Syringa Josikaea Research Articles

ТЕОРЕТИЧЕСКОЕ И ПРАКТИЧЕСКОЕ ОБОСНОВАНИЕ ВЫБОРА ПОДВОЯ ПРИ ВЕГЕТАТИВНОЙ РЕПРОДУКЦИИ ИНТРОДУЦЕНТОВ РОДА SYRINGA L. (OLEACEAE) В УСЛОВИЯХ ОРЕНБУРГСКОЙ ОБЛАСТИ

The proper selection of rootstock and graft combinations in lilac introducers, in order to take full advantage of grafting, requires a thorough understanding of the synergy of cultivar-rootstock combinations, as well as the identification of factors that may influence this process. The article analyzes the results of three grafting experiments using Syringa vulgaris L. and Syringa josikaea J. Jacq. ex Rchb. seedlings and vegetative rootstocks (rooted shoots) of Syringa vulgaris L. as rootstocks. The grafting material was the dormant buds of four highly ornamental cultivars of S. vulgaris L. – ‘Au- cubaefolia’, ‘Sensation’, ‘Marc Micheli’, ‘Congo’ and the late hybrid Syringa × prestoniae МсКelveу ‘Miss Canada’. It was found that the survival rate of cultivars on a particular rootstock may depend on the systematic affiliation of the mother plants of the cultivars. The best survival rate among all studied cultivars in the climatic conditions of the Orenburg region is achieved when using rooted vegetative shoots of S. vulgaris as a rootstock (over 90%), the worst – on the seed rootstock of S. josikea J. Jacq. ex Rchb. (up to 40%). The influence of the ambient temperature and humidity at the time of oculant fusion on the survival rate of grafts using S. vulgaris L. vegetative rootstock has been demonstrated (Wilcoxon T-test, statistical significance level p <<0.05). It is recommended to select the rootstock individually for each cultivar in order to achieve maximum survival rates of lilac cultivars in the climatic and geographical conditions of the Orenburg region and/or regions with similar conditions.

Analysis of the ecological state of urban green spaces in the Medeu district of Almaty

This article examines the environmental problems of the cities of Kazakhstan, using the example of the Almaty metropolis, where, with the development of the urbanization process, the natural environment in cities is changing very much, which is characterized by a specific ecological environment with a special type of circulation of substances and energy, not typical of natural communities. The importance of green spaces in urbanized areas is very difficult to overestimate. Green plants play a major role in protecting the population of large cities from dust, smoke and harmful gases. In the city of Almaty, more than 70 species of trees and shrubs were introduced into production recommended by the botanical garden. Of the trees, these are Phellodendron amurense, Faidherbia albida, Crataegus sanguinea, Crataegus maximowiczii, Crataegus submollis, Crataegus punctata, Crataegus chrysocarpa, Ulmus laevis, Ulmus glabra, Gleditsia triacanthos, Catalpa bignonioides, Aesculus hippocastanum, Acer ginnala, Acer platanoide s, Acer saccharum, Juniperus virginiana, Juglans mandshurica, Padus maackii, from shrubs - Amorpha fruticosa, Swida alba, Syringa josikaea, Spiraea vanhouttei, Spiraea thunbergii, Spiraea japonica and others. A detailed floristic analysis of the tree and shrub flora of the city of Almaty showed that green spaces are represented by 208 species belonging to 58 genera and 34 families. Among tree and shrub species, 54 species (20%) represent the natural flora of Kazakhstan (9 coniferous and 45 deciduous species) from 13 genera and 9 families, and 154 species (80%) are introduced species, i.e. plants grown in soil outside their natural distribution range.

