Pulsatilla vulgaris is one of the rarest vascular plant species in Russia. In the Red Data Book of the Russian Federation, it is classified as critically endangered (category 1). The only population of P. vulgaris in Russia is known from the Leningrad Region and it is rapidly declining. The analysis of the population ontogenetic structure demonstrates low level of the population self-sustainment due to lack of seed reproduction. One of the factors that prevent P. vulgaris generative reproduction is the biotope transformation caused by succession. Typical habitats of P. vulgaris are heaths, sparse and low pine forests, dry low-grass meadows and pastures. Successful seed reproduction of the species requires the factors that inhibit woody vegetation development and lead to the damage of dense ground cover and soil (i.e. moderate grazing, weak ground fires etc.). To avoid a complete loss of the species in Russia, artificially damaged sites suitable for successful seed regeneration of P. vulgaris were formed in 2020–2021 in “Nizhnevolkhovskiy” Protected Area (Leningrad Region, Volkhovskiy District). Trees uprooting, grass vegetation removal or damage, soil damage were performed to form exposed and well-warmed sites with sparse vegetation ground cover. These measures have significantly increased germination capacity of the seeds on the managed plots compared to the left untreated (control) areas. Over a two-year period, the population of P. vulgaris has increased by more than 10%. The success of the measures applied allows to recommend them for the restoration of rare and highly specialized species populations growing in similar habitats.
Helianthus occidentalis is poorly studied embryologically, but it may be very useful in breeding due to its high resistance to pests and diseases. Significant variation in the viability and size of pollen grains in the samples of different origin is characteristic for this species. No essential deviations in the anther development were noticed before microsporogenesis start. Further, the following anomalies were found: late chromosomes outside of the spindle; dyads with one nucleus being degenerating on anaphase I; formation of micro- and macronuclei during the second division of meiosis; degeneration of several nuclei within a tetrad; formation of triads, dyads and monads of microspores instead of tetrads. We have noticed significant heterogeneity of pollen grains by size. Deformed and compressed ones were noticed, as well as those with the structure of dyad or tetrad of cells within their wall. There is some data in literature on similar anomalies both in plants of other taxa and in Helianthus plants, mainly of the hybrid origin. One of the supposed reasons of the multiple anomalies in development and deterioration of pollen quality in the sample of H. occidentalis under investigation is a possible introgression of chromosomes from one of closely related diploid species as a result of hybridization that took place in the natural population. The conducted study once again confirms the need for cytological analysis to identify potential pollinating plants for sunflower breeding.
St. Petersburg is the largest city in the world north of 60° N. Urban areas neighbor on relatively undisturbed sites with natural south taiga landscapes (about 30% of the city area). The conventionally primary vegetation is represented by spruce, pine and black alder forests, different types of bogs, maritime meadows, coastal-aquatic vegetation. Secondary vegetation includes small-leaved forests and upland meadows. For many years, comprehensive environmental surveys of the city territories have been carried out in St. Petersburg in order to justify the feasibility of creating natural protected areas there. Currently, there are 17 protected areas of regional status in St. Petersburg with a total area of 92 km2. Another 17 territories (about 70 km2) have been surveyed and recognized as having a high conservation value. One of the tasks of geobotanical research is to identify plant communities rare in the city and needing protection. The existence of these communities is due to a number of factors related to the geographical location and history of the city’s development. The conservation value of communities The communities conservation value is based on their rarity and is determined by a number of criteria. Based on these criteria, four categories are proposed: floristic (dominance of a rare species), structural (combinations of structural components formed by species with contrasting ecological-coenotic characteristics), ecotopic (presence of rare ecotopic conditions), rare communities (encountered 1 to 3 times over the entire research). Totally, more than twenty types of rare communities have been identified. The first category includes communities with the species listed in the Red Book of St. Petersburg – Myrica gale, Viola uliginosa and Euphorbia palustris. The second category includes forest communities of Kotlin Island with structural features of the lower layers. The third, largest category includes small-leaved nemoral forb forests, maritime meadows, extrazonal broad-leaved forests and hazel bushes. Their existence is determined by rare ecotopic conditions, which depend on the coastal position and geological and geomorphological features of the city. The fourth category includes old-growth spruce forests, plant communities with rare species Equisetum hiemale and Carex brizoides, and unique for the city ridge-hollow-lake complex on the Sestroretskoye bog. The location within the city, characteristic habitats and dominants of the layers are described for each community. For many types of communities, tables with relevés are provided.
