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Vladimir Aleksandrovich Koshkin was a prominent representative of the school of plant physiologists at the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). He introduced his ideas on the mechanisms of photosynthesis intensity as well as the distribution of photoperiod sensitivity and the rate of development among plant species diversity. He was the first to examine in detail and disclose the relationship between the carbon dioxide compensation point and leaf temperature in C3 and C4 plants. According to Dr. Koshkin, there was no change in the sign of the photoperiodic reaction in the generic evolution of Triticum L. and Aegilops L., while the spring forms of bread and durum wheat widespread in the equatorial zone demonstrated weak photoperiod sensitivity. In his work with the resource departments of VIR, Dr. Koshkin was interested in plant breeding problems in the context of developing earlier-ripening cereal cultivars with a certain reaction to the photoperiod. His joint research projects with a number of breeding centers in Russia on this problem proved effective. He participated in collecting missions in Latin American countries (Cuba, Mexico, Colombia, and Brazil) and was awarded a Timiryazev Gold Medal. Dr. Koshkin was the author of 163 scientific publications and had about 20 certificates of authorship and patents for inventions, crop cultivars and lines. Dr. Vladimir Koshkin was quick to perceive the essence of any problem and used adequate modern methods to set up and analyze high-precision experiments.

Background. The use of barley cultivars resistant to greenbug (Schizaphis graminum Rondani) is an effective, economical and ecology-friendly way to control the dangerous phytophage. The insect is able to overcome the resistance of the host plant, which necessitates a relentless search for new genes to ensure reliable protection of barley fields from the pest.Materials and methods. Resistance to the Krasnodar greenbug population was assessed in 345 barley accessions from the Asian part of Russia. Besides, resistance to S. graminum was studied in cv. ‘Post’ (carrier of the Rsg1 gene), a pure line derived from cv. ‘Onokhoisky’ (k-16626, Buryatia) heterogeneous for this trait, and landraces from Mongolia (k-3885, k-3904, and k-4080). Juvenile plants were infested with aphids in the laboratory, and when a susceptible control died, the damage to experimental barley accessions was assessed using a scoring scale. Genetic control of greenbug resistance in the line derived from cv. ‘Onokhoisky’ was studied using the insect’s test clones and an analysis of the segregation in F2 hybrids from crossing the resistant line with cv. ‘Belogorsky’ susceptible to the aphid, when the plants were infested with the Krasnodar population of the phytophage and with clones of S. graminum.Results and conclusions. We identified 7 accessions heterogeneous for aphid resistance. Among them, plants with a high level of greenbug resistance were found in three landraces from Tuva (k-14714, k-14718, and k-14733). Resistance was also clearly expressed in the line derived from cv. ‘Onokhoisky’. This cultivar is protected by a dominant allele that differs from the previously identified Rsg1, as well as from the alleles found in Mongolian landraces k-3904, k-4080, and k-3885. ‘Onokhoisky’ also has genes with low expressivity, which manifest themselves when the main gene for resistance to S. graminum appears ineffective.

Background. Barley is an ancient crop currently cultivated in more than 100 countries. High adaptability makes it possible to cultivate it in environments unfavorable for many other crops. At the same time, fungal diseases can have a negative impact on its grain yield and quality. One of the most harmful is the fungus Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Marchal. The pathogen can overcome a cultivar’s resistance, resulting in significant harvest losses. There is a need for a constant search for new effective sources of resistance to powdery mildew for barley breeding.Materials and methods. A set of 950 barley accessions from the East Asian center of the crop’s morphogenesis were studied at the adult stage of plant development. They were screened and crossed in the fields of Pushkin and Pavlovsk Laboratories of VIR (St. Petersburg, Russia). Genetic control of barley resistance to B. graminis was analyzed in a climate chamber under artificial infection pressure with the northwestern population of the fungus. Scoring scales were used for screening.Results and conclusions. Weak development of B. graminis during the heading phase was observed on plants of 38 barley accessions from the East Asian center. High resistance at all stages of development was manifested by 20 genotypes that can be used in breeding programs. Resistance genes in 18 selected forms differed in their effectiveness at the seedling stage of development and during the heading phase. Accessions k-3433, k-10931, k-10934, k-11608, k-17545, k-20272, k-20279, k-20354 and k-27867 had one dominant resistance gene each. Accessions k-11608, k-12278, and k-17545 are protected by the identical gene, while the resistance of k-3433 is induced by a gene that differs from the genes present in accessions k-10931 and k-20279.

