhanced iron bioavailability compared to the parent variety. Mutant lines were also characterized by higher means of yield associated traits such as grain number per main spike, grain weight per main spike, grain weight per plant, and thousand-grain weight.MethodsThe homologous genes of bread wheat from several groups were selected for gene expression studies exploring the tight control of iron uptake, translocation rate and accumulation in leaves and roots, and comprised the following: (1) S-adenosylmethionine synthase (SAMS), nicotianamine synthase (NAS1), nicotianamine aminotransferase (NAAT), deoxymugineic acid synthetase (DMAS), involved in the synthesis and release of phytosiderophores; (2) transcription factor basic helix-loop-helix (bHLH); (3) transporters of mugineic acid (TOM), involved in long-distance iron transport; (4) yellow stripe-like (YSlA), and the vacuolar transporter (VIT2), involved in intracellular iron transport and storage; and lastly (5) natural resistance-associated macrophage protein (NRAMP) and ferritin (Fer1A).ResultsThe wheat homologous genes TaSAMS, TaNAS1, and TaDMAS, were significantly up-regulated in the roots of both mutant lines by 2.1–4.7-fold compared to the parent variety. The combined over-expression of TaYSlA and TaVIT2 was also revealed in the roots of mutant lines by 1.3–2.7-fold. In one of the mutant lines, genes encoding intracellular iron transport and storage genes TaNRAMP and TaFer1A-D showed significant up-regulation in roots and leaves (by 1.4- and 3.5-fold, respectively). The highest expression was recorded in the transcription factor TabHLH, which was expressed 13.1- and 30.2-fold in the roots of mutant lines. Our research revealed that genotype-dependent and organ-specific gene expression profiles can provide new insights into iron uptake, translocation rate, storage, and regulation in wheat which aid the prioritization of gene targets for iron biofortification and bioavailability.

Genome wide association study for stripe rust resistance in spring bread wheat (Triticum aestivum L.)

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst) is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide causing huge yield losses every year. Development and deployment of resistant varieties is the most economical and environment friendly approach for controlling this disease. However, because of the continuous evolution of the pathogen, resistant genes are easily overcome by new virulent Pst races, which necessitates a continuous identification and introgression of resistance genes to develop resistant wheat varieties. To identify effective source of resistance, a genome-wide association study was performed using 426 elite bread wheat genotypes based on 5176 polymorphic Diversity Arrays Technology (DArT) markers. Adult-plant-resistance was evaluated under field conditions for yellow rust resistance for two consecutive years (2014 and 2015) at ICARDA Merchouch station, Morocco. Out of the 426 genotypes, 51.17% were highly resistant with 5–10% level of severity to yellow rust. Genome wide association studies (GWAS) using a mixed linear model (MLM) identified three DArT markers on chromosomes 1B, 2B and 7B which are significantly associated with stripe rust resistance at false discovery rate p ≤ 0.05. BLAST analysis confirmed that the marker 412,394 in chromosome 2B overlapped with two previously reported QTLs (QYrlu.cau-2BS1 Luke and QYrid.ui-2B.1_IDO444). However, the two other markers 542,318 (1B) and 583,038 (5B) were not mapped within any of the previously reported gene/QTL regions; therefore, these markers may represent novel resistance loci for yellow rust. The highly resistant elite genotypes and linked molecular markers are recommended for further gene introgression and pyramiding purposes in the wheat breeding programs after validation.

Spring bread wheat response to kernel smut pathogens (Tilletia caries and T. laevis) in the Republic of Tatarstan

Wheat kernel smut (KS) is a disease of the reproductive organs. With low-cost and organic farming, grain farmers can face significant losses from this disease. The purpose of the current study was to identify resistant samples to KS pathogens in the Republic of Tatarstan during artificial inoculation of seeds with smut spores. There have been studied the spring wheat varieties recommended for cultivation in the Republic of Tatarstan, almost isogenic lines of the Red Bobs variety carrying the known Bt-genes Bt 1–10 from the collection of the All-Russian Institute of Genetic Resources of Plants named after N.I. Vavilov. When analyzing the species structure of the KS population spread in Tatarstan for 9 years (2012–2020), it was found that the species Tilletia caries prevailed over T. levis and the ratio of species depended on the soil pH before sowing. The minimum ratio of the number of spores of T. laevis / T. caries species in the studied samples was noted at the soil pH of 4.5. The correlation coefficient between indicators of soil solution response and species ratio was 0.86 (tfact˃ttheor at 1% significance level). The genes Bt 2, Bt 5, Bt 8, Bt 9, Bt 10 were highly effective for the Tatarstan KS population in the period of 2018–2021. The samples ‘M83-1621’ (cat. VIR 66238) of the USA and ‘AC Cadillac’ (cat. VIR 64565) of Canada carrying the Bt 10 gene had no signs of the disease. Most of the varieties recommended for cultivation (65%) are highly and very strongly susceptible to KS. Three varieties ‘Chernozemnouralskaya 2’, ‘Sitara’ and ‘Burlak’ are found weakly susceptible to KS.

