Resistance of synthetic hexaploid wheat to the leaf rust pathogen

Background. One of the promising sources for enrichment of the common wheat (Triticum aestivum L.) gene pool with new alleles is synthetic hexaploid wheat (SHW), or allopolyploids from crossing tetraploid wheats (2n = 4x = 28, BBAA) with accessions of Aegilops tauschii Coss. (2n = 2x = 14, DD), and subsequent doubling of the chromosome number in the hybrids. Objectives of the study were to evaluate the SHW accessions from the VIR collection for resistance to Puccinia triticina Erikss. populations collected in Russia; genotype the accessions; and summarize information from the published sources concerning the resistance of the studied accessions to other harmful diseases and pests.Materials and methods. Resistance of 36 SHW accessions from the VIR collection to the populations of P. triticina was assessed in the laboratory and in the field, under artificial infection pressure, using the techniques developed by the Institute of Plant Protection. A phytopathological test and PCR markers were used to identify the Lr genes.Results and conclusion. The SHW accessions were characterized according to their resistance to the Russian populations of the wheat leaf rust pathogen. The sources of resistance in the phase of emergence and in adult plants were identified. The phytopathological test isolated three accessions with Lr23; the PCR marker of Lr21=Lr40 was found in 11 accessions, Lr39=Lr41 in 19, and Lr22a in 3. At the same time, k-65496, k-65515 and k-65517 had si multaneously Lr21=Lr40 and Lr39=Lr41, while k-65497, k-65503 and k-65508 had Lr22a and Lr39=Lr41. The analysis of published data showed that many of the studied SHW accessions were also resistant to other harmful diseases and insect pests, so they are of interest for further studying and possible use in domestic breeding

Population genetics studies of <i>Puccinia striiformis</i> f. sp. <i>tritici</i> in Dagestan and Northwestern Russia

Background. Yellow rust (Puccinia striiformis West.) is a harmful disease of cereal crops. Significant yellow rust in cidence has systematically been registered on VIR’s experimental fields in Derbent (Dagestan) and Pushkin (North western Russia). Resistance assessment and subsequent selection of resistance sources for breeding require proper monitoring of the virulence in the pathogen’s local populations. The purpose of this work was to characterize the virulence of P. striiformis on VIR’s experimental fields in Derbent and Pushkin, and use molecular markers to find out whether the studied P. striiformis isolates belong to any of the most dangerous invasive groups PstS1 and PstS2.Materials and methods. In Derbent, leaves with uredinio pustules were collected from bread and durum wheat accessions; in Pushkin, from bread wheat and triticale plants. The pathogen’s virulence was analyzed in the laboratory using the world and European sets of differential cultivars, and isogenic Avocet Yr lines. In 2020, the resistance of differential sets was tested in the field in Derbent under a high natural infection pressure. SCAR markers were used to identify the invasive PstS1 and PstS2 isolates. Results and conclusion. A total of 18 phenotypes (races) of striiformis were identified (4 in Derbent, and 14 in Pushkin). The Yr5, Yr10, Yr15, Yr17, Yr24 and Yr26 genes manifested high effectiveness in both locations. In the field, immune responses were observed in the Avocet lines with the Yr5, Yr7, Yr8, Yr10, Yr15, Yr24 and YrAR genes, and in the differential cvs. ‘Vilmorin 23’, ‘Moro’, ‘Reichersberg 42’, ‘Heines Peko’, ‘Nord Desprez’, ‘Compare’, ‘Carstens V’, ‘Spaldings Prolific’ and ‘Heines VII’. Moderate resistance was recorded for the line Jupateco 73R (damage up to 5%), and cvs. ‘Heines Kolben’ and ‘Strubes Dickkopf’ (5–10%). Using molecular markers, 2 isolates from the invasive group PstS2 were identified in the Pushkin collection of P. striiformis

Diversity of new Russian bread wheat cultivars according to leaf rust resistance genes