Helianthus occidentalis is poorly studied embryologically, but it may be very useful in breeding due to its high resistance to pests and diseases. Significant variation in the viability and size of pollen grains in the samples of different origin is characteristic for this species. No essential deviations in the anther development were noticed before microsporogenesis start. Further, the following anomalies were found: late chromosomes outside of the spindle; dyads with one nucleus being degenerating on anaphase I; formation of micro- and macronuclei during the second division of meiosis; degeneration of several nuclei within a tetrad; formation of triads, dyads and monads of microspores instead of tetrads. We have noticed significant heterogeneity of pollen grains by size. Deformed and compressed ones were noticed, as well as those with the structure of dyad or tetrad of cells within their wall. There is some data in literature on similar anomalies both in plants of other taxa and in Helianthus plants, mainly of the hybrid origin. One of the supposed reasons of the multiple anomalies in development and deterioration of pollen quality in the sample of H. occidentalis under investigation is a possible introgression of chromosomes from one of closely related diploid species as a result of hybridization that took place in the natural population. The conducted study once again confirms the need for cytological analysis to identify potential pollinating plants for sunflower breeding.
The article characterizes psammophytic herb communities on fallow lands, treated as two new associations Berteroo incanae–Hieracietum umbellati ass. nov. and Polytricho juniperini–Viscarietum vulgaris ass. nov. within the class of psammophytic herb vegetation Koelerio–Corynephoretea canescentis Klika in Klika et Novák 1941. Their communities represent secondary vegetation at different stages of regenerative succession on the site of oligotrophic pine forests. Based on floristic comparison, assessment of ecological regimes of community habitats and NMDS-ordination of coenofloras based on the H. Ellenberg’s optimal scales, the differences between the new syntaxa of the Southern Nechernozemye (Non-Chernozem region) of Russia from previously established European units are demonstrated.
The vegetation of swampy lakes in the Caucasus is considered using the example of Khmelevsky lakes, located on the territory of the Sochi National Park (Krasnodar Territory). On Khmelevsky lakes, different stages of mire formation are observed, from open lakes to mires originated from completely overgrown lakes. Five associations of mire vegetation and one of coastal-aquatic vegetation were identified. The communities of these associations form the following belts on overgrowing lakes: a swampy mineral shore covered with communities of ass. Cariceto rostratae-Sphagnetum jensenii, Cariceto rostratae-Warnstorfietum fluitantis, Junceto-Polytrichetum communae; watered sites occupied by thickets of ground-rooted sedges (ass. Caricetum rostratae) or covered with sedge-sphagnum floating mats formed by communities of ass. Cariceto rostratae-Sphagnetum jensenii or Cariceto rostratae-Sphagnetum flexuosi; open water, in some places with coastal-aquatic communities ass. Eleocharitetum austriacae. For the first time in the Caucasus, communities with the moss cover dominated by Sphagnum jensenii and species of the genus Polytrichum have been described. Based on research materials by V.V. Akatov (1987) and satellite images, the dynamics of stabilization of floating mat on one of the lakes and overgrowing of another lake were traced. A strong negative impact of grazing was noted.
Pulsatilla vulgaris is one of the rarest vascular plant species in Russia. In the Red Data Book of the Russian Federation, it is classified as critically endangered (category 1). The only population of P. vulgaris in Russia is known from the Leningrad Region and it is rapidly declining. The analysis of the population ontogenetic structure demonstrates low level of the population self-sustainment due to lack of seed reproduction. One of the factors that prevent P. vulgaris generative reproduction is the biotope transformation caused by succession. Typical habitats of P. vulgaris are heaths, sparse and low pine forests, dry low-grass meadows and pastures. Successful seed reproduction of the species requires the factors that inhibit woody vegetation development and lead to the damage of dense ground cover and soil (i.e. moderate grazing, weak ground fires etc.). To avoid a complete loss of the species in Russia, artificially damaged sites suitable for successful seed regeneration of P. vulgaris were formed in 2020–2021 in “Nizhnevolkhovskiy” Protected Area (Leningrad Region, Volkhovskiy District). Trees uprooting, grass vegetation removal or damage, soil damage were performed to form exposed and well-warmed sites with sparse vegetation ground cover. These measures have significantly increased germination capacity of the seeds on the managed plots compared to the left untreated (control) areas. Over a two-year period, the population of P. vulgaris has increased by more than 10%. The success of the measures applied allows to recommend them for the restoration of rare and highly specialized species populations growing in similar habitats.
Calicium notarisii and Cladonia humilis are reported as new to the lichen flora of Dagestan. Herewith the species C. humilis was not known before in the Caucasus. Descriptions of the specimens with information of their habitats, distribution and some notes are given. Morphological and chemical distinctions between C. humilis and similar species are discussed.
