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This paper presents new data on the species of genus Vaucheria in Russia from analysis of original and museum collections. In total, 20 species were identified in 152 locations of 22 administrative regions of the European Russia, Western Siberia, and the Russian Far East. Vaucheria lii, a rare multiregional species new to Russia, has been found in 6 locations of the Vologda, Moscow, Nizhny Novgorod, Yaroslavl regions and North Ossetia. V. cruciata, V. schleicheri, V. taylorii, V. uncinata were recorded for the European Russia for the first time. V. birostris and V. pseudogeminata are new records for Western Siberia. Rank of V. terrestris var. nuoljae was raised up to separate species with V. terrestris var. major as a new synonym. The distributions of the frequently reported species, V. dichotoma and V. geminata, are critically analyzed.

CRISPR/Cas genome editing of plants is realized in three basic variants, including knockout mutations as indels, insertion of alien DNA fragments, and base editing via deamination of nitrogenous bases. The most important stages of the CRISPR/Cas-based genome editing are the choice of a target site, design of guide RNAs, creation of genetically engineered constructions, and delivery of CRISPR/Cas components into a plant cell. Rapid developments in the field of plant genome editing with the use of CRISPR/Cas systems requires more detailed consideration of the last stage, so this review is dedicated to the description of the main ways to deliver CRISPR/Cas components into cells of higher plants. In the first studies on the genome editing of different plant species, these components were delivered to the target site mainly by Agrobacterium tumefaciens. This approach supposes integration of T-DNA into a genome and a stable expression of CRISPR/Cas components or their transient expression in the case of agroinfiltration. Another widespread approach included the use of plant viruses as delivery platforms; in this case, viruses were used mainly for production of an increased amount of guide RNAs that significantly improved the efficiency of genome editing. Another approach provides for the use of another bacterium, A. rhizogenes, as a platform for delivery of CRISPR/Cas components. This bacterium induces hairy root formation that may be an indirect confirmation of successful genome editing and assist in the selection of genetically modified forms. Other common ways to obtain genetically edited plants are the biolistic delivery of genetically engineered constructions into explants and various protoplast transformation technologies. The review also considers some issues transgenic and GM status of CRISPR/Cas-edited plants to transgenic and GM plants. There are a number of cases in which new organisms created by a CRISPR/Cas genome editing without any introduction of alien DNA were not considered as transgenic ones; it is quite possible that such plants will not fall under Russian legislation prohibiting GMO cultivation.

We present current information on the conservation of aquatic vascular plants in West and East Siberia and the Russian Far East. This includes the region from the Ural Mountains in the west to the eastern seaboard of Russia from Kamchatka and Chukotka in the north to Vladivostok in the south, including Sakhalin, the Kuril and Commander Islands. A list of aquatic vascular plant species protected in the region is presented with an indication of their conservation status derived from regional Red Data Books, combined with population trend data from the literature, as well as field observations made by the authors. The region as a whole supports a total of 246 aquatic plant species, of which 96 are listed as threatened in regional Red Lists. The main threats to these species are habitat degradation, eutrophication and pollution of water bodies as a consequence of human activity and climate change. Many species which are specialized, relict or endemic, and others occurring here on the edge of their range, are vulnerable because of these factors. The main conservation action needed includes protection of natural habitats, establishment of monitoring protocols for the most severely threatened species and research into the autecology of threatened species. There is also a need to resolve taxonomic questions obstructing conservation.

