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    4534 results match your criteria American journal of botany[Journal]

    1 OF 91

    The ontogenetic bases for variation in ovary position in Melastomataceae.
    Am J Bot 2017 Aug 21. Epub 2017 Aug 21.
    Universidade de São Paulo (USP), Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Av. do Café, s/n, Ribeirão Preto, SP 14040-903, Brazil
    Premise Of The Study: Although the ovary position is considered a stable character in angiosperms, Melastomataceae species have perigynous flowers in which the ovary varies from superior to inferior. Thus, we investigated the ontogenetic process involved in variation of the ovary position in Melastomataceae. We focused on histogenesis of the floral apex in search of developmental patterns for each type of ovary position. Read More

    Comparative transcriptomics indicate changes in cell wall organization and stress response in seedlings during spaceflight.
    Am J Bot 2017 Aug 21. Epub 2017 Aug 21.
    University of North Carolina at Greensboro, Department of Biology, Greensboro, North Carolina 27412 USA
    Premise Of The Study: Plants will play an important role in the future of space exploration as part of bioregenerative life support. Thus, it is important to understand the effects of microgravity and spaceflight on gene expression in plant development.

    Methods: We analyzed the transcriptome of Arabidopsis thaliana using the Biological Research in Canisters (BRIC) hardware during Space Shuttle mission STS-131. Read More

    Fungal endophyte communities in the temperate fern Polystichum munitum show early colonization and extensive temporal turnover.
    Am J Bot 2017 Aug 16. Epub 2017 Aug 16.
    Department of Biology, Portland State University, Portland, Oregon 97201, USA.
    Premise Of The Study: Fungal endophytes have been shown to colonize all land plants, yet surprisingly little attention has been given to their community composition in ferns. We examined the diversity and temporal turnover of fungal endophytes in foliar tissue of the temperate western sword fern, Polystichum munitum, comparing taxa in newly emerged leaflets and in the same fronds after 1 mo of exposure in the field.

    Methods: Utilizing next-generation sequencing, we sampled pinnae from P. Read More

    Comparative epigenetic and genetic spatial structure of the perennial herb Helleborus foetidus: Isolation by environment, isolation by distance, and functional trait divergence.
    Am J Bot 2017 Aug 16. Epub 2017 Aug 16.
    Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Americo Vespucio 26, 41092 Sevilla, Spain.
    Premise Of The Study: Epigenetic variation can play a role in local adaptation; thus, there should be associations among epigenetic variation, environmental variation, and functional trait variation across populations. This study examines these relationships in the perennial herb Helleborus foetidus (Ranunculaceae).

    Methods: Plants from 10 subpopulations were characterized genetically (AFLP, SSR markers), epigenetically (MSAP markers), and phenotypically (20 functional traits). Read More

    Can asexuality confer a short-term advantage? Investigating apparent biogeographic success in the apomictic triploid fern Myriopteris gracilis.
    Am J Bot 2017 Aug 16. Epub 2017 Aug 16.
    Department of Biological Sciences, Wichita State University, Wichita, Kansas 67260 USA
    Premise Of The Study: Although asexual taxa are generally seen as evolutionary dead ends, asexuality appears to provide a short-term benefit in some taxa, including a wider geographic distribution compared to sexual relatives. However, this may be an illusion created by multiple, morphologically cryptic, asexual lineages, each occupying a relatively small area. In this study we investigate the role of multiple lineages in the biogeography of Myriopteris gracilis Fée (Pteridaceae), a North American apomictic triploid fern species with a particularly large range. Read More

    Adaptive spatiotemporal changes in morphology, anatomy, and mechanics during the ontogeny of subshrubs with square-shaped stems.
    Am J Bot 2017 Aug 16. Epub 2017 Aug 16.
    Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
    Premise Of The Study: Plant stems can be regarded as fiber-reinforced structures characterized by anatomical heterogeneity, mechanical anisotropy, and adaptability to changing internal and external constraints. Our study focused on adaptive spatiotemporal changes in morphology, anatomy, and mechanical properties during the ontogeny of Leonurus cardiaca L. (Lamiaceae) internodes, proving considerable functional adaptability. Read More

    Evolution and development of monocot stomata.
    Am J Bot 2017 Aug 9. Epub 2017 Aug 9.
    Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
    Premise Of The Study: Leaves of monocots are typically linear with parallel venation, though a few taxa have broad leaves. Studies of stomatal patterning and development in monocots required updating in the context of rapidly improving knowledge of both the phylogenetic and development-genetic context of monocots that facilitate studies of character evolution.

