Mertensia Maritima Research Articles

Comparison of two subspecies of a halophytic multi-use plant Mertensia maritima in vitro and ex vitro: propagation, salinity tolerance and mineral nutrition

The aim of the present study was to compare morphological and physiological responses to increasing salinity of the two subspecies of Mertensia maritima during in vitro propagation in two different systems, and subsequent ex vitro cultivation. Plants were brought into culture using seeds and further propagated on Murashige and Skoog medium supplemented with thidiazuron and naphthaleneacetic acid either on agar-solidified or liquid medium with a temporary immersion system (Plantform bioreactors). Salinity tolerance were tested both in tissue culture and with ex vitro greenhouse-cultivated plants. Low concentration of NaCl increased explant biomass in agar-solidified medium, with no negative consequences even at high concentration. However, the effect of salinity on liquid medium was genotype-specific. Explants in Plantform bioreactors showed several-fold higher biomass in comparison to that on agar-solidified medium, but the multiplication potential was not significantly affected. Ex vitro plants were negatively influenced by increasing NaCl concentration in substrate. In contrast to in vitro plants, accumulation potential of Na⁺ in ex vitro plants was low. One of adaptations to salinity at the whole plant level was maintenance of adequate tissue mineral nutrient homeostasis, as mineral nutrient concentrations were not negatively affected by increasing salinity.

Dimethyl sulphide: The oyster-like odourant of Mertensia maritima

The oyster plant (Britain) or oyster leaf (North America), Mertensia maritima (L.) Gray has a strong oyster-like odour. Headspace volatiles from fresh crushed leaves of this plant were analysed using solid phase microextraction (SPME) and gas chromatography– mass spectrometry (GC–MS). Dimethyl sulphide was detected emanating from the crushed leaves, a compound that is noted for being a major part of the odour profile of raw oysters.

Salinity and nitrogen source affect productivity and nutritional value of edible halophytes.

Saline agriculture may contribute to food production in the face of the declining availability of fresh water and an expanding area of salinized soils worldwide. However, there is currently little known about the biomass and nutrient/antinutrient accumulation response of many edible halophytes to increasing levels of salinity and nitrogen source. To address this, two glass house experiments were carried out. The first to study the shoot biomass, and nutrient accumulation response, measured by ICP-MS analysis, of edible halophyte species, including Mesembryanthemum crystallinum (ice plant), Salsola komarovii (Land seaweed), Enchylaena tomentosa (Ruby Saltbush), Crithmum maritimum (Rock Samphire), Crambe maritima (Sea Kale) and Mertensia maritima (Oyster Plant), under increasing levels of salinity (0 to 800 mM). The second experiment studied the effects of nitrogen source combined with salinity, on levels of oxalate, measured by HPLC, in ice plant and ruby saltbush. Species differences for biomass and sodium (Na), potassium (K), chloride (Cl), nitrogen (N) and phosphorus (P) accumulation were observed across the range of salt treatments (0 to 800mM). Shoot concentrations of the anti-nutrient oxalate decreased significantly in ice plant and ruby saltbush with an increase in the proportion of N provided as NH4+ (up to 100%), while shoot oxalate concentrations in ice plant and ruby saltbush grown in the absence of NaCl were not significantly different to oxalate concentrations in plants treated with 200 mM or 400 mM NaCl. However, the lower shoot oxalate concentrations observed with the increase in NH4+ came with concurrent reductions in shoot biomass. Results suggest that there will need to be a calculated tradeoff between oxalate levels and biomass when growing these plants for commercial purposes.

Plant Production and Leaf Anatomy of Mertensia maritima (L.) Gray: Comparison of In Vitro Culture Methods to Improve Acclimatization

Mertensia maritima is a commercially interesting herb with edible leaves and flowers, characterized by oyster flavor and taste. Plant propagation and traditional cultivation are challenging for this species. Therefore, the main purpose of the present study was to establish successful protocols aimed at ensuring oyster plant shoot propagation, rooting and in vivo acclimatization. Both micropropagation and rooting were tested, comparing the traditional in vitro solid substrate in jar vs. the liquid culture in a temporary immersion system (TIS) bioreactor (Plantform™). A Murashige and Skoog (MS) medium added with 4-μM thidiazuron (TDZ) and 1-μM α-naphthaleneacetic acid (NAA) was employed for micropropagation, while a half-strength MS medium supplemented with 4-μM indole−3-butyric acid (IBA) was used for rooting. Different acclimatization conditions in the greenhouse or in growth chamber were tested. Morphometric and microscopical analyses were performed on the oyster plant leaves at the propagation, rooting and acclimatization stages both in a jar and in a TIS. Micropropagation in a TIS allowed to obtain large shoots, while a great number of shoots was observed in the jar. M. maritima shoots rooted in TIS produced more developed roots, leaves with more developed waxy glands and well-formed stomata; moreover, the plants coming from the TIS showed the best acclimatization performances.

