Persian walnut is a valuable nut crop whose fruits are rich in unsaturated fatty acids, phenolic compounds, and trace elements, determining their high nutritional value and health benefits. The development of trait-specific collections and the preservation of their genetic and phenotypic diversity are relevant directions in breeding and genetic research aimed at improving the efficiency of breeding programs. This article presents the results of genetic diversity analysis using SSR markers, along with data on a set of fruit quality traits in promising walnut breeding forms. The study involved 43 hybrid forms of Persian walnut from the germplasm collection of the North Caucasian Federal Scientific Center of Horticulture, Viticulture, and Winemaking (NCFSCHVW). The Rodina cultivar was used as a control. During the study period (2022–2025), fruits were comprehensively evaluated for key quality traits, including fruit weight (ranging from 6.42 to 14.27 g in the studied sample), kernel percentage (41.14–61.83 %), shell thickness (0.92–1.83 mm), kernel color, kernel extraction ease, kernel filling, and total fat content (61–77 %). Overall, 11 promising forms that simultaneously possessed three or more valuable fruit quality traits were identified. Using 12 microsatellite DNA markers, the level of genetic diversity and the genetic relationships among the 43 hybrid forms, as well as with several domestic and foreign cultivars, were assessed. A total of 90 alleles were detected, with an average of 7.5 alleles per locus. Polymorphism indices (observed heterozygosity = 0.451; expected heterozygosity = 0.670) also indicated a relatively high level of genetic heterogeneity within the studied sample. Bayesian clustering analysis (STRUCTURE, K = 4) and Principal Coordinates Analysis (PCoA) were used to determine genetic relationships among the hybrid forms and domestic and foreign cultivars. Four major groups of samples were identified, and their distribution was consistent with the origin of the samples. Based on genetic distance estimates and cluster assignment, recommendations were developed for the selection of parental combinations in breeding programs aimed at developing cultivars with improved fruit characteristics while maintaining a high level of genetic diversity within the germplasm. 

The development of new cultivars that meet the demands of changing climatic and economic conditions depends on the availability and composition of genebank collections and on the use of ecological, geographical, and genetic diversity in initial breeding material, including autochthonous cultivars. This study evaluated the contribution of autochthonous cultivars from the Bioresource Collection of the Russian Research Institute of Fruit Crop Breeding (VNIISPK) to the development of modern adaptive cultivars and assessed their breeding value. More than 50 local cultivars were analyzed as potential sources of valuable agronomic and biological traits. Artificial freezing tests showed that cultivars derived from winter-hardy autochthonous parents exhibit the same level of tolerance to low mid-winter temperatures as their parental forms. Many autochthonous cultivars, as well as modern domestic cultivars developed with their participation, represent valuable material for further breeding. The following local cultivars are recommended as donors of specific traits: Krasnoe Letnee, Khoroshavka Alaya, Korobovka, Popovka, and Titovka for high winter hardiness; Grushovka Moskovskaya, Malinovka Zhyoltaya, and Korobovka for precocity and early fruit ripening; Bel Rozovaya and Renet Zolotoy Kurskiy for field resistance to apple scab; Suyslepskoe, Titovka, and Khoroshavka Alaya for high market quality and attractive fruits with tender, wine-sweet flesh; and Skryzhapel and Renet Zolotoy Kurskiy for extended consumption period. Cultivars in the VNIISPK collection were tested for DNA markers linked to the scab-resistance genes Va1 ( Rvi17 ), Vf ( Rvi6 ), and Vm ( Rvi5 ). DNA markers linked to Va1 ( Rvi17 ) were detected in the old cultivars Antonovka Obyknovennaya and Antonovka Krasnobochka, as well as in Bessemyanka Michurinskaya and in several VNIISPK cultivars that inherited this gene (Zaryanka, Patriot, Sokovinka, Orlik, and Svezhest). An allele linked to Vm ( Rvi5 ) was amplified in the descendants of local cultivars, including Zaryanka, Patriot, Sokovinka, Orlovim, Slavyanin, and Chistotel. Several other descendants (Zdorov’e, Imrus, Maslovskoe, Svezhest, and Yablochny Spas) carried an allele associated with Vf ( Rvi6 ). Among the cultivars developed at VNIISPK using local germplasm, several adaptive, scab-resistant cultivars with high market quality and harmonious fruit flavor were identified. These include summer cultivars (Avgusta, Osipovskoe, and Yablochny Spas), winter cultivars (Bolotovskoe, Vavilovskoe, Imrus, and Orlik), and late-winter cultivars (Sinap Orlovsky and Svezhest).