Продолжительность жизненного цикла и зимостойкость древесных интродуцентов в сухостепной зоне Хакасии

The introduction of woody plants began in Siberia in the middle of the 18th century. We aimed at determining the limiting factors affecting the life expectancy and winter hardiness of introduced plants of different geographical origin in the dry-steppe zone of the Republic of Khakassia. The research objects of were plants of different geographical origin and age, growing in the arboretum of the Research Institute of Agricultural Problems of Khakassia. Long-term studies have identified the plants with the highest life expectancy from the flora of Siberia, such as Larix sibirica Ledeb., Pinus sylvestris L., Caragana frutex (L.) C. Koch.; trees from the flora of other regions, such as Pyrus ussuriensis Maxim., Crataegus maximowiczii Schneid., Salix babylonica L., Larix leptolepis (Sieb. et Zucc.) Gord., Morus alba L., Acer Semenovii Rgl. et Herd., A. tataricum L., Fraxinus lanceolata Borkh., A. negundo L. and shrubs, such as Corylus heterophylla Fisch. ex Trautv., Berberis tibetica Schneid., B. sphaerocarpa Kar. et Kir., Philadelphus caucasicus Koehne, Syringa Josikaea Jacq., S. vulgaris L., Eleagnus argentea Pursh. The majority of winter-resistant species are of Siberian (80 % of them are hardy) and Far Eastern (60 %) origin. The main limiting factors affecting the life expectancy of Siberian plants are found: low winter hardiness and noncompliance of edaphic conditions with the biology of the studied species; for non-regional species (in addition to the above mentioned) – low atmospheric humidity during flowering and early completion of the life cycle. The dependence of plant resistance in dry conditions on its geographical origin and ecological group has been found. The most adapted to local conditions of the dry-steppe zone of the Republic of Khakassia were representatives of Siberian and Far East flora.

The effectiveness of agrotextile cover with organic photoluminophore in rooting cuttings of Hungarian lilac (Syringa josikaea J. Jacq. ex Rchb.)

The effectiveness of the use of a light-transforming shelter of vegetation structures consisting of a polypropylene spunbond with an organic photoluminophore integrated into its structure during the rooting of physiologically active stem cuttings of Hungarian lilac was studied. The object of the study was reproductively mature Hungarian lilac plants located in the arboretum of the Nizhny Novgorod State Agricultural Academy with geographical coordinates 56°14'32.7” N 43°57'20.7”E. The unequal reaction of the tested samples of Hungarian lilac to the use of luminophore in the shelters of vegetation structures during the rooting of cuttings was established, which manifested itself in all characteristics of regeneration processes. High rates of callus formation were in the shelter variants with a higher concentration of luminophore: 73.16 ± 5.95% and 65.25± 4.80%. Lower than in other shelters, the result was recorded in the variant with the lowest luminophore density: 47.00 ± 3.62%.

ADDITIONS TO THE FLORA OF THE REPUBLIC OF MORDOVIA, RUSSIA

The biodiversity conservation is based on our knowledge of the complete composition of plants and animals within a certain area. In this paper, we present data of biodiversity research in the Republic of Mordovia (European Russia). The obtained results are reflected in six vascular plant found for the first time in the studied region. Of them, four alien taxa (Philadelphus coronarius, Rosa x majorugosa, Spiraea japonica, Syringa josikaea) are known only in the Mordovia State Nature Reserve now. This underlines the need paying our attention to alien plants that escape into the wild (naturalize) in the least disturbed ecosystems of this Protected Area. The Urtica galeopsiifolia distribution needs to be clarified in more details because of its similarity to the widely known Urtica dioica. Thus, a majority of the species under discussion are alien plants considered as cultivated plants escaping in the wild. Taking into account the newly revealed species, the vascular plant flora of the Republic of Mordovia currently includes 1,472 species. In this study, we propose the continuing the study of man-made habitats in terms of accidentally or intentionally introduced alien species, as well as the searching of hidden taxa, such as Urtica galeopsiifolia found in this study.

The composition and state of native and introduced woody species in the zone of railway transport influence in the Kola Polar region

The paper analyzes the state and the diversity of native and introduced woody plants used in landscaping railway stations in 5 cities of the Kola Polar region. The species composition is represented by 22 species, 16 genera, and 9 families. Sorbus gorodkovii (39%) is the most common among trees, Rosa rugosa (44%) is the most common among shrubs. The authors have observed two rare introduced woody species (Larix sibirica Ledeb., Syringa josikaea Jacq. fil.) included in Red Data Books of various ranks. 6 categories of plant state have been identified. Betula pubescens has the largest share of healthy plants among indigenous trees species, Malus baccata and Larix sibirica among introduced species, Rosa pimpinellifolia, Caragana arborescens, Crataegus sanguinea among shrubs in the station territories. Sorbus gorodkovii and Padus avium are in a critical state. The agrochemical soil study showed a low availability of nitrogen compounds and a high content of phosphorus and potassium exchange forms. It has been revealed that the main weakening causes are old age of plants, violation of maintenance technology, and failure to comply with environmental conditions.