    Methods: We used an existing microscope-slide collection to obtain data on stomatal structure across all the major monocot clades, including some species with relatively broad leaves. Read More

    Floristic response to urbanization: Filtering of the bioregional flora in Indianapolis, Indiana, USA.
    Am J Bot 2017 Aug 9. Epub 2017 Aug 9.
    The Morton Arboretum, Lisle, Illinois 60523.
    Premise Of The Study: Globally, urban plant populations are becoming increasingly important, as these plants play a vital role in ameliorating effects of ecosystem disturbance and climate change. Urban environments act as filters to bioregional flora, presenting survival challenges to spontaneous plants. Yet, because of the paucity of inventory data on plants in landscapes both before and after urbanization, few studies have directly investigated this effect of urbanization. Read More

    Learning in two butterfly species when using flowers of the tropical milkweed Asclepias curassavica: No benefits for pollination.
    Am J Bot 2017 Aug 8. Epub 2017 Aug 8.
    Laboratório de Interações Inseto-Planta, Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, P.O. Box 68020, 21.941-902 Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil.
    Premise Of The Study: The ability of insect visitors to learn to manipulate complex flowers has important consequences for foraging efficiency and plant fitness. We investigated learning by two butterfly species, Danaus erippus and Heliconius erato, as they foraged on the complex flowers of Asclepias curassavica, as well as the consequences for pollination.

    Methods: To examine learning with respect to flower manipulation, butterflies were individually tested during four consecutive days under insectary conditions. Read More

    Transitions from distyly to homostyly are associated with floral evolution in the buckwheat genus (Fagopyrum).
    Am J Bot 2017 Aug 8. Epub 2017 Aug 8.
    School of Life Sciences, Central China Normal University, Wuhan 430079, China
    Premise Of The Study: Documenting trait transitions among species with dimorphic flowers can help to test whether similar patterns of selection are responsible for divergence in floral traits among different species. Heterostyly is thought to promote outcrossing. Theory suggests that the evolutionary transition from heterostylous to homostylous flowers should be accompanied by a reduction in floral size in which pollen size and style length are expected to covary. Read More

    Karyological patterns in the European endemic genus Soldanella L.: Absolute genome size variation uncorrelated with cytotype chromosome numbers.
    Am J Bot 2017 Aug 8. Epub 2017 Aug 8.
    Plant Science and Biodiversity Centre, Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84523 Bratislava, Slovak Republic
    Premise Of The Study: Detailed knowledge about the karyological diversity of organisms undoubtedly represents one of the crucial steps toward a better understanding of their evolutionary trends and history. We investigated the cytotype and absolute genome size (AGS) patterns in the European mountain-dwelling genus Soldanella (Primulaceae) in light of its geographic distribution and ecological diversification.

    Methods: Our chromosome number survey was based on 34 newly determined and 125 previously published chromosome counts. Read More

    Divergent evolution and niche differentiation within the common peatmoss Sphagnum magellanicum.
    Am J Bot 2017 Jul 28. Epub 2017 Jul 28.
    NTNU University Museum, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
    Premise Of The Study: Populations with phenotypic polymorphism in discrete characters may be good models for investigating genome evolution and speciation. Sphagnum magellanicum Brid. is found throughout the northern hemisphere, and despite considerable variation in morphological characters, it is considered one of the least taxonomically controversial peatmoss species. Read More