Karyology of Some Coastal and Water Plants from Far East (Russia)

Cytogenetic studies on four species of vascular coastal and water plants from Russian Far East are presented. During the present investigation the next chromosome numbers have been revealed: Gypsophila pacifica (2 n = 34), Allium sacculiferum (2 n = 32), Mertensia maritima (2 n = 24), and Nelumbo komarovii (2 n = 16). Unusual chromosome numbers for these species have not been noted but it was the first case of karyological studies of Nelumbo komarovii from the Jewish Autonomous Region and most northern habitat. The number of nucleoli in interphase nuclei of these species was counted. Interphase nuclei of studied species contain 1–4 nucleoli except in A. sacculiferum so far which have 1–2 nucleoli per cell. Different points of view on polyploidy of studied species are discussed.

Screening of Bioactive Metabolites and Biological Activities of Calli, Shoots, and Seedlings of Mertensia maritima (L.) Gray.

Mertensia maritima (L.) Gray is threatened with extinction owing to climate change, poor seed germination, and ocean warming. In vitro explant-culture is used for ex situ preservation and plantlet massive production. In vitro cell and organ cultures serve as an alternative plant material source to investigate the biological activities and phytochemical profiles of rare plants. We aimed to develop an efficient callus and shoot production protocol and investigate bioactive metabolites, antioxidants, and enzyme inhibitory potential of M. maritima calli, shoots, and in vivo seedlings. The effects of combinations of different plant growth regulators, 6-BA (N6-benzyladenine), 6-KN (Kinetin), TDZ (Thidiazuron), and NAA (1-Naphthylacetic acid), in MS (Murashige and Skoog) nutrient medium were studied. The highest callus proliferation was obtained after 5-week cultivation over a 16-h photoperiod on growth medium MS enriched with 4 µM each of 6-BA and NAA. The medium with 2 µM 6-BA and 4 µM 6-KN had the best shoot induction rate (91.1%) with a mean of 13.4 shoots. The combination of two cytokinins (6-BA and 6-KN) was found to be effective in M. maritima shoot regeneration. The rooting frequency was 100% in ½ MS with Indole-3-butyric acid (IBA 2 µM). The number of detected compounds and chemical composition in the M. maritima shoots and seedlings extracts were similar. The total amount of phenolics in the shoots was 216.4% and 369.5% higher than in seedlings and calli, respectively. The total amount of flavonoids in the shoots was 241.1% and 429.3% higher than in seedlings and calli, respectively. The best antioxidant activity was obtained in the shoots, followed by seedlings and calli. However, the order was seedlings > calli > shoots regarding metal chelating ability. The strongest acetylcholinesterase inhibition properties were obtained in the calli, followed by seedlings and shoots. However, the tested samples can be ranked as seedlings > shoots > calli in butylcholinestrase inhibition assay. This study is the first report on the enzyme inhibitory effects of M. maritima extracts, providing valuable contributions to the scientific community.

Micropropagation and Quantification of Bioactive Compounds in Mertensia maritima (L.) Gray

The goal of this study was to establish an efficient protocol for the large-scale propagation of Mertensia maritima (L.) Gray, and evaluate the carotenoid, fatty acid, and tocopherol contents in the leaves of in vitro regenerated shoots. Surface-disinfected node and shoot tip explants were placed on semisolid Murashige and Skoog (MS) medium with 0–16 µM N6-benzyladenine (BA), kinetin, (KN), and thidiazuron (TDZ) alone, or in combination with, 1 or 2 µM α-naphthaleneacetic acid (NAA). Of the three different cytokinins employed, TDZ elicited the best results for axillary shoot proliferation. A maximum frequency of shoot initiation above 84%, with a mean of 8.9 and 4.8 shoots per node and shoot tip, respectively, was achieved on the culture medium supplemented with 4 µM TDZ. A combination of TDZ + NAA significantly increased the percentage of multiple shoot formation and number of shoots per explant. The best shoot induction response occurred on MS medium with 4 µM TDZ and 1 µM NAA. On this medium, the node (93.8%) and shoot tip (95.9%) explants produced an average of 17.7 and 8.6 shoots, respectively. The highest root induction frequency (97.4%) and number of roots per shoot (25.4), as well as the greatest root length (4.2 cm), were obtained on half-strength MS medium supplemented with 4 µM indole-3-butyric acid (IBA). The presence of six carotenoids and α-tocopherol in the leaf tissues of M. maritima was confirmed by HPLC. Gas chromatography-mass spectrometry analysis confirmed the presence of 10 fatty acids, including γ-linolenic acid and stearidonic acid in the leaf tissues of M. maritima. All-E-lutein (18.49 μg g−1 fresh weight, FW), α-tocopherol (3.82 μg g−1 FW) and α-linolenic acid (30.37%) were found to be the significant compounds in M. maritima. For the first time, a successful protocol has been established for the mass propagation of M. maritima with promising prospects for harnessing its bioactive reserves.