Humidity effect on epiphytic microflora development and seed germination of spring bread wheat

The study of accumulated seed funds of spring bread wheat was carried out at the seed production department of the SibRIA (FSBSI “Omsk ARC”). The purpose of the current work was to characterize the development of epiphytic microflora on seeds of spring bread wheat and the change in their germination capacity during a long-term storage with different humidity. There was found out that the seed germination on 88% depended on the moisture content during storage and a number of fungi on their surface. On increasing the initial moisture content of seeds to 17%, the number of microorganisms on them increased significantly, and germination decreased after three years of storage in plastic containers to 0–1.9% in 28 months (2.3 years). There has been established multiple correlation between grain germination (x), moisture content (y) and a number of fungi on its surface (z), significant at the 5% level rxyz = 0.94. Seeds with high humidity, as well as feeble, shrivelled seeds were better stored under aerobic conditions, linen bags in a warehouse with a wooden floor. In polyethylene bags, ripe dry grain (with a moisture content of 6–14%) was stored for a long time, regardless of the floor type in the warehouse, wood or cement. When harvesting seeds in damp cool weather and drying them to a standard moisture content of 14%, it is better to pack the seeds in plastic bags, the type of floor in the warehouse does not matter. At a higher humidity of 17%, it is better to store the seeds in linen bags in a warehouse with a wooden floor to maintain germination.

Stem solidness as an important factor for wheat protection from European wheat stem sawfly (Cephus pygmaeus L.) in Altai

Background. European wheat stem sawfly (Cephus pygmaeus L.) is the main pest of wheat in Altai Territory, Russia. Resistance of host plants to this insect is based on a solid stem. The effect of a solid stem on the infestation of wheat stem sawfly larvae and on agronomic traits of spring bread wheat under the conditions of Altai Territory has not been studied.Materials and methods. The study was conducted on the experimental field of the Federal Altai Scientific Centre of Agro-BioTechnologies, Barnaul, Russia, in 2019–2021. The index of stem solidness was assessed according to a 20 point scale. The interplay between stem solidness and wheat stem sawfly larvae infestation of wheat plants was studied on 12 genotypes. The effect of stem solidness on agronomic traits was studied on 6 pairs of sister lines. One hundred cultivars were studied for the stem solidness index and 184 cultivars were tested for their resistance to wheat stem sawfly.Results. Stem solidness negatively correlated with wheat stem sawfly infestation (Spearman’s rank correlation coefficient was rs = –0.77 in 2019 and rs = –0.80 in 2020). Sister lines with a solid stem had significantly shorter plant height (–5 cm), less kernels per spikelet (–0.11 kernels), 1000 grain weight (–1.7 g) and grain weight per spike (–0.08 g), but higher grain weight per tiller spike (+0.11 g), compared to sister lines with a hollow stem averaged over two years. Stem solidness had no negative effect on yield or grain quality. Eleven cultivars with a solid stem index higher than 15 points were identified (‘Ershovskaya 33’, ‘Izera’, ‘Kvintus’, ‘KWS Akvilon’, ‘Tybalt’, ‘Cunningham’, ‘KW 240-3-13’, ‘KWS 3.13’, ‘Lillian’, ‘Sparrow’, ‘WW-4’).Conclusion. Stem solidness significantly decreases the damage from wheat stem sawfly and has no negative effect on yield or gluten and protein content in grain. The abovementioned cultivars with a solid stem are recommended for use in breeding for resistance to wheat stem sawfly.

Drought-Tolerance QTLs Associated with Grain Yield and Related Traits in Spring Bread Wheat.

The present research aims to identify the efficient combination of drought-tolerance selection criteria and associated quantitative trait loci. A panel of 197 bread wheat genotypes was evaluated for yield- and drought-tolerance-related traits in two environments (favorable and semiarid) for 2 years (2015–2016). Grain number, biomass, number of fertile spikes per plant and ground cover exhibited a significant correlation with grain yield and constitute potential secondary selection criteria for yield under drought conditions. About 73 significant marker–trait associations were detected along various chromosomal positions. The markers “wsnp_Ex_Rep_c67786_66472676” and “ExcalibuR_c24593_1217” exhibited important genetic gains associated with yield increase under drought (11 and 7%, respectively). The markers “KukRi_c94792_127” and “wsnp_Ex_c298_580660” showed a significant correlation with grain yield, biomass and grain number and were associated with a significant increase in yield performance at the semiarid site (+6 and +7%, respectively). The ground cover was found associated with grain yield and biomass through the markers “wsnp_Ex_Rep_c67786_66472676” (+11%) and “KukRi_c49927_151” (+10%). One marker “TduRuM_contig25432_1377” on chromosome 5B at 20 cM was consistently correlated with the number of fertile spikes across both environments. Further research should be considered to validate the efficiency of these markers to undertake selection for drought tolerance under various environments and genetic backgrounds.

