Vallisneria americana (Hydrocharitaceae) as a biomonitor of aquatic ecosystems: comparison of cloned genotypes.

abstract：PREMISE OF THE STUDY:To enhance our knowledge of the diversity of microalgae, a phycological survey of the Canary Islands (Spain) was undertaken. Here we report the discovery of a (semi)terrestrial green filamentous alga isolated from a steep volcanic canyon on La Palma. This alga is continually exposed to changing wea...

journal_title：American journal of botany

authors： Caisová L,Reyes CP,Álamo VC,Quintana AM,Surek B,Melkonian M

更新日期：2015-09-01 00:00:00

abstract：PREMISE OF THE STUDY:Species formation is an intuitive endpoint of reproductive isolation, but circumscribing taxa that arise during speciation can be difficult because of gene flow, morphological continuity, hybridization or polyploidization, and low sequence variation among newly diverged lineages. Nonetheless, speci...

journal_title：American journal of botany

authors： Stoughton TR,Kriebel R,Jolles DD,O'Quinn RL

更新日期：2018-03-01 00:00:00

abstract：:The balance between clonal and sexual reproduction can vary widely among plant populations, and the extent of clonality may be influenced by the combined effects of historical land use and variation in environmental conditions. We investigated patterns of clonal spread in five Trillium cuneatum populations, two in the...

journal_title：American journal of botany

authors： Gonzales E,Hamrick JL,Smouse PE

更新日期：2008-10-01 00:00:00

abstract：:Seed and pollen morphology were studied by light microscopy and scanning electron microscopy in 39 North and Central American species of Houstonia (including Hedyotis, but excluding Oldenlandia). Chromosome counts were obtained for eight taxa, of which five lacked previous chromosome data. A chromosome number of n = 1...

journal_title：American journal of botany

authors： Terrell EE,Lewis WH,Robinson H,Nowicke JW

更新日期：1986-01-01 00:00:00

abstract：:Pinus rzedowskii is an endangered pine species from Michoacán (central México), which has been previously reported from only three localities. Classified within the subgenus Strobus, it exhibits intermediate morphological characters between subgenera Strobus and Pinus. We analyzed genetic aspects that could shed light...

journal_title：American journal of botany

authors： Delgado P,Piñero D,Chaos A,Pérez-Nasser N,Alvarez-Buylla ER

更新日期：1999-05-01 00:00:00

abstract：PREMISE:Distylous species possess two floral morphs with reciprocal positioning of stigmas and anthers that is hypothesized to promote disassortative pollination. Theoretical models predict equal morph frequencies, but many populations depart from the expected 1:1 ratio, a pattern that often correlates with asymmetric ...

journal_title：American journal of botany

authors： Matias R,Pérez-Barrales R,Consolaro H

更新日期：2020-06-01 00:00:00

abstract：PREMISE OF THE STUDY:Identifying recently diverged taxa can be useful for studying the process of speciation. Ipomoea lacunosa and I. cordatotriloba, along with a putative homoploid hybrid, I. ×leucantha, are closely related taxa, which are promising for investigating the early stages of speciation. The objectives of t...

journal_title：American journal of botany

authors： Duncan TM,Rausher MD

更新日期：2013-11-01 00:00:00

abstract：:Cleistogamous capitula formed by Centaurea melitensis display a number of morphological and functional changes with respect to chasmogamous capitula that ensure self-fertilization. Because no studies have hitherto addressed the evolution of cleistogamy in Asteraceae, it was considered useful to ascertain whether these...

journal_title：American journal of botany

authors： Porras R,Muñoz JM

更新日期：2000-07-01 00:00:00

abstract：:The timing, geographical locations, causes, and consequences of crop domestication have long been major concerns of archaeologists, and agricultural origins and dispersals are currently more relevant than ever to scientists seeking solutions to elusive problems involving food insecurity and global health disparities. ...

journal_title：American journal of botany

authors： Langlie BS,Mueller NG,Spengler RN,Fritz GJ

更新日期：2014-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Microsatellite primers were developed in the traditional Tibetan medicinal plant Halenia elliptica D. Don to investigate its genetic diversity and population genetic structure. METHODS AND RESULTS:Using the Fast Isolation by AFLP of Sequences Containing (FIASCO) repeats protocol, 24 primer sets we...