    Intraspecific life history variation in contrasting habitats: Insights from an obligate symbiotic organism.
    Am J Bot 2017 Jul 28. Epub 2017 Jul 28.
    Rey Juan Carlos University, Biodiversity and Conservation Area, E-28933 Móstoles, Madrid, Spain.
    Premise Of The Study: Life history theory predicts that plants in unfavorable habitats for juvenile growth and survival will commence reproduction at smaller sizes and exhibit higher reproductive allocations than those in favorable habitats. The scope of life history theory will increase if these predictions apply to a broad range of organisms. Populations of organisms in contrasting habitats may experience different demographic rates. Read More

    Plastome sequences of an ancient fern lineage reveal remarkable changes in gene content and architecture.
    Am J Bot 2017 Jul 28. Epub 2017 Jul 28.
    Lewis B. and Dorothy Cullman Program for Molecular Systematics, The New York Botanical Garden, Bronx, New York 10458, USA.
    Premise Of The Study: Comparative analyses of plastid genomes have suggested that gene order and content are relatively stable across the main groups of land plants, with significant changes rarely reported. We examine plastome organization and RNA editing in ferns and report changes that add valuable information on plastome evolution in land plants.

    Methods: Using next-generation sequencing methods, we fully sequenced plastomes from three species of Schizaeaceae, and compared their plastomes with other groups of land plants to study changes in gene composition, plastome architecture, and putative RNA editing sites. Read More

    First discovery of the charophycean green alga Lychnothamnus barbatus (Charophyceae) extant in the New World.
    Am J Bot 2017 Jul 27. Epub 2017 Jul 27.
    Academy of Natural Sciences of Drexel University, 1900 Benjamin Franklin Parkway, Philadelphia, Pennsylvania 19103 USA.
    Premise Of The Study: Although some species of Characeae, known as stoneworts, can be found on every continent except Antarctica, many species and some genera have limited geographic distributions. The genus Lychnothamnus, represented by a single extant species L. barbatus, was known only from scattered localities in Europe and Australasia until it was recently discovered in North America. Read More

    High growth temperatures and high soil nitrogen do not alter differences in CO2 assimilation between invasive Phalaris arundinacea (reed canarygrass) and Carex stricta (tussock sedge).
    Am J Bot 2017 Jul 25. Epub 2017 Jul 25.
    Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409 USA
    Premise Of The Study: Global change in temperature and soil nitrogen availability could affect plant community composition, potentially giving an advantage to invasive species compared to native species. We addressed how high temperatures affected CO2 assimilation parameters for invasive Phalaris arundinacea and a sedge, Carex stricta, it displaces, in natural and controlled environments.

    Methods: Photosynthetic parameters were measured in a wetland in Indiana, USA during the abnormally warm year of 2012. Read More

    Anatolian origins and diversification of Aethionema, the sister lineage of the core Brassicaceae.
    Am J Bot 2017 Jul 25. Epub 2017 Jul 25.
    Biosystematics, Plant Science Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
    Premise Of The Study: The Irano-Turanian region harbors three biodiversity hotspots and ∼25% of Brassicaceae species are endemic to the region. Aethionema (∼61 species) is the sister lineage to the core Brassicaceae and occurs mainly in the Irano-Turanian region. The evolutionary important position of Aethionema makes it an ideal reference for broader comparative genetics and genomics. Read More

    Less is more: Independent loss-of-function OCIMENE SYNTHASE alleles parallel pollination syndrome diversification in monkeyflowers (Mimulus).
    Am J Bot 2017 Jul 19. Epub 2017 Jul 19.
    Department of Biology, Box 351800, University of Washington, Seattle, Washington 98195 USA
    Premise Of The Study: Pollinator-mediated selection on flower phenotypes (e.g., shape, color, scent) is key to understanding the adaptive radiation of angiosperms, many of which have evolved specialized relationships with a particular guild of animal pollinators (e. Read More

