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Background. Cherry leaf spot (caused by the fungus Coccomyces hiemalis Higg.) has been one of the most harmful diseases of stone fruits for many years. The increasing genetic homogeneity of plant forms used in breeding promotes the acceleration of the pathogen’s adaptive microevolution and the overcoming of previously effective resistance genes. The structure of C. hiemalis populations from Krasnodar Territory in terms of their virulence to a set of differentiators and the effectiveness of new leaf spot resistance donors were studied.Materials and methods. The polymorphism in three populations of the fungus was assessed by the frequencies of virulence phenotypes which were identified using six differentiators. The resistance of new distant hybrids to 50 monopustular isolates was assessed in laboratory experiments.Results and conclusions. Five phenotypes of the fungus, differing in virulence to six cherry genotypes, were identified. An increase was observed in the frequencies of virulence phenotypes capable of strongly affecting donors used in breeding for resistance. Five hybrids are proposed to expand the genetic diversity of sour and sweet cherry cultivars resistant to C. hiemalis: 3-61-4-139, 3-39-5-47, 3-107-6-28, AI 5 B-D-2-4-27, and 3-76. They are protected by the leaf spot resistance genes that have been transferred from Prunus serrulata Lindl. The alleles of the resistance genes in these plants are not identical to the resistance alleles in the genotypes Seyanets No. 1, Mutant 561, ‘Almaz’, Kusumkent 8, Vetrovoe 11 (P. kurilensis Miyabe), and BG-35 (P. sargentii Rehd.), all used in breeding. Seedling 3-20-5-23 (P. serrulata × Northstar) was not resistant to a number of C. hiemalis clones. It is assumed that this genotype and Vetrovoe 11 (P. kurilensis) are protected by identical alleles of resistance genes, which differ from the alleles present in the five new hybrid forms.

Background. The greenbug (Sсhizaphis graminum Rondani) can significantly reduce the yield of barley and other cereals in the southern regions of Russia. Cultivation of resistant varieties can significantly limit the pathogen’s harmfulness. At the same time, specific interaction with the genotypes of the host plant, characteristic of S. graminum, requires a continuous search for new resistance donors to broaden the genetic diversity of barley cultivars. Materials and methods. The resistance of 178 accessions of barley landraces from Uzbekistan to the Krasnodar greenbug population was tested in laboratory experiments. Juvenile plants were infested with aphids of different ages, and when the susceptible control died (cv. ‘Belogorsky’), resistance was assessed on a 0 to 10 (plant death) rating scale. Plants with a damage rate of 1–4 points (up to 30% of the leaf surface being damaged) belonged to the resistant class; damage rate of 5–8 points indicated moderate resistance of plants, and that of 9–10 meant susceptibility. In addition, we assessed the aphid damage of the winter barley cultivar ‘Post’, protected by the previously identified resistance gene Rsg1.Results and conclusions. We identified 52 barley accessions as heterogeneous for the studied trait. In six accessions, plants with high (points 3 to 4) and moderate (5 to 8) resistance were identified; 6 accessions were differentiated into 3 phenotypic classes: resistant, moderately resistant, and susceptible; and in 40 accessions the manifestation of the resistance component varied within 5 to 7 points (from 31 to 60% of the leaf surface being damaged). The distinctly expressed resistance of 12 accessions is controlled by alleles of resistance genes that differ from Rsg1. After selection for resistance, the identified accessions can be used in breeding.

