Full Text Available Maximum depth of colonization (zC and total area covered by a population of Lobelia dortmanna, as well as underwater light regime were studied in 25 soft water lobelia lakes in north-western Poland. Variations in underwater light conditions among the lakes were described by Secchi disc depths (zSD, and by attenuation coefficients of irradiance within photosynthetically active radiation range (Kd,PAR, and euphotic zone depths (zEU derived from photometric measurements conducted twice a year (in midspring and midsummer during the period 2014–2015. Maximum depth of colonization of water lobelia ranged from 0.1 to 2.2 m (median zC = 0.8 m; mean zC = 1.0 m. Nine lakes showed the relative coverage of the littoral zone (RCLZ by L. dortmanna to be greater than the mean value, which was 4.8%. Studies showed that light requirements of water lobelia increase when the maximum depth of colonization also increases. This pattern could be partially related to the greater energy needs of deeper growing individuals due to enlarged seed production and their incubation, and for the creation of much heavier inflorescences. Assessment of the light requirements of L. dortmanna along the depth gradient indicates that relative irradiance (percentage of subsurface irradiance of PAR should be at the level of: (i 47–50% (annual total of quantum irradiance 3083–3280 mol m−2 yr−2 for plants growing within a depth range of 2.0–2.5 m; (ii 44–47% (2886–3083 mol m−2yr−1 for plants growing within a depth range of 1.5–2.0 m; (iii 41–44% (2690–2886 mol m−2yr−2 for plants growing within a depth range of 1.0–1.5 m; and (iv 34–41% (2230–2690 mol m−1 yr−1 for those growing in the littoral zone at a depth of between 0.5 and 1.0 m. In average conditions in the Pomeranian lakes, the maximum depth of colonization by L. dortmanna accounts for approximately a third of the Secchi disc depth and a fifth of the depth of the euphotic zone with irradiance
Full Text Available The giant lobelias in East African mountains are good models for studying molecular mechanisms of adaptation to different altitudes. In this study, we generated RNA-seq data of a middle-altitude species Lobelia aberdarica and a high-altitude species L. telekii, followed by selective pressure estimation of their orthologous genes. Our aim was to explore the important genes potentially involved in adaptation to different altitudes. About 9.3 Gb of clean nucleotides, 167,929 – 170,534 unigenes with total lengths of 159,762,099 – 171,138,936 bp for each of the two species were generated. OrthoMCL method identified 3,049 1:1 orthologous genes (each species was represented by one ortholog. Estimations of non-synonymous to synonymous rate were performed using an approximate method and a maximum likelihood method in PAML. 85 orthologous genes were under positive selection. At least 8 of these genes are possibly involved in DNA repair, response to DNA damage and temperature stimulus, and regulation of gene expression, which hints on how giant lobelias adapt to high altitudinal environment that characterised by cold, low oxygen and strong ultraviolet radiation. The negatively selected genes are over-represented in Gene ontology terms of hydrolase, macromolecular complex assembly among others. This study sheds light on understanding the molecular mechanism of adaptation to different altitudes, and provides genomic resources for further studies of giant lobelias.
P. William Hughes
Full Text Available Premise of the study: Nuclear microsatellite markers were developed for Lobelia inflata (Campanulaceae, an obligately self-fertilizing plant species, for use in the study of temporal fluctuation in allele frequency and of the genetic structure within and among populations. Methods and Results: We developed 28 primer pairs for L. inflata, all of which amplify CT dinucleotide repeats. We evaluated amplification of these loci in 53 L. inflata individuals at three sites in eastern North America and found that 24 loci showed microsatellite polymorphism. We also found that 16 loci amplified successfully in L. cardinalis, and 11 amplified successfully in L. siphilitica. Conclusions: These primers will be useful for assessing allelic diversity within and among populations of L. inflata, and show potential for use in congeneric species.
Weng Hing Thong
Full Text Available Lobelia chinensis served as an important herb in traditional chinese medicine. It is rare in the field and infected by some pathogens. Therefore, encapsulation of axillary buds has been developed for in vitro propagation of L. chinensis. Nodal explants of L. chinensis were used as inclusion materials for encapsulation. Various combinations of calcium chloride and sodium alginate were tested. Encapsulation beads produced by mixing 50 mM calcium chloride and 3.5% sodium alginate supported the optimal in vitro conversion potential. The number of multiple shoots formed by encapsulated nodal segments was not significantly different from the average of shoots produced by non-encapsulated nodal segments. The encapsulated nodal segments regenerated in vitro on different medium. The optimal germination and regeneration medium was Murashige-Skoog medium. Plantlets regenerated from the encapsulated nodal segments were hardened, acclimatized and established well in the field, showing similar morphology with parent plants. This encapsulation technology would serve as an alternative in vitro regeneration system for L. chinensis.