Plant infection with Agrobacterium rhizogenes leads to the development of a hairy root disease notable for the rapid agravitropic growth of roots on hormone-free nutrient media. In order to look into the interaction of A. rhizogenes with plants and assess opportunities of practical application of hairy root culture, new approaches to their production are elaborated. A method of bacterium-free and plasmid-free production of genetically modified roots (hairy roots) by means of biolistic transformation of leaf explants with a DNA fragment (size of 5461 bp) consisting of genes rolA, rolB, rolC, and rolD are proposed. In most cases, such transformation resulted in the emergence of only adventitious roots with transient expression of rol-genes, and the growth of such roots on hormone-free media ceased in 2–3 months in contrast to genuine hairy roots capable of unrestricted growth. Molecular analysis of different systems of target genes’ expression showed an important role of transgene rolC and host gene of cyclin-dependent protein kinase CDKB1-1 in the maintenance of rapid growth of hairy roots in vitro (in isolated cultures).

The peculiarities of root growth and stress tolerance of transgenic tobacco plants with constitutive expression of NtEXPA1 and NtEXPA5 genes, as well as plants with reduced expression of NtEXPA4 gene encoding α-expansins of Nicotiana tabacum, were studied during prolonged cultivation under conditions of drought, salinity, and low positive temperatures. Increased expression of expansin genes led to an increase in the growth rate and root length both under normal plant growth conditions and at 12°C and 50 mM NaCl. Increased expression of expansin genes influenced the changes in the fresh and dry mass of a shoot, leading to an increase in their exposure to hypothermia. Transgenic plants with a reduced level of NtEXPA4 expansin gene expression were characterized by a reduction in the fresh and dry weight of a shoot due to drought and low positive temperatures. The totality of the data obtained may indicate the involvement of NtEXPA1, NtEXPA4, and NtEXPA5 tobacco expansin genes in the regulation of growth under hypothermia, drought, and salinity.

Possible routes in which aquatic plants have spreaded across their vast ranges from ancestral areas and refugia still remain poorly known. We have chosen Eurasian yellow water-lilies (Nuphar Sm. sect. Nuphar, Nymphaeaceae) as a model group for a wide-scale phylogeographical study as they represent a common component of the continental freshwater flora. To elucidate the history of diversification of the section Nuphar, we sequenced nuclear ribosomal ITS and chloroplast intergenic spacers (trnH-psbA, trnL–trnF) from 117 localities from almost all the section area. Sequence data were analysed with a statistical parsimony approach using the network algorithm. We also incorporated data on morphological variation and pollen viability. The section Nuphar originated and diversified into several evolutionary lineages in Eastern Asia. Two lineages, represented by N. pumila and N. lutea, spread from the Russian Far East westwards to Siberia and further to Europe. Nuphar pumila also migrated from the Far East to North America (where it is referred to as N. microphylla). Nuphar lutea colonized deglaciated north-eastern Europe not only from the south, but also from the Siberian refugia. Nuphar lutea and N. pumila hybridize rarely in Eastern Europe and Asia and warrant species status. We provide the first evidence, based on a phylogeographical approach, for the origin and diversification of aquatic flowering plants in Eastern Asia. Our results indicate that phylogeographic analysis on the area-wide scale is one of the most efficient ways to deduce possible routes in which aquatic plants have spread across their total range from ancestral areas and refugia.

The expression level of the gene PtrXTH1 encoding xyloglucan endo-transglycosylase in the leaves of Populus tremula L. of wild-type and in response to exogenous phytohormones treatment was analyzed. The highest level of transcripts of PtrXTH1 was detected in young, intensively growing leaves of aspen. In young aspen leaves, the expression of PtrXTH1 was induced by cytokinins, auxins, and brassinosteroids. The content of PtrXTH1 transcripts increased under the constitutive expression of the PnARGOS-LIKE gene. Bioinformatic analysis of PtXTH1 putative promoter region in P. trichocarpa Torr. and A. Gray ex. Hook showed the presence of cis-regulatory elements associated with the regulation of growth and stress resistance. To determine the role of the gene under study, we also created transgenic tobacco plants with constitutive expression of the PnXTH1 gene (the ortholog of PtrXTH1 from the black poplar P. nigra). Transgenic tobacco plants were characterized by an increase in leaf size and fresh and dry weight of the aboveground part under normal growth conditions. When grown under conditions of salinization and drought, transgenic plants were distinguished by increased stress resistance due to the maintenance of cell expansion in roots and stems at a higher level and the ability to more effectively retain water in leaves compared with wild-type plants.