The study examined the agronomic and biological traits of the new apricot cultivar Tsesar, developed at the I. V. Michurin Federal Scientific Center, Tambov Region, Russia, in comparison with the regional standard Ulyanikhinsky, to determine the suitability of both cultivars for commercial orchards and breeding programs in the Central Black Earth Region. Field trials were conducted in 2018, 2019, 2020, and 2025 in a dryland orchard in Michurinsk (planting scheme 6 × 3 m; rootstock SVG 11-19; soil: leached loamy chernozem, humus 4.8-5.7 %, pH 5.3–5.6). Low winter temperatures and late spring frosts remain the major limiting factors for apricot cultivation in this region. During the study period, the mean yield of Tsesar was 7.90 t/ha, exceeding the control by 2.38 t/ha (43.1 %, LSD₀₅ = 1.73 t/ha). The mean fruit mass was 42.3 g (+31.4 % relative to the control). The total soluble sugar content reached 10.8 % (+2.9 %), and the ascorbic acid content was 14.4 mg/100 g (+22.0 %). Leaf infection by shot-hole disease (clasterosporiosis) averaged 1.7 points, which was 1.8-fold lower than the standard. The intensity coefficient (Ci = 90.3 %) was 2.4-fold higher than that of the control, and the adaptability coefficient (Ca = 1.18) indicated high ecological plasticity. Even in the stressful year 2025, the minimum yield of Tsesar (5.12 t/ha) significantly exceeded the control by 0.78 t/ha (LSD₀₅ = 0.73 t/ha). The cultivar Tsesar is recommended for production-scale trials and for use as a donor of large fruit size, high yield, and adaptability in breeding programs for the Central Black Earth Region.

The development of breeding material is a fundamental stage in creating new cultivars with predefined traits. In research on Ribes nigrum L., inbreeding is a promising approach for assessing the breeding potential of parental genotypes, as it enables evaluation of the breeding value of parental forms. This study evaluated the progeny of black currant obtained through self-pollination. Superior parental forms and inbred genotypes were identified, and material for subsequent breeding stages was selected. The research was carried out in 2022–2025 at the Center for Collective Use “Genetic Bioresource Collection of Plants” of the Federal Horticultural Center for Breeding, Agrotechnology, and Nursery (Russia). Progeny derived from self-pollination of 40 cultivars and 5 selected forms distinguished by valuable traits were examined. The study included inbred seedlings produced by self-pollination conducted in 2015–2020 and planted in the breeding field in spring 2017–2022. The contrasting weather conditions during the observation period enabled a comprehensive evaluation of seedlings across a range of economically important traits. In most cases, the inbred progeny exhibited undesirable characteristics, including premature fruit drop, poor berry flavor, dwarfism, and susceptibility to pathogens. These traits were frequently expressed in the I₁ generation, while the economically significant attributes for which the initial forms were selected often remained unexpressed in the progeny. Nonetheless, several parental forms demonstrated breeding value, including the cultivars Litvinovskaya, Chernavka, Debryansk, Kipiana, Bryansky Agat, Tisel, and Ben Gairn, as well as elite selections 8-4-1, 8-4-6, 7-49-3, and 12-17. Comprehensive evaluation of the self-pollinated progeny allowed us to identify several plants suitable for further breeding. These include selection 1-91-01 (Sanyuta I₁), which combines resistance to leaf spot diseases and powdery mildew and produces up to 10 berries per cluster; form 5-43-01 (Litvinovskaya I₁), characterized by high field resistance to fungal diseases and dessert-quality fruit; and the inbred seedling 1-79-01 (Fortuna-17 I₁), which exhibits abundant fruit clustering and berries with excellent flavor (5 points). The best forms will be incorporated into subsequent stages of the breeding program.