Chemical and biological studies of Lobelia flaccida (C. Presl) A.DC leaf: a medicinal plant used by traditional healers in Eastern Cape, South Africa. ... (85 mg/kg, intraperitoneally)-induced convulsion model in mice, normal saline and diazepam (1 mg/kg, i.p.) served as negative and positive control groups respectively.
Møller, Claus Lindskov; Jensen, Kaj Sand
• Lobelia dortmanna thrives in oligotrophic, softwater lakes thanks to O(2) and CO(2) exchange across roots and uptake of sediment nutrients. We hypothesize that low gas permeability of leaves constrains Lobelia to pristine habitats because plants go anoxic in the dark if O(2) vanishes from...... sediments. • We added organic matter to sediments and followed O(2) dynamics in plants and sediments using microelectrodes. To investigate plant stress, nutrient content and photosynthetic capacity of leaves were measured. • Small additions of organic matter triggered O(2) depletion and accumulation of NH(4......)(+), Fe(2+) and CO(2) in sediments. O(2) in leaf lacunae fluctuated from above air saturation in the light to anoxia late in the dark in natural sediments, but organic enrichment prolonged anoxia because of higher O(2) consumption and restricted uptake from the water. Leaf N and P dropped below minimum...
Ommen, Daniela Oliveira; Vinther, Hanne Fogh; Krüger, Laila
Lake Hampen is representative of a group of lakes called Lobelia lakes. These are oligotrophic, clear water lakes which tend to have a low alkalinity. These lakes are termed “Lobelia lakes” due to the characteristic isoetid species which thrive in these conditions. Isoetids are small, evergreen...... aquatic plants whose leaves grow in a rosette form and have a large root base. The large root system enables the plants to better assimilate nutrients from the sediments, and the uptake of CO2 which is used for photosynthesis, and to release O2 into otherwise anoxic sediments. Lake Hampen is situated high...... up in the Jylland ridge and lies close to the groundwater boundary. This means that the groundwater flow between the aquifer and the lake is not constant, sometimes the groundwater flows from the aquifer into the lake (discharge) and other times it flows from the lake into the aquifer (recharge...
Pulido, Cristina; Keijsers, Danny J. H.; Lucassen, E. C. H. E. T.; Pedersen, Ole; Roelofs, J. G. M.
The increase in alkalinity and SO4 2- in softwater lakes can negatively affect pristine isoetid population because the increase in alkalinity and SO4 2- can stimulate sediment mineralization and consequently cause anoxia. The consequences of increased sediment mineralization depend on the ability of isoetids such as Lobelia dortmanna to oxidize the rhizosphere via radial O2 loss. To study how alkalinity and SO4 2- affect the isoetid L. dortmanna, and if neg...
Full Text Available The paper presents the results of an investigation of physical-chemical features of water as well as rotifer and crustacean abundance and diversity measures, relating to the taxonomic richness and species diversity index, in three lobelia lakes differing in trophic status and morphometric features. The main purpose of this study was to establish the diversity of zooplankton communities in the open water area of lobelia lakes, including extracting species common for each lake and also to find environmental predictors which are responsible for the development of zooplankton communities. Despite the fact that the three studied lakes are of the same origin, located in the same vicinity and have generally similar environmental factors, zooplankton community structure revealed a great variation in reference to species diversity (only ca. 20% of the species were common for all lakes and particularly in inhabiting species. Obrowo Lake had the most diverse assemblages of both rotifers and crustaceans compared to Modre and Pomysko lakes. In the taxonomic structure species that are rare for the Polish fauna, such as e.g. Holopedium gibberum and Heterocope appendiculata, occurred. Even though the examined lobelia lakes are ecosystems that undergo varying human-induced impacts, they still remain taxonomically very variable aquatic ecosystems, containing rare species of very high ecological status. The observed symptoms of deterioration of water quality, reflected in the zooplankton biocoenotic features, showed that the best conditions were attributed to Obrowo Lake in comparison with the two remaining lakes – Modre and Pomysko. Total nitrogen and chlorophyll a concentration were decisive for the distribution of zooplankton species in Pomysko and Obrowo lakes, while in case of Modre lake water reactivity and conductivity were of higher impact.
