The current investigation aimed to present an overview of the conservation of biological diversity of rare and endangered plant species. Methods of biodiversity conservation as well as several overview recommendations for the preservation of various rare species have been considered. An overview of the taxa included in the red book has been presented on the example of the Russian Federation. Global and local codes and classifiers of plant rarity were also presented. Future prospects for the conservation of biological diversity and the creation and development of bioresource collections have been considered.

Micropropagation is an effective way to preserve the gene pool of threatened plants. This study is devoted to the mathematical modeling of nutrient media and the study of the effect of mT (meta-topoline) on the multiplication of shoots of Hedysarum grandiflorum, Hyssopus cretaceus, and Matthiola fragrans in vitro in comparison with benzylaminopurine (BAP) and kinetin (KT). Initiation was performed on an MS medium with 0.5 mg/L BAP. For shoots multiplication, MS, B5, and WPM media were used with the addition of mT, BAP, KT. For H. grandiflorum, the multiplication coefficient of shoots was highest on medium B5 with the addition of mT at a concentration of 1 mg/L—2.90 shoots per plant, for H. cretaceus—B5 + 0.5 mg/L mT, and for M. fragrans—B5 + 1 mg/L KT. A positive effect of mT on H. grandiflorum and M. fragrans in vitro was found. The efficiency of using KT for H. cretaceus shoot multiplication is shown. The effectiveness of the B5 nutrient medium for H. grandiflorum and M. fragrans was determined. The positive effect of WPM for H. cretaceus micropropagation has been demonstrated. It is not recommended to use the MS media for micropropagation of these plant species.

No abstract

<em>Hedysarum cretaceum</em> Fisch<em> </em>is a critically endangered herbaceous species with high ornamental and phytomeliorative properties; thus, it needs urgent conservation and protection methods to conserve. In the present study, an efficient method for microtonal propagation of <em>H. cretaceum</em> is developed. The seed sterilization was optimized as treatment with 96% alcohol (2 min) and burned (1 sec) through a burner flame. Murashige and Skoog (MS) medium with the addition of 0.5 mg/L 6-Benzylaminopurine (BAP) (shoots per explant – 18.0) and 1.0 mg/L BAP and 0.1 mg/L Indole-3-acetic acid (IAA) (shoots per explant – 18.4) for the shoot and ⅓ MS supplemented with 0.1 mg/L IAA (rooting indicator – 62%) for roots were identified best composition for the proliferation and regeneration. Additionally, the medium for maintaining callus culture was determined – DKW with the addition of 2.5 mg/L BAP and 0.1 mg/L IAA, the possibility of direct organogenesis <em>in vitro</em> in the studied plant was also standardized. In addition, seed germination after various pre-sowing treatments was studied. It is shown that scarification makes achieving 80% germination of seeds possible. Also, sulfuric acid was used as a pre-sowing seed treatment, germination was 45%. Thus, using the protocols we developed, it is possible to maintain the <em>H. cretaceum</em> culture <em>in vitro</em> and increase seed germination using pre-sowing treatment.

The article presents the results of the monitoring research of Hedysarum grandiflorum Lower Don basin populations (Rostov Region). Eight new populations of the species are revealed in the region, their habitat conditions are described. Quantitative characters of populations studied and coenotic role of H. grandiflorum are lower than it is observed in optimal conditions. In relation to their ontogenetic structure, the populations are normal, mostly incomplete, having right-sided or centered ontogenetic spectrum. According to delta-omega classification, they belong to mature and ripening; according to replacement index, most of them are unstable or rarely perspective. The principal limiting factors in populations observed are an anthropogenic impact, mainly grazing, and partially discordance between climatic conditions of the region and ecologic requirements of the plant species. H. grandiflorum coenopopulations of the Aksay District are characterized by extremely low number and proportion of the viable seeds per fruit because of seed developmental disorder. Actual seed productivity values vary significantly between years that may condition fluctuations of total seed productivity per individual plant and cause an irregular renewal by seed. In years good for seed maturing, seed productivity of H. grandiflorum may be considered satisfactory.