The article presents two little-known facts from the biography of the outstanding botanist Ivan V. Palibin: his entry, self-taught, into the milieu of professional botanists and his long-term co-operation with the Troitskosavsk-Kyakhta Branch (TKB) of the Imperial Russian Geographical Society (IRGS). In both cases, the driving motive behind his actions was a selfless love of botany and an early interest in the flora of the East Asian region, be it Transbaikalia, the Russian Far East, or northern Mongolia and Korea. The primary sources for the work were documents from St. Petersburg and Moscow archives and materials from the Proceedings of the TKB. He worked on a pro bono basis in the Herbarium of the Moscow University and the Herbarium of the Imperial Botanical Garden in St. Petersburg. In 1898 he became a member of the IRGS, which sent him to eastern Mongolia in 1899 for geographical and natural history research. During the trip the scientist established scientific contacts with the leadership of the Troitskosavsk-Kyakhta branch of the IRGS. At the request of the chairman of the department Y.D. Talko-Gryntsevich, Palibin identified plant species collected by local collectors and assisted in the preparation for publication of the department's scientific papers.
The analysis of genomic DNA polymorphism is one of widely used approaches for studying the genetic structure of natural populations. It has been successfully applied to various plants. However, many species have not yet been studied, which is primarily due to methodological difficulties in isolating well-purified and non-degraded genomic DNA. These difficulties are due to the fact that plants possess numerous bioorganic compounds (polysaccharides, polyphenols, lipids, etc.) that contaminate DNA and significantly reduce its quality. Such species include marsh waxweed (Myrica gale L.), a perennial sub-Atlantic shrub with presumably vegetative propagation (in nature, waxweed seedlings are quite rare). We developed a simple protocol for isolation of high-quality genomic DNA from waxweed leaves and performed AFLP analysis of 42 plants of this species from three subpopulations in the Lebyazhiy Nature Reserve. Using three primer pairs, we isolated 22 amplification fragments, 8 of which were monomorphic. For the remaining 14 fragments, the average level of their polymorphism was low: depending on the subpopulation studied, it varied from 0.079 to 0.129. As shown by our analysis, all three studied subpopulations are polymorphic with a predominance of two common AFLP-genotypes. The corresponding plants are apparently the vegetative descendants of the founders. The rare AFLP-genotypes (represented by just one or two plants; a total of 12 such genotypes were identified) are likely the result of mutational and recombination processes. Our data give evidence that in the life cycle and dispersal of waxweed, the role of sexual reproduction is also noticeable.
Evergreen species of temperate zone acclimate to seasonal climates by reorganizations of mesophyll cell structure including chloroplast movement as a photoprotective reaction. However the exact factor inducing structural changes is still unexplored. To reveal the specific pattern of chloroplast arrangement during the annual cycle and the effect of temperature on their movement, the mesophyll cell structure in Pinus sylvestris grown out- and indoors was studied. The serial block-face scanning electron microscopy (SBF SEM) was used for the 3D imaging of mesophyll cells to show the spatial position and shape modification of chloroplasts. It has been shown that during the growing season, chloroplasts have a well-developed thylakoid system, they are located along the cell wall and occupy predominantly the part of the cell wall faced the intercellular airspace. Chloroplast movement starts in October-November, and during the winter they aggregate in the cell lobes clumping together. At that time, the thylakoid system is reorganised and consists mainly of long doubled thylakoids and small grana. The 3D reconstruction shows that the chloroplasts are irregularly oriented, swollen, and develop multiple protrusions filled by stroma that can be recognized as stromules. In indoor plants, seasonal reorganization of the mesophyll ultrastructure does not occur suggesting low temperatures but not photoperiod and light quality induce seasonal chloroplast movement in P. sylvestris mesophyll. Finally, we indicate 3D reconstruction is a powerful tool in study of low temperature-induced change of chloroplast positioning.
This article presents the results of the first study of the morphological and genetic diversity of 6 populations of Corydalis bracteata Pers. s. l., growing in plant communities of the Krasnoyarsk forest-steppe, Western Sayan, Kuznetsk Alatau, Altai. The morphological analysis shows the division of the populations into two groups. A large elongated tuber near basal scales, large bracts and flowers, a large height of the plants unites the from the Krasnoyarsk and Western Sayan populations with a recently described species C. talpina Stepanov. These results are also confirmed by the ISSR-PCR analysis of the genetic variability of Corydalis populations. A high subdivision coefficient (Gst = 37.58%) indicates the presence of different species in the total sample. The division into two groups is also demonstrated when clustering the genotypes using the Bayesian approach implemented in the STRUCTURE 2.3.4 software. Phylogenetic analysis based on comparison of the nucleotide polymorphism of the matK chloroplast gene sequences and the rpoB-trnC intergenic spacer also has revealed differences in three nucleotides in the plant with an additional tuber. These substitutions are absent in the sequenced plants without nodules and in sequences of other species with tufts of tubers published in GenBank. Similar results of morphological and genetic analyzes prove the differentiation of populations of yellow-flowered Corydalis in South Siberia, originally assigned to the species C. bracteata, and indicate the morphological and genetic isolation of C. talpina.