Volatile Composition of Oyster Leaf (Mertensia maritima (L.) Gray)

Oyster leaf (Mertensia maritima), also called vegetarian oyster, has a surprising oyster-like aroma. Its volatile composition was investigated here for the first time. In total, 109 compounds were identified by gas chromatography-mass spectrometry (GC-MS) and quantified by GC-FID. The use of GC-olfactometry on both polar and nonpolar columns allowed the detection of the molecules having an oyster-like, marine odor. Four compounds were identified and confirmed by synthesis: (Z)-3-nonenal, (Z)-1,5-octadien-3-ol, (Z,Z)-3,6-nonadienal, and (Z)-1,5-octadien-3-one. After evaluation of freshly prepared reference samples, these compounds were confirmed to be reminiscent of the oyster-like marine notes perceived in the tasting of cut leaves.

Production of allantoin, rabdosiin and rosmarinic acid in callus cultures of the seacoastal plant Mertensia maritima (Boraginaceae)

A callus culture of the extreme halophyte seacoastal plant Mertensia maritima (Boraginaceae) was established from apical shoots of the plant using a modified Murashige and Skoog medium supplemented with 6-benzyladenine (0.5 mg/L) and α-naphthaleneacetic acid (2.0 mg/L). Three main compounds, (−)-R-allantoin, (+)-rabdosiin and rosmarinic acid, were isolated from extracts of M. maritima calli by liquid chromatography and identified by 1H and 13C NMR, UV, ECD and HPLC–MS. Quantitative HPLC analysis showed that the calli produce (+)-rabdosiin (0.14% dry wt), rosmarinic acid (0.74% dry wt) and (−)-R-allantoin (3.7% dry wt). Allantoin was detected in plant cell cultures for the first time. All of these metabolites were also present in lower quantities in different parts of the plant. The presence of rabdosiin and rosmarinic acid, in combination with the skin-conditioning agent (−)-R-allantoin, represents a potentially useful novel composition for skin protection.

Plants and Insects New to Sable Island, Nova Scotia

During recent inventories, particularly in 2008 and 2009, 8 plants and 17 insects were found that are additions to the flora and fauna of Sable Island, respectively. Additions to the flora include Alnus incana subsp. rugosa, Carex nigra, Frangula alnus, Isoetes tuckermanii, Linaria vulgaris, Mertensia maritima, Panicum dichotomiflorum, and Solidago rugosa. Additions to the insect fauna include Apateticus bracteatus, Barce fraterna, Carabus maeander, Conocephalus fasciatus, Danaus plexippus, Eulithis explanata, Haliplus cribrarius, Harmonia axyridis, Lasioglossum novascotiae, Lateroligia ophiogramma, Lycophotia phyllophora, Muirodelphax arvensis, Nemoria rubrifrontaria, Neoconocephalus retusus, Paraphlepsius irroratus, Scaphytopius acutus, and Spilodiscus arcuatus. The occurrence of Spilodiscus arcuatus is of interest with respect to an apparent decline throughout much of its range. Neoconocephalus retusus and species of Catocala provide an indication of the capability of storms to transport even large insects over substantial distances. The increasing numbers of Danaus plexippus observed may be part of a trend toward the northward movement of migratory insects. Some of the 7 plants are likely recent arrivals, but Isoetes tuckermanii and others may have been previously overlooked.