Background. Cultivation of resistant cultivars is an effective method of wheat protection against leaf rust. The purpose of this work was to characterize the juvenile leaf rust resistance of bread wheat cultivars listed in the State Register for Selection Achievements in 2021 and identify their Lr genes using molecular markers.Materials and methods. The material included 18 cultivars of winter bread wheat and nine spring ones. Juvenile resistance in the seedling phase was assessed with two test clones (kLr9 и kLr19) and the Krasnodar population of Puccinia triticina Erikss. Molecular markers were used to identify 18 Lr genes.Results and discussion. A high level of resistance (score 0 or 0;) was shown by cvs. ‘Khamdan’, ‘Sharm’ and ‘Omskaya 44’; moderate resistance (score 2, 2+) by ‘Albidum 2030’. Reactions of ‘Polina’, ‘Rossyp’, ‘Status’, ‘Balkysh’ and ‘Bogema’ were variable. The studied cultivars did not contain juvenile genes Lr9, Lr24, Lr25, Lr28, Lr29, Lr39, Lr47 or Lr66 and adult plant resistance genes Lr21 and Lr35. Markers of identifiable genes were not detected in cv. ‘Sharm’, highly resistant to leaf rust. ‘Khamdan’ had an ineffective Lr10 gene and a partial resistance gene Lr34, which offered no protection in the seedling stage. These cultivars seem to contain additional resistance genes. A high level of resistance to leaf rust in ‘Omskaya 44’ is provided by a combination of the Lr19, Lr26, Lr1 and Lr3 genes. In ‘Nemchinovskaya 85’, the partially effective adult plant resistance gene Lr37 was identified. In other tested cultivars, Lr1, Lr3, Lr10, Lr26 and Lr34 were widely represented

POPULATION STRUCTURE OF LEAF PATHOGENS OF COMMON SPRING WHEAT IN THE WEST ASIAN REGIONS OF RUSSIA AND NORTH KAZAKHSTAN IN 2017

Wheat diseases affecting leaves like leaf rust (Puccinia triticina), tan spot (Pyrenophora tritici-repentis) and spot blotch (Сochliobolus sativus = Bipolaris sorokiniana) are widely spread and potentially dangerous in the West-Asian region of Russia and North Kazakhstan. The study of these pathogens’ populations is very important for genetic protection of wheat. The objective of this study was to explore the population structure of the causative agents of leaf rust and tan spot on spring wheat based on virulence traits and assessing the distribution of the causative agent of spot blotch in the West-Asian region of Russia and North Kazakhstan. The source of inoculum were wheat leaves affected by leaf rust and spot diseases collected in the Chelyabinsk and the Omsk region of Russia and in North Kazakhstan. Virulence analysis of P. triticina using 20 lines with known Lr genes demonstrated that all 109 monopustule isolates were avirulent on ТсLr24. The isolates virulent on ТсLr19 were identified only in the Chelyabinsk population. The prevalence of isolates virulent on ТсLr2a, ТсLr2b, ТсLr2c, ТсLr11, ТсLr15, ТсLr16, ТсLr20 and ТсLr26 was higher in the Omsk and the North Kazakhstani population, while virulence to ТсLr9 was higher in Chelyabinsk. Using 20 TcLr-lines, we identified 27 virulent phenotypes of P. triticina: 12 in the Omsk, 19 in the Chelyabinsk and 8 in the Kazakhstani population. The phenotypes TLTTR (avirulent to TcLr16, TcLr19, TcLr24, TcLr26), TCTTR (avirulent to TcLr9, TcLr16, TcLr19, TcLr24), and TBTTR (avirulent to TcLr9, TcLr16, TcLr19, TcLr24, TcLr26) were observed in all the populations. The phenotypes TQTTR (avirulent to TcLr19, TcLr24, TcLr26) and TGTTR (avirulent to TcLr9, TcLr19, TcLr24, TcLr26, TcLr9, TcLr19, TcLr24, TcLr26) were common in the Omsk and the North Kazakhstani population, while THPTR (avirulent to avTcLr9, TcLr11, TcLr19, TcLr24) and TCTTQ (avirulent to TcLr9, TcLr16, TcLr19, TcLr20, TcLr24) were common in the Omsk and the Chelyabinsk population. There was a high genetic similarity in virulence and phenotypic composition between the Omsk and the North Kazakhstani population as well as between the Omsk and the Chelyabinsk population and a moderate similarity between the Chelyabinsk and the North Kazakhstani population. The prevalence of the spot blotch pathogen was higher in the material collected from the Omsk region, while none of this pathogen was identified in the North Kazakhstani material. The isolates of tan spot were identified in all the regions. Five races of P. tritici-repentis were identified among Chelyabinsk isolates based on the toxins produced by the following pathogens: race 1 (PtrToxA PtrToxС); race 2 (PtrToxA); race 7 (PtrToxA, PtrToxВ), race 8 (PtrToxA, PtrToxВ, PtrToxС), and race 4 (does not produce toxins). Three races were identified in the Omsk region (1 – 3) and four, in North Kazakhstan (1 – 4). A total of 26 P. tritici-repentis phenotypes were identified by virulence analysis using 11 differential lines: two were present in all the populations; two. in Chelyabinsk and North Kazakhstan; one, in Omsk and Chelyabinsk; and all the others were original. A high degree of similarity between the obligate pathogen P. triticina and the saprophytic pathogen P. tritici-repentis in the West-Asian region of Russia and in North Kazakhstan demonstrates that this is one epidemiological region across this wheat production area. The presence of common phenotypes suggests there is a the possibility of gene exchange between the populations and this shall be considered while releasing genetically protected wheat varieties