Over recent decades, global raspberry production has seen considerable growth. The popularity of raspberry stems not only from the excellent flavor but also from the rich biochemical composition of the berries, which exhibit antioxidant properties. Many breeding programs globally have identified the improvement of fruit quality traits as a separate strategic direction. This study aims to provide a concise review of the polyphenolic composition of raspberry fruits from modern cultivars of both Russian and foreign breeding, to identify sources of high polyphenolic accumulation, and to propose a contemporary cultivar model suitable for the conditions of central Russia. The paper reports biochemical data on total phenolic compounds, flavonoids (ellagitannin and anthocyanin), total phenolic acids and their individual components (ellagic, gallic, chlorogenic, caffeic, p-coumaric, syringic, ferulic, protocatechuic, and carbonic acids), as well as ascorbic acid. Analysis of published studies revealed a wide range of variability for all these parameters. Depending on the cultivation region and genotype, mean total phenolic content varies from 47 to 3664 mg/100 g, expressed as gallic acid equivalents. High levels were recorded in Gusar, Poklon Kazakovu, Balzam, Polana, and Bristol cultivars. For flavonoid content, maximum values were found in the Silvan raspberry-blackberry hybrid and the 1-45-2 selection line. High ellagitannin content was observed in Glen Moy and Bristol; high anthocyanin content was found in Skromnitsa, Polana, Glen Moy, Tulameen, Bristol, and Cumberland; and high vitamin C levels were recorded in Perseya, Garmoniya, Skromnitsa, and No. 9/15 line. Considering the environmental and geographic factors of central Russia, the results of the present analysis suggest that new raspberry cultivars should combine the following content levels: total phenolic compounds exceeding 500 mg/100 g, total phenolic acids exceeding 40 mg/100 g, flavonoids exceeding 200 mg/100 g, ellagitannins and anthocyanins exceeding 100 mg/100 g, and ascorbic acid exceeding 50 mg/100 g.

A production procedure for grapevine seedlings and other planting material was developed, which includes the following stages: identification of primary breeding material, followed by cultivar evaluation, clonal selection, and phytosanitary screening; diagnostic testing of selected material for viruses, phytoplasmas, viroids, and bacteria; sanitation by chemoand thermotherapy and in vitro culture; repeated testing for pathogens; and establishment of mother plants of the “initial” category in a phytotron. The procedure also incorporates mandatory diagnostic testing of candidate plants, verification of cuttings collected from these plants, repeated testing following sanitation treatments (thermotherapy, chemotherapy, and in vitro culture), and continuous phytosanitary monitoring of mother plant collections. To minimize the risk of reinfection, mother plants should be maintained exclusively under greenhouse conditions. In accordance with Order No. 525 of the Ministry of Agriculture of the Russian Federation (24 May 2023), the cultivar and phytosanitary evaluation of initial-category mother plants is carried out only after plants have completed their second growing season. Standardized production protocols were developed for the initial-category grapevine planting material. These include cultivar and phytosanitary evaluation of grapevine plantings, selection of candidate plants, production of initial-category planting material, and establishment of initial-category mother plant collections under protected cultivation. The production of basic-category planting material includes site selection and pre-plant soil preparation, preparation of cuttings for nursery planting, establishment of a grapevine nursery using cuttings, nursery management, lifting of seedlings, and certification as basic-category planting material. These production protocols were subsequently used to estimate production costs and evaluate production efficiency.