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Plant-growth-promoting bacteria are an important economic and environmental resource as biofertilizers that can stimulate plant growth and improve agricultural yields. In this study, potential plant growth-promoting bacteria were isolated from soil samples collected in Russia. Strains that manifested active growth on a nitrogen-free medium, the Pikovskaya medium (with insoluble phosphates) and CAS (Chrome Azurol S) agar, were selected for the study. All bacterial isolates were identified by 16S rRNA gene sequencing analysis. Seventeen bacterial isolates of different species were purified and quantified for their ability to grow on nitrogen-free media; dissolve phosphate; and produce ammonium, indole-3-acetic acid, siderophores, and antifungal activity. Principal component analysis identified three groups of strains: one with the maximum signs of providing "plant nutrition"; one with signs of "antimicrobial activity"; and a group "without outstanding signs". All 17 strains were involved in experiments involving growing inoculated wheat seeds (Triticum aestivum) in pots under natural environmental conditions, and were assessed by their effect on the wheat growth and yield as well as on the chemical composition of the soil. For the "plant nutrition" group, regression analysis revealed a connection between indicators of plant growth, ear length, and ammonium accumulation in the soil. However, in other groups, there were also strains showing a positive effect on plant growth, which suggests the necessity of involving additional factors to predict the ability of strains to affect plants when screened in the laboratory. [ABSTRACT FROM AUTHOR]

Pesticide treatment leads to a significant increase in wheat yield and enhances pest resistance. However, pesticides, particularly the insecticide cypermethrin, which is used for wheat Triticum aestivum L. field and grain storage treatment, are toxic xenobiotics. To reduce their toxicity, it is possible to pre-treat seeds with plant growth-promoting rhizobacteria (PGPR), which can enhance plant resistance to adverse environmental factors. In this study, we used a previously unused as PGPR representative of the genus Azospirillum, A. thiophilum BV-ST, isolated in Russia, which makes it interesting for agricultural use in the same climatic zone. We optimized the detection method of A. thiophilum using PCR. Then, we demonstrated that this bacterium successfully inoculates to wheat roots. We showed that cypermethrin treatment of one- and two-week-old wheat seedlings caused an increase in mtDNA damage, and in one-week-old seedlings, it induced a decrease in chlorophyll levels. However, three- and four-week-old seedlings were more resistant to damage, possibly due to their approximately 5-fold higher expression of NDOR-1 and GST genes, which play an important role in xenobiotic detoxification. Pre-treatment of wheat seeds with A. thiophilum contributed to the upregulation of NDOR-1 and GST gene expression in one- and two-week-old seedlings, resulting in the protection of mtDNA from cypermethrin-induced damage and prevented the decrease in chlorophyll levels. [ABSTRACT FROM AUTHOR]

Over the last decade, the significance of yellow rust caused by Puccinia striiformis (Pst) has substantially increased worldwide, including in Russia. The development and cultivation of resistant genotypes is the most efficient control method. The present study was conducted to explore the yellow rust resistance potential of modern common winter wheat cultivars included in the Russian Register of Breeding Achievements in 2019–2022 using the seedling tests with an array of Pst races and molecular markers linked with Yr resistance genes. Seventy-two winter wheat cultivars were inoculated with five Pst isolates differing in virulence and origin. Molecular markers were used to identify genes Yr2, Yr5, Yr7, Yr9, Yr10, Yr15, Yr17, Yr18, Yr24, Yr25 and Yr60. Thirteen cultivars were resistant to all Pst isolates. The genes Yr5, Yr10, Yr15 and Yr24 that are effective against all Russian Pst races in resistant cultivars were not found. Using molecular methods, gene Yr9 located in translocation 1BL.1RS was detected in 12 cultivars, gene Yr18 in 24, gene Yr17 in 3 and 1AL.1RS translocation with unknown Yr gene in 2. While these genes have lost effectiveness individually, they can still enhance genetic diversity and overall yellow rust resistance, whether used in combination with each other or alongside other Yr genes. [ABSTRACT FROM AUTHOR]