Background. The most rational way to reduce barley crop losses from diseases, pests and adverse edaphic factors is cultivation of resistant varieties. The specificity of the host– pathogen interactions necessitates a constant search for new donors of resistance for breeding, and phytosanitary monitoring of cultivars.Materials and methods. The research material comprised 248 barley cultivars included in the State Register of Selection Achievements Admitted for Usage in the Russian Federation – 168 were developed domestically, and 80 by foreign breeders. Their resistance to powdery mildew and leaf rust was studied in under laboratory and field conditions. Barley cultivars distinguished for powdery mildew resistance were analyzed using molecular markers. In the laboratory, barley was screened for greenbug resistance. To study the sensitivity to toxic aluminum ions in barley, we used the laboratory method for the early diagnosis of the trait – the root test method.Results and conclusions. Field and laboratory screening revealed a fairly wide diversity of barley cultivated in Russia in terms of resistance to harmful organisms and the edaphic stressor. It was established that 24 barley cultivars were resistant to powdery mildew, and 14 accessions were carriers of the effective mlo11 allele. Two cultivars manifested combined resistance to powdery mildew and barley leaf rust. In 11 cultivars, a distinct greenbug resistance was revealed. High resistance to toxic aluminum ions according to the root and sprout length indices was observed in 26 cultivars. Accessions with the complex resistance to harmful organisms and the edaphic stressor were identified.

Background. One of the most harmful diseases of barley in all areas of its cultivation is scald. The causal agent Rhynchosporium commune Zaffarano, B.A. McDonald & A. Linde (formerly – Rhynchosporium secalis (Oudem.) J.J. Davis) is characterized by a high level of variability, which leads to the emergence of new pathotypes and the loss of resistance of a number of cultivars. Most barley cultivars recommended for cultivation are highly affected by the pathogen. The aim of the study was to find new donors of effective barley resistance genes to R. commune.Materials and methods. Resistance to the fungus was tested in 99 accessions of barley landraces from 18 countries under laboratory and field conditions. The experiments employed isolates and clones of R. commune isolated from plants collected in Leningrad Province. Plant resistance was scored using point scales. Genetic control of fungal resistance was studied in the selected accessions using hybridological analysis.Results and conclusions. We identified 3 accessions of barley landraces, which retained high resistance to the fungus for six years of study in the field under inoculation with different populations of R. commune. Accessions k-31504 (Macedonia), k-31505 (Ethiopia) and k-31503 (India) are protected by R. commune resistance genes, which differ from each other, are not allelic to the previously identified effective Rrs9 gene, and manifest themselves throughout all stages of barley ontogenesis. Each of accessions k-31504 and k-31505 incorporates 2 recessive pathogen resistance genes; k-31503 carries 3 recessive resistance genes.

Background. The genetic variability of the period between the germination and heading phases was analyzed in barley accessions from the Republic of Dagestan planted in the southern area of Dagestan (Derbent) and the Northwest of Russia (Pushkin, St. Petersburg). Testing barley development rates under contrasting climate conditions of Russia makes it possible to assess the paratypic variability and a norm of reaction in the tested accessions in order to identify environmentally adaptable plant forms useful for breeding.Materials and methods. Under spring sowing, 173 spring barley accessions were studied for the duration of the period from germination to heading. To compare the earliness of accessions planted at two sites with different sowing schedules, “the rate by which the germination-to-heading period of an accession exceeded its minimum value across the sample” was used as a criterion for calculations.Results and conclusions. Accession k-15013 was the earliest at both test sites during two years of studying. In Dagestan, accessions k-11439 and k-11475 with a low norm of reaction in 2016 and 2017 were also identified as early. Environmental conditions were found to have a significant effect on the development rate of barley accessions in Derbent and St. Petersburg. Dagestani barleys in the North-west of Russia ripened earlier than in the south of Dagestan during all the years of study. Vernalization temperatures proved to be the main factor affecting maturation schedules of local Dagestani barleys in the area of their distribution. A longer day and the absence of high temperatures in St. Petersburg contributed to the earliness of barley accessions.