Jorge G. Chiapella
Full Text Available Se registra por primera vez en la Argentina la presencia de Lobelia aquatica Cham., L. hassleri Zahlbr. y L. nummularioides Cham. var. prostrata (Zahlbr. E. Wimm., dos especies encontradas anteriormente sólo en la provincia de Misiones, están ahora registradas para Corrientes. La presencia de L. nana L. H.B.K. var. nana en la Argentina también es confirmada. Se proveen descripciones e ilustraciones para L. aquatica y L. nummularioides var. prostrata. Se incluye también una clave para la identificación de las seis especies presentes en el país.
Sun, Wei; Yan, Song; Li, Jingjian; Xiong, Chao; Shi, Yuhua; Wu, Lan; Xiang, Li; Deng, Bo; Ma, Wei; Chen, Shilin
There is an unmet need for herbal medicine identification using a fast, sensitive, and easy-to-use method that does not require complex infrastructure and well-trained technicians. For instance, the detection of adulterants in Lobelia chinensis herbal product has been challenging, since current detection technologies are not effective due to their own limits. High Resolution Melting (HRM) has emerged as a powerful new technology for clinical diagnosis, research in the food industry and in plant molecular biology, and this method has already highlighted the complexity of species identification. In this study, we developed a method of species specific detection of L. chinensis using HRM analysis combined with internal transcribed spacer 2. We then applied this method to commercial products purporting to contain L . chinensis . Our results demonstrated that HRM can differentiate L. chinensis from six common adulterants. HRM was proven to be a fast and accurate technique for testing the authenticity of L. chinensis in herbal products. Based on these results, a HRM approach for herbal authentication is provided.
Vodopivec, Branka Mozetič; Wang, Jing; Møller, Anne L; Krake, Jacob; Lund, Torben; Hansen, Poul Erik; Nielsen, Søren Laurentius
The foliar anthocyanin profiles of two amphibious plants, Nesaea crassicaulis and Lobelia cardinalis were analysed for the first time. N. crassicaulis produced very simple anthocyanins, achieving the highest concentrations when grown submerged. In contrast, L. cardinalis produced leaves with a high content of very complex, acylated anthocyanins, especially when growing emergent. Anthocyanins were separated by high performance liquid chromatography. Nesaea crassicaulis anthocyanins were identified according to their fragment mass spectra and ultra-visible-violet spectral characteristics and 1D and 2D NMR spectra as -3,5-di-O-β-glucosides of delphinidin, cyanidin, petunidin, malvidin and peonidin as well as cyanidine and peonidin-3-O-β-glucoside. In L. cardinalis cyanidin-3-O-[6-O-(4-O-E-p-coumaroyl-O-α-rhamnopyranosyl)-β-glucopyrano]-5-O-β-glucopyranoside was the major anthocyanin and contributed more than 98% of total anthocyanin content. The remaining 2% was made up by cyanidin-3-O-[6-O-(4-O-E-caffeoyl-O-α-rhamnopyranosyl)-β-glucopyrano]-5-O-β-glucopyranoside and pelargonidin-3-O-[6-O-(4-O-E-p-coumaroyl-O-α-rhamnopyranosyl)-β-glucopyrano]-5-O-β-glucopyranoside.
A. G. Lapirov
Full Text Available This article covers the morphology of the vegetative and generative sphere of a rare relic species, Lobelia dortmanna L. (Lobelioideae. This is the first time that using the modular approach a study has analysed the shoot system of this species and described the structures of all three categories: elementary (EM, universal (UM and basic (OM. This paper describes the life form and analyses the rhythm of seasonal development of the species in the lakes of Tver oblast, and provides data on the seed productivity. As a life form, L. dortmanna is a herbaceous polycarpic, un clearly polycentric shallow-rooted plant with a fibrous root system and non-specialized morphological disintegration. The sympodially growing shoot-system of the plant is formed by two types of different-aged anisotropic replacement shoots: dicyclic vegetative-generative semirosette and annual vegetative rosette shoots. The indicator of actual seed productivity equals on average up to 1621 ± 451 seeds per single vegetative-generative shoot. The module structure of L. dortmanna is presented by 10 variants of elementary modules. The main modules are formed on the basis of a monocarpic dicyclic anisotropic monopodial shoot with the following morpho-functional zones distinguished: 1 the lower zone of inhibition; 2 the recovery zone; 3 the upper zone of inhibition 4 the latent generative zone; 5 the main inflorescence. The functional role of the first three morpho-functional zones of a monocarpic shoot is performed by a minimum number of variants of elementary modules. In the rhythm of seasonal development, the authors distinguished 7 consecutive stages: 1 the period of relative rest; 2 vegetative phase; 3 the phase of budding; 4 flowering; 5 frui ting; 6 secondary activities. By the character of rhythm of seasonal development, L. dortmanna belongs to the group of evergreen plants with a long growing season and middle-late summer flowering.