journal_title：American journal of botany

authors： Zhang ZR,Yang J,Sun Y,Gao TG,Li DZ,Xue CY

更新日期：2011-07-01 00:00:00

abstract：:Bumble bee pollinated Chamaecrista fasciculata provides pollen as the sole reward to its pollinators. Male sterility, expressed as an absence or nearly complete absence of pollen production, occurs in low frequency in populations of C. fasciculata. Here we describe experiments, using C. fasciculata, to examine frequen...

journal_title：American journal of botany

authors： Williams HL,Fenster CB

更新日期：1998-09-01 00:00:00

abstract：PREMISE OF THE STUDY:Documented fossil floras in the neotropics are sparse, yet their records provide evidence on the spatial and temporal occurrence of taxa, allowing for testing of biogeographical and diversification scenarios on individual lineages. A new fossil Piper from the Late Cretaceous of Colombia is describe...

journal_title：American journal of botany

authors： Martínez C,Carvalho MR,Madriñán S,Jaramillo CA

更新日期：2015-02-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Fungal plant pathogens exert much of their effect on plant cells through alterations in the host cell walls. However, obtaining biochemical proof for this change is difficult because of the relatively small number of cells that are affected by the pathogen relative to the bulk of host ...

journal_title：American journal of botany

authors： Bowling AJ,Vaughn KC,Hoagland RE,Stetina K,Boyette CD

更新日期：2010-12-01 00:00:00

abstract：:The cell division pattern in the apical meristem of Psilotum nudum was examined using epi-illumination microscopy and a paraffin method. In the subterranean axis, about half of the derivative cells of the apical cell produce tetrahedral daughter apical cells by the first three or more oblique divisions. Roughly half o...

journal_title：American journal of botany

authors： Takiguchi Y,Imaichi R,Kato M

更新日期：1997-05-01 00:00:00

abstract：:Gas exchange was measured in two subalpine herbs during alternating periods of sun and shade that simulated natural cloud patterns. Stomatal conductance (g) in the subalpine herb Helianthella quinquenervis was reduced by as much as 75% during 5-min shade periods that ranged in photosynthetic photon flux density (PPFD)...

journal_title：American journal of botany

authors： Knapp AK,Smith WK

更新日期：1990-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Gravity has been a major force throughout the evolution of terrestrial organisms, and plants have developed exquisitely sensitive, regulated tropisms and growth patterns that are based on the gravity vector. The nullified gravity during spaceflight allows direct assessment of gravity roles. The mic...

journal_title：American journal of botany

authors： Zupanska AK,Denison FC,Ferl RJ,Paul AL

更新日期：2013-01-01 00:00:00

abstract：PREMISE OF THE STUDY:In angiosperm seeds, the developing embryo acquires nutrients via a suspensor that typically undergoes programmed cell death (PCD) at the early cotyledon stage. However, in Leguminosae (the third largest angiosperm family), the suspensors can disappear at the heart-shaped stage (i.e., prior to the ...

journal_title：American journal of botany

authors： Endo Y

更新日期：2012-08-01 00:00:00

abstract：:Survival and fecundity are basic components of demography and therefore have a strong influence on population dynamics. These two key parameters and their relationship are crucial to understand the evolution of life histories. It remains, however, to be empirically established how life span, fecundity, and population ...

journal_title：American journal of botany

authors： García MB,Picó FX,Ehrlén J

更新日期：2008-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Subtribe Hakeinae (526 spp.) represents a large Australian plant radiation central to our understanding of that flora's evolution and ecology. It contains Grevillea-the third largest plant genus in Australia and a group inferred to have among the highest diversification rates in the angiosperms. Ho...

journal_title：American journal of botany

authors： Mast AR,Olde PM,Makinson RO,Jones E,Kubes A,Miller ET,Weston PH

更新日期：2015-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Seabirds often cause significant changes to soil properties, and seabird-dominated systems often host unique plant communities. This study experimentally (1) examined species-specific responses to seabird guano gradients, (2) considered the role that differential functional traits among species pla...

journal_title：American journal of botany

authors： Young HS,McCauley DJ,Dirzo R

更新日期：2011-02-01 00:00:00

abstract：PREMISE:Medullary bundles, i.e., vascular units in the pith, have evolved multiple times in vascular plants. However, no study has ever explored their anatomical diversity and evolution within a phylogenetic framework. Here, we investigated the development of the primary vascular system within Nyctaginaceae showing how...