Background. Analyzing the adaptive potential of cultivated barley with the aim of using new genotypes selected and developed in the process of work is a priority trend in scientific research. The Ethiopian barleys adapted to a variety of soil and climate conditions are characterized by many valuable biological and agronomic traits. Of particular value are genotypes that combine resistance to harmful organisms and environmental stressors.Materials and methods. The collection accessions of Ethiopian barley possessing powdery mildew resistance were studied for tolerance to adverse edaphic factors (chloride salinity and high content of toxic aluminum ions in the soil). Resistance to abiotic stressors was assessed in laboratory experiments. In the study of salt tolerance, a ‘roll-based’ assessment technique was used, which takes into account the inhibition of root growth under salt (NaCl) stress conditions, compared with the reference conditions without salinization. Aluminum sensitivity of barley accessions was diagnosed in the early stages of plant development using the root test.Results and conclusions. A polymorphism of Ethiopian barleys for resistance to adverse edaphic factors was revealed. Twentyone new sources of barley resistance to toxic aluminum ions were identified, of which accessions k-8552 and k-22933 were classified as highly resistant. Accessions k-17554, k-19975, k-20029, k-20048, k-22752, k-23450 and k-25009 proved resistant to soil salinization. Barley accessions k-17554, k-22752 and k-25009 were characterized by complex resistance to powdery mildew, toxic aluminum ions, and chloride soil salinity.

Background. Resistance to lodging is a factor that significantly affects the yield of barley under the conditions of irrigated agriculture and intensive type of farming. Barley resistance to lodging depends on many features, among which the length of the plant stem is more important.Materials and methods. In the southern planar area of Dagestan, from 1993 till 2008, a research was conducted on the intraspecific diversity of cultivated barley (Hordeum vulgare L.) belonging to different ecogeographic groups, and growth types (2,021 accessions). The F1, F2 and F3 hybrids from crosses of the long-stemmed cultivar ‘Sonet’ with semi-dwarf forms were also studied. The selected recombinant lines were evaluated for their productivity and resistance to frit fly (Oscinella frit L.).Results and conclusions. Wide variability (55–155 cm) of cultivated barley in plant height was observed. Under irrigation in the southern Dagestan, the optimum height of plants, providing high resistance to lodging, was 100–115 cm. A number of semidwarf cultivars were identified; among them, ‘Camincent’ (k-30374, Estonia), ‘Pyramid’ (k-30564, France), ‘Ramos’ (k-30315, Moscow Province) and ‘Jo 1632’ (k-30459, Finland) were the most interesting for their set of traits. The short stem of these cultivars is controlled by recessive alleles of genes. We selected productive lines that significantly exceeded their parental forms in grain weight per area unit and resistance to frit fly: L 15/4 (F6 Sonet × Camincent) and L 16/12 (F6 Sonet × Pyramid). These lines can be used to breed lodging-resistant large-grain barley cultivars for cultivation on irrigated lands.

Background. The 2S albumins of sunflower and other oilseed plants possess a high nutritional quality, the defense activity against fungi diseases casual gents and also valuable functional properties. The major component of albumin fraction, the SFA8 protein consists of 103 amino acid residues among which methionine constitutes 15 Mole %. In the cultivated sunflower gene pool the SFA8 structural gene is represented by the two alleles the products of which have different isoelectric points and differ by the electrophoretic mobility, however molecular mechanisms of the polymorphism are still unknown. Results. The amplified sequences of the SFA8 gene from seven Helianthus annuus L. accessions and three accessions of wild Helianthus L. species from VIR collection were sequences. The intron of 258-303 bp length depending on the genotype was firstly found in the central part of the gene. The length of the first exon constitutes 99 bp, the second exon is of 210 bp length. The nucleotide and translated amino acid sequences are polymorphic among different genotypes. The line VIR 130 in which the two expressing SFA8 proteins, the normal polypeptide with isoelectric point (pI) approximately 6.0 (normal SFA8) and its allelic variant with pI 6.5 (variant SFA8) have been earlier revealed possesses two types of the SFA8 encoding sequence. In one sequence the substitution 108С—G is present that results in the substitution of the polar uncharged amino acid serine for the positively charged arginine and respectively in alteration of the protein charge and isoelectric point. The intron sequence is also polymorphic and characterized by the presence of indels of approximately 45 bp. The intron sequences of all accessions contain dinucleotides GT at the 5΄ end and AG at the 3΄ end which are characteristic for consensus sequences of splicing sites in the U2-type introns. The variants of the secondary structure of the SFA8 intron sequences of H. argophyllus Torr. & A. Gray and all the analyzed H. annuus genotypes are similar and differ from those of H. petiolaris Nutt. and H. giganteus L. Conclusions. The data on the SFA8 gene sequence polymorphism are important understanding the molecular mechanisms of genotypic differences in biochemical and functional properties of the protein, and he revealed differences in the intron secondary structure can be important for understanding expression patterns of the protein.