Lenzewski, Nikola; Mueller, Peter; Meier, Robert Johannes; Liebsch, Gregor; Jensen, Kai; Koop-Jakobsen, Ketil
Root-mediated CO 2 uptake, O 2 release and their effects on O 2 and CO 2 dynamics in the rhizosphere of Lobelia dortmanna were investigated. Novel planar optode technology, imaging CO 2 and O 2 distribution around single roots, provided insights into the spatiotemporal patterns of gas exchange between roots, sediment and microbial community. In light, O 2 release and CO 2 uptake were pronounced, resulting in a distinct oxygenated zone (radius: c. 3 mm) and a CO 2 -depleted zone (radius: c. 2 mm) around roots. Simultaneously, however, microbial CO 2 production was stimulated within a larger zone around the roots (radius: c. 10 mm). This gave rise to a distinct pattern with a CO 2 minimum at the root surface and a CO 2 maximum c. 2 mm away from the root. In darkness, CO 2 uptake ceased, and the CO 2 -depleted zone disappeared within 2 h. By contrast, the oxygenated root zone remained even after 8 h, but diminished markedly over time. A tight coupling between photosynthetic processes and the spatiotemporal dynamics of O 2 and CO 2 in the rhizosphere of Lobelia was demonstrated, and we suggest that O 2 -induced stimulation of the microbial community in the sediment increases the supply of inorganic carbon for photosynthesis by building up a CO 2 reservoir in the rhizosphere. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.
Klamt, Anna-Marie; Reitzel, Kasper; Mortensen, Morten F.
Lake Grane Langsø is characterized by nutrient-poor soft water with very high visibilities and hence contains rare isoetid species (such as Isoetes lacustris, Littorella uniflora and Lobelia dortmanna). Pollen data and old maps show that the dominating vegetation in the catchment area of Lake Grane...... clearly reduced the amounts of macrofossils for Isoetes sp., Lobelia sp. and Characeans. This suggests a reduction in their maximum distribution depth because of enhanced influx of terrestrial material and subsequently reduced water transparencies. Overall this paleo-study underlines the sensitivity...... of nutrient-poor soft water lakes to changes in their catchments vegetation and their partial irreversible consequences and is therefore of importance for lake management....
Givnish Thomas J
Full Text Available Abstract Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.
Sand-Jensen, Kaj; Pedersen, Ole; Binzer, Thomas
BACKGROUND: and Aims Submerged plants possess well-developed aerenchyma facilitating intra-plant gas-phase diffusion of O2 to below-ground tissues, which are usually buried in anoxic sediments. However, aquatic habitats differ in terms of O2 fluctuations in the water column and in O2 consumption...... roots and low O2 consumption of sediments means that sediment, aerenchyma and water are important O2 sources for respiration during the following night, while Z. marina relies on the water column as the sole source of O2 because its sediments are anoxic. These differences between L. dortmanna and Z...
spectroscopy GC/MS while an infusion extract of the herb was obtained by soaking in hot boiled ... Results: EO yield was 0.022 % w/w and the two major compounds identified were acetophenone .... carrier gas, nitrogen with a flow rate of 3.0.
Frost-Christensen, Henning; Jørgensen, Lise Bolt; Floto, Franz
oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants......oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants...
This paper studies the effects of Lobelia chinensis on colon precancerous lesions and on colonic epithelial proliferation and apoptosis in. DMH-induced rats. After two weeks of feeding, 50 Wistar rats were randomly divided into five groups, namely the normal group, model group,. Lobelia chinensis low-dose group, ...
A study on the effect of aqueous extract of Lobelia chinensis on colon .... Evaluation of the toxicological profile of the leaves and young twigs of Caesalpinia bonduc ... Antimicrobial and antiplasmodial activities of a quaternary compound from ...
Alberto C. Slanis
Full Text Available The genus Diastatea (Campanulaceae, Lobelioideae is recorded for the first time for Argentina in antropic enviroments of the Yungas phytogeographic province (Jujuy, between 1,100 and 2,000 m. We describe and illustrate D. micrantha, the only species collected up to now, including a key to discern it from Lobelia xalapensis, its closest taxon.