Leaf rust, caused by Puccinia triticina (Pt), is a widely occurring disease of wheat in the North-Western Region of Russia. Annual Pt surveys of wheat in this region have been conducted between 2001 and 2021. In total, 740 single urediniospore isolates were analyzed over 20 years. Virulence to Lr9, Lr19 and Lr24 were rare in 2001–2010 and was not detected after 2010. Temporal variation in virulence was determined on Thatcher lines with Lr1, Lr2a, Lr2b and Lr2c genes and was found to be relatively high. Virulence to Lr1 increased to 100% from 2001 to 2014. Until 2010, most northwestern Pt isolates were avirulent to Lr2a and virulent to Lr2b and Lr2c. In the middle of 2010, avirulence to Lr2a, Lr2b, Lr2c and Lr15 began to increase. Strong variability between years was revealed for virulence to Lr20 and Lr26. Based on a set of 20 differential lines, 122 virulence pathotypes were detected. More than half of those were observed only once across all years. Pathotypes were divided into groups of B-, C-, D- and F-, virulent to Lr1 and Lr2a, dominating until 2009. From 2010 pathotype groups M- and P-, virulent to Lr1 and avirulent to Lr2a, began to dominate. Temporal differentiation of northwestern Pt population for virulence was determined. High similarity was observed for Pt accessions in 2001–2009 and 2010–2015 and these two groups differed moderately from each other. Pt accessions from 2016–2019 and 2020–2021 differed from each other and from accessions from the previous collection period. Field response of Lr differential lines was studied in the North-Western Region during 1998–2022. Wheat genotypes with genes Lr9, Lr19, Lr23, Lr24, Lr25, Lr28, Lr29, Lr35, Lr39, Lr42, Lr43, Lr45, Lr47, Lr48, Lr49, Lr50, Lr51, Lr53 and Lr57 remained resistant throughout the period of the study. Leaf rust severity in lines TcLr12, TcLr21, TcLr22a, Gatcher (Lr27+31), TcLr44 and Pavon (Lr46) varied from 1% to 30% before 2014 and significantly decreased after 2014. A general trend of decreasing virulence of the Pt pathogen has been observed in the North-Western Region over the recent years. [ABSTRACT FROM AUTHOR]

The Septoria blotch is one of the most economically harmful diseases of common wheat in Russia and the world. The disease is mainly caused by two pathogen species: Zymoseptoria tritici that damages the leaves, and Parastagonospora nodorum that strikes the leaves and ears. Resistance genes of the alien relatives are traditionally used for genetic defense of cultivars. The aims of the research were to study the resistance of the tall wheatgrass Thinopyrum ponticum (Podp.) Z.-W. Liu and R.-C. Wang and perspective introgressive lines of spring common wheat with its genetic material to Septoria blotch, and to characterize their agronomical properties to be used in breeding programs in Western Siberia. The studies were carried out in 2015–2019 in the field conditions of the southern forest-steppe (Omsk, Russia) on a natural infection background and according to standard methods. The Septoria diseases developed on the wheat in the period of milk-wax ripeness, independently of humid or dry weather conditions. In 2016, a sharp increase in leaf lesion was noted, probably associated with changes in the Z. tritici population. In 2017, the ratio of Z. tritici and P. nodorum was similar, and in 2019 Z. tritici prevailed. During the research, the lines that combined leaf and ear resistance to damage with high yield and grain quality were selected. [ABSTRACT FROM AUTHOR]

Common wheat cultivars have been protected from stem rust for several decades worldwide by the Sr31 resistance gene transferred from Secale cereale L. (cv. Petkus). In 1998, Sr31 was overcome in Uganda by the Ug99 race of Puccinia graminis f. sp. tritici Eriks. & Henn. (Pgt). The Ug99 race and its derivatives have spread widely in Africa, neighboring regions and Europe. However, Sr31 remains effective in other areas of the world, including Russia. To breed wheat with durable resistance, it is promising to research the resistance mechanisms of nonhost species and introgressive cultivars. The aim of the research was to estimate the resistance of S. cereale and Triticum aestivum cultivars with Sr31 to stem rust and to study the mechanisms of incompatibility of Pgt with plants at the cellular level. The research was carried out in Western Siberia (Russia, Omsk region) in 2018–2022. Rye and wheat with Sr31 (cvs. Kavkaz, Seri 82, Bacanora (=Kauz's'), NIL Thatcher TcLr26/Sr31) were resistant at the stages of seedling and adult plant, and cv. PWB343 was more susceptible to disease. Cytological studies have shown that Pgt died on the rye plants on the surface, and cv. Petkus intensively suppressed the development of the appressoria necessary to penetrate into tissues. Wheat cultivars inhibited the Pgt development mainly on the surface and while it attempted to penetrate into the stomata (pre-haustorial resistance). It has been demonstrated that Pgt has to adapt step-by-step to the surface and tissue properties for compatible interaction, which may be the reason for the durable effectiveness of Sr31. [ABSTRACT FROM AUTHOR]