Background. A significant reduction in the yield of barley may be provoked by powdery mildew (causative agent: Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Marchal). A vast majority of cultivars approved for use in Russia are susceptible to the pathogen. Including genotypes protected by previously unused resistance genes into breeding practice is necessary to ensure the national food security. Barley landraces could become a fairly rich source of replenishment for the bank of effective pathogen resistance genes.Materials and methods. The study covered 950 barley accessions from the East Asian center of crop origin and domestication: 449 accessions from Japan, 313 from China, 173 from Mongolia, and 15 from Nepal. The experiments were carried out on young plants in a climatic chamber under artificial infection conditions. The northwestern (Pushkin, St. Petersburg) population of B. graminis served as an inoculum. Plant resistance was assessed using a scoring scale. The resistance of the selected forms was assessed twice.Results and conclusions. Significant variability of barley accessions from the countries of East Asia in their resistance to powdery mildew was observed. Symptoms of the disease were not found on plants of 16 studied forms. Weak or moderate development of the B. graminis mycelium was recorded for 21 accessions. Twenty-seven accessions were heterogeneous in the studied trait. Various levels of resistance were identified in 64 studied accessions (6.73%), among which 44 represented cultivars and breeding lines, and 20 were landraces. The percentage of accessions susceptible to the studied population of the pathogen was 93.27%.

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. Microsatellite (SSR) markers are an effective tool for certifying collections of plant genetic resources, as well as for identifying genes that determine valuable biological and agronomic traits. The knowledge of their polymorphism is important for characterizing genetic diversity within the sunflower (Helianthus annuus L.) collection. The present study was aimed at analyzing nucleotide polymorphism of SSR-markers linked with the genes for fertility restoration (Rf1) and downy mildew resistance (Pl5/Pl8). Materials and methods. The material included 84 self-pollinated lines of VIR sunflower genetic collection, F1 and F2 hybrids from crosses between fertile lines VIR 365 and RIL130, and offspring from test crosses. Polymorphism of SSR markers ORS224, ORS511, ORS799 and НА4011 was studied by means of PCR analysis. To determine the microsatellite structure and variability, the amplified fragments were cloned and sequenced. Results. The unique alleles which differed from the typical ones (characteristic for most genotypes) were revealed in the ORS224 marker locus of four lines, and the unique alleles in the ORS511 locus were observed in 10 lines. The ORS511 unique allele of line VIR 365 included two 161 and 240 bp fragments, while line RIL130 was characterized by a typical 159 bp fragment. The profiles of typical and unique markers were inherited as allelic variants of the same locus in F2 of (VIR 365 × RIL130) and a population from VIR 111A × (VIR 365 × RIL130). The nucleotide sequences of unique alleles differed from typical allelic variants in the length and number of repeat units (GA in ORS224 and AT/GT in ORS511), and also by the presence of indels and nucleotide substitutions. Differences in length of НА4011 marker 240 and 200 bp allele variants were caused by 80, 47 and 44 bp indels. Conclusions. A number of lines in the VIR sunflower genetic collection are marked by the unique alleles of microsatellite loci ORS224 and ORS511, which differ from the frequently occurring variants in the length and number of repeat units, as well as in the presence of indels and nucleotide substitutions. Polymorphism of allele variants of HA4011 microsatellite is associated with the presence of indels of 80, 47 and 4 bp.