For the first time, a new invasive species Artemisia verlotiorum Lamotte has been identified in the flora of Azerbaijan (western Greater Caucasus, Lankaran Lowland, Absheron and northern Lesser Caucasus). Information is provided regarding discovered populations of the species, their number, occupied area, as well as a brief description of the phytocenoses in the places where they occur.
Magadania olaënsis (Gorovoi et N.S. Pavlova) Pimenov et Lavrova is a species of the oligotypic genus Magadania, endemic to North-Eastern Asian Russia, included in the Red Data Book of the Russian Federation. Information on its distribution in the Magadan Region, phytocenotic confinement and some features of biology is given. The herbarium specimens of M. olaënsis are kept in 4 herbaria: MAG – 38, VLA – 8, MHA – 5, MW – 1. The type specimen (holotypus) is deposited in VLA, the paratypes are probably lost. There are 39 specimens in digital Herbaria (MAG – 38, MW – 1). The main part of the range of M. olaënsis is located in the Magadan Region. An isolated locality on the Dzhugdzhur Ridge in the Khabarovsk Territory is also known, 730 km away from the nearest localities in the Magadan Region (Island Spafaryev). The identified area of the range of M. olaënsis in the Magadan Region is about 390 km2. The largest part of the range (about 380 km2) is located on the Okhotsk–Kolyma watershed on the Ola Plateau, where the area of habitats with the highest population density (2500–3000 per km2) is about 1.5 km2. Habitats on the coast of the Sea of Okhotsk take 4–5 km2, and on the islands – 0.1–0.5 km2. The total number of populations is approximately 4000–8500: 3500–7500 on the Okhotsk–Kolyma watershed, 600–900 on the coast, and about 50 plants on the islands. olaënsis is a perennial monocarpic plant. The formation of generative shoots occurs at the age of 5–10 years. The number of generative plants in the populations is approximately the same in different years. However, there was the season when generative plants were missing in the populations on the coast. In a plant at the generative stage, in addition to the central inflorescence, 2 lateral inflorescences are usually formed (somewhat less often none or one, rarely 3–5 lateral inflorescences), but the seeds on them, even if formed, rarely reach full maturity. Real seed productivity varies significantly from year to year from 0 to 694, and averages from 146 to 326 mature seeds per plant. Seeds do not germinate at temperature +18...+22°С. The total germination percentage after two periods of stratification was 84±3.7%. Seeds of M. olaënsis are in dormancy of different depths and probably only partially germinate in the next growing season, while the rest germinate over the next few years. olaënsis grows mainly in herb-shrub or shrub tundra, less often on open gravel screes at altitudes from over 700 to 1300 m a. s. l. (Okhotsk–Kolyma watershed, Zavyalov Island), or in communities with a large participation of forbs at 50–350 m a. s. l. (Atargan-Kharbiz coast, Spafaryev Island). The main limiting factors are a strict ecological confinement of the species to basic rocks (mostly basalts), as well as exclusively seed reproduction and irregular seed renewal in different years. Magadania olaënsis is a rare species (category 3), with III priority of conservation measures. According to the categories and criteria of the IUCN Red List the species is vulnerable (Vu). It is assigned to this category on the base of criterion B2a: a species with a limited range less than 2000 km2 with a highly fragmented habitat area. Existing local protected areas in the Magadan Region do not provide protection of the species. Current data on its presence at the territory of the Dzhugdzhur Nature Reserve are contradictory and need to be clarified.
The paper analyzes data on the processes occurring before and during fertilization in flowering plants. At the gametophyte stage, the gametes are formed from haploid microspores and megaspores. They are sperms, egg and central cell. The fusion of male and female gametes occurs after the pollen tube enters any synergid. One sperm fuses with the egg cell, and another from the same pollen tube joins with the central cell. The angiosperms are likely to have four types of fertilization. These types differ in the degree of completion of syngamy. Premitotic and postmitotic types are characterized by complete syngamy, and androgamic and gynandrogamic types are inherent in incomplete syngamy. In this case, the behavior of the sperm nuclei is of great significance. They, as a rule, combine with the nuclei of female gametes (premitotic and postmitotic types), but the sperm nuclei can remain independent (gynandrogamic type) or a female nucleus is replaced by a male one (androgamic type). The premitotic type of fertilization follows the way in which the gamete protoplasts and nuclei are united before the mitosis in the zygote nucleus. As for the postmitotic type, it is carried out on a completely different basis. It is possible that in angiosperms the chromosomes of sperm and egg cell do not unite during mitosis. They further divide independently, and a diploid set of chromosomes arises in a 2-celled embryo.