Cardiovascular status and echocardiographic changes in survivors of COVID-19 pneumonia three months after hospital discharge

Coronavirus disease 2019 (COVID-19) affects the function of all organs and systems. Today, studying the effect of COVID-19 on cardiovascular system, including on echocardiographic characteristics, is relevant.Aim. To study the prevalence of symptoms, cardiovascular disease and changes in echocardiographic data in persons after documented COVID-19 pneumonia 3 months after discharge from the hospital.Material and methods. The study included 106 patients after documented COVID-19 pneumonia. The patients underwent a comprehensive examination during hospitalization and 3 months±2 weeks after discharge from the hospital. The mean age of participants was 47±16 years (19-84 years); 49% of subjects were women.Results. Three months after hospital discharge, the symptoms persisted in 86% of examined patients. There were significant echocardiographic changes as follows: a decrease in LV end-diastolic, end-systolic and stroke volume (113,8±26,8 ml vs 93,5±29,4 ml; 37,7±13,0 ml vs 31,3±14,2 ml; 77,2±17,8 ml vs 62,2±18,7 ml, respectively, p&lt;0,001 for all). The right ventricular anteroposterior dimension and the pulmonary trunk diameter decreased over time (26,0 [24,0-29,3] mm vs 25,0 [23,0-27,0] mm, p=0,004; 21,7±3,6 mm vs 18,7±2,5 mm, p&lt;0,001), the same as the pulmonary artery systolic pressure, estimated by tricuspid regurgitation gradient (28,0 [25,0-32,25] mm Hg vs 21,5 [17,0-25,0] mm Hg). The right atrial volume (42,0 [37,0-50,0] m&gt;&lt;0,001), the same as the pulmonary artery systolic pressure, estimated by tricuspid regurgitation gradient (28,0 [25,0-32,25] mm Hg vs 21,5 [17,0-25,0] mm Hg). The right atrial volume (42,0 [37,0-50,0] ml vs 31,0 [22,0-36,5] ml, p&lt;0,001) a&gt;&lt;0,001) and maximum width (36,1±4,6 mm vs 34,5±6,5 mm, p=0,023) decreased, while the right atrial maximum length increased (46,7±6,8 mm vs 48,6±7,1 mm, p=0,021).Conclusion. In survivors of COVID-19 pneumonia three months after hospital discharge, complaints persisted in 86% of cases. Cardiovascular diseases were detected in 52% of participants, including hypertension in 48,1% and coronary artery disease in 15,1%. Compared with in-hospital data, the echocardiographic characteristics improved, which was expressed mainly in a decrease in right heart load

Echocardiographic characteristics of COVID-19 pneumonia survivors three months after hospital discharge

Coronavirus disease 2019 (COVID-19) is an infectious disease that affects almost all organs and systems. The main target is the respiratory system, but cardiovascular involvement is also common. Today, it is relevant to study the effect of complicated COVID-19 course on the patient’s cardiovascular system after hospital discharge — in particular, echocardiographic parameters.Aim. To study the echocardiographic parameters of patients with COVID-19 pneumonia 3 months after discharge from the hospital.Material and methods. The study included 106 patients with documented COVID-19 pneumonia. Patients underwent a comprehensive examination during hospitalization and 3 months ± 2 weeks after hospital discharge. The mean age of participants was 47±16 years (from 19 to 84 years), while 49% were women.Results. Three months after discharge, the average body mass index of the subjects was 28,2±5,7 kg/m2. Obesity was noted in 37,1%, cardiovascular diseases — in 52%. According to echocardiography, the prevalence of right ventricular (RV) dilatation was 2,9%, a decrease in tricuspid annular plane systolic excursion (TAPSE) — 9,5%, grade ≥2 tricuspid regurgitation — 1,9%, pulmonary hypertension (pulmonary artery systolic pressure &gt;36 mm Hg) — 3,8%. The mean value of RV global longitudinal myocardial strain (GLMS RV) and global longitudinal myocardial strain (GLES RV) was 19,6±4,5 and 20,6±4,6, respectively. We found moderate correlations between GLMS RV and blood flow time through the left ventricular outflow tract (OT) (r=-0,436), through the mitral valve (r=-0,390; both p&lt;0,0001) and through the RVOT (r=-0,348; р=0,004), with cardiac index (CI) (r=0,316; p=0,009), as well as between GLES RV and blood flow time through the LVOT (r=-0,411; p&lt;0,0001) and RVOT (r=-0,300; p=0,005), and with CI (r=0,302; p=0,004). At the same time, the correlation of GLES RV with RV fractional area change (FAC) was weak (r=-0,283; p=0,007), while there was no correlation with the TAPSE. In addition, correlation of GLMS RV with these parameters were not defined.Conclusion. Three months after COVID-19 pneumonia, RV strain parameters were shown to have stronger relationships with time characteristics of flows in LVOT and RVOT, as well as with CI, than with such generally accepted characteristics of RV function as FAC and TAPSE