Background. The search for barley (Hordeum vulgare L.) genotypes that carry effective genes for resistance to powdery mildew agent Blumeria graminis f. sp. hordei is a present-day issue for Russian plant breeding. The mlo11 allele that confers long-term protection of barley against the pathogen is rarely found among the varieties, approved for cultivation in the territory of Russia. There is no information on the occurrence among Russian varieties of another effective allele, mlo11 (cnv2), therefore, the search for its source is a current necessity. Materials and methods. Seven barley accessions from Ethiopia and 7 accessions from Japan have been tested for resistance to the northwestern population of the powdery mildew agent in the field and in laboratory conditions. To identify of the Mlo gene alleles, nucleotide sequences of the Stowaway-MITE (Miniature Inverted-repeat Transposable Elements) and the adjacent promoter fragments were determined. Results. Phytopathological tests in the field and greenhouse conditions, as well as molecular markers were used to study 14 barley accessions from Ethiopia and Japan. According to the preliminary tests, plants were resistant to powdery mildew. The highly effective allele of powdery mildew resistance mlo11 (cnv2) was for the first time identified in four barley accessions from Ethiopia, k-20087, k-20523, k-20524 and k-28126. Under field conditions, adult plants were resistant, and in the greenhouse they were moderately damaged by powdery mildew (1-2 points). The disease symptoms were similar to those described for the sample Eth295, a carrier of the mlo11(cnv2) allele variant: single pustules and the absence of necrotic spots on the leaves. The fragments of Stowaway-MITE and adjacent Mlo 5' promoter sequences were amplified in all 14 accessions. The amplicons were cloned and sequenced. The unique marker SNPs within the MITE and Mlo 5’ promoter sequences, i.e. the substitutions of cytosine by thymine in positions 262 and 452, were found only in k-20087, k-20523, k-20524 and k-28126. These accessions belong to different botanical varieties and differ from each other in a number of morphological features, i.e. they are not duplicates. Conclusions. The genotypes selected as a result of the study can serve as a source of the mlo11(cnv2) allele in breeding powdery mildew-resistant barley varieties.

Background. The development of heterotic hybrids based on cytoplasmic male sterility (CMS) is the leading strategy in breeding sorghum (Sorghum bicolor (L.) Moench). The trait of pollen fertility restoration in forms with CMS A1 (milo), predominantly used in sorghum breeding, is determined by at least two dominant complementary genes Rf1 and Rf2, and also gene Rf5. The development of accessible molecular markers of sorghum Rf genes is highly relevant for hybrid breeding, since they can significantly accelerate the process of creating female sterile forms (A lines), sterility maintainers (B lines) and pollen fertility restorers (R lines).Material and methods. The studied material included 36 sorghum accessions from the VIR collection, which differed by the ability to restore pollen fertility in forms with A1-type CMS. The nucleotide polymorphism of 935 bp fragments of the PPR genes Sobic.002G057050, Sobic.002G054100, and Sobic.002G054200 located at the chromosome 2 was studied.Results. The fragments obtained with the use of a pair of 2459403fw and 2459403 primers were 935 bp long and included parts of three genes: Sobic.002G057050, Sobic.002G054100, Sobic.002G054200. For identifying the sequence variant Sobic.002G057050-1090 associated with the Rf2 gene, Tru9 I restrictase was chosen, which allows obtaining a 572 bp fragment unique for all the studied R lines. Such a marker was found in 10 sorghum lines from West China and Kyrgyzstan, which are widely used in breeding as fertility restorers. The fragment was found neither in three lines with sterile cytoplasm and their fertile analogues, nor in 7 accessions of kafir sorghum, which lacked functional alleles of Rf genes.Conclusions. It has been demonstrated that the marker can be used for selection and checking purity of R and B/A lines. It is also applicable for verifying hybridity of F1 seeds and analyzing hybrid populations from crosses of R lines 924-4, 928-1, 929-3, 931-1, 933-1/6, 1237-3, 1243-2, 1251, 1150-1, F10BC2 with A lines Nizkorosloe 81s, А-83 and А-10598. It may be suggested that the ability to restore pollen fertility in R lines, which lack the marker CAPS- 572, is determined by another Rf gene. The studied 935 bp fragment of Sobic.002G057050 harbours 22 SNP, therefore the development of CAPS-markers for their identification and differentiation can be promising.

