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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. Anthracnose black rot caused by the phytopathogenic fungus Colletotrichum acutatum Simmonds became an extremely harmful disease of strawberries in Southern Russia. The disease is widespread throughout the world, and relatively recently it appeared in Russia. Yield losses due to the disease reach up to 80%; besides, the pathogen causes significant plant losses in mother plantations. The most reliable protection against the pathogen is the cultivation of resistant varieties. In strawberries, resistance is controlled by different genes, including Rca2. To identify this gene, molecular markers STS_Rca2_240 and STS-Rca2_417 have been developed. The purpose of this study was to use the markers for screening the VIR collection of strawberry varieties at the VIR Maikop Experiment Station (Maikop ES VIR). Material and methods. The present work studied 135 varieties of Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier, 83 domestic and 52 foreign ones. The domestic varieties included 17 created at the Maikop ES. Plants were evaluated for anthracnose field resistance in the Republic of Adygea from 2018 to 2021. Molecular screening was performed using STS_Rca2_240 and STS-Rca2_417, the molecular markers closely linked to the Rca2 gene. Microsatellite primers EMFv020 were used to control the PCR. The cultivar ‘Sudarushka’, in which the presence of STS_Rca2_240 marker was described in the literature, served as a positive control. Results and discussion. The marker Rca2_240 was detected in 22 cultivars from 135 studied. Among domestic varieties, the frequency of the marker was 18.1%, while among the foreign varieties it was slightly lower and amounted to 13.0%. Among the 17 varieties created at the Maykop SE, the marker was found in three: ‘Majkopskaya rannyaya’, ‘Peryt’, and ‘Shapsugskaya’. The association of the diagnostic fragment with resistance was 73.0%. The marker efficiency was not very high due to the significant number of resistant varieties which do not generate the diagnostic fragments. The resistance in such varieties can be provided by other genes, for example, FaRCa1. The STS-Rca2_417 marker was not effective during screening. Conclusion. Twenty-two varieties with the STS_Rca2_240 marker were identified in the VIR collection, maintained at the Maykop ES VIR, 16 of which were resistant to C. acutatum. These varieties represent a valuable breeding material. The STS-Rca2_240 marker can be used as an important diagnostic trait for the certification of varieties.

Background. The use of alien genetic material of bulbous barley Hordeum bulbosum L. to increase the diversity of cultivated barley Hordeum vulgare L. is an important task, since H. bulbosum is characterized by a number of valuable traits. One of the ways to use the genetic potential of bulbous barley is the interspecific hybridization and obtaining fertile introgressive lines of H. vulgare based on interspecific hybrids. The aim of the study was to obtain new introgressive forms of spring barley using interspecific triploid (H^vH^bH^b) and tetraploid (H^bH^bH^vH^v) hybrids of cultivated barley with bulbous barley to expand the collection of introgressive lines of H. vulgare. Materials and methods. To create new introgressive forms, diploid barley H. vulgare (2x) cv. ‘Roland’,  was crossed with interspecific hybrids H. vulgare cv. ‘Roland’(2x) × H. bulbosum W851 (4х) (H^vH^bH^b), and H. bulbosum A17 (4x) × H. vulgare ‘Borwina’ (4x) (H^bH^bH^vH^v). Cultivated barley forms with introgression of the bulbous barley genetic material were selected from the offspring from these crosses; then the selection was continued in two progenies from self-pollination of selected BC1 plants with three alien introgressions. Identification and localization of introgressions was carried out using the method of fluorescent in situ hybridization (GISH and FISH with chromosome-specific markers). Results. The crossing of cultivated barley with triploid and tetraploid interspecific hybrids H. vulgare × H. bulbosum yielded new forms of cultivated barley with recombinant chromosomes, among which two plants with three terminal introgressions of the genetic material of bulbous barley were identified. The first plant, derived from a triploid hybrid, showed introgressions in chromosomes 5HL, 1HL and 3HS. When two homologues with the 5HL introgression of the initial size are combined in the karyotype, the lethality of seedlings is observed in the offspring plants. In the second plant obtained on the basis of a tetraploid hybrid introgression was revealed in chromosomes 5HL, 2HL, and 7HS. In the offspring from self-pollination of this form, the presence of the 2HL introgression of the original size in both homologues led to plant sterility. Forms with a change in size of the introgression in 5HL and 3HS in the offspring of the first plant and with a change in size of the introgression in 2HL in the offspring of the second plant were detected, which indicated that meiotic recombination had occurred in those chromosome regions in BC1 plants. Conclusions A barley plant with the introgression of bulbous barley chromatin into chromosomes 1HL, 5HL, and 3HS of cultivated barley was identified in the offspring from a cross of cultivated barley with a triploid interspecific hybrid H. vulgare × H. bulbosum. In crosses with a tetraploid interspecific hybrid, a barley plant with the introgression into chromosomes 2HL, 5HL, and 7HS was found. On the basis of ‘Roland’ spring barley cultivar, two series of new introgressive forms of H. vulgare with various combinations of recombinant chromosomes have been created.

The breeding of ornamental plants as a branch of crop production is an integral part of the set of measures aimed at obtaining a wide range of different plants with high decorative characteristics. The main objective of this branch is the creation of plants that are attractive to the consumer and commercially characterized by such valuable biological features as adaptability, resistance to diseases, pests, frost and others. Most ornamental plant varieties were bred by means of traditional breeding methods such as selection, distant hybridization, clone breeding, radiation and chemically induced mutagenesis. However, the use of traditional breeding tools is limited by the potential for intraspecific variability. The development of modern biotechnological and genetic approaches to the breeding of new varieties has made it possible to modify the plant genotype at a qualitatively new level. The present review covers the directions in and methodology of modern ornamental plant breeding in Russia, ways of mobilizing the genetic resources of the main ornamental crops such as rose, clematis, canna, chrysanthemum, pelargonia, iris, daylily, tulip, lilac, and rhododendron. Aslo, the review offers examples of ornamental plant breeding work uderway in the leading specialized scientific institutions such as the Russian State Agrarian University – the K.A. Timiryazev Moscow Agricultural Academy, I.V. Michurin Federal Research Centre, Nikitsky Botanical Gardens – National Scientific Center of the RAS, Subtropical Scientific Center of the Russian Academy of Sciences, Botanical Garden of the M.V. Lomonosov Moscow State University, All-Russian Scientific Research Institute of Tobacco, Mahorka and Tobacco Products. The world and Russian flower and ornamental plants markets, the problem and methods of resolving the issue of quality import substitution, and prospects for the development of floriculture in Russia in the foreseeable future are also briefly considered.