Lobelia anaena (Hewitt, 1939), and L. trialata Buch-Ham. (Kausik and. Subramanyam, 1945b). In L. syphilitica L. (Crete, 1938) and Cephalo- stigma Schimperi Hochst. (Kausik and Subramanyam, in Press), however, it is the primary embryonal cell that divides first. In the three-celled pro- embryo the middle and basal cells ...
Klamt, Anna-Marie; Reitzel, Kasper; Andersen, Frede Østergaard
This study aims to answer the question if temporary drawdowns could be a beneficial restoration measure for endangered Lobelia lakes. Intact littoral sediment cores with and without plants were used to simulate a drawdown over an almost 5 months period and a subsequent rewetting. During drawdown...... dying of plants. Upon rewetting effluxes of total dissolved phosphorus and dissolved organic carbon were observed which are most likely attributable to the degraded plant material. A phosphorus uptake experiment with dried and rewetted sediment cores without plants showed that the initial high P binding...
Winkel, Anders; Borum, Jens
freshwater plants with different morphology and growth characteristics (Lobelia dortmanna, Lilaeopsis macloviana, Ludwigia repens, Vallisneria americana and Hydrocotyle verticillata) are able to support photosynthesis supplied by uptake of CO2 from the sediment. Methods: Gross photosynthesis was measured......Background and Aims: Submersed plants have different strategies to overcome inorganic carbon limitation. It is generally assumed that only small rosette species (isoetids) are able to utilize the high sediment CO2 availability. The present study examined to what extent five species of submersed......, the shoot to root ratio on an areal basis was the single factor best explaining variability in the importance of sediment CO2. For Ludwigia, diffusion barriers limited uptake or transport from roots to stems and transport from stems to leaves. Conclusions: Submersed plants other than isoetids can utilize...
Hayashi, T.; Todoriki, S.; Nakakita, H.; Dohino, T.; Tanabe, K.
The effects of electron beams on spider mite (Tetranychus urticae) and flour beetle (Tribolium freemani) were slightly smaller than those of gamma-rays. 'Soft-electrons' (low-energy electrons) at an energy of 170 keV inactivated eggs, larvae, pupae, and adults of the flour beetle. Electron beams at doses up to 400 Gy killed or sterilized all the pests for cut flowers tested; spider mite (Tetranychus urticae), mealybug (Pseudococcus comstocki), leaf miner (Liriomyza trifolii), thrips (Thrips palmi, Thrips tabaci), cutworm (Spodoptera litura), and aphid (Myzus persicae). Carnation, alstromeria, gladiolus, tulip, statice, stock, dendrobium, prairie gentian, oncidium, campanula, gloriosa, fern, gypsophila, freesia, lobelia, triteleia, and gerbera were resistant to radiation, while chrysanthemum, rose, lily, calla, antherium, sweet pea, and iris were sensitive. Radiation-induced deterioration of chrysanthemum could be prevented by post-irradiation treatment with commercial preservative solutions or sugar solutions. (author)
Møller, Claus Lindskov; Jensen, Kaj Sand
1. Littorella uniflora and Lobelia dortmanna are prominent small rosette species in nutrient-poor, soft-water lakes because of efficient root exchange of CO2 and O2. We hypothesise that higher gas exchange across the leaves of L.similar to uniflora than of L.similar to dortmanna ensures O2 uptake...... from water and underlies its greater tolerance to sediment anoxia following organic enrichment. 2. We studied plant response to varying sediment O2 demand and biogeochemistry by measuring photosynthesis, gas exchange across leaves and O2 dynamics in plants during long-term laboratory and field studies....... Frequent non-destructive sampling of sediment pore water was used to track changes in sediment biogeochemistry. 3. Addition of organic matter triggered O2 depletion and accumulation of , Fe2+ and CO2 in sediments. Gas exchange across leaf surfaces was 1316 times higher for L.similar to uniflora than for L...
Herrmann, Martina; Schramm, Andreas
AMMONIA-OXIDIZING ARCHAEA AND BACTERIA IN THE RHIZOSPHERE OF FRESHWATER MACROPHYTES Martina Herrmann and Andreas Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Aquatic macrophytes such as Littorella uniflora and Lobelia dortmanna release oxygen from...... their roots and thereby stimulate nitrification and coupled nitrification-denitrification in their rhizosphere. However, oxygen release and inorganic nitrogen concentrations differ markedly between macrophyte species. We therefore propose (i) that the rhizosphere of freshwater macrophytes harbours a species......-specific microbial community distinct from that of unvegetated sediment and (ii) that aquatic macrophytes have an impact on abundance and activity of nitrifying and denitrifying bacteria in freshwater sediment. The goal of this study was to test these hypotheses for the key functional group for coupled nitrification...