There is a huge polymorphism in wheat grain storage protein, gliadin. The currently known number of gliadin-encoding loci (Gli) and their allelic variants (genetic markers) allows, theoretically, to distinguish more than one billion (109) of wheat homozygous genotypes differing among them at least at one Gli locus. It was discovered that most genotypes of common wheat cultivars bred and grown in the south of Ukraine contain the unique combination of two genetic markers, Gli-A2f + Gli-B2o. This allelic combination occurred in a few genotypes of cultivars bred in regions of Russia geographically close to South Ukraine and nowhere else in the world. The two markers can be easily identified using any modification of the simple method of acid electrophoresis (APAGE) widely-used for analysis of gliadin polymorphism. [Display omitted] • Genotypes of Ukrainian and Russian wheat differ strongly. • The high frequency of the combination Gli-A2f + Gli-B2o occurs in the Ukrainian wheat, and nowhere else in the world. • Gliadin alleles could be used as forensic evidence of Ukrainian origin. [ABSTRACT FROM AUTHOR]

Leaf rust, caused by the fungus Puccinia triticina, is one of the most damaging rust diseases of wheat in Russia. Populations of P. triticina were monitored in seven regions of Russia from 2001 to 2018, with a total of 5,191 single urediniospore isolates from bread wheat (Triticum aestivum) being analysed. Populations have changed significantly in all regions since 2012, after 2 years of drought (2010–2011). Regional collections of P. triticina were also significantly different between the two periods 2001–2009 and 2012–2018, with changes along two geographic gradients from West Siberia to the north‐west and south‐west (North Caucasia) of the European part of Russia. All tested isolates were avirulent to resistance gene Lr9 in 2001–2009 but, since 2010, virulence to Lr9 has occurred and annually increased in the Asian part of Russia (Ural and West Siberia) due to deployment of cultivars with the Lr9 gene. Virulence to Lr2a and Lr15 was considerably lower in Dagestan (6%–33%) and all European regions (35%–67%) than in Asian regions (84%–96%). During 2001–2009, virulence on Lr1 was also lower in Dagestan (33%) and the European regions (50%–77%) than in Asia (91%–96%); however, by 2012–2018, nearly all isolates were virulent on Lr1. Remarkable changes were observed in frequencies of P. triticina races defined by their virulence/avirulence to Lr1 and Lr2a genes. We postulate the P. triticina population in Dagestan is specific to that area and pathogen populations in European and Asian parts of Russia are distinct. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine whether genetically distinct groups of Puccinia triticina are present in four regions of the Russian Federation. Collections of P. triticina were obtained from the Central, North Caucasus, Volga and West Siberia regions from 2006 to 2010. Ninety-nine single uredinial isolates were tested for virulence phenotype with 20 Thatcher near-isogenic lines of wheat. Forty-one virulence phenotypes were found in the four regions, with eight in common between the widely separated Central and West Siberia regions. A total of 72 isolates were tested for molecular genotype with 23 simple sequence repeat ( SSR) primer pairs, and 66 isolates were used for further analysis after clone correction for virulence and molecular genotype. Analysis of variation showed no overall differentiation of SSR genotypes or virulence phenotypes based on region of origin. Linkage disequilibria for SSR genotypes were high across the entire population. The regional populations had higher than expected levels of allelic heterozygosity that indicated clonal reproduction. Based on cluster analysis of SSR genotypes there were two groups of P. triticina isolates that were widely distributed across Russia. The two SSR groups also differed significantly for virulence. Puccinia triticina may be dispersed from a common source of inoculum in the European or Caucasus regions of Russia. The Russian P. triticina populations were highly differentiated for SSR genotype from populations in Tajikistan, Kyrgyzstan, Uzbekistan, Armenia, Georgia and Azerbaijan and more similar to populations from southern Kazakhstan and northern Kazakhstan. [ABSTRACT FROM AUTHOR]