Background. Narrow-leaved lupine (Lupinus angustifolius L.) is an important high-protein forage and green manure crop, also promising for food use. This is a plastic species produced under various ecogeographic conditions and the only cultivated species of lupine adapted to high northern latitudes – up to 60° NL. Gradual expansion of lupine production areas led to the accumulation of pathogens, damage to lupine crops by harmful organisms, and significant harvest losses. Breeding and cultivating resistant varieties is the most profitable and environmentally sound way to control diseases and pests. Studying the species composition of pathogens and searching for source material are the necessary stages of plant breeding for immunity.Materials and methods. A set of 101 accessions of L. angustifolius from the VIR collection were studied in the northwest of the Russian Federation (Pushkin, St. Petersburg) in 2019, and 62 accessions from the same set in 2020. Mycological examination of the affected leaves was carried out on potato sucrose agar medium under laboratory conditions. The degree of damage to plants by diseases and infestation by pests was assessed during the period of flowering, fruit formation and ripening using point scales.Results and conclusions. A wide range of harmful organisms were identified for their negative impact on the growth and development of narrow-leaved lupine plants. The dominant pest was the lupine aphid (Macrosiphum albifrons Essig), discovered in Russia for the first time. A whole set of fungal pathogens was identified, among which the most common and harmful were the causative agents of Fusarium, brown leaf spot, powdery mildew, gray mold, and Sclerotinia stem rot. Narrow-leaved lupine accessions with weak degrees of pathogenic damage were selected.

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.

Powdery mildew caused by the parasitic fungus Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Marchal is one of the most common diseases of barley. Growing resistant varieties can significantly minimize harmful effects of the pathogen. The specificity in the interaction between the fungus and its host plant requires a continuous search for new donors of the resistance trait. The powdery mildew resistance of 264 barley accessions from Dagestan and genetic control of the trait in resistant forms were studied under field and laboratory conditions. Forty-seven barley lines carrying previously identified powdery mildew resistance genes were also examined. During three years, the experimental material was evaluated under severe infection pressure at the Dagestan Experiment Station of VIR (North Caucasus, Derbent). Juvenile resistance against the Northwest (St. Petersburg, Pushkin) pathogen population was evaluated in a climatic chamber. The genetic control of B. graminis resistance in the selected accessions was studied with the application of hybridological and molecular analyses. The level of genetic diversity of Dagestan barley for effective resistance to powdery mildew is very low. Only two accessions, VIR-23787 and VIR-28212, are resistant against B. graminis at both seedling and adult plant stages. The high-level resistance of breeding line VIR-28212 originating from barley landrace VIR-17554 (Ep-80 Abyssinien) from Ethiopia is controlled by the recessive gene mlo11. Accession VIR-17554 is heterogeneous for the studied trait, with the powdery mildew resistant genotypes belonging to two varieties, dupliatrum (an awnless phenotype) and nigrinudum (an awned phenotype). In accession VIR-23787, a recessive resistance gene distinct from the mlo11 allele was identified. This accession is supposed to be protected by a new, effective pathogen resistance gene.