Ommen, Daniela Oliveira; Vinther, Hanne Fogh; Krüger, Laila
into the lake; and a smaller recharge zone where water from the lake flows back into the aquifer. This variable groundwater pattern combined with only minor surface inlets and outlets provides good conditions for studying the interactions between groundwater and Littorella uniflora. Preliminary results from......Lake Hampen is a Lobelia lake situated high up in the Jutland ridge and which lies close to the groundwater boundary. This means that the groundwater flow between the aquifer and the lake is not constant. Lake Hampen has a large discharge zone where the groundwater flows from the aquifer......,49 to 0,88mg NO3-N L-1 in the recharge zone. There are also indications that the plants have the capability to effectively reduce high nitrate concentrations within the rhizosphere (reduction of 30 to 0,1mg NO3-N L-1 was observed)....
Raun, Ane-Marie Løvendahl; Borum, Jens; Jensen, Kaj Sand
1. Lake eutrophication has increased phytoplankton blooms and sediment organic matter. Among higher plants, small, oligotrophic rosette species (isoetids) have disappeared, while a few tall, eutrophic species (elodeids) may have persisted. Despite recent reduction of nutrient loading in restored...... lakes, the vegetation has rarely regained its former composition and coverage. Patterns of recovery may depend on local alkalinity because HCO3- stimulates photosynthesis of elodeids and not of isoetids. In laboratory growth experiments with two isoetids (Lobelia dortmanna and Littorella uniflora......) and two elodeids (Potamogeton crispus and P. perfoliatus), we test whether organic enrichment of lake sediments has a long-lasting influence by: (i) reducing plant growth because of oxygen stress on plant roots and (ii) inhibiting growth more for isoetids than elodeids. We also test whether (iii...
Raun, Ane-Marie Løvendahl
nutrient levels facilitate the formation of pelagic alga blooms which lead to poor light conditions (Nielsen et al., 2002). However, the lack of re‐colonization after reduced nutrient loading for Zostera marina and other seagrasses indicates that other factors influence the pattern. Sedimentation...... in combination with high temperature affect internal oxygen concentrations, growth and survival of aquatic macrophytes. Measurements of internal oxygen levels were made on several north temperate and tropical marine seagrass species exposed to a range of water column oxygen concentrations. The combined effects...... of eutrophication and temperatures were clarified for the temporal seagrass Zostera marina. Furthermore, the direct effect of sediment enrichment with labile organic matter was examined for four freshwater species with different growth strategies (isoetids: Lobelia dortmanna and Littorella uniflora, and elodeids...
Hughes, P William; Simons, Andrew M
• Life-history theory predicts a trade-off between current and future reproduction for iteroparous organisms-as individuals age, the expected value of future reproduction declines, and thus reproductive effort is expected to be higher in later clutches than in earlier. In contrast, models explaining the evolution of semelparity treat semelparous reproduction as instantaneous, with no scope for intraindividual variation. However, semelparous reproduction is also extended, but over shorter time scales; whether there are similar age- or stage-specific changes in reproductive effort within a semelparous episode is unclear. In this study, we assessed whether semelparous individuals increase reproductive effort as residual reproductive value declines by comparing the reproductive phenotype of flowers at five different floral positions along a main inflorescence.• Using the herbaceous monocarp Lobelia inflata, we conducted a longitudinal study of 409 individuals including both laboratory and field populations over three seasons. We recorded six reproductive traits-including the length of three phenological intervals as well as fruit size, seed size, and seed number-for all plants across floral positions produced throughout the reproductive episode.• We found that while the rate of flower initiation did not change, flowers at distal (late) floral positions developed more quickly and contained larger seed than flowers at basal (early) floral positions did.• Our results were consistent with the hypothesis that, like iteroparous organisms, L. inflata increases reproductive effort in response to low residual reproductive value. © 2014 Botanical Society of America, Inc.
Bartkowska, M P; Johnston, M O
Stronger pollen limitation should increase competition among plants, leading to stronger selection on traits important for pollen receipt. The few explicit tests of this hypothesis, however, have provided conflicting support. Using the arithmetic relationship between these two quantities, we show that increased pollen limitation will automatically result in stronger selection (all else equal) although other factors can alter selection independently of pollen limitation. We then tested the hypothesis using two approaches. First, we analysed the published studies containing information on both pollen limitation and selection. Second, we explored how natural selection measured in one Ontario population of Lobelia cardinalis over 3 years and two Michigan populations in 1 year relates to pollen limitation. For the Ontario population, we also explored whether pollinator-mediated selection is related to pollen limitation. Consistent with the hypothesis, we found an overall positive relationship between selection strength and pollen limitation both among species and within L. cardinalis. Unexpectedly, this relationship was found even for vegetative traits among species, and was not found in L. cardinalis for pollinator-mediated selection on nearly all trait types. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.