We identified a Populus nigra auxin-regulated gene involved in organ size (PnARGOS)-LIKE, encoding one organ size related protein in black poplar. It is homologous to AtARGOS and AtARGOS-LIKE genes of Arabidopsis thaliana. ABRE-like, G-box, GATA and I-box motifs were discovered in the promoter region of the poplar ARGOS-LIKE gene. In wild type aspen (Populus tremula) plants, an ortholog of the PnARGOS-LIKE gene (PtrARGOS-LIKE) was noticeably expressed in actively dividing and expanding young leaves and calli, whereas its mRNA content increased in response to exogenous 6-benzylaminopurine, 1-naphthaleneacetic acid, and 24-epibrassinolide. Expression of the PtrARGOS-LIKE gene was reduced under a salinity treatment. In addition, we generated transgenic tobacco and aspen plants with an up-regulated expression of the PnARGOS-LIKE gene. A constitutive expression of the gene contributed to an increase in size of stems and leaves of the transgenic tobacco plants. In the transgenic aspen, a constitutive expression of the PnARGOS-LIKE gene promoted an increase in the frequency of leaf initiations and in leaf length and area. The size of transgenic tobacco and aspen leaves increased due to the enlargement of individual cells. The results show the significance of the PnARGOS-LIKE gene for control of leaf initiation and organ growth by cell expansion in poplar.

The Nicotiana tabacum AINTEGUMENTA-like gene (NtANTL), encoding one of AP2/ERF transcription factors, is a putative ortholog of the AtANT gene from Arabidopsis thaliana. In wild-type tobacco plants, the NtANTL gene was expressed in the actively dividing young flowers, shoot apices, and calluses, while the level of its mRNA increased considerably after treatment with exogenous 6-benzylaminopurine, indoleacetic acid and 24-epibrassinolide. We found a positive correlation among the expression levels of NtANTL, cyclin NtCYCD3;1 and cyclin-dependent kinase NtCDKB1-1 genes, suggesting possible molecular links between AINTEGUMENTA and cell cycle regulators in tobacco plants. However, no correlation was observed between NtANTL, NtCYCD3;1 and NtCDKB1-1 expression levels in response to NaCl and ABA. These observations indicate that the transcription factor NtANTL was not involved in the regulation of the cellular response to salinity nor did it affect the expression of NtCYCD3;1 and NtCDKB1-1 when tobacco plants were exposed to salt stress and ABA. In addition, we generated transgenic tobacco plants with both up-regulated and down-regulated expression of the NtANTL gene. Constitutive expression of the NtANTL gene contributed to an increase in the size of leaves and corolla of transgenic plants. Transgenic plants with reduced expression of the NtANTL gene had smaller leaves, flowers and stems, but showed a compensatory increase in the cell size of leaves and flowers. The results show the significance of the NtANTL gene for the control of organ growth by both cell division and expansion in tobacco plants.

Aegagropila linnaei (Chlorophyta, Cladophoraceae) is reported for the first time for the territory of the Udmurt Republic from Pazelinskiy Bay of Izhevsk Reservoir. The habitat description and morphological characteristics of the alga are provided. It is suggested that the species is threatened in the habitat. A. linnaei is recommended to include in the Red Data Book of the Udmurt Republic.

The effect of cadmium acetate (200 and 400 μM Cd(CH3COO)2) on the transcriptional promoter activity of rice (Oryza sativa L.) phytochelatin synthase gene 900 bp in size was studied. The reporter gene of glucuronidase was placed under the control of this promoter in transgenic tobacco (Nicotiana tabacum L.) plants. For determining boundaries of this gene promoter responsive to cadmium, deletion constructs were created and their transcriptional activity was measured under the influence of different cadmium concentrations. Deletion of 189 bp from the 5′-terminus of this gene promoter resulted in some transcription activation, whereas deletion of successive 95 bp from the 5′-terminus resulted in cadmium-independent activation of the promoter.