    Vascular development in very young conifer seedlings: Theoretical hydraulic capacities and potential resistance to embolism.
    Am J Bot 2017 Jul 19. Epub 2017 Jul 19.
    875 Perimeter Drive MS 1133, College of Natural Resources, University of Idaho, Moscow, Idaho 83844 USA.
    Premise Of The Study: Conifers have the highest rates of mortality during their first year, often attributed to water stress; yet, this tree life stage is the least studied in terms of hydraulic properties. Previous work has revealed correlations between xylem anatomy to both hydraulic transport capacity and resistance to hydraulic dysfunction. In this study, we compared xylem anatomical and plant functional traits of Pseudotsuga menziesii, Larix occidentalis, and Pinus ponderosa seedlings over the first 10 wk of growth to evaluate potential maximum hydraulic capabilities and resistance to drought-induced embolism. Read More

    Evidence for environment-dependent introgression of adaptive genes between two red oak species with different drought adaptations.
    Am J Bot 2017 Jul 19. Epub 2017 Jul 19.
    School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, Michigan 49931-1295 USA
    Premise Of The Study: Introgression of adaptive alleles between hybridizing species is likely an important mechanism to generate new genetic variation for adaptation to rapidly changing environmental conditions. Oaks provide a model for the study of adaptive gene introgression because environmental selection maintains high interspecific differentiation at a few outlier loci and species-specific adaptations despite recurrent interspecific gene flow. Previously, we identified a CONSTANS-like gene under strong divergent selection between drought-tolerant Quercus ellipsoidalis and drought-averse Quercus rubra. Read More

    Floral evolution and phylogeny of the Dialioideae, a diverse subfamily of tropical legumes.
    Am J Bot 2017 Jul 14;104(7):1019-1041. Epub 2017 Jul 14.
    Institut de Recherche en Biologie Végétale and Département de Sciences Biologiques, Université de Montréal, 4101 rue Sherbrooke Est, Montréal, Québec, H1X 2B2, Canada.
    Premise Of The Study: The Dialioideae is an early diverging clade of caesalpinioid legumes containing approximately 85 species in 17 genera. Dialioideae floral morphology is highly variable and may provide clues to caesalpinioid evolution, but a well-resolved phylogeny is needed. Here, we have carried out a comprehensive morphological study of 78 Dialioideae and four outgroup species. Read More

    Incomplete lineage sorting and hybridization in the evolutionary history of closely related, endemic yellow-flowered Aechmea species of subgenus Ortgiesia (Bromeliaceae).
    Am J Bot 2017 Jul 14;104(7):1073-1087. Epub 2017 Jul 14.
    Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Programa de Pós-graduação em Genética e Biologia Molecular, Avenida Bento Gonçalves 9500, P.O. Box 15053 91501-970, Porto Alegre, RS, Brazil
    Premise Of The Study: The yellow-flowered Aechmea subgenus Ortgiesia (yfAsO) (Bromeliaceae) is a group of seven morphologically similar bromeliads found mostly in the southern Brazilian Atlantic rainforest. The recent origin of this group probably contributes to its taxonomic complexity. The aims of this study were to investigate the levels of genetic diversity and structure at the population and species levels, to gain insight into the processes behind the diversification of the group, and to contribute to the establishment of species boundaries. Read More

    Visualization of extracellular DNA released during border cell separation from the root cap.
    Am J Bot 2017 Jul 14;104(7):970-978. Epub 2017 Jul 14.
    Department of Soil, Water and Environmental Science, 429 Shantz Building #38, The University of Arizona, Tucson, Arizona 85721, USA
    Premise Of The Study: Root border cells are programmed to separate from the root cap as it penetrates the soil environment, where the cells actively secrete >100 extracellular proteins into the surrounding mucilage. The detached cells function in defense of the root tip by an extracellular trapping process that also requires DNA, as in mammalian white blood cells. Trapping in animals and plants is reversed by treatment with DNase, which results in increased infection. Read More

