A collection of rhizobial strains isolated from root nodules of the narrowly endemic legume species Oxytropis erecta, O. anadyrensis, O. kamtschatica, and O. pumilio originating from the Kamchatka Peninsula (Russian Federation) was obtained. Analysis of the 16S ribosomal RNA gene sequence showed a significant diversity of isolates belonging to families Rhizobiaceae (genus Rhizobium), Phyllobacteriaceae (genera Mesorhizobium, Phyllobacterium), and Bradyrhizobiaceae (genera Bosea, Tardiphaga). A plant nodulation assay showed that only strains belonging to genus Mesorhizobium could form nitrogen-fixing nodules on Oxytropis plants. The strains M. loti 582 and M. huakuii 583, in addition to symbiotic clusters, possessed genes of the type III and type VI secretion systems (T3SS and T6SS, respectively), which can influence the host specificity of strains. These strains formed nodules of two types (elongated and rounded) on O. kamtschatica roots. We suggest this phenomenon may result from Nod factor–dependent and –independent nodulation strategies. The obtained strains are of interest for further study of the T3SS and T6SS gene function and their role in the development of rhizobium-legume symbiosis. The prospects of using rhizobia having both gene systems related to symbiotic and nonsymbiotic nodulation strategies to enhance the efficiency of plant-microbe interactions by expanding the host specificity and increasing nodulation efficiency are discussed.

— The morphogenetic potential of in vitro culture of the valuable medicinal plant Rhodiola roseafrom six natural habitats was evaluated as a basis for developing effective methods for the...

New data on distribution of 8 vascular plant species in Northern Koryakia (mainland part of Kamchatka Territory) is presented. Five native species (Bryanthus gmelinii D. Don, Cassiope lycopodioides (Pall.) D. Don, Listera cordata (L.) R. Br., Lonicera chamissoi Bunge ex P. Kir., Saxifraga tolmiei Torr. et Gray) and 3 alien species (Galium mollugo L., Leucanthemum vulgare Lam., Linaria vulgaris Mill.) are new to the mainland of the Kamchatka Territory.

Новые данные о флоре и растительности Олюторского района Корякского округа (Камчатский край): редкие и охраняемые виды и редкие растительные сообщества

Five Gram-negative, rod-shaped, motile microorganisms were obtained from root nodules of Arctic and Subarctic Oxytropis species. The strains were designated as RCAM 04772^T, RCAM 04855, RCAM 06350^T, RCAM 05645, and RCAM 04822^T. Phylogenetic and phylogenomic analyses placed them in the genus Mesorhizobium. Genome sizes ranged from 7.70 to 8.45 Mb, with a DNA G + C content of 62.2–62.5%. ANI and dDDH values with the closest type strains (89.85–94.29% and 38.2–56.7%, respectively) were below the species delineation thresholds. Two strain pairs shared values above these thresholds—RCAM 04772^T with RCAM 04855 (99.65% ANI, 97.9% dDDH), and RCAM 05645 with RCAM 06350^T (97.50% ANI, 77.6% dDDH), while RCAM 04822^T remained distinct, indicating three novel species. The cellular fatty acid profile was dominated by C16:0 and C18:1Δ9c. The strains were psychrotolerant and capable of growth at 1 °C. Analysis of the symbiotic genes nodC and nifH placed all five strains in a one clade together with previously described Arctic isolates, and they were therefore assigned to symbiovar oxytropidis. All strains nodulated Oxytropis spp. and several other legumes from the tribes Galegeae, Hedysareae, and Robinieae. Based on genomic, phenotypic, and chemotaxonomic evidence, we propose Mesorhizobium kamtschaticum sp. nov. (RCAM 04772^T = B-2194^T and RCAM 04855 = B-2195), Mesorhizobium oxytropidicola sp. nov. (RCAM 06350^T = B-2197^T and RCAM 05645 = B-2198), and Mesorhizobium subarcticum sp. nov. (RCAM 04822^T = B-2203^T).

Herbarium specimens of ferns kept at the Central Siberian Botanical Garden SB RAS (NS, NSK) were digitised in 2021. Specimens of 20 families of Polypodiopsida were included in this dataset except Equisetaceae. Family Ophioglossaceae was digitised and published separately (Kovtonyuk et al., 2021). Specimens published in datasets "Vascular plants from European Russia in the CSBG SB RAS Digital herbarium" (Kovtonyuk, Han, Gatilova, 2020, 2021) and "Foreign Asia herbarium collection in CSBG (NS)" (Gatilova et al., 2020) were also excluded. In the dataset specimens from 43 countries of Europe, Asia, America, Africa and Australia (Oceania) are presented, most of them are from Russia (6918). 5092 specimens from Russia are published in the first time. Collectors with most gathered specimens are: Krasnoborov I. M. (913), Ivanova M. M. (565), Shaulo D. N. (538), Malyshev L. I. (296), Kiseleva A. A. (281), Lashchinsky N. N. (270), Hanminchun V. M. (251), Vodopyanova N. S. (230), Bardunov L. V. (196), Peshkova G. A. (147), Lomonosova M. N. (133), Petrochenko Yu. N. (126), Andrulaitis S. Yu. (126), Artemov I. A. (116), Arslanova N. K. (Kovtonyuk N. K.) (104), Molchanov E. F. (93), Bolshakov N. M. (88), Chepurnov A. A. (85), Maskaev Yu. M. (81), Vlasova N. V. (76), Ronginskaya A.V. (73), Vereshchagin V. I. (73), Doronkin V. M. (71), Friesen N. V. (67), Popov M. G. (62), Zuev V. V. (61), Titov E. (49), Starovoitova Z. (49), Pospelov I. N. (44), Tyulina L. N. (42), Nechaev A. A. (42).