LONG TERM RESULTS OF PERCUTANEOUS CORONARY INTERVENTIONS COMPARING WITH CONSERVATIVE MANAGEMENT IN TREATMENT OF STABLE ISCHEMIC HEART DISEASE PATIENTS UNDER REAL CIRCUMSTANCES

Aim. To evaluate long term results of percutaneous coronary interventions (PCI) in stable ischemic heart disease patients (IHD) under real clinical circumstances.Material and methods. The PCI group consisted of 150 patients with stable IHD after PCI, randomly selected from the Registry of Coronary Angiography. Comparison group consisted of randomly selected from the Registry 150 patients with stable IHD receiving only drug therapy (DT).Results. In long term perion it was found that total mortality (4,0% vs. 11,3%, p=0,017) and cardiovascular mortality (3,3% vs. 10,7%, p=0,013) were lower in PCI group. After PCI there was rarer coronary bypass operation need (2,0% vs. 10,0%, p=0,004). By the prevalence of myocardial infarction in compared groups there were no statistically significant differences (6,7% vs. 5,3%, p=0,627). Kaplan-Meier curve analysis showed that positive effect of PCI was fulfilled in 15 months and progressively increased until the end of follow-up. In stepped regression of Cox proportional risks it was revealed that in long term period PCI performing associated with the increase of survival rate 2,8 times (RR=2,81, 95% CI 1,03-7,69, p=0,044). Long term survival showed independent relation with the grade of coronary lesion. In PCI group, as in DT group, there were no positive dynamics of angina functional classes. In MT group during the follow-up functional class of heart failure became harder than in PCI group, and in PCI groupthere were no significant dynamics of heart failure functional class.Conclusion. Real clinical practice proved the effectiveness of PCI with DT in treatment of stable IHD. In long term results evaluation, PCI for stable IHD associated with the increase of survival 2,8 times comparing with the group with only DT. Positive PCI effect realized after 15 months and progressively increased to the end of follow-up

LEAF RUST RESISTANCE IN COMMON WHEAT VARIETIES AND LINES FROM THE COLLECTION OF THE VAVILOV PLANT INDUSTRY INSTITUTE CARRYING ALIEN GENETIC MATERIAL

Leaf rust resistance was estimated in 83 common wheat accessions from the collection of the Vavilov Institute carrying alien genetic material. Eight accessions with seedling resistance and 27 accessions with adult plant resistance were found. Analysis with molecular markers revealed genes highly and moderately efficient in Russia – Lr24, Lr39, Lr21, and Lr37 – and a rye translocation 1AL.1RS. The samples accessions effective Lr genes are promising donors in Russian breeding programs. Lines raised with the use of T. timopheevii were heterogeneous for resistance. No molecular markers of the Lr50 gene known for this species were detected there. These lines demand further examination and selection

Evaluation of resistance of spring durum wheat germplasm from Russia and Kazakhstan to fungal foliar pathogens

Spring durum wheat (Triticum durum) is an important crop in Russia and Kazakhstan. There are substantial yield losses due to fungal diseases. The research focused on host plant resistance to fungal diseases, and identifcation of the sources of multiple resistance which can be deployed in durum wheat breeding programs. Extensive environmental varietal testing experiments at places with diverse meteorological factors allows the selection of valuable material. In 2017 and 2018, a collection of 21 spring durum wheat accessions from the Kazakhstan-Siberian Network for Wheat Improvement (KASIB) was studied under high disease pressure. The following diseases were evaluated in three regions of Russia (Omsk, Altai and Samara), in Southern Kazakhstan and in Kenya: leaf, stem and yellow rusts, powdery mildew, glume blotch, tan spot and spot blotch. As the result, three breeding lines with multiple disease resistance to three rust species, powdery mildew and leaf blotches were identifed: Hordeiforme 178-05-02, Hordeiforme 05-42-12 and Hordeiforme 1591-21. Furthermore, the accessions resistant to rusts or spots were also identifed. Phytopathological studies and molecular marker analysis showed absence of genes Lr1, Lr3, Lr9, Lr10, Lr19/Sr25, Lr20/Sr15, Lr24/Sr24, Lr26/Sr31/Yr9/Pm8, Lr34/Sr57/Yr18 and Lr37/ Sr38/Yr17. Clustering of durum wheat accessions based on similarity in resistance and susceptibility revealed three main groups; accessions susceptible to all three rusts, those with some resistance to one or two rusts, and those with seedling resistance to leaf rust only