    "Diminishing returns" in the scaling of leaf area vs. dry mass in Wuyi Mountain bamboos, Southeast China.
    Am J Bot 2017 Jul 12;104(7):993-998. Epub 2017 Jul 12.
    Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, Fujian Province 350007, China
    Premise Of Study: Leaf area and dry mass are crucial for plant metabolic performance. The "diminishing returns" hypothesis predicts that leaf area will scale less than one with respect to leaf dry mass, indicating that the cost of light interception increases with leaf area. However, it remains unclear whether and how this scaling relationship varies among species growing in different environments. Read More

    The East Asian origin of the giant lobelias.
    Am J Bot 2017 Jun;104(6):924-938
    Department of Biology, Indiana University, Bloomington, Indiana 47405 USA.
    Premise Of The Study: Rapid radiations are difficult to reconstruct when organismal diversification and biogeographic movement outpace the evolution of genes typically used in phylogenetic analyses. The 125 kb of unique sequence from complete plastid genomes (= plastomes) largely solves the molecular sampling problem, and taxon sampling that triangulates the base of each major subclade largely solves the long-branch attraction problem. This combination of molecular and phylogenetic sampling is used to reconstruct the cosmopolitan radiation of lobeliads, with special focus on the origin of the giant lobelias. Read More

    Common garden test of range limits as predicted by a species distribution model in the annual plant Mimulus bicolor.
    Am J Bot 2017 Jun;104(6):817-827
    School of Biological Sciences, Washington State University, P.O. Box 644236, Pullman, Washington 99164.
    Premise Of The Study: Direct tests of a species distribution model (SDM) were used to evaluate the hypothesis that the northern and southern edges of Mimulus bicolor's geographical range are limited by temperature and precipitation.

    Methods: Climatic suitability was predicted using an SDM informed only by temperature and precipitation variables. These predictions were tested by growing plants in growth chambers with temperature and watering treatments informed by weather stations characteristic of environments at the geographic center, edges, and outside the range. Read More

    Two fossil species of Metrosideros (Myrtaceae) from the Oligo-Miocene Golden Fleece locality in Tasmania, Australia.
    Am J Bot 2017 Jun 20;104(6):891-904. Epub 2017 Jun 20.
    School of Biological Sciences, University of Adelaide, Adelaide SA 5005, Australia.
    Premise Of The Study: The capsular-fruited genus Metrosideros (Myrtaceae) is one of the most widely distributed flowering plant genera in the Pacific but is extinct in Australia today. The center of geographic origin for the genus and the reason for and timing of its extinction in Australia remain uncertain. We identify fossil Metrosideros fruits from the newly discovered Golden Fleece fossil flora in the Oligo-Miocene of Tasmania, Australia, shedding further light on these problems. Read More

    Molecular systematics and historical biogeography of Maianthemum s.s.
    Am J Bot 2017 Jun 20;104(6):939-952. Epub 2017 Jun 20.
    Department of Life Science, Gachon University, Seongnam 13120, Republic of Korea
    Premise Of The Study: Understanding the underlying mechanisms for the evolution of intercontinental disjunct patterns has long fascinated botanists. We present a molecular phylogenetic reconstruction of Maianthemum s.l. Read More

    Population genetic structure of Bromus tectorum in the mountains of western North America.
    Am J Bot 2017 Jun 20;104(6):879-890. Epub 2017 Jun 20.
    USFS Rocky Mountain Research Station, Shrub Sciences Laboratory, 735 North 500 East, Provo, Utah 84606 USA
    Premise Of The Study: Invasive species are often initially restricted to a narrow range and may then expand through any of multiple mechanisms including phenotypic plasticity, in situ evolution, or selection on traits preadapted for new habitats. Our study used population genetics to explore possible processes by which the highly selfing invasive annual grass Bromus tectorum has expanded into montane environments.