644. MERTENSIA MARITIMA

Summary.The Mertensia maritima aggregate is discussed, with the primary focus on M. maritima (L.) Gray sensu stricto which is illustrated and described. Its highly specialised habitat is examined and some unusual physical adaptations noted, together with its history, occurrence in ethnobotanical records, and reported performance in cultivation. Some problems encountered in attempting to clarify the nomenclature and taxonomy of the aggregate are discussed, notably those concerning the segregates M. maritima subsp. asiatica Takeda, and Mertensia simplicissima G.Don.

Genetic variation and biogeography of Mertensia maritima (Boraginaceae)

To elucidate the population dynamics and biogeographic connections of Mertensia maritima in the North Atlantic we studied the genetic variation within and among 16 local populations in the Oslofjord region (south‐east Norway), Finnmark (northern Norway), Iceland and Svalbard, using starch gel isozyme electrophoresis. We also tested the self‐compatibility experimentally. Mertensia maritima was found to be self‐compatible and able to self‐pollinate by autodeposition. The total level of genetic variation was extremely low. All the screened individuals were homozygous at all loci. All individuals from the populations of mainland Norway and Iceland were isozymatically identical, whereas individuals from Svalbard differed from these at three loci (AAT‐1, PGM‐3 and SKD‐2). The genetic identity between any population at Svalbard and any population on the mainland was 0.86. These genetic patterns may have resulted from a combination of inbreeding, frequent local population extinctions, and long‐distance dispersal. The isozymatic distinctness of the Svalbard populations is consistent with the arctic distribution of the morphologically based var. tenella, here raised to subspecific rank as Mertensia maritima ssp. tenella.

Diaspore ecology ofMertensia maritima: effects of physical treatments and their relative timing on dispersal and germination

This paper reports an experimental study of water dispersal potential and germination of the shingle beach plantMertensia maritimain which we consider the effects of physical factors (cold treatment, mechanical wear of the pericarp and salt‐water exposure) on the diaspores. Our approach also includes testing effects of different orders of the treatments, in contrast to most earlier studies of diaspore ecology. A cold period was necessary to break seed dormancy, and prolonged cold treatment (stratification at 2°C) enhanced germination. Mechanical wear of the pericarp before cold treatment did not affect germination, whereas mechanical wear after cold treatment increased germination significantly. Seeds exposed to 6 weeks of cold treatment before floating in salt water for 6 weeks did not germinate. In contrast, for seeds given the same cold treatment after floating, the germination was more than 50%. Most undamaged and slightly damaged nutlets stayed afloat throughout the dispersal experiment (9 weeks) in 3% salt water, whereas seeds that fell out of damaged nutlets sunk immediately. Thus, the results suggest that the potential for long‐distance dispersal is high unless the diaspores (nutlets) are severely damaged, but the order of cold treatment and water dispersal seems to be of great importance for germination: seeds dispersed in autumn (before cold periods) have a much higher probability of germinating than seeds dispersed in winter or early spring (after a cold period). Similar effects of the relative timing of physical processes have hitherto only been reported for two other water‐dispersed beach plants. Future studies in diaspore ecology should consider such timing effects as they may be important determinants of the distribution and abundance of plants.

Numerical classification of the coastal vegetation of Attu Island, Aleutian Islands, Alaska

Abstract. This phytosociological study of the beaches, dunes, and associated lower mountain slopes of Attu Island is the first effort to identify the major coastal vegetation types of the Aleutian Islands using numerical methods. It is the first attempt to use the relevé method in southern coastal Alaska and provides a basis for future comparison with other areas. 76 relevés represent the range of structural and compositional variation in the matrix of vegetation and landform zonation at 16 locations. Data are analyzed by multivariate methods using the MULVA‐4 computer package and ordered with Wildi's numerical procedure to produce results similar to traditional phytosociological tabular classification. Nine major community types are distinguished in four physiognomic groups: 1. Dwarf‐shrub mire: Vaccinium uliginosum‐Empetrum nigrum; 2. Meadow: Athyrium filix‐femina‐Streptopus amplexifolius, Artemisia tilesii‐Veratrum album, Elymus mollis‐Montia (Claytonia) sibirica, Ligusticum scoticum‐Elymus mollis; 3. Beach meadow: Elymus mollis‐Senecio pseudo‐arnica, Lathyrus maritimus‐Elymus mollis; and 4. Beach: Mertensia maritima and Arenaria (Honckenya) peploides. These community types are described and interpreted in response to a complex, topographic gradient. Phytogeographic comparison of Attu Island with neighboring areas suggests close relationship to the beach and beach‐meadow types of eastern Kamchatka and to the mesic meadows of the Alaskan Semidi Islands; there is a slightly lower relationship to the mesic meadows of nearby Buldir Island.