A comprehensive analysis of the species composition of the steppe communities of the laccolith mountains of the Caucasus Mineral Waters region (CMW), as well as of Jinal and Borgustan ridges in the vicinity of Kislovodsk was carried out. The research area is located in the Fore-Caucasus, in the south of the Stavropol Territory, and is characterized by a high diversity of steppe-type vegetation communities. The list of the flora of the CMW steppes is based on 294 relevés of steppe vegetation, and comprises 633 vascular plant species belonging to 278 genera and 66 families, which is 28.7% of the flora of the Upper Kuma floristic region. The composition and proportions of the family and generic spectra of the studied communities characterize their floristic composition as predominantly boreal, with several features characteristic of Mediterranean floras. In the composition of the steppe communities of the study area, the leading role belongs to a group of species of boreal range types with the dominance of the Caucasian geographic element. According to the ecological-cenogenetic spectrum, the species composition of the communities of the studied steppes can be characterized as meadow-steppe, with equally represented steppe and meadow components of flora. The main dominants of the steppe communities of the CMW are cespitose grasses, with a large share of rhizomatous polycarpic herbs and tap-rooted polycarpics and monocarpics in the floristic composition. In the studied communities, six endemics of the North Caucasus and three endemics of the Fore-Caucasus were recorded. The results of the complex analysis emphasize the heterogeneity and mountain-steppe nature of the floristic composition of the studied vegetation, caused by its geographical location, a combination of a complex set of conditions (relief, parent rocks, soils, etc.), florogenesis and the history of anthropogenic impact.
This article provides information about the ultrastructure of intercellular communications in Chaetopteris plumosa. The structure and variants of plasmodesmata localization in its cells are described, data on the distances between plasmodesmata and the density of their location in cell walls are provided. In C. plumosa, both independent plasmodesmata and cell wall areas with multiple closely spaced plasmodesmata were found. Such localization of intercellular connections may represent a transitional variant between independent plasmodesmata and pit fields or another variant of plasmodesmata organization previously not described in brown algae. The arrangement of plasmodesmata in Sphacelariaceae is discussed. The plasmodesmata in C. plumosa have a structure typical of brown algae. In the longitudinal walls of the medulla, there are independent plasmodesmata, the distance between which on sections is (268 ± 147) nm (mean ± SD, n = 255). In the longitudinal and transverse walls of corticating rhizoids, plasmodesmata are often located much more densely and evenly, the distance between them is (90 ± 29) nm (n = 2863), and there are 39 ± 4 (n = 54) plasmodesmata per 1 μm2. It is advisable to classify this variant of localization of plasmodesmata as pit fields or transitional variant between independent plasmodesmata and pit fields.
For the first time, a complete annotated list of vascular plant species is provided and the local flora (LF) “Burulginsky Cape” is analyzed. It is the richest known LF in the lower reaches of the Indigirka River (262 species and subspecies, 109 genera, 41 families), including a number of the species rare in the northern Yakutia and seven species listed in the regional Red Book, as well as taxa endemic to the Arctic ×Trisetokoeleria jurtzevii Probat. and ×T. taimyrica Tzvel. The similarity of the studied flora with LFs from the East Siberian and Chukotka provinces of the Arctic floristic region (lower reaches of the Anabar, Lena, Indigirka, Kolyma Rivers, and Western Chukotka) is discussed; its type is determined as the East Siberian hypoarctic flora, with a predominance of mesophytes in its composition and with a noticeable participation of the species of arid habitats. The territory of the Burulginsky Cape LF with an area of about 200 km2 is recommended to include in the category of specially protected objects as an area of increased diversity of vascular plants.
The information is given on 8 species of vascular plants new for the flora of Sakhalin Island: Arthraxon langsdorffii (Trin.) Hochst., Carex neurocarpa Maxim., Clematis serratifolia Rehder, Digitaria ischaemum (Schreb.) H.L. Muehl., Dracocephalum charkeviczii Prob., Eriochloa villosa (Thunb.) Kunth, Geranium maximowiczii Regel et Maack., and Sisyrinchium septentrionale E.P. Bicknell. The localities of the newly found species are indicated, brief data on their geographical distribution and growing conditions are presented.