Background. Paratypic variability of the development rates of barley accessions from the Republic of Dagestan was analyzed for five years in the Northwe st of Russia (Pushkin, St. Petersburg) and in the North Caucasus (Derbent, Dagestan). Responses to vernalization, photoperiodism and earliness per se were tested in contrasting environments to assess their effect on barley development. Such studies make it possible to identify valuable adaptable plant forms in the barley germplasm collection for further use in breeding practice.Materials and methods. In Dagestan, the duration of the period from shooting to heading was measured for 12 samples of barley accessions in winter and spring sowing trials. Twenty samples sown in spring in both regions were compared. An empirical indicator of plant development rate was used for barley: the criterion “the number of days by which the period from shooting to heading of an accession exceeds the minimum across a sample” (DPSH).Results and conclusions. Early barley accessions with a low norm of responsiveness were identified: k-3772, k-15013, k-15034, k-15036, k-15186, k-15192, k-21803 and k-23785 – they combined weak sensitivity to a short photoperiod and vernalizing temperatures, so they are promising for breeding in regions where the length of the growing season is a limiting factor. The effect of the responses of barley accessions from Dagestan to vernalization and a short photoperiod on the duration of the period from shooting to heading was on average 8 (5.1–10.6) days and on their earliness per se 6 (4.8–8.2) days. Paratypic variability reflects the range of variation for these indicators. In Dagestan, vernalization temperatures and insensitivity to a short day are the main factors determining the earliness of local barleys in their native environment.

Background. The most effective way of protecting crops from diseases and pests is the breeding and cultivation of resistant varieties. The hydrothermal regime in the southern plains of Dagestan favors damage to barley plants by the causative agent of powdery mildew. The high level of disease progress observed annually helps to reliably assess the resistance of collection accessions to the pathogen.Materials and methods. The research material included 1361 barley accessions (570 improved cultivars and 791 landraces) of different ecogeographic origin and growth habit. Field experiments were launched concurrently with winter sowing. Powdery mildew resistance was scored during the heading period and in the milk ripeness phase using a point scale. Each accession was assessed for at least three years.Results and conclusions. The results of a long-term study disclosed a significant intraspecific variability of barley collection accessions in their resistance to powdery mildew. A significant part of the studied barley accessions (63.1%) appeared susceptible to the pathogen. The occurrence frequency of disease-resistant accessions was 11.0%, while those with medium resistance reached 25.9%. Among the landraces, four resistant accessions from the Abyssinian, West Asian and Mediterranean centers of crop origin were identified. Seventeen barley varieties resistant to powdery mildew (predominantly originated from Western Europe) are recommended for use in breeding for immunity.

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 breeding of resistant varieties is an effective way to control greenbug Schizaphis graminum Rondani, an economically important pest of oat and other cereals in southern Russia. The insect-host differential interaction necessitates a constant search for new resistance donors.Materials and methods. One hundred and ninety one accessions (mostly landraces) from the Caucasian countries (Armenia, Azerbaijan and Georgia) as well as from the North Caucasus of the Russian Federation (Dagestan) were assessed for greenbug resistance. The Krasnodar (Gulkevichi District) insect population was used in the experiments. The intact plants were uniformly infested with differentaged aphids in the phase of two leaves by shaking insects onto them. When the susceptible control (cv. Borrus) died, the plant damage score was determined using the scale from 0 (no damage) to 10 (91–100% of the leaf surface damaged, plant’s death). The plants with the score of 1–4 points were classified as resistant, 5–8 moderately resistant, and 9–10 susceptible.Results and conclusions. A local oat accession from Georgia (k-4308) was noted for its high insect resistance. Also, heterogeneity of the studied trait was demonstrated by 38 oats forms, most of which were differentiated into two phenotypic classes, and a wide range of plant damage variation was characteristic of 16 accessions. The specific occurrence of resistant forms was the highest among oat landraces from Azerbaijan: two out of five studied accessions (40%) carry resistance genes with a distinct phenotypic manifestation. They are followed by accessions from Georgia (25%), Armenia (17.3%) and Dagestan (13.8%). After selection for resistance, the identified forms can be used in plant breeding.