Artificially Created Objects of the Nature Reserve Fund Parks-Monuments of Landscape Gardening Art and their Representativenessin the Volyn Region

Purpose. To give an objective assessment of the current ecological condition of artificially created objects of the nature reserve fund. Methods. Comparative-geographical, generalization, systematization, statistical, comparative-analytical, descriptive, cartographic. Results. Not all types of artificial objects of nature reserve fund of Volyn region are represented. There are 12 park-monuments of landscape art, 1 botanical garden, 1 zoo and no dendrological park. On the whole, the number of artificial objects of nature reserved fund in the region is the lowest in Ukraine. On the territory of the region there is an uneven distribution of artificial objects of the nature reserve fund. An analysis of the distribution of artificial objects of nature reserve fund by area revealed that the largest one is the park-monument of landscape art «Slovianskyy» (27,35 hectares). It is located in the Volodymyr-Volynskyy district. From 12 to 21,6 hectares of landscapes in Lutsk, Gorokhiv, Turiysk, Lyubeshiv and Kivertsy districts is occupied by the park- monuments of landscape art. In the Starovyzhivsky district, the area of park-monuments of landscape art is 2 hectares, while in other districts there are no areas for artificial objects of nature reserve fund. All artificial objects of nature reserve fund were created in 1960-1990. Only one park-monuments of landscape art was created in 2018. It is called «Sydorukiv Park» and is located in the city of Horokhiv. Most of the park-monuments of landscape art are located within settlements and only 2 parks are located in the territory of forestry. In total, more than 150 species of flora are protected in the territory of park-monuments of landscape art. Conclusion. As a result of the analysis, 3 species of flora were identified that grow on the territory of parks of monuments of landscape gardening art and are included in environmental lists (Epipactis helleborine, Syringa josikaea, Epipactis palustris). The most dangerous for them is tearing, digging, picking up bouquets, as well as a partial violation of the structure of ecotopes (deforestation, excessive recreation, etc.). It is proposed to strengthen the protection of these species by increasing the status of the nature conservation object and assigning them to the territories of the nature reserve fund - botanical nature reserve of local importance.

Potential for using ornamental bushes for greening the city of Novosibirsk: in case of the genus Syringa L.

Species composition, quantity participation and spreading of ornamental bushes in current system of Novosibirsk green areas are determined. Upper zone (“Verkhnyaya zona”) of Academgorodok is not taken into research as far as it is a cultural heritage site and a significant site of landscape architecture of the 20th century. Special attention is given to participation of lilac species and cultivars (Syringa vulgaris L., Syringa amurensis Rupr., Syringa josikaea J. Jacq. ex Rchb.). It is pointed out that 62 species of bushes are used in the city, including 3 species of lilac, however their quantity participation is not enough and does not satisfy regulatory limits. Twenty six cultivars from the collection Syringa vulgaris L. of the Central Siberian Botanical Garden SB RAS are recommended additionally. Three cultivars, ‘Nadezhda’, ‘Pamyat’ o S. M. Kirove’ and ‘Olimpiada Kolesnikova’, successfully tested in urban environment are highly recommended. Besides, it is recommended to use wider Syringa amurensis Rupr., and to introduce late-flowering Preston hybrids (Syringa x prestoniae Mc. Kelvey (S. reflexa x S. villosa)), curretly absent in green urban areas, in urban greening in Siberia.

