Characterization of genetic diversity in germplasm collections requires an efficient set of molecular markers. We assessed the efficiency of 36 new SCoT markers, 10 new ISSR markers, and 5 microsatellites for the characterization of genetic diversity in chrysanthemum core collection of 95 accessions (Russian and foreign cultivars). Seven new SCoT (SCoT12, 20, 21, 23, 29, 31, 34) and six new ISSR markers ((GA)8T, (CT)8G, (CTTCA)3, (GGAGA)3, (TC)8C, (CT)8TG) were efficient for the genetic diversity analysis in Chrysanthemum × morifolium collection. After STRUCTURE analysis, most Russian cultivars showed 20–50% of genetic admixtures of the foreign cultivars. Neighbor joining analysis based on the combination of SSR, ISSR, and SCoT data showed the best accordance with phenotype and origin compared to the separate analysis by each marker type. The position of the accessions within the phylogenetic tree corresponded with the origin and with some important traits, namely, plant height, stem and peduncle thickness, inflorescence type, composite flower and floret types, flower color, and disc color. In addition, several SCoT markers were suitable to separate the groups distinctly by the phenotypical traits such as plant height (SCoT29, SCoT34), thickness of the stem and peduncle (SCoT31, SCoT34), and leaf size and the floret type (SCoT31). These results provide new findings for the selection of markers associated with important traits in Chrysanthemum for trait-oriented breeding and germplasm characterization.

Osmotic stress is a major factor reducing the growth and yield of many horticultural crops worldwide. To reveal reliable markers of tolerant genotypes, we need a comprehensive understanding of the responsive mechanisms in crops. In vitro stress induction can be an efficient tool to study the mechanisms of responses in plants to help gain a better understanding of the physiological and genetic responses of plant tissues against each stress factor. In the present study, the osmotic stress was induced by addition of mannitol into the culture media to reveal biochemical and genetic responses of tea microplants. The contents of proline, threonine, epigallocatechin, and epigallocatechin gallate were increased in leaves during mannitol treatment. The expression level of several genes, namely DHN2, LOX1, LOX6, BAM, SUS1, TPS11, RS1, RS2, and SnRK1.3, was elevated by 2–10 times under mannitol-induced osmotic stress, while the expression of many other stress-related genes was not changed significantly. Surprisingly, down-regulation of the following genes, viz. bHLH12, bHLH7, bHLH21, bHLH43, CBF1, WRKY2, SWEET1, SWEET2, SWEET3, INV5, and LOX7, was observed. During this study, two major groups of highly correlated genes were observed. The first group included seven genes, namely CBF1, DHN3, HXK2,SnRK1.1, SPS, SWEET3, and SWEET1. The second group comprised eight genes, viz. DHN2, SnRK1.3, HXK3, RS1, RS2,LOX6, SUS4, and BAM5. A high level of correlation indicates the high strength connection of the genes which can be co-expressed or can be linked to the joint regulons. The present study demonstrates that tea plants develop several adaptations to cope under osmotic stress in vitro; however, some important stress-related genes were silent or downregulated in microplants.

This paper presents the results on the breeding work carried out by the Subtropical Scientific Centre of the Russian Academy of Sciences. Currently, the Centre’s breeders are doing a lot of work aimed at breeding new fine yielding cultivars of subtropical and flower crops that will be resistant to growing conditions; they include kaki persimmon, feijoa, mandarin, freesia, crown anemone, pelargonium and chrysanthemum. The sources of high-level priority traits in flower crops that are valuable for further breeding in order to improve decorative (colour, flower shape, inflorescence), economic and biological traits (flowering period, a large number of flowers in the inflorescence, storage period of cut flowers, disease resistance, high reproduction coefficient) were recorded. The aim of the research is to improve the subtropical and flower crops assortment. The objects of the research were 989 hybrid forms: 136 citrus crops, 56 persimmon, 36 feijoa, 38 tea plant, 11 pear, 24 hazel, 108 freesia, 398 crown anemone, 120 pelargonium and 62 chrysanthemum hybrids. New cultivars with a complex of valuable traits have been created as a result of the scientific work. Over the past five years, FRC SSC of RAS has created 50 new cultivars: 26 pelargonium, 15 anemone, 5 freesia, 2 chrysanthemum, 1 persimmon and 1 apple and submitted them to the State Cultivar Commission. The “State Register of Selection Achievements Authorized for Use for Production Purposes” has included 63 cultivars developed by FRC SSC RAS, including 26 pelargonium, 13 anemone, 9 chrysanthemum, 7 freesia, 4 hazel, 3 feijoa and 1 tea plant cultivars. 46 patents for breeding achievements have been obtained.

