TO THE QUESTION OF MORPHOLOGY OF MYRICA GALE L. GENERATIVE PLANTS

The distribution of Myrica gale on the coast of the Gulf of Finland is confined to regularly flooded coastal habitats, characterized by milder environmental conditions compared to the uplands and under the residual influence of the Gulf Stream. In Russia, M. gale is located on the northeastern border of the range. The study of the features of the species that contribute to the dispersal in the northern direction, and the properties of the environment that prevent such dispersal, is always of great interest. Growth in colder conditions in comparison with other members of the family, mainly inhabitants of the tropical and subtropical areas, affected the formation of such adaptations as deciduousness, changes in the structure of flowers and bark, as well as the presence of a large number of protective leaf organs. Their quantitative and qualitative analysis made it possible to establish the presence of 4 lignified parchment-like scales that do not fall completely and 6 membranous with partially lignified tops scales that stretch out while unfolding. An attempt was made for the first time to analyze the spatial structure of the shoots of the species. A sympodial growth of shoots and the phenomenon of acrotonia, as well as a spiral formation of lateral shoots, were established. In the structure of the mature generative branch of M. gale there were identified 3 types of shoots: long growth, medium and short, and also their leaf series were analyzed. Leaf series of short and medium shoots are characterized by significant asymmetry compared to leaf series of long shoots and are incomplete. The curves were constructed on the basis of such characteristics of leaf organs as their total number, length along the central vein, including the petioles (if they are presented), and internode lengths. A large number of rudiments of leaf organs determines the gradual formation of the buds, and the imperfection of the structure of the scales reflects the weak protective ability of these organs. Both features indicate the deep ancientness of the species and the difficulty in adapting to cold environmental conditions. Mature generative branches of M. gale are similar in habit to small trees, which is of particular interest in the context of modeling possible directions of adaptation during the spread of species of subtropical origin to more northern regions.

Propagation of Five Species in a Commercial-scale Submist System

The novel propagation system submist, which applies water to the bases of cuttings rather than overhead, is a promising alternative. We developed and tested a commercial-scale submist system to make this propagation system more accessible to commercial propagators. Five species, including blue star flower (Amsonia tabernaemontana), faassen nepeta (Nepeta ×faassenii ‘Six Hills Giant’), panicle hydrangea (Hydrangea paniculata ‘Grandiflora’), sweetgale (Myrica gale), and sweetfern (Comptonia peregrina), were propagated from cuttings in commercial-scale submist and overhead mist systems. Blue star flower and faassen nepeta cuttings had greater root length, root rating, and root number with the submist system. Panicle hydrangea cuttings had more roots in submist, but longer roots in overhead mist. There were no differences in rooting between the systems for sweetgale and sweetfern cuttings. The comparable or superior rooting of these five species in a submist system compared with traditional overhead mist systems is evidence that submist is a viable alternative propagation system. Water use in submist systems was 98% less than that for overhead mist systems.

Communities with Myrica gale L. in mires of the Gulf of Finland coast (St. Petersburg and Leningrad Region)

Сommunities of Myrica gale L. (sweet gale), their ecology and geography in coastal mires of the Gulf of Finland within St. Petersburg and the Leningrad Region on the Southeastern border of their range are described based on 70 relevés, made in 1981–2018. This species is included in the Red Data Books of Russia (2008), Leningrad Region (2018), St. Petersburg (2018), and Republic of Karelia (2007). The distribution of the communities in the studied area is as follows (Fig. 1) — the Yuntolovskiy reserve (the largest population), vicinity of the Lisiy Nos ­settlement, forest-park “Gagarka”, Tarkhovskiy Mys, Yuntolovskiy fo­rest-park (within St. Petersburg); vicinity of the Pesochnoe ­settlement, the Bolshoy Berye­zovyy Isl., near the port “Primorsk” (the Nor­thern coast of the Gulf of Finland) and the vicinity of Bolshaya Izhora ­settlement (Southern coast of the latter) in the Leningrad Region area. Communities are found mainly in coastal mires of various types (raised bogs, transitional mires, fens) in the place of former lagoons and in inter-dune depressions in different trophic conditions; most diverse in the last two. Communities are assigned into 12 associations, two of which with the shrub layer formed by Myrica gale. Sphagnetum myricosum galis is the most common association in transitional mires (Table 3). The communities are two-layers: Myrica gale shrub one and closed moss layer of Sphagnum species of diffe­rent ecological groups. The association is subdivided into 3 subassociations by dominanting Sphagnum species and groups of determinant species: sphagnosum angustifolii, sphagnosum flexuosi, and sphagnosum teretis. The communities of this association are located­ in newly formed mires, and their species composition is in the process of formation. These are succession stages between the fens and transitional mires. The ass. Myricetum caricosum lasiocarpae (table 4) includes communities of fens with close (50 to 80 %) Myrica gale shrub layer. Carex lasiocarpa is the dominant of the herb layer, in some communities there is the lower herb sublayer of Comarum palustre. There is no moss layer. Association Myricetum comaroso–betulosum with sparse Betula pubescens 5–12 m high tree layer is also recorded in fens (Table 4). Communities of the ass. Salicetum myricoso–paludiherbosum with the dominance of shrub willows and Myrica gale are rather widespread in coastal fens. They have closed (up to 100 %) shrub layer formed by various willows and M. gale. The composition and cover of paludal herbaceous species is variable, the only constant, sometimes abundant, species is Comarum palustre. The association is subdivided into 3 subassociations (salicosum phylicifoliae, salicosum phylicifoliae-myrsinifoliae and salicosum rosmarinifoliae-myrsinifoliae) according to the dominating willows and mire grasses. Besides the above associations with high abundance of Myrica gale, this species occurs with low abundance in the communities of other, often widespread mire associations, as their coastal variants (Tables 2–4). The discussed community types in the Leningrad Region and St. Petersburg have regional features and differ in species composition from the sweet gale communities of Western and Northern Europe. Due to the rarity in the European part of Russia communities with both low abundance and dominance of Myrica gale need protection as well as their habitats.