Biochemical Markers of Contact with the Organic Pollutants of Urban Atmosphere in the Leaves of Woody Plants

Changes caused by contact with typical organic pollutants of urban atmosphere (formaldehyde, benzaldehyde, hydroperoxides) in the chemical composition of the leaves and shoots of woody plants are investigated. A decrease in quinic acid content and an increase in shikimic acid content were detected in the young shoots of Picea obovata Ledeb. and Picea pungens Engelm.. Investigation of changes in the chemical composition of shoots in contact with pollutants under laboratory conditions revealed that the contact with formaldehyde and hydroperoxide affects the biochemical cycle of quinic acid. High concentration of gaseous formaldehyde was found to cause an increase in the content of lactic acid in the leaves of Padus maackii (Rupr.) Kom.. In the leaves of Tilia cordata Mill. and Syringa josikaea Jacq. fil., high formaldehyde concentration caused a decrease in glycolic acid content and an increase in oxalic acid content, while after the contact with gaseous benzaldehyde this compound was detected in the leaves in rather high concentration, Analysis of the ligneous parts of plants from the territories with heavy air pollution revealed increased content of syringaldehyde, which may be a consequence of the oxidative degradation of lignin under the action of atmospheric pollutants.

Assessment of deciduous trees introduction prospect in the taiga zone (Karelia)

The article aimed at assessing introduction prospect for 32 species of the genera Acer L., Betula L., Fraxinus L., Padus Mill., Syringa L. and Sorbus L. at the Botanical Gardens of Petrozavodsk State University (Southern Karelia, central taiga subzone). The degree of introduction prospect was assessed with the use of the integral assessment method by P. I. Lapin and S. V. Sidneva. Such indicators as annual maturing of shoots, regular growth of axial shoots, winter hardiness of plants, habit preservation, shoot-forming capability, generative reproduction capability, capability to reproduce in plantation were taken into account. It was found that Acer ginnala, Acer platanoides, Betula platyphylla, Betula ulmifolia, Fraxinus excelsior, Padus virginiana, Padus pensylvanica, Padus maackii, Syringa vulgaris, Syringa pubescens, Syringa emodi, Syringa × henryi, Syringa josikaea, Syringa villosa, Syringa vulgaris var. Congo, Sorbus decora, Sorbus virginianis and Sorbus аmericana have the highest prospect rates (80–100 points), the other studied species – fairly high prospect rates (56–79 points). All the studied introduced species of deciduous trees can be successfully used in Karelia for gardening and landscaping purposes. Acer platanoides, Betula platyphylla, Fraxinus excelsior, Padus pensylvanica, Padus maackii, Syringa vulgaris и Sorbus decora show the highest degree of introduction prospect (about100 points).

Plants species for ecological landscaping in urban territory in Central Siberia

Green spaces such as parks and street trees represent a key component of urban ecosystems. Planting trees and shrubs in cities provides a number of environmental, economic, social and health benefits and also preserves biodiversity in highly urbanized areas. The key problem of the ecological landscaping in Central Siberia is to select plants species resistant both to high level of pollutants and to large variations in temperature. Basing on the comparative study of growth characteristics and physiological state of plants in natural and urban ecosystems we recommend 31 plants species of 16 families for ecological landscaping. Recommended species for ecological landscaping in Central Siberia are Abies sibirica, Acer platanoide, Amorpha fruticosa, Berberis thunbergii, Berberis vulgaris, Cornus alba, Cotoneaster lucidus, Crataegus sanguine, Dasiphora spp., Forsythia spp., Juglans mandshurica, Juniperus Sabina, Larix sibirica, Philadelphus spp., Physocarpus opulifolius, Picea obovata, Picea pungens, Pinus sibirica, Pinus sylvestris, Ribes aureum, Rosa rugosa, Salix alba, Salix ledebouriana, Salix purpurea, Sorbaria sorbifolia, Sorbus aucuparia, Spiraea salicifolia, Syringa josikaea, Tamarix ramosissima, Tilia cordata, Viburnum opulus. Coniferous plants are presented with 7 species of 5 genera. Deciduous plants are presented with 24 species of 21 genera. The list of recommended plants species includes both trees and shrubs.