Changes in the expression levels of tobacco expansin genes NtEXPA1, NtEXPA4, NtEXPA5, and NtEXPA6 were studied in different organs of tobacco (Nicotiana tabacum L.) as well as in response to phytohormone and stress treatments. It was shown that NtEXPA1, NtEXPA4 and NtEXPA5 transcripts were predominantly expressed in the shoot apices and young leaves, but almost absent in mature leaves and roots. The NtEXPA6 mRNA was found at high levels in calluses containing a large number of undifferentiated cells, but hardly detectable in the leaves of different ages and roots. In young leaves, expression levels of NtEXPA1, NtEXPA4 and NtEXPA5 genes were induced by cytokinins, auxins and gibberellins. Cytokinins and auxins were also found to increase NtEXPA6 transcripts in young leaves but to the much lower levels than the other expansin mRNAs. Expression analysis demonstrated that brassinosteroid phytohormones were able either to up-regulate or to down-regulate expression of different expansins in leaves of different ages. Furthermore, transcript levels of NtEXPA1, NtEXPA4, and NtEXPA5 genes were increased in response to NaCl, drought, cold, heat, and 10μM abscisic acid (ABA) treatments but reduced in response to more severe stresses, i.e. cadmium, freezing, and 100μM ABA. In contrast, no substantial changes were found in NtEXPA6 transcript level after all stress treatments. In addition, we examined the involvement of tobacco expansins in the regulation of abiotic stress tolerance by transgenic approaches. Transgenic tobacco plants with constitutive expression of NtEXPA1 and NtEXPA5 exhibited improved tolerance to salt stress: these plants showed higher growth indices after NaCl treatment and minimized water loss by reducing stomatal density. In contrast, NtEXPA4-silenced plants were characterized by a considerable growth reduction under salinity and enhanced water loss. Our findings indicate that expression levels of all studied tobacco expansins genes are modulated by plant hormones whereas NtEXPA1, NtEXPA4, and NtEXPA5 expansins may be involved in the regulation of stress tolerance in tobacco plants.

The AINTEGUMENTA gene encodes a transcription factor involved in the regulation of growth of both reproductive and vegetative plant organs. Two conserved regions of this gene were amplified and cloned in antisense orientation. The produced genetic constructs were used to obtain transgenic tobacco plants with the AINTEGUMENTA gene expression downregulated. Over half of the transgenic plants were characterized by smaller leaves, stems, and flowers with their shapes and symmetry not changed. The transgenic plants ceased to grow earlier, flowered later, and had fewer flowers than controls. The main reason for smaller organs was shown to be the lower cell number in an organ with cell sizes unchanged. The genetic constructs can be used to obtain transgenic plants of various species with smaller organs.

In the process of obtaining transgenic plants suitable for phytoremediation of heavy metal-contaminated soils, a synthetic pseudophytochelatin gene coding for a phytochelatin analog Met(GluCys)6Gly was de novo designed and cloned. Contrary to natural enzymatically synthesized phytochelatins, this peptide can be made by a template synthesis. A construct carrying the gene in question under the control of the viral constitutive 35S promoter was made on the basis of a binary vector pCAMBIA 1305.1. This construct was used to express the pseudophytochelatin gene in the model transgenic tobacco plants (Nicotiana tabacum L.), and the above plants acquired additional resistance to various cadmium concentrations.

