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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. Modern production of sunflower seeds is currently based on the cultivation of high-yielding heterotic F1 hybrids from crossbreeding of lines with cytoplasmic male sterility (CMS) of PET1-type and fertility restorer lines. The paternal parent serves as a donor of the nuclear Rf1 gene functional allele, which is responsible for pollen fertility restoration in F1 plants. The detection of carriers of the Rf1 locus recessive and dominant alleles using diagnostic molecular markers accelerates breeding of female and male parental lines for creating hybrids.Materials and methods. The material for the study included 75 lines of various origins from the VIR sunflower genetic collection as well as hybrids from crosses of VIR 116A sterile line with fertile lines differing in the type of cytoplasm (fertile or sterile) and the presence of molecular markers, most of which were linked to the Rf1 locus. For marker validation, two different approaches were used: either by analyzing associations between the ability of a line to restore pollen fertility and the presence of molecular markers in its genotype, or by estimating recombination frequency between the Rf1 locus and marker loci in four segregating hybrid populations.Results. According to the obtained results, no markers demonstrated 100% efficiency in the analysis of the sample of genotypes. The ORS511 marker was most frequently observed among the lines presumably carrying the dominant allele Rf1. Pollen fertility of F1 hybrids from interline crossings was 89-99%. The segregation for fertility/sterility in F2 fitted the theoretical ratio of 3:1 expected in case of the monogenic control of the trait. The markers HRG01, HRG02 and ORS511 were linked to the fertility restoration trait, with recombination rates between Rf1 locus and markers varying in different cross combinations. The analysis of VIR 116А × VIR 740 and VIR 116А × RIL 130 hybrids showed that among the marker loci studied, the ORS511 was closest to the Rf1 locus Rf1 (recombination frequency of 2.2 and 3.3%, respectively). The recombination rate between the Rf1 and ORS511 loci equaled 7.5% in the cross VIR 116А × VIR 210 and 8.9% in VIR 116 × VIR 195.Conclusion. The markers ORS511, HRG01 and HRG02 are the most efficient for the identification of alleles of the Rf1 gene and for the marker assisted selection in hybrid populations produced involving sunflower lines from the VIR collection.

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. Downy mildew (DM) caused by the fungus Plasmopara halstedii (Farl) Berl. & De Toni) is one of the most harmful diseases of sunflower (Helianthus annuus L.). Due to the pathogen’s attacks, annual seed harvest losses range between 30% and 70%. Lines resistant to new races of the pathogen should be obtained for the development of commercial sunflower hybrids.Materials and methods. Downy mildew resistance of 323 lines and 10 cultivars from the sunflower collection was assessed in the field at the Kuban Experiment Station of VIR in 2017–2018. Line VIR 845, susceptible during all years of observations, was used as a control. Resistance genes were identified by means of the molecular analysis using diagnostic markers of the Plarg, Pl6 and Pl8 genes that confer resistance to many known P. halstedii races.Results. The founder varieties of VIR’s lines were susceptible to a varying extent. Thirty-nine lines were resistant in 2016 and 2018; among those, 36 lines were susceptible in 2017. Presumably, a more virulent P. halstedii race became widespread in 2017, compared to the races that prevailed in 2016 and 2018, so the genes that determined resistance in 2016 and 2018 turned out to be ineffective. Lines ТА 716-18, VIR 768, and VIR 800, having originated from interspecific hybrids, exhibited absence of pathogenic damage during 3 years of the trials. Molecular markers of the Plarg, Pl6 and Pl8 genes were detected in most lines that demonstrated resistance in 2016 and 2018. There were no markers in lines VIR 768 and VIR 800, whereas in ТА 716-18 the markers of Plarg and Pl8 were present.Conclusion. As a result of the long-term studies, a trait-specific genetic collection was established for sunflower. It comprises genotyped lines with various effective DM resistance genes. Lines ТА 716-18, VIR 768 and VIR 800 appeared highly resistant to the pathogen and probably possess new resistance genes/alleles introgressed from wild species.

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.

This paper presents the data of evaluation of late blight resistance in hybrids derived from crosses of Solanum tuberosum L. with the diploid Bolivian potato species S. berthaultii Hawk. and S. ruiz-ceballosii Card. selected previously for their resistance. In field and laboratory evaluation large share of resistant phenotypes was found. Both hybrids produced tubers in the field under long daylight conditions. S. berthaultii possesses a triploid number of chromosomes (2n = 36) and is completely sterile. Pollen grains of S. ruiz-ceballosii hybrid are partially fertile.

Ninety five lines of sunflower genetic collection differing by their ability to suppress the CMS phenotype were molecularly marked with the use of 7 primer pairs. Using the STS marker orfH522, a sterile (PET1) cytoplasmon was identified in 79 lines, which confirmed indirectly the presence of fertility restoration genes in their genotypes. The majority of these lines also have a complex of molecular markers linked to the Rf1 gene. The HRG01, HRG02 and STS115 markers showed the best diagnostic value in revealing the Rf1 gene in the examined material. The data on allelic variation of the microsatellite loci ORS224, ORS511 and ORS799 were obtained for the first time.

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.