Full Text Available The time budget and behavioural patterns of Gelada were studied on the Gich Plateau of the Simien Mountains National Park, Ethiopia. The plateau is dominated mainly by Afroalpine grasses and the endemic giant Lobelia rhynchopetalum. Gich lies on the climatic and altitudinal limits of the Gelada’s geographical distribution. Activity data were collected using continuous focal animal scan sampling method during 10 consecutive days each month (from May 2013 to April 2014. Data were recorded for different age/sex classes. The Gelada spent on average 56.7% of daylight hours feeding, 14.1% travelling, 10.7% resting, 17.5% socializing and 1.1% in other non-social activity. There was seasonal variation in activity budgets, indicating a significant increase in time allocation for feeding activity, but a decrease in resting time during the dry season. The age/sex classes showed variation in activity budgets, except for social activity.
Roelofs, J G.M.
During the last decades a strong decline has been noticed in the number of waters dominated by Littorellion species, mostly isoetids such as Lobelia dortmanna L., Isoetes lacustris L. and Littorella uniflora (L.) Aschers. Sixty-eight waters, which were known to be dominated by L. uniflora after 1950 were investigated. In 1980, L. uniflora appeared to be absent or to have strongly decreased in 53 (78%) of the waters. In 41 of them, Littorella had been replaced by submerged Juncus bulbosus L. and/or Sphagnum spp. These changes seem to have been caused by changed inorganic carbon budgets as a consequence of acidification. In the remaining 12 waters, eutrophication of the water and/or sediment seems to be responsible for the changes in the plant communities. Enrichment with phosphate of the mineral sediment alone, leads to luxurious growth of submerged, rooted macrophyte species such as Myriophyllum alterniflorum DC and Ranunculus peltatus Schrank, whereas phosphate-enrichment of both sediment and water leads to luxurious growth of pleustophytes such as Riccia fluitans L. and Lemna minor L. in small, shallow waters, and to plankton bloom and luxurious growth of epiphytes in larger, deeper waters. In these cases light limitation seems to be responsible for the disappearance or decline of the Littorellion species. 41 references, 1 figure, 4 tables.
Hayashi, Toru; Imamura, Taro; Miyanoshita, Akihiro; Todoriki, Setsuko
Effects of electron beams with an energy of 2.5 MeV on insect pests were slightly smaller than those of gamma-rays. Electron beams at 400 Gy inactivated all the pests for cut flowers tested; spider mite (Tetraychus urticae), mealybug (Pseudococcus comstocki), leaf miner (Liriomyza trifolii), thrips (Thrips palmi, and Thrips tabaci), cutworm (Spodoptera litura) and aphid (Myzus persicae). Carnation, alstromeria, gladiolus, tulip, statice, stock, dendrobium, prairie gentian, oncidium, campanula, gloriosa, fern, gypsophila, freesia, lobelia, triteleia and gerbera were tolerant to electron beams at 400-600 Gy, while chrysanthemum, rose, lily, calla, antherium, sweet pea and iris were intolerant. Radiation-induced deterioration of chrysanthemum could be prevented by post-irradiation treatment with commercial preservative solutions or sugar solutions. Soft-electrons at 60 keV effectively inactivated eggs, larvae and pupae of red flour beetle (Tribolium castaneum) and Indian meal moth (Plodia interpunctella) and eggs of adzuki bean weevil (Callosobruchus chinensis) at a dose of 1 kGy. The adults of T. castaneum and P. interpunctella were inactivated by electron treatment at 5.0 kGy and 7.5 kGy, respectively. Adults of C. chinensis survived at 7.5 kGy, but were inactivated having lost ability to walk at 2.5 kGy. Soft-electrons at 60 keV could not completely inactivate the larvae of C. chinensis and smaller larvae (2nd instar) of maize weevil (Stiophilus zeamais) inside beans and grains, because the electrons with low penetration did not reach the larvae due to the shield of beans or grains. However, soft-electrons at 60 keV inactivated eggs, larger larvae (4th instar) and pupae of S. zeamais in rice grains, which indicated that S. zeamais was exposed to electrons even inside the grains. (author)