Communities of macroscopic red algae in rivers of the Upper Volga region and adjacent territories are considered. Their classification based on the Braun-Blanquet approach is proposed. Phytocoenoses belong to the class Lemaneetea fluviatilis and the order Lemaneetalia fluviatilis. Two alliances Lemaneion fluviatilis and Batrachospermion gelatinosi separate the plant communities of fast and slow flowing waters. The first mentioned alliance includes the association Lemaneetum fluviatilis only, the second one unites the associations Batrachospermetum gelatinosi, Batrachospermetum turfosi and the community Sirodotia suecica. Almost all syntaxa are published validly for the first time. The characteristics of syntaxonomical units are given. Data on species composition, structure, ecology and distribution of the revealed phytocoenoses are presented. The communities of red algae are the most diverse in the rivers of the western part of the Vologda region, where all studied syntaxa are recorded. The plant communities of the association Batrachospermeum gelatinosi are the most common in watercourses of the region. Investigated rhodophyte phytocoenoses are rather sensitive to any changes of environmental conditions indicating the purity of river waters. They can be recommended for conservation purposes.

Expansins are non-enzymatic plant proteins breaking hydrogen bonds between cellulose microfibrils and hemicellulose polymer matrix. Each plant has many expansin genes, whose protein products participate in the regulation of plant growth and development mainly by regulating cell expansion. To analyze the effects of elevated expansin expression on the plant organ sizes, we cloned the AtEXPA10 gene from Arabidopsis thaliana and PnEXPA1 gene from Populus nigra. Transgenic tobacco plants expressing the target genes were obtained. The obtained transgenic tobacco plants were shown to have significantly larger leaves and longer stems compared to control plants. The flowers were quite insignificantly larger, but at the same time transgenic plants had more flowers. The microscopic studies showed that the organs of AtEXPA10-carrying plants were larger mainly due to stimulated cell proliferation, whereas the overexpression of the PnEXPA1 gene activated cell expansion.

The auxin-inducible gene ARGOS from Arabidopsis thaliana is expressed in growing tissues and controls the plant organ size by regulating cell proliferation and meristematic competence. The promoter of the dahlia (Dahlia pinnata Cav.) mosaic virus (DMV) resembles the well-known cauliflower mosaic virus 35S promoter but shows a higher activity in transgenic tobacco plants (Nicotiana tabacum L.). We obtained transgenic tobacco plants expressing the Arabidopsis ARGOS gene under the control of the DMV promoter. Several of the T0 generation plants exhibited an accelerated transition to flowering, a slight increase in flower size, and a significant increase in the leaf size. The T1 transgenic plants were characterized by faster growth, the increased leaf size, and somewhat enlarged flowers as compared with control plants. These phenotypic traits, as well as stability and inheritance of the transgene were demonstrated also in T2 transgenic plants.

Nitellopsis obtusa (Charophyta) is reported for the Bering Island (Commander Islands) for the first time. It is the most north-eastern record in Russia and Eurasia. The species is found in atypical habitat, in a shallow lakelet of coastal tundra. Possibility of distribution of the species by migratory water birds is discussed.

By the techniques of DNA shuffling, PCR, and restriction-ligation, chimeric forms of cauliflower (Brassica oleracea) mosaic virus (CaMV), dahlia (Dahlia pinnata) mosaic virus (DMV), and carnation (Dianthus caryophillus) etching ring virus (CERV) promoters were obtained at various combinations. Twelve chimeric promoters were cloned into pCambia binary vectors comprising the reporter GUS gene, and their activities in transgenic tobacco (Nicotiana tabacum) plants were determined fluorimetrically. 35S promoter and those of DMV (442 bp) and CERV (371 and 501 bp) were used as controls. Seven of analyzed promoters displayed higher and seven promoters lower activity in transgenic tobacco plants than 35S promoter. The highest activity was characteristic of natural DMV promoter, and the least one — natural CERV promoter 501 bp in size. The CERV promoter 371 bp in size was approximately similar in strength to 35S promoter.