Ordinary cereal aphid causes great damage to rice plants in the Rostov region and the Krasnodar Territory. Its harmful effects can be limited with the help of plant genetic resistance. The study of resistance of collection rice material to aphids has only recently begun. Therefore, there is a need to analyze the hereditary polymorphism of rice samples according to resistance to ordinary cereal aphid. 494 collection samples of the laboratory for rice breeding and seed production at the FSBSI Agricultural Research Center “Donskoy” were the material for the research. In laboratory VIR conditions, young rice plants were infected by the Krasnodar ordinary aphid, after which there was performed a phenotypic damage assessment using a scale from 0 (no damage) to 10 (plant death). Due to the study it was found that most of the samples were unstable or weakly stable. There were identified 15.1% of relatively stable forms, their damage was 1–4 points. Most samples showed a wide range of variation in plant damage from 1 to 10 points. Only 41 samples out of the 494 studied ones were homogeneous, all plants of which received the same point (1, 2, 3, 4, 8, or 10); the rest samples were heterogeneous. 167 samples received two variants of points, 226 samples received three, 60 samples received four. The rice samples ‘Kandidat’, ‘Komandor’, ‘PF-4186’, ‘Norin 31’, ‘Priozerny 61’, ‘Don 7243’, ‘Don 4237’ can be recommended as sources of resistance to ordinary cereal aphid to develop new rice varieties.

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.

Background. Scald (caused by Rhynchosporium secalis (Oudem.) J.J. Davis) is one of the most harmful barley diseases. The pathogen is characterized by the differential interaction with the host plant genotypes. Therefore, the most rational plant breeding strategy should envisage broadening of genetic diversity of cultivated varieties. It has been found that the majority of the recently released barley varieties and of the previously identified sources of resistance to R. secalis are now susceptible to the pathogen. Only the resistance gene Rrs9 maintains efficiency against the pathogen populations in the Russian Northwest. Earlier, we have found scald resistant barleys to be frequent among barley landrace accessions. It was demonstrated by the hybridological analysis that accessions k-3307, k-15868, k-18989 and k-3481 are protected by effective scald resistance genes that differ from each other, and which are not allelic to the Rrs4, rrs6, rrs7 or Rrs9 genes. The goal of the present work was to study genetic control to the dangerous pathogen in four other barley landraces.Materials and methods. The inheritance of scald resistance was analyzed in barley accessions k-16233, k-27205 (China), k-27768 (India) and k-22299 (Ecuador). The study employed two experimental techniques, that is, the pathogen/host plant differential interactions analysis in the lab, and the hybridological analysis in the field. The experiments were carried out using R. secalis isolates and clones from the pathogen populations sampled in the North Caucasus and the Russian Northwest. Resistance was scored against the scales from 0 (no symptoms) to 4 points (in the lab), and from 0 to 5 points (in the field). Plants that scored 0-2 points were regarded as resistant.Results and conclusions. The analysis of the pathogen clone/host plant interaction has shown that the landraces k-16233, k-27205 (China), k-27768 (India) and k-22299 (Ecuador) are protected by effective genes of scald resistance which differ from each other and are non-allelic to the previously effective genes Rrs4, rrs6, rrs7 and the currently effective Rrs9. According to the hybridological analysis data, k-27205 has one dominant gene of scald resistance; k-16233, k-27768 and k-22299 are protected by two dominant effective resistance genes, all of which manifest themselves at all the stages of plant ontogenesis.

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.

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.

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.

For three years 265 barley accessions from Dagestan were analyzed for the duration of the period between shooting and earing stages. Under the conditions of south planar area of Dagestan, the early accessions k-15008 and k-15013 have been selected. The accession k-15027 was characterized by a high rate of development in the Northwestern area of the country. The Dagestanian barleys were found to be strongly affected by the growing conditions, notably they have a high norm of reaction. It is concluded that vernalization temperatures, short day and high temperatures during the vegetation period promote earliness of barley.

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.

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.