The tree vegetation of the Kherson State Agrarian University Arboretum

One of the largest objects of landscaping on the territory of the city of Kherson is the Arboretum of the Kherson State Agrarian University (further the arboretum of KSAU). The harsh natural conditions of southern Ukraine caused the poor species composition of aboriginal tree plants. Therefore, on the arboretum territory the process of introduction, adaptation and naturalization of various types of ornamental plants has been carrying out for 70 years. In 1983, the Arboretum was given the conservation status of a park-monument of landscape architecture of local significance. Throughout the history of its creation, experimental research has been conducted on the introduction decorative species of trees and shrubs into the culture. Therefore, a comprehensive analysis of tree plants at the KSAU Arboretum, as well as the development of proposals for the formation of a range of tree plants for inclusion in the investigated object and for greening the city of Kherson are relevant to date.During the inventory of the species composition of tree plants in the Arboretum of KSAU, 126 species belonging to 87 genera, 44 families, 21 orders, 2 classes and 2 divisions have been identified. The Magnoliophyta division (120 species; 95.2%) prevails in the taxonomic structure of the arboretum dendroflor. The division of Pinophyta is represented by only six species (4.8%). The leading families of the given dendroflora are Rosaceae Juss. (32 species; 25.4% of the total species numnber), Salicaceae Lindl. (10 species; 7.9%), Caprifoliaceae Juss. (6 species; 4.8%), Oleaceae Lindl. (6 species; 4.8%), Ranunculaceae Juss. (5 species; 4.0%). The Families of Cupressaceae Bartl. and Fabaceae Lindl. are presented by four species each (3.2%). Other families are represented by fewer species. There have been discovered 10 life forms of tree and semi-tree plants in the Arboretum. The most numerous is a group of single-stranded deciduous trees (51 species; 40.5%) and erect deciduous shrubs (39 species; 31.0%). Most plants are erect and deciduous.The vast majority of species (111 species; 88.1%) are introduced from different parts of the world (Europe, Asia, and North America). Only 15 species of tree plants are aboriginal ones: Betula borysthenica Klok, Populus nigra L., P. alba L., P. tremula L., Quercus robur L., Corylus avellana L., Ephedra distachya L., Amygdalus nana L. and others. The analysis of the ecological structure showed that the groups of scioheliophytes (49 species; 38.9%) and heliophytes (44 species; 34.9%) predominate among the heliomorphs, xeromesophytes (56 species; 43.8%) are quantitatively predominant in the hygromorphs. Thermomorphs are represented by megathermophytes (68 species; 53.1%) and mesothermophytes (60 species; 46.9%). In relation to the trophy of the substrate, plants that grow on poor substrates – oligotrophy (86 species; 67.2%) dominate. Sozological analysis showed that in the KSAU Arboretum has plants from the Red Book of Ukraine: Betula borysthenica Klokov, the endemic of the Northern Black Sea and Syringa josikaea J.Jacq. ex Rchb., as well as species included in the List of Protected Plants in the Kherson Region: Clematis integrifolia L., Ephedra distachya L. and Quercus robur L. The dominant of formation of Amygdalieta nanae – Amygdalus nana L. grows on the territory of the Arboretum.Taking into account the climatic conditions of the city of Kherson, high solar activity during the summer period, low rainfall, temperature fluctuations during the year and seasons, as well as the microclimatic conditions of the Arboretum location, we propose to expand its range of tree plants in the future by including plants that combine decorative qualities with resistance to the environmental conditions: Magnolia soulangeana Soul.-Bod., Liriodendron tulipiferum L., Cornus alba L., Cotoneaster horizontalis Dcne. and C . multiflorus Bunge, Prunus serrulata Lindl., Cercis canadensis L., Picea pungens f. glauca , Acer ginnala (Maxim.) Maxim. and Acer platanoides L., Cotinus coggygria Scop., as well as to expand the range of glacial plants of Metasequoia glyptostroboides Hu et Cheng, Pseudotsuga menziesii (Mirb.) Franco, decorative forms of the genera Taxus L., Buxus L., Quercus L., Tilia L., Berberis L., Thuja L., Juniperus L., Chamaecyparis Spach and others. Decorative species that will grow successfully on the territory of the Kherson State Agrarian University Arboretum can be planted in other landscaping facilities of Kherson City.

Increased size of epidermal cells in Syringa josikaea Jacq. smaller leaf side as an adaptive mechanism for reducing its asymmetry

Comparative study of quantitative anatomy of the epidermis in Syringa josikaea Jacq. leaf halves of different width was conducted in order to analyze the possible mechanism of formation of the value of fluctuating leaf asymmetry. A regular decrease in the density of main epidermal cells in the smaller leaf half compared with the bigger one was traced during leaf ontogeny. Stomatal index was equal in different-sized leaf halves. Adaptive response was found in fully formed leaves; it was aimed at reducing leaf blade fluctuating asymmetry by 23% on average and consisted of compensatory growth--further elongation of main epidermal cells in the smaller half of the leaf. It was concluded that the level of fluctuating leaf asymmetry in Hungary lilac is mainly due to a lower rate of cell division, as well as due to their greater elongation in the smaller half of adult leaf compared with the bigger half.