Characteristics of the new malting spring barley cultivar ‘Omsky 100’ are presented. This cultivar, bred at the Siberian Research As a result of studying the Krasnodar Schizaphis graminum population, a high level of the insect’s overall and seasonal variability in its virulence to sorghum resistance genes was detected. The greenbug population feeding on sorghum was shown to be labile in virulence to barley accessions as well. The selection of S. graminum genotypes specifically adapted to host plant species was observed. During the reproduction of the insect on barley plants, the individuals without “redundant” genes of virulence to sorghum had an advantage in competition. Replacement of the host led to rapid accumulation of clones virulent to the sorghum resistance genes Sgr1 - Sgr4 and Sgr12.

The period between shooting and earing stages was investigated in a group of 265 barley accessions from Dagestan. The accessions k-15008 and k-15013 were characterized by the highest development rate in South Dagestan. In Northwest Russia the early accession k-15027 was revealed. In 207 barley accessions the dominant and recessive alleles of the Ppd and VRN genes involved in control of the period between shooting and earing stages were identified with the use of allele-specific molecular markers. Twenty two groups with different allelic combinations of the loci were revealed. The most numerous groups possessed the Ppd-H1Ppd-H2vrn-H1 Vrn-H2vrnH3 and ppd-H1Ppd-H2vrn-H1Vrn-H2vrnH3 allelic combinations and included 59 and 91 accessions correspondingly.

During recent years the harmfulness of greenbug for rice crops has significantly increased. Laboratory experiments were conducted to study insect resistance of 200 accessions from the collection of the Donskoy Agrarian Scientific Center. The overwhelming majority of the studied forms were heterogeneous in their resistance. Twelve forms (5.5%) with the resistance score 2.2-3.0 were identified. The accessions NSH-1 (Hungary), ‘Musa Karem’ (Iran) and Zlatyi х Strelets (Russia) do not contain susceptible components and can be recommended as sources of aphid resistance for breeding rice varieties.

A sample of 131 sunflower lines from VIR genetic collection which differed for the ability to suppression of the CMS phenotype was studied using molecular markers specific for the CMS PET1 associated mitochondrial locus orfH522 and Rf1 nuclear gene, and also for CAPS-markers developed on the bases of single nucleotide polymorphism of RFL-PPR genes homologs. With the use of hybridological analysis a tight linkage of HRG01 and HRG02 marker fragments with the Rf1 gene controlling pollen fertility restoration trait was confirmed. The allelic variants of the RFL-PPR genes sequences were associated with the allelic state of the Rf1 locus. However, the CAPS marker elaborated for the QHL12D20 fragment showed independent inheritance from pollen fertility restoration trait in the F2 of the hybrid VIR116xVIR740.

The mlo11 allele associated with the loss of function of the Mlo locus and controlling mildew resistance in the majority of modern barley cultivars was identified in Ethiopian barley landraces. Twenty-seven accessions from Ethiopia were studied during laboratory experiments which resulted in identifying k-5448 as an accession resistant to powdery mildew. Three accessions (k-8555, k-8682 k-17554) were heterogeneous by the studied trait. With the help of molecular markers we showed that the resistant components of the selected forms are protected by the mlo11 gene.