Study of new spring bread wheat cultivar quartet in multi location test according to the KASIB system

The results of the study of a new spring bread wheat cultivar Quartet, production by introgressive breeding for economically useful traits are presented. This cultivar have a combination genes Lr39(=Lr41) (from Aegilops tauschii), Lr19/Sr25 (7DS-7DL-7Ae#1L translocation from Agr. elonga-tum) and Lr26/Sr31/Yr9/Pm8 (1BL·1R#1S translocation from S. cereale) It has been established that this cultivar has good adaptability and plasticity both in the conditions of the Saratov region Russia and when tested according to the KASIB system (. This cultivar was not inferior to local cultivar standards, but in many regions significantly exceeded them in grain productivity. At the same time, the cultivar Quartet have the good bread making quality, even though it contains the 1BL·1R#1S translocation from S. cereale. The resistance of the cultivar Quartet to leaf rust populations has been established, both in the Lower Volga region and in Western Siberia and Kazakhstan, as well as to most local stem rust populations, including the dangerous Ug99 race of this pathogen. Cultivar Quartet was slightly affected by powdery mildew. When evaluating this cultivar according to the KASIB system, it gave a differentiated degree of damage by local powdery mildew populations and had a reaction from 0 to 3 points and a degree of damage from 0% to 40%, but it should be noted that Quartet was resistant to most pathogen populations. Evaluation of a new spring bread wheat cultivar Quartet for a number of agronomic valuable traits and adaptability, revealed the prospects of using a combination of translocations 7DS-7DL-7Ae#1L + 1BL•1R#1S, in combination with chromatin from Aegilops tauschii. At the same time, a compensatory effect of the cultivar L505 was observed in the Quartet, which reduces the negative impact on the quality of flour and dough of 1BL•1R#1S translocation.

Genome-Wide Association Study of Root-Lesion Nematodes Pratylenchus Species and Crown Rot Fusarium culmorum in Bread Wheat.

Triticum aestivum L., also known as common wheat, is affected by many biotic stresses. Root diseases are the most difficult to tackle due to the complexity of phenotypic evaluation and the lack of resistant sources compared to other biotic stress factors. Soil-borne pathogens such as the root-lesion nematodes caused by the Pratylenchus species and crown rot caused by various Fusarium species are major wheat root diseases, causing substantial yield losses globally. A set of 189 advanced spring bread wheat lines obtained from the International Maize and Wheat Improvement Center (CIMMYT) were genotyped with 4056 single nucleotide polymorphisms (SNP) markers and screened for root-lesion nematodes and crown rot resistance. Population structure revealed that the genotypes could be divided into five subpopulations. Genome-Wide Association Studies were carried out for both resistances to Pratylenchus and Fusarium species. Based on our results, 11 different SNPs on chromosomes 1A, 1B, 2A, 3A, 4A, 5B, and 5D were significantly associated with root-lesion nematode resistance. Seven markers demonstrated association with P. neglectus, while the remaining four were linked to P. thornei resistance. In the case of crown rot, eight different markers on chromosomes 1A, 2B, 3A, 4B, 5B, and 7D were associated with Fusarium crown rot resistance. Identification and screening of root diseases is a challenging task; therefore, the newly identified resistant sources/genotypes could be exploited by breeders to be incorporated in breeding programs. The use of the identified markers in marker-assisted selection could enhance the selection process and cultivar development with root-lesion nematode and crown rot resistance.

The comparative analysis of the new spring bread wheat variety ‘Arseya’ with the zoned varieties

There has been presented the information on the purposeful process of developing the spring bread wheat variety ‘Arseya’, which was included in the state list of breeding achievements of the Russian Federation in the Central Region in 2020. The mean productivity of the variety plots of the Central region was 3.0 t/ha, the maximum productivity of 4.8 t/ha was obtained in the Bryansk region in 2018. The purpose of the current study was to estimate the valuable traits of the new spring bread wheat variety ‘Arseya’ with the zoned varieties of the Central region in a comparative analysis. As a result, there was found that the mean productivity of the variety ‘Arseya’ was 4.94 t/ha in the competitive variety testing for 2015–2020. Through the years of study, the lowest and highest levels of productivity exceeded the standard values of the variety ‘Agata’ on 0.30–0.49 t/ha. The comparative analysis of the varieties zoned in the Central Region showed that the new variety ‘Arseya’ exceeded them in productivity on 0.50–0.88 t/ha, or 10.1–17.8% on average. There was established that the highest level of productivity was formed under the optimal weather conditions of 2017. The largest productivity values were given by the varieties ‘Dariya’ and ‘Arseya’ with 6.28 t/ha and 5.72 t/ha, respectively. The lowest productivity range was identified in the varieties ‘Agata’ and ‘Arseya’ with 11.6% and 11.9%, respectively. The variety ‘Arseya’ under the generally accepted cultivation technology, showed the productivity potential by 86%. When calculating the stability factor (S.F.) indicators and the productivity range (d), there has been identified that the varieties ‘Agata’ and ‘Arseya’ have the lowest values of 1.33 and 1.35, i.e. 24.7% and 25.9% respectively. The spring bread wheat variety ‘Arseya’ is fully adapted to local agroclimatic conditions.