Yellow (stripe) rust, caused by Puccinia striiformis Westend. (Pst), is a major disease of cereals worldwide. We studied Pst virulence phenotypes on Triticum aestivum, Triticum durum, and triticale in three geographically distant regions of the European part of Russia (Dagestan and Krasnodar in North Caucasus, and Northwest) with different climate and environmental conditions. Based on the set of twenty differential lines, a relatively high level of population diversity was determined with 67 different Pst pathotypes identified among 141 isolates. Only seven pathotypes were shared by at least two hosts or occurred in the different regions. No significant differentiation was found between regional Pst collections of pathotypes either from T. aestivum or from T. durum. A set of Pst pathotypes from triticale was subdivided into two groups. One of them was indistinguishable from most durum and common wheat pathotypes, whereas the second group differed greatly from all other pathotypes. All sampled Pst isolates were avirulent on lines with Yr5, Yr10, Yr15, and Yr24 genes. Significant variation in virulence frequency among all Pst collections was observed on lines containing Yr1, Yr3, Yr17, Yr27, and YrSp genes and cvs Strubes Dickkopf, Carstens V, and Nord Desprez. Relationships between Russian regional collections of Pst from wheat did not conform to those for P. triticina. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess genetic diversity within old and modern common spring wheat ( Triticum aestivum L.) varieties cultivated in Siberia and to find out whether old Siberian varieties could be a potential source for genetic diversity in modern wheat breeding in Siberia. A set of 54 varieties was analysed using 22 wheat microsatellite markers (WMS), determining 23 loci located on 19 different chromosomes. In total, 151 alleles were detected with an average of 6.6, ranging from three to 11 alleles per locus. The average genetic diversity value (polymorphic information content) was 0.70. WMS located in the B genome produced more alleles per locus (7.6) compared with WMS located in the A (6.0) and D (6.0) genomes. Genetic similarity values between varieties ranged from 0.19 to 0.96 and were used to produce a dendrogram. With a few exceptions the varieties studied were clustered in two nearly equal groups consisting of predominantly old (released before 1960) and modern (released in 1960–90s) varieties, respectively. Genetic diversity values within these two groups were similar with 0.60 and 0.58, respectively. The numbers of group-specific alleles were 34 and 29, respectively. A significant variation in frequencies of 79 shared alleles was observed. The results obtained by using genomic microsatellite sequences demonstrated that breeding has not resulted in a decrease in the genetic diversity in Siberian spring wheat. However, significant quantitative and qualitative changes in allelic frequencies of different loci were detected. It may be suggested, that old Siberian common spring wheat varieties are a potential basis for genetic diversity in modern wheat breeding in Siberia. [ABSTRACT FROM AUTHOR]

The southern Ural is consistently among the 10 best regions in Russia for agricultural production, including wheat. Breeding in the Chelyabinsk Research Institute of Agriculture aims to develop wheat cultivars genetically protected from the main diseases (leaf and stem rust, septoria leaf blotch and tan spot). The genes for resistance to leaf rust, Lr1, Lr9, Lr10 and Lr26/Sr31, alone or in combination, are widespread in cultivars grown in the southern Ural. In 2012, a new wheat cultivar, Chelyaba 75, was proposed for commercial production in the southern Ural, being highly resistant to leaf rust with the highly effective genes LrSp and SrSp transferred from the cuckoo line with the genetic material Aegilops speltoides. Isolates virulent to cv. Chelyaba 75 were not found in Russian populations of Puccinia triticina. Additionally, for a long period, genes Lr29, Lr 41, Lr42, Lr45, Lr47, Lr50, Lr51, Lr53 and Lr57 were characterized by high efficiency. Virulence frequencies to other Lr genes vary annually, but no races with new virulence have been identified. The resistance of lines with the Sr31 and Sr24 genes indicates that the Puccinia graminis population does not contain genotypes with the potentially damaging race Ug99. Mixed septoria and tan spot infections occurred in the southern Ural, with the latter dominating. Races producing the exotoxin ToxA are widely distributed in Pyrenophora tritici-repentis populations. Two causal agents of septoria leaf blotch (Parastagonospora nodorum and P. avenae f. sp. tritici) occur in the region, with the first dominating. Aggressiveness of P. nodorum isolates to wheat cultivars was higher than that of P. avenae f. sp. tritici. All Parastagonospora isolates showed the presence of the SnTox3 marker. SnToxA and SnTox1 markers were found in P. nodorum isolates, usually separately, but in one isolate, these genes were found together. The analysis of the genetic diversity of wheat cultivars grown in the southern Ural, and the pathogenic complex present, indicate that pathogens continuously evolve under the influence of the host plant. [ABSTRACT FROM AUTHOR]