Chemical composition and antimicrobial activity of fruit essential oils of Myrica gale, a neglected non-wood forest product

The study aimed to establish the chemical composition of fruit essential oils of M. gale and test their activities against the selected pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii), yeasts (Candida albicans, C. parapsilosis), fungi (Aspergillus fumigatus, A. flavus) and dermatophytes (Trichophyton rubrum, T. mentagrophytes). Fruit samples from natural (Western Lithuania) and anthropogenic (Eastern Lithuania) M. gale populations were studied separately. Essential oils were isolated from dried fruits by hydrodistillation and analysed by GC/FID and GC/MS methods; enantiomeric composition of α-pinene was established by chiral-phase capillary GC. Minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) of essential oils were determined using the broth microdilution method. Plants from the natural population with a humid marine climate accumulated significantly higher amounts of fruit essential oils (3.34±0.05%) than those from the anthropogenic population with a more continental climate (2.71±0.22%). In total, 39 volatiles including α-pinene (23.52–27.17%), 1,8-cineole (17.19–18.84%) and α-phellandrene (9.47–10.03%) as main compounds were identified. Chiral analysis demonstrated that (1S)-(–)-α-pinene prevailed over (1R)-(+)-α-pinene and amounted to 94.09–95.28% of all fraction of this monoterpene. The antimicrobial study in vitro indicated that C. parapsilosis, dermatophytes and Aspergillus fungi were more susceptible to fruit essential oils of M. gale, whereas E. coli and C. albicans were weakly inhibited even at the highest essential oil concentration. The strongest growth-inhibitory and bactericidal effect of sweet gale essential oil was established on S. aureus. This could be attributed to the major essential oil compounds with known antimicrobial activity, such as α-pinene, 1,8-cineole and a-phellandrene. Keywords: Myrica gale; essential oil; chemical compounds; terpenes; enantiomers; antimicrobial.

Propagation of Sweetgale, Rhodora, and Catberry by Stem Cuttings

Sweetgale (Myrica gale), rhodora (Rhododendron canadense), and catberry (Ilex mucronata) are shrubs of eastern North America that may have potential for broader use in horticultural landscapes. Because information on their vegetative propagation is scarce, we conducted experiments over 2 years to evaluate the effects of cutting collection date, wounding, substrate composition, and the concentration of applied potassium salt of indole-3-butyric acid (K-IBA) on rooting of each species. In 2015, we collected cuttings of each species on three dates to obtain both softwood and semihardwood cuttings. Cuttings were unwounded or wounded with a razor blade, and treated by dipping into water containing K-IBA at concentrations ranging from 0 to 15,000 mg·L−1, after which they were inserted into a substrate of 3:1 perlite:peat (by volume) and placed under intermittent mist. In 2016, semihardwood cuttings of each species were all wounded, treated with K-IBA from 0 to 15,000 mg·L−1, and inserted into substrates of 100%, 75%, or 50% perlite, with the remaining volume occupied by peat. In both years, the greatest percentage of sweetgale cuttings rooted when no K-IBA was applied. K-IBA application also reduced root ratings, root dry weights, and root lengths of sweetgale. For rhodora and catberry, maximal responses for all measures of rooting occurred when 5000 to 15,000 mg·L−1 K-IBA was applied. We recommend that growers use no exogenous auxin to propagate sweetgale, and 5000 to 10,000 mg·L−1 K-IBA to propagate rhodora and catberry. Cuttings of all three species can be collected from softwood or semihardwood shoots. Finally, sweetgale can be rooted in perlite alone, whereas rhodora and catberry required the addition of peatmoss for satisfactory root development.

Three new species of Incrucipulum (Lachnaceae, Helotiales, Ascomycota) from Japan

Three new species of Incrucipulum were described from Japan: I. foliicola and I. pseudosulphurellum on Myrica gale subsp. tomentosa and I. hakonechloae-macrae on Hakonechloa macra. Disposition to Incrucipulum was justified by molecular phylogenetic analysis based on ITS-5.8S, LSU and RPB2 regions, and monophyly of Incrucipulum was also confirmed. Some apomorphic characters of Incrucipulum were identified. By addition of three new species, the genus Incrucipulum now contains 13 species.