Phylogeography ofSyringa josikaea(Oleaceae): Early Pleistocene divergence from East Asian relatives and survival in small populations in the Carpathians

Tertiary relict plant species of Europe have had a large distribution range before the Pleistocene but today are confined to small refugial areas. Syringa josikaea of the largely East Asian genus Syringa is a shrub of temperate forests in the Carpathians, restricted to altogether 25 small populations in two disjunct areas, the Apuseni Mountains (Romania) and the Ukrainian Carpathians. Miocene and Pleistocene fossil remains indicate the long-term presence of the species in Central Europe; hence S. josikaea has been considered a Tertiary relict. We aimed at clarifying the historical biogeography of S. josikaea by estimating the divergence time between S. josikaea and its Asian relatives, and by analysing intraspecific variation using multiple DNA sequences as well as microsatellites. The estimated divergence time between S. josikaea and its closest relatives based on nuclear ribosomal DNA sequences is 1.88 Mya [0.30–4.04 Mya highest posterior density], suggesting a relatively recent disruption of a formerly continuous distribution area. This time corresponds to the period of Early Pleistocene extinctions, when many Tertiary plant taxa went extinct in Europe. Sequence variation was found to be very low within S. josikaea. Complete identity among all samples in cpDNA may imply a bottleneck. Four different ribotypes found showed no geographic differentiation between the Apuseni Mountains and the Ukrainian Carpathians, and differentiation between these two areas was weak when considering microsatellite variation. Together these observations may imply that the extant disjunct distribution of the species arose only recently, either through colonization from one glacial refugial area or from disruption of one such area. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, ●●, ●●–●●.

Characterization of Nuclear Microsatellite Markers for the Narrow Endemic Syringa josikaea Jacq. fil. ex Rchb.

The species of the genus Syringa L. are among the most popular ornamental plants worldwide. One particular species, Syringa josikaea, a rare endemic of the Carpathian Mountains, is of great conservation interest. Although microsatellite markers may be useful for studying the genetic variability of varieties and populations, no microsatellites have previously been characterized for any species of the Syringa genus. Our aim was therefore to test the applicability of microsatellite primers developed for neighboring genera (Olea and Ligustrum) and to complement these with markers isolated and characterized for S. josikaea. Twelve primer pairs of Olea and Ligustrum were tested by optimizing PCR conditions and checking the variability in 40 samples of two populations of S. josikaea. Two of them proved to be easy to PCR amplify and variable at the same time. To develop new primers we constructed a microsatellite enriched library and sequenced 48 clones. 18 sequences contained microsatellite motifs, and three of the designed primer pairs presented high allele variability. The five primer pairs characterized for S. josikaea proved to be highly informative and sufficient to distinguish between individuals. These microsatellite primers are valuable tools to study genetic variation of native populations, genetic lineages of hybrids and cultivars of S. josikaea.

Biosynthesis of iridoids in Syringa and Fraxinus: Carbocyclic iridoid precursors

Feeding experiments with deuterium-labelled precursors to Fraxinus excelsior, Syringa josikaea and S. vulgaris have shown that the biosynthesis of the oleoside-type secoiridoids (e.g. oleuropein) proceeds via iridodial, iridotrial, deoxy-loganic acid aglucon and deoxy-loganic acid. Hydroxylation of the 7α-position is followed by oxidation and methylation of C-11 to give 7-ketologanin, the last carbocyclic iridoid precursor of the oleosides. The sequences of the steps between deoxy-loganic acid and 7-ketologanin may differ with plant species and time of year. 8-Epi-kingisidic acid and 8-epi-kingiside can be formed from 8-ketologanic acid (and its methyl ester). The secoiridoids, fliederoside and lilacoside, from S. vulgaris have been characterized.