Records of new and rare pondweeds (Potamogeton, Potamogetonaceae) in the rivers in the north-eastern Central Russia are reported. New localities in Kostroma Region are revealed for P. × angustifolius J. Presl, P. × nitens Web., P. P. × sparganiifolius Laest. ex Fries and P. × suecicus K. Richt. For Kirov Region P. × angustifolius, P. × nitens, P. × olivaceus Baagøe ex G. Fisch, P. × salicifolius, P. × sparganiifolius and P. × suecicus are reported for the first time. For all mentioned pondweeds the distribution, ecology and some other aspects are discussed. The record of a very rare hybrid P. × olivaceus is the first reliable collection for the flora of Russia. The hybrid pondweeds turned out rather widespread and abundant in the studied watercourses, preferring running water ecotopes (riffles, rapids).

Promoters of carnation etched ring virus (CERV) and dahlia mosaic virus (DMV) were cloned into binary vectors pCambia 1304, pCambia 1281Z, and pCambia 1291Z with reporter GFP and GUS genes. Activities of these promoters in tobacco protoplasts and transgenic plants were determined using these constructs. Histochemical GUS analysis demonstrated the absence of tissue-specificity in transgenic plants transformed with these promoters. The quantitative analysis of these promoter activities in transgenic tobacco plants, using 4-methylumbelliferone as a substrate, showed that 35S CaMV, CERV, and DMV promoters displayed approximately similar activities in transgenic tobacco plants.

Effects of salinity of nutrient solution on expression of ZmEXPA1 expansin gene and leaf growth were studied on maize plants (Zea mays L.). Rapid activation of the gene transcription was shown to precede the resumption of extension growth in leaf cells under water deficit induced by NaCl salinity. Auxins were found to accumulate in leaves during salinity treatment, the accumulation being faster than activation of ZmEXPA1 transcription. In addition, exogenous IAA was shown to enhance the gene expression. Our results indicate that the hormone is involved in regulation of cell extension growth at high salinity through the expression of expansin gene.

The effect of benzyladenine (BA) on the activation of rRNA gene transcription was studied in wheat (Triticum aestivum and T. urartu) as related to the phenomenon of nucleolar dominance and the changes in the extent of methylation of the intergenic spacers in the subgenome A. The method of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze the fragments of rDNA promoter regions amplified with the primers designed to recognize the sites of DNA isolated from BA-treated seedlings of diploid T. urartu and hexaploid T. aestivum and desaminated with metabisulfite. The subsequent genomic bisulfite sequencing of the amplification products was used to evaluate the level of methylation/demethylation of the particular cytosine residues. BA diminished methylation of cytosine residues in rDNA promoter regions to the level, which was different in two wheat species; these data presume that the transcriptional activities of rRNA genes in various wheat subgenomes depend on the extent of their methylation.

The survey of communities of the macroscopic green filamentous and yellow-green siphon algae has been carried out in some regions of Russia. Their classification according to the Braun-Blanquet ap­proach was offered. Communities were distinguished into a separate class Cladophoretea cl. nov. with the type order Cladophoretalia ord. nov. Two alliances, Cladopho­rion fractae all. nov (type of the order) and Vaucherio—Cladophorion glome­ratae all. nov., refer to algae phytocoenoses of stagnant and running waters, respectively. The first alliance consists of the asso­ciations Cladophoretum glomeratae Sauer 1937 (type of the alliance), Cladophoretum fractae Sauer 1937, Nitello—Vaucherietum dichotomae (S. Pass. 1904) Krausch 1964, Aegagropiletum holsaticae (Jöns 1934) Sauer 1937, Сladophoretum koktschetavensis Sviri­denko ass. nov. and Ulothricetum zonatae Sauer 1937. Whereas the second one includes the type association Vaucherio-Cladophoretum Weber-Oldecop ex ass. nov., also Cladophora rivularis, Vaucheria cf. geminata and Vaucheria terrestris communities and ass. Stigeo­clonie­tum tenuis (Fjerdingstad 1964) Arendt 1982. For all the syntaxonomical units the description is given and the information on composition, structure, ecology and distribution of the mentioned phytocoenoses is brought.