Persimmon germplasm in the Western Caucasus represent one of the most northerly collections. In our study, 51 commercial cultivars of D. kaki, 3 accessions of D. virginiana and 57 D. lotus accessions from six geographically distant populations were investigated using 19 microsatellite and 10 inter simple sequence repeat (ISSR) markers. After STRUCTURE analysis, the single accessions of Diospyros were allocated to three genetic clusters. Genetic admixtures in the important genotypes of D. kaki were revealed, whereas D. lotus accessions showed no admixture with other genetic clusters. The correspondence of genetic data and phenotypical traits was estimated in the D. kaki collection. The most frost tolerant genotypes of the collection, such as “Mountain Rogers”, “Nikitskaya Bordovaya”, “Rossiyanka”, “MVG Omarova”, “Meader”, “Costata”, “BBG”, and “Jiro”, showed a high percentage of genetic admixtures and were grouped close to D. virginiana. Some of these genotypes are known to be interspecific hybrids with D. virginiana. A low level of genetic diversity between the distant D. lotus populations was revealed and it can be speculated that D. lotus was introduced to the Western Caucasus from a single germplasm source. These results are an important basis for the implementation of conservation measures, developing breeding strategies, and improving breeding efficiency.

Tea has historically been one of the most popular beverages, and it is currently an economically significant crop cultivated in over 50 countries. The Northwestern Caucasus is one of the northernmost regions for industrial tea cultivation worldwide. The domestication of the tea plant in this region took approximately 150 years, during which plantations spreading from the Ozurgeti region in northern Georgia to the southern city of Maykop in Russia. Consequently, tea plantations in the Northern Caucasus can serve as a source of unique genotypes with exceptional cold tolerance. Tea plants are known to be recalcitrant to Agrobacterium-mediated transfection. Research into optimal transfection and regeneration methodologies, as well as the identification of tea varieties with enhanced transformation efficiency, is an advanced strategy for improving tea plant culture. The aim of this study was to search for the optimal Agrobacterium tumefaciens-mediated transfection protocol for the Kolkhida tea variety. As a result of optimizing the transfection medium with potassium phosphate buffer at the stages of pre-inoculation, inoculation and co-cultivation, the restoration of normal morphology and improvement in the attachment of Agrobacterium cells to the surface of tea explants were observed by scanning electron microscopy. And an effective method of high-efficiency Agrobacteria tumefaciens-mediated transfection of the best local tea cultivar, Kolkhida, was demonstrated for the first time.

The Mzymta and Sochi watersheds, located on the southern slopes of the Caucasus Mountains on Russia’s Black Sea coast, are characterized by a remarkably complex geological setting. The predominant rocks are mudstones, siltstones, and shales, with smaller amounts of carbonate and clay-carbonate rocks, and occasionally igneous rocks. The area is also characterized by the occurrence of polymetallic, gold, sulfide, rare metal, and rare-earth mineralizations in addition to hosting a thermal hydrogen sulfide groundwater aquifer. The objective of this study was to determine groundwater genesis patterns in an area with such contrasting geological and hydrogeological structures. Based on the chemical analysis of 33 natural groundwater springs, five chemical types of water were identified dictated by the composition of the host rock as well as the occurrence of mineralizations, seepage of mineralized water, and local geochemical features of the host rock. The high sodium concentration and mineralization of groundwater near the thermal hydrogen sulfide groundwater aquifer are due to the infiltration of seawater. The consistent presence of excessive amounts of rare-earth elements (REEs) in all groundwaters in the area is a reflection of the regional geochemical specialization of the rocks. Groundwater, like the terrestrial components of the natural environment, inherits rare-earth fractionation patterns from the rocks that make up the area. Thus, rare-earth totals and fractionation patterns can be used as a reliable criterion to interpret the regional specificity of groundwater.