Biosynthesis of iridoids in Syringa and Fraxinus: Secoiridoid precursors

Several deuterium-labelled secoiridoids have been prepared and tested as possible precursors for the iridoids in Fraxinus excelsior, Syringa josikaea and S. vulgaris. Oleoside 11-methyl ester was an efficient precursor for the oleosides, whereas secologanin-type iridoids gave only significant incorporation in S. josikaea. In this plant low incorporations into the oleosides were also seen for kingiside and 8-epi-kingiside. The major pathway to the oleosides therefore seems to proceed via a direct ring fission of ketologanin to oleoside 11-methyl ester. A Baeyer-Villiger-like mechanism which explains the different compounds found in the plants is proposed, and the taxonomy of the Oleaceae is discussed. Due to the unique presence of the usual pathway leading to secologanin and its congeners in Fontanesia, the Oleaceae is considered to be a member of the Gentiananae rather than Scrophulariales/Lamianae.

Biosynthesis of secoiridoid glucosides in oleaceae

The biosynthesis of the oleoside-type of glucosides (oleosides) has been investigated in two species of Oleaceae, namely Fraxinus excelsior and Syringa josikaea. Deuterated analogues of deoxyloganic acid, 8-epi-deoxyloganic acid, 7-epi-loganic acid and loganic acid were prepared. On administration of the above compounds high incorporations of deoxyloganic acid as well as of loganic acid and its 7-epimer were obtained, strongly implying that 7-ketologanic acid is an intermediate in the biosynthesis of oleosides. The incorporations were measured by 2H NMR in several isolated secoiridoids all belonging to the oleosides. In addition, the content of acidic iridoids (both carbocyclic and seco-type) in two additional species of Oleaceae, namely Ligustrum ovalifolium and Phillyrea latifolia, were examined. Based on these results, a plausible biosynthetic route from deoxyloganic acid, 7-epi-loganic acid, 7-ketologanic acid, 8-epi-kingisidic acid, oleoside 11-methyl ester, 7-β-1- d-glucopyranosyl 11-methyl oleoside and ligstroside to oleuropein can now be presented.

Verbascoside production by plant cell cultures

Verbascoside was found to be produced in all calli derived from eleven species that contained the compound in their leaves. Cell suspension cultures were also established in three species, i.e., Leucosceptrum japonicum f. barbinerve, Syringa josikaea, and Sy. vulgaris, all of which were found to produce verbascoside at more than 1 g/l. Of the three species, suspension cultures of L. japonicum f. barbinerve showed rapid growth and the highest yield of verbascoside (1.89 g/l). In these cultures, the effects of major salt concentration in B5 medium on cell growth and verbascoside production were examined. Maximum cell growth and maximum verbascoside production were both achieved by reducing the major salt concentration to half that of the original medium.

The Mechanism of Low Temperature Dormancy in Mature Seeds of Syringa Species

AbstractThe mechanism of seed dormancy at low temperatures (15‐9°C) was investigated in the seeds of Syringa josikaea, S. reflexa and S. vulgaris. Low temperature dormancy in Syringa species was mainly imposed by endosperm embedding the radicle. Different degrees of embryo dormancy may occur in S. reflexa seeds. In most cases the low temperature dormancy was broken completely by removing the endosperm around the radicle. The endosperm did not seem to contain significant quantities of germination inhibitors, and the results indicate that it prevents germination mainly due to its mechanical resistance. The mechanical resistance of endosperm did not change during chilling or during induction of dormancy by high temperature incubation. The strength of the endosperm decreased rapidly in non‐dormant seeds before visible germination. Similar changes were not observed in dormant seeds. Generally, the strength of the endosperm was lower in the non‐ (or less) dormant species S. josikaea and S. vulgaris than in the more dormant S. reflexa seeds. The growth potential of the embryos, measured as their ability to germinate in osmotic solutions (mannitol or polyethylen glycol 4000), was increased by chilling and by GA3‐treatment. The growth potential of untreated S. josikaea and S. vulgaris embryos was generally higher than that of S. reflexa embryos. Acid ethyl acetate fractions of methanol extracts from embryos of all three species contained substances with GA3‐like activity in the lettuce hypocotyl test. The activity was found at Rf 0.9–1.0 on paper chromatograms run in distilled water. No significant changes in the activity were detected during chilling or prior to visible germination.