We have found a taxonomically unclear linear-leaved Potamogeton (section Graminifolii , Potamogetonaceae) in Central Yakutia (Asian Russia). This form resembles P . friesii and P . pusillus , two common species in the republic, and the mainly European species P . rutilus and North American P . strictifolius . These species, except P . strictifolius , did not differ by variation of the nuclear ITS region. The chloroplast markers petL-psbE and rpl32-trnL clearly separated the unclear Yakutian plants from P . friesii and P . pusillus , and the latter marker revealed similarity between the European P . rutilus and the Yakutian samples. The latter fit well within the morphological circumscription of P . rutilus . We confirmed the presence of P . rutilus in five localities in Central Yakutia and 13 more in other regions of North Asia. These records greatly extends to the east the distribution range of this species known before mainly west of the Middle Volga. Potamogeton rutilus prefers clean, mainly mesotrophic lakes with alkaline waters, and occurs in coastal areas or in limestone and sandstone catchments. The species usually grow in deep waters on silt-sandy bottom, in species-rich communities. It is sensitive to pollution and competition with more robust aquatic plants. Due to local distribution and specific habitat requerments P . rutilus can be regarded as threatened species and deserve the category Vulnerable in regional and global Red Lists.

Phalaroides arundinacea - dominated сommunities of small river sources and valleys in the Upper Volga Region correspond to the 2 associations in Braun-Blanquet system: Phalaridetum arundinaceae W. Koch ex Libb. 1931 (class Phragmito-Magnocaricetea Klika 1941, order Magnocaricetalia Pign. 1953, alliance Magno­caricion elatae W. Koch 1926) and Filipendulо-Phala­roidetum (Sambuk 1931) nom. nov. (class Molinio-Arrhe­natheretea R. Tx. 1937, order Molinietalia caeruleae W. Koch 1926, alliance Filipendulion Segal 1966). The first of them comprises phytocenoses of damp, wet or periodically flooded habitats on fresh alluvia, whereas the second one is bound to moderately moist ecotopes with richer soils. Communities of the both associations differ from similar coenoses of other regions in low species richness and small areas occupied.

In this paper Potamogeton × clandestinus (Potamogetonaceae), a hybrid between P . crispus and P . natans , is described and illustrated. Hybrid populations were discovered in the rivers Koloshma, Nozhema and Suda in the northern part of European Russia (Vologda reg., Babaevo distr.). Confirmation of the hybrid origin is based on morphological and anatomical data and independently was tested by a direct sequencing of the nuclear ribosomal ITS region and rpl32-trn L intergenic spacer of chloroplast DNA. The additive ITS sequence pattern confirmed that P . × clandestinus is a hybrid between P . crispus and P . natans . The rpl32-trn L intergenic spacer data revealed that P . crispus was the maternal parent of the hybrid. A detailed morphological and ecological description of P . × clandestinus is provided and the taxonomic differences between the new hybrid and similar taxa are outlined.

Sea-buckthorn (Hyppopha L.) transgenic roots transformed with the lectin gene were obtained using the wild-type strain of Agrobacterium rhizogenes 15834 preliminary transformed with the plasmid pCAMBIA 1305.1, which contained the full-size pea lectin gene. Effects of lectin gene expression on symbiotic responses of sea-buckthorn to inoculation with rhizobia (Rhizobium leguminosarum, pea symbiont) and actinomycetes of genus Frankia (sea-buckthorn symbiont) were studied. In sea-buckthorn seedlings, whose transgenic roots were inoculated with both microsymbionts simultaneously, atypical nodule-like structures were found along with typical actinorhizal nodules. Random amplified polymorphic DNA (RAPD) analysis of bacteria, isolated from these structures, revealed the presence of R. leguminosarum rhizobia and the absence of Frankia actinomycetes.