    Methods: We used 69 single nucleotide polymorphic (SNP) markers to genotype ca. Read More

    Widespread paleopolyploidy, gene tree conflict, and recalcitrant relationships among the carnivorous Caryophyllales.
    Am J Bot 2017 Jun 20;104(6):858-867. Epub 2017 Jun 20.
    Department of Ecology & Evolutionary Biology, University of Michigan, 830 North University Avenue, Ann Arbor, Michigan 48109-1048 USA
    Premise Of Study: The carnivorous members of the large, hyperdiverse Caryophyllales (e.g., Venus flytrap, sundews, and Nepenthes pitcher plants) represent perhaps the oldest and most diverse lineage of carnivorous plants. Read More

    Pollinia transfer on moth legs in Hoya carnosa (Apocynaceae).
    Am J Bot 2017 Jun 16;104(6):953-960. Epub 2017 Jun 16.
    Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan.
    Premise Of The Study: The genus Hoya (Apocynaceae; Asclepiadoideae) is characterized by a set of complex floral characters unique among the asclepiads, but their role in pollination is poorly understood. Here, we report a new mechanism of asclepiad pollination in the wax plant Hoya carnosa: the pollinaria are transferred on the legs of medium or large settling moths.

    Methods: Floral visitors and their behavior were observed on Amami-Oshima Island during 2013-2015, and the efficacy of different pollinators was determined by counting the pollinarium loads on different flower visitors. Read More

    The role of idioblasts in leaf water relations of tropical Rhododendron.
    Am J Bot 2017 Jun 16;104(6):828-839. Epub 2017 Jun 16.
    Department of Biological Sciences, 2119 Derring Hall, 1405 Perry Street, Virginia Tech, Blacksburg, Virginia 24061 USA
    Premise Of The Study: Although much is known about the anatomy of idioblasts, the relationship of leaf idioblasts to leaf physiology is poorly known. Our goal was to understand the relationship between idioblast abundance and leaf water relations. Tropical epiphytic and shrub Rhododendron species were the model system. Read More

    Phenology of perennial, native grass, belowground axillary buds in the northern mixed-grass prairie.
    Am J Bot 2017 Jun 16;104(6):915-923. Epub 2017 Jun 16.
    USDA-ARS, Northern Great Plains Research Laboratory, P.O. Box 459, Mandan, North Dakota 58554 USA.
    Premise Of The Study: Vegetative reproduction from belowground bud banks is the primary driver of grassland systems. Despite the importance of bud banks, the timing of recruitment and the crucial link between formation and maintenance is unknown.

    Methods: We assessed patterns of belowground bud development, dormancy, and mortality associated with three perennial native grasses in the northern Great Plains. Read More

    Autopolyploidization, geographic origin, and metabolome evolution in Arabidopsis thaliana.
    Am J Bot 2017 Jun 16;104(6):905-914. Epub 2017 Jun 16.
    RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Kanagawa-ken, 230-0045, Japan.
    Premise Of The Study: Autopolyploidy, or whole-genome duplication, is a recurrent phenomenon in plant evolution. Its existence can be inferred from the presence of massive levels of genetic redundancy revealed by comparative plant phylogenomics. Whole-genome duplication is theoretically associated with evolutionary novelties such as the development of new metabolic reactions and therefore contributes to the evolution of new plant metabolic profiles. Read More

    Population genetic structure of the rock outcrop species Encholirium spectabile (Bromeliaceae): The role of pollination vs. seed dispersal and evolutionary implications.
    Am J Bot 2017 Jun 13;104(6):868-878. Epub 2017 Jun 13.
    Systematics and Morphology of Plants, Institute of Biology, University of Kassel, Heinrich-Plett-Str. 40 34132 Kassel, Germany.
    Premise Of The Study: Inselbergs are terrestrial, island-like rock outcrop environments that present a highly adapted flora. The epilithic bromeliad Encholirium spectabile is a dominant species on inselbergs in the Caatinga of northeastern Brazil. We conducted a population genetic analysis to test whether the substantial phenotypic diversity of E. Read More

    Decoupled leaf and root carbon economics is a key component in the ecological diversity and evolutionary divergence of deciduous and evergreen lineages of genus Rhododendron.
    Am J Bot 2017 Jun 13;104(6):803-816. Epub 2017 Jun 13.
    International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, Florida 33199, USA.
    Premise: We explored trait-trait and trait-climate relationships for 27 Rhododendron species while accounting for phylogenetic relationships and within-species variation to investigate whether leaf and root traits are coordinated across environments and over evolutionary time, as part of a whole-plant economics spectrum.