Full Text Available This study demonstrates the effect of drastic water-level changes to the aquatic vegetation in three small oligotrophic lakes situated in Kurtna Kame Field in north-eastern Estonia. The area holds around 40 lakes in 30 km2 of which 18 lakes are under protection as Natura Habitat lakes (Natura 2000 network. The area is under a strong human impact as it is surrounded by oil shale mines, sand quarry, peat harvesting field etc. The most severe impact comes from the groundwater intake established in 1972 in the vicinity of three studied lakes. The exploitation of groundwater led to drastic water-level drops. In 1980s the water-level drops were measured to be up to 3 to 4 meters compared to the levels of 1946. Lake Martiska and Lake Kuradijärv were severely affected and only 29% and 45% of lake area respectively and 21% of initial volume remained. Both lakes were described as oligotrophic lakes before severe human impact and held characteristic macrophytes such as Isoëtes lacustris L., Sparganium angustifolium Michx and Lobelia dortmanna L. As the water level declined the lakes lost their rare characteristic species and can now be described more as a meso- or even eutrophic lakes. When the volume of groundwater abstraction decreased in the 1990s the water levels started to recover but did not reach the natural levels of pre-industrialized era. Also the vegetation did not show any signs of recovery. In 2012 the pumping rates increased again causing a new rapid decline in water levels which almost exceed the previous minimum levels. The water-level monitoring alongside with the macrophyte monitoring data gives us a good case study on how the long term abrupt water-level changes can affect the aquatic vegetation
Field experiments were conducted in Tovdal, Southern Norway, to investigate the effects of low pH on decomposition, primary production and nutrient recycling in the littoral zone of softwater lakes. Sediment cores were incubated in throughflow boxes at pH 4, variable pH (4.5 to 5.6) and pH 6 at natural temperature conditions. One dark experiment with cores enriched with allochtonous material, and one natural light experiment with natural cores were conducted, lasting for 6 and 3 months respectively. The results show an overall reduction in decomposition with increasing acidity as measured by oxygen uptake and glucose turnover, although successions and adaptions occurred in enriched cores. Primary production of the flowering plant Lobelia dortmanna l. was inhibited at pH 4, while the acid conditions favoured epiphytic growth of the filamentous algae Mougeotia sp. turnover of phosphate reflected the activity of decomposers, while no pH-effect of phosphate uptake in plants was evident. Enriched cores developed heavy growth of ilamentous fungi at the surface, indicating a shift from bacterial to fungal decomposition with increasing acidity. More reduced conditions in sediments with increasing acidity were observed in some cases, which may be due to reduced oxygen diffusion through surface layers of gelatinous masses of fungi and bacteria. The results correlate very well with field observations of increased accumulation of organics and a reduction in macrophyte vegetation reported from Swedish lakes. It is concluded that the effects observed may have serious implications for the productivity in the littoral zone and in oligotrophic soft water lakes as a whole.
Shields, Morgan W; Tompkins, Jean-Marie; Saville, David J; Meurk, Colin D; Wratten, Stephen
were A. inermis 'purpurea' and Lobelia angulata (Lobeliaceae). Soil beneath all plant species had a higher microbial activity than in control plots, with L. dioica being highest in this respect. Survival proportion to the adult stage of the moth pest, E. postvittana, on all plant species was poor (<0.3). When judged by a ranking combining multiple criteria, the most promising plant species were (in decreasing order) G. sessiliflorum, A. inermis 'purpurea', H. chathamica, M. axillaris, L. dioica, L. angulata, L. squalida and S. uniflorus. Winegrowers surveyed said that they probably would deploy endemic plants around their vines. This research demonstrates that enhancing plant diversity in vineyards can deliver SPUs, harbour ESPs and therefore deliver ES. The data also shows that growers are willing to follow these protocols, with appropriate advice founded on sound research.
Morgan W. Shields
in this context were A. inermis ‘purpurea’ and Lobelia angulata (Lobeliaceae. Soil beneath all plant species had a higher microbial activity than in control plots, with L. dioica being highest in this respect. Survival proportion to the adult stage of the moth pest, E. postvittana, on all plant species was poor (<0.3. When judged by a ranking combining multiple criteria, the most promising plant species were (in decreasing order G. sessiliflorum, A. inermis ‘purpurea’, H. chathamica, M. axillaris, L. dioica, L. angulata, L. squalida and S. uniflorus. Winegrowers surveyed said that they probably would deploy endemic plants around their vines. This research demonstrates that enhancing plant diversity in vineyards can deliver SPUs, harbour ESPs and therefore deliver ES. The data also shows that growers are willing to follow these protocols, with appropriate advice founded on sound research.