The main growing regions for winter wheat in the Russian Federation are the North Caucasian, Central Black Earth, and Central agroecological regions. Spring wheat crops dominate in the Urals, Volga region, and Western Siberia. Wheat leaf rust, caused by Puccinia triticina, is an important disease, impacting greatly on wheat production. In Russia, the disease was an annual problem until 2010 but has since been more effectively controlled. However, changes in virulence in pathogen populations may arise from climate change, evolving cropping practices, intense use of chemical protectants, and an increase in the release of resistant cultivars. In the 2000s, the State Register of the Russian Federation included an increase in the number of winter and spring wheat cultivars resistant to leaf rust. However, successful genetic protection requires a diversity of cultivars with different resistance genes (Lr genes). Studies by the All Russian Institute of Plant Protection identified Lr genes in Russian cultivars' phenotypes and molecular markers. In addition, the prevalence of virulence in pathogen populations was studied and the influence of the cultivar used in wheat production on the changes in these populations was evaluated. This paper reviews research on the genetic diversity of winter and spring wheat cultivars included in the State Register of Russia from 2000 to 2020 and analyzes their impact on the prevalence of virulence in pathogen populations. These data demonstrate the continuous evolution of P. triticina in response to wheat breeding efforts. Populations of the pathogen showed higher variability in regions where pathotype-specific resistance cultivars were commonly grown. [ABSTRACT FROM AUTHOR]

Stem rust caused by Puccinia graminis f. sp. tritici Eriks. is a dangerous disease of common wheat worldwide. Development and cultivation of the varieties with genetic resistance is one of the most effective and environmentally important ways for protection of wheat against fungal pathogens. Field phytopathological screening and genome-wide association study (GWAS) were used for assessment of the genetic diversity of a collection of spring wheat genotypes on stem rust resistance loci. The collection consisting of Russian varieties of spring wheat and introgression lines with alien genetic materials was evaluated over three seasons (2016, 2017 and 2018) for resistance to the native population of stem rust specific to the West Siberian region of Russia. The results indicate that most varieties displayed from moderate to high levels of susceptibility to P. graminis; 16% of genotypes had resistance or immune response. In total, 13,006 single-nucleotide polymorphism (SNP) markers obtained from the Infinium 15K array were used to perform genome-wide association analysis. GWAS detected 35 significant marker-trait associations (MTAs) with SNPs located on chromosomes 1A, 2A, 2B, 3B, 5A, 5B, 6A, 7A and 7B. The most significant associations were found on chromosomes 7A and 6A where known resistance genes Sr25 and Sr6Ai = 2 originated from Thinopyrum ssp. are located. Common wheat lines containing introgressed fragments from Triticum timopheevii and Triticum kiharae were found to carry Sr36 gene on 2B chromosome. It has been suggested that the quantitative trait loci (QTL) mapped to the chromosome 5BL may be new loci inherited from the T. timopheevii. It can be inferred that a number of Russian wheat varieties may contain the Sr17 gene, which does not currently provide effective protection against pathogen. This is the first report describing the results of analysis of the genetic factors conferring resistance of Russian spring wheat varieties to stem rust. [ABSTRACT FROM AUTHOR]