The problem of aphid resistance of potato genetic resources is discussed. Generally, resistance to the green peach aphid (Myzus persicae Sulzer) and the potato aphid (Macrosiphum euphorbiae Thomas) is analyzed in all available literature sources. The Solanum tuberosum L. gene pool contains very few resistant forms. Accessions highly resistant to M. persicae were revealed among 36 of 86 examined wild potato species. The largest number of resistant forms was found among S. bulbocastanum Dun., S. tarijense Hawkes, S. infundibuliforme Phil., S. canasense Hawkes and S. stoloniferum Schlechtd. et Bché. The forms highly resistant to M. euphorbiae belong to 24 of 85 studied species, namely to 10 of 18 series; the species S. bulbocastanum, S. stoloniferum and S. demissum Lindl. include the maximum number of resistant forms. Wild species accessions with specific and group resistance to aphids were revealed. Glandular pubescence of leaves and stems in such species as S. polyadenium Greenm., S. tarijense and S. berthaultii Hawkes is considered as the main mechanism of resistance. Hybrids between S. tuberosum and S. berthaultii were widely used in breeding programs; however, the presence of glandular trichomes was linked to a number of undesirable characters. It is expected that association between the trichome conditioned insect resistance of S. berthaultii and undesirable agronomic traits could be overcome with the use of molecular genetic methods. Studies of the antifeedant activity of potato glycoalkaloids and their aglucons produced controversial results. In numerous works the aphid resistance of potato is connected with plant physiological state. Differences among wild potato accessions in the localization of resistance factors (leaf surface, epidermis, mesophyll, floema) were found that were indicative of differences of resistance mechanisms in the studied forms. Works on investigating induced aphid resistance in potato have great theoretical and practical significance.

Scald (Rhynchosporium secalis (Oudem.) J.J. Davis pathogenic agent) is one of the most harmful barley diseases. A high variability of this fungi explains the occurrence of new aggressive pathotypes and, accordingly, loss of cultivar resistance. It was found that many recently selected varieties of barley and previously identified sources of resistance to R. secalis are now susceptible to the pathogen. There is only one gene, Rrs9, that maintains efficiency against pathogen populations in Russia. The aim of this study is to find donors of genes for effective resistance to scald with the ability to easily transfer this trait for hybridization. The inheritance of scald resistance in 33 barley landraces was studied. Analysis of the interaction between the pathogen test clones and the host plant revealed a difference between the alleles determining fungal resistance in 32 barley forms, the previously effective genes Rrs4, rrs6, rrs7, and currently effective Rrs9. It was found that 30 accessions are protected by new unidentified genes for scald resistance. Accessions k-18398 and k-16231 from China are likely to possess allelic genes for scald resistance, while the gene (or genes) of accession k-31075 from Nepal is allelic to the Rrs9 gene. It was demonstrated by hybridological analysis that accessions k-3307, k-15868, k-18989 and k-3481 are protected by effective genes for scald resistance, which differ from each other and which are not allelic to the Rrs4, rrs6, rrs7 or Rrs9 genes. Accessions k-15868 and k-3481 possess two complementary recessive genes for scald resistance, k-18989 has two recessive genes, and k-3307 carries one recessive gene for pathogen resistance. The resistance genes of these forms are manifested during all the stages of plant ontogenesis.

A high level of overall and seasonal variabilityof the Krasnodar greenbug population for virulence to sorghum and barleyresistance genes as well for RAPD markers was revealed. The selection of insectgenotypes specificallyadapted to hostplantspecies was recorded. Aphid clones avirulentto resistantsorghum accessions were mostabundanton the barley. Greenbug migration from barleyto sorghum led to rapid accumulation of clones virulentto sorghum genes for resistance: Sgr1– Sgr4 and Sgr12. After alteration of the host, a significantshiftof genotype groups similar in RAPD profiles was observed. The distribution of RAPD markers was independentof alleles for virulence of the aphid.

The resistance of Triticum ssp. to English grain aphid (Sitobion avenae F.) and bird cherry-oat aphid (Rhopalosiphum padi L.) has been studied in different regions of Russia and the former Soviet Union. The dependence of resistance to aphids on the wheat genome constitution was determined. Diploid species with genomes Au (Triticum urartu) and Ab (T. boeoticum, T. monococcum) are the most resistant. Possessing a D genome in the species T. kiharae and T. miguschovae gives high resistance. Resistance controlled by the G genome is overcome by the pests.