    Methods: We examined specific leaf area (SLA) and four root traits: specific root length (SRL), specific root tip abundance (SRTA), first order diameter, and link average length, for plants growing in a cold, seasonal climate (Kirtland, Ohio) and a warmer, less seasonal climate (Federal Way, Washington) in the United States. We estimated a phylogeny and species' climate of origin, determined phylogenetic signal on mean traits and within-species variation, and used phylogenetically informed analysis to compare trait-trait and trait-climate relationships for deciduous and evergreen lineages. Read More

    Seedling response to environmental variability: The relationship between phenotypic plasticity and evolutionary history in closely related Eucalyptus species.
    Am J Bot 2017 Jun 13;104(6):840-857. Epub 2017 Jun 13.
    National Herbarium of New South Wales, Royal Botanic Gardens and Domain Trust, Sydney, Australia.
    Premise Of The Study: Phenotypic plasticity is an important means through which organisms cope with environmental variability. We investigated seedling plasticity in the green ash eucalypts within a phylogenetic framework to examine the relationship between plasticity and evolutionary history. The green ashes are a diverse group, which include the tallest flowering plant in the world (Eucalyptus regnans) and a rare mallee less than 1 m tall (E. Read More

    Diverse early dwarf mistletoes (Arceuthobium), ecological keystones of the Eocene Baltic amber biota.
    Am J Bot 2017 May 21;104(5):694-718. Epub 2017 May 21.
    Department of Geobiology, University of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany.
    Premise Of The Study: Extant dwarf mistletoes (Arceuthobium M. Bieb., Viscaceae) are hemiparasites with complex roles in nature. Read More

    Floral traits influencing plant attractiveness to three bee species: Consequences for plant reproductive success.
    Am J Bot 2017 May 21;104(5):772-781. Epub 2017 May 21.
    Department of Entomology, 1630 Linden Drive, University of Wisconsin, Madison, Wisconsin 53706, USA
    Premise Of The Study: The ability to attract pollinators is crucial to plants that rely on insects for pollination. We contrasted the roles of floral display size and flower color in attracting three bee species and determined the relationships between plant attractiveness (number of pollinator visits) and seed set for each bee species.

    Methods: We recorded pollinator visits to plants, measured plant traits, and quantified plant reproductive success. Read More

    Are phloem sieve tubes leaky conduits supported by numerous aquaporins?
    Am J Bot 2017 May 19;104(5):719-732. Epub 2017 May 19.
    Centre de Recherche en Horticulture, Université Laval, Envirotron, Québec, QC G1V0A6, Canada.
    Premise Of The Study: Aquaporin membrane water channels have been previously identified in the phloem of angiosperms, but currently their cellular characterization is lacking, especially in tree species. Pinpointing the cellular location will help generate new hypotheses of how membrane water exchange facilitates sugar transport in plants.

    Methods: We studied histological sections of balsam poplar (Populus balsamifera L. Read More

    Phylogeography and genetic structure of endemic Acmispon argophyllus and A. dendroideus (Fabaceae) across the California Channel Islands.
    Am J Bot 2017 May 19;104(5):743-756. Epub 2017 May 19.
    Department of Biology, University of South Dakota, Vermillion, South Dakota 57069, USA.
    Premise Of The Study: Taxa inhabiting the California Channel Islands exhibit variation in their degree of isolation, but few studies have considered patterns across the entire archipelago. We studied phylogeography of insular Acmispon argophyllus and A. dendroideus to determine whether infraspecific taxa are genetically divergent and to elucidate patterns of diversification across these islands. Read More

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