journal_title：American journal of botany

authors： da Cunha Neto IL,Pace MR,Douglas NA,Nee MH,de Sá CFC,Moore MJ,Angyalossy V

更新日期：2020-05-01 00:00:00

abstract：:Studies of developmental stability can provide insights into the amount of genetic or environmental stress experienced by individuals or populations. In the present study, we used young plants of Acer platanoides (Norway maple) and Betula pendula (silver birch), two distantly related tree species with widely different...

journal_title：American journal of botany

authors： Black-Samuelsson S,Andersson S

更新日期：2003-08-01 00:00:00

abstract：PREMISE OF THE STUDY:Collinsia was the subject of classic biosystematic studies by Garber and colleagues and is increasingly investigated to address major evolutionary questions. Lack of phylogenetic data from more than one gene region and one taxonomic exemplar has left relationships, diversity, and phytogeography of ...

journal_title：American journal of botany

authors： Baldwin BG,Kalisz S,Armbruster WS

更新日期：2011-04-01 00:00:00

abstract：PREMISE OF THE STUDY:Phylogenetic and morphological studies have helped clarify the systematics of large and complex groups such as the tribe Crotoneae (Euphorbiaceae). However, very little is known about the diversity, structure, and function of anatomical features in this tribe. Crotoneae comprises the species-rich p...

journal_title：American journal of botany

authors： Vitarelli NC,Riina R,Caruzo MB,Cordeiro I,Fuertes-Aguilar J,Meira RM

更新日期：2015-06-01 00:00:00

abstract：:Phylogenetic relationships among embryophytes (tracheophytes, mosses, liverworts, and hornworts) were examined using 21 newly generated mitochondrial small-subunit (19S) rDNA sequences. The "core" 19S rDNA contained more phylogenetically informative sites and lower homoplasy than either nuclear 18S or plastid 16S rDNA...

journal_title：American journal of botany

authors： Duff RJ,Nickrent DL

更新日期：1999-03-01 00:00:00

abstract：PREMISE OF THE STUDY:The life histories of lichen fungi are not well known and cannot be readily studied in laboratory culture. This work documents in situ the complete life cycle of the widespread crustose lichen Calopadia puiggarii, which reproduces sexually and asexually on the surfaces of leaves. METHODS:Plastic c...

journal_title：American journal of botany

authors： Sanders WB

更新日期：2014-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Robust markers are required (inter alia) for assessing origins of Calophyllum inophyllum populations on the Bonin Islands, Japan. Therefore, informative expressed sequence tag (EST)-based microsatellite or simple sequence repeat (SSRs) markers in the species were sought. METHODS AND RESULTS:Using ...

journal_title：American journal of botany

authors： Setsuko S,Uchiyama K,Sugai K,Hanaoka S,Yoshimaru H

更新日期：2012-01-01 00:00:00

abstract：:Many plant species are characterized by a life cycle with a long-lived, subterranean phase that is completely dependent on mycorrhizal fungal symbionts for fixed carbon. This type of life cycle is both phylogenetically and ecologically widespread and is found in diverse vascular plant lineages from the tropics to suba...

journal_title：American journal of botany

authors： Winther JL,Friedman WE

更新日期：2007-07-01 00:00:00

abstract：PREMISE OF THE STUDY:Recurrent formation of polyploid taxa is a common observation in many plant groups. Haploid, cytoplasmic genomes like the plastid genome can be used to overcome the problem of homeologous genes and recombination in polyploid taxa. Fragaria (Rosaceae) contains several octo- and decaploid species. We...

journal_title：American journal of botany

authors： Dillenberger MS,Wei N,Tennessen JA,Ashman TL,Liston A

更新日期：2018-05-01 00:00:00

abstract：:Nuphar comprises 13 species of aquatic perennials distributed in the temperate Northern Hemisphere. The European species N. lutea and N. pumila in Norway, the Netherlands, and Germany are pollinated by bees and flies, including apparent Nuphar specialists. This contrasts with reports of predominant beetle pollination ...

journal_title：American journal of botany

authors： Lippok B,Gardine AA,Williamson PS,Renner SS

更新日期：2000-06-01 00:00:00