Losses and gains to the Scottish Flora

Summary Several examples are discussed of plants which have been exterminated from or introduced to Scotland as a result of human activities, and an attempt is made to draw lessons from these case histories. Four rare or threatened Scottish plants, Homogyne alpina, Mertensia maritima, Primula scotica, and Pteridium aquilinum ssy. latiusculum are considered to illustrate future plant conservation imperatives. Threats to the Scottish flora of a more “institutional” nature are discussed, and it is suggested that these point to the need for botanical societies to consider a more “campaigning” role.

Plant Colonization of a Volcanic Island, Surtsey, Iceland

Surtsey is the newest member of a group of islands named Vestmannaeyjar (Westmann Islands) off the southern coast of Iceland. All the islands are of volcanic origin with palagonite tuff or basaltic lava. The eruption, which gradually built up Surtsey, started on 14 November 1963 and lasted over 3.5 yr. The island reached the size of 2.7 km2. In the spring of 1964 the first biological observations were performed on the island and the vascular plants have been investigated annually since 1965, when the first plant was discovered growing on Surtsey. The investigation of colonization of vascular plants on Surtsey involves the study of source of available species, means of dispersal, types of habitats on the island, and performance of the plants. The amount of plant material dispersing to Surtsey is in reverse proportion to the distance to the source of available plants, the nearest one being a rock 5.1 km away, but from the mainland the distance for dispersal is over 35 km. The Surtsey ecosystem is still immature and only pioneer organisms are present. By 1986 about 23 species of vascular plants have been recorded growing there and only a few coastal species have become successful colonizers. The sandwort Honkenya peploides has been the most prolific. In 1978, it showed a tendency towards the formation of an association with lyme grass, Elymus arenarius, and later with lungwort, Mertensia maritima. A study of the establishment of vegetation by pioneers

Root Respiration and Temperature Limits to the North-South Distribution of Four Perennial Maritime Plants

Summary Two northern coastal plants in the British Isles which do not occur south of the 15°C July isotherm Ligusticum scoticum and Mertensia maritima were compared in their temperature-respiration responses with two southern species. The southern species which do not occur north of the 4 °C January isotherm were Crithmum maritimum and Limonium binervosum. The over-wintering roots of the northern species had higher respiration rates than the southern species at all the temperatures tested (5—30°C). Arrhenius plots of temperature against respiration rate gave straight lines in the range 7—30°C for the southern species but showed consistent breaks in the 18—20°C range for both the northern species. Energy of activation values were therefore always lower above 20°C for the northern species. In spite of this declining response to temperature above 20°C it was estimated that the carbohydrate reserves would be reduced by 50% in the over-wintering roots twice as rapidly in the northern species as in the southern, irrespective of the temperature at which it was measured. This inability to conserve over-wintering carbohydrate supplies at high temperatures is suggested as a possible reason for the geographical limitation in the distribution of these northern species.

Breeding Bird Distribution and Abundance in the Barren Islands, Alaska

Tidal currents of considerable velocity occur in the Barren Islands with the flood current setting approximately northwestward and the ebb southeastward (U.S. Coast and Geodetic Survey 1964). Severe tide rips and strong winds occur in the vicinity of the islands and are frequently dangerous for small vessels. The wind and ocean currents among the islands are usually much stronger than a few miles away. Tide rips produce upwellings where food for marine birds and mammals is more readily available. Slack waters do not occur in the Barrens at the change of tides, and tidal vicissitudes exceed 20 feet at certain times of the year. Although Homer is only 55 miles from the Barren Islands, the climate in the Barrens is probably more similar to that of Kodiak, 80 miles distant. Homer is in the lee of the Kenai Mountains and thus receives an average of only 23.06 inches of precipitation compared to 56.71 inches per year in Kodiak. The annual mean temperature for the Barren Islands is probably about 40°F, as annual means for Kodiak and Homer are 40.7 F and 36.5 F, respectively. The annual mean wind velocity in the Barrens is surely considerably higher than that of Kodiak where it is 10.1 mph. The prevailing wind direction most of the year is northwest in Kodiak and northeast in Homer. Cloud cover, mainly fog, is most extensive in the Barren Islands region during spring and summer. Sky obscuration in Kodiak ranges from an average of 61 percent in January to 84 percent in May. Beach plant communities in the Barren Islands are composed mainly of Elymus arenarius mollis, Honckenya peploides, Mertensia maritima, Lathyrus maritimus, and Senecio