Pollen structure and development in Nymphaeales: insights into character evolution in an ancient angiosperm lineage.

abstract：:The pollination biology of the cactus Pachycereus pecten-aboriginum was studied in a tropical location in western Mexico (ca. 18° N latitude) to compare with data from a northern population (ca. 28° N latitude). Throughout this range, the nectar-feeding bat Leptonycteris curasoae is resident within the tropics but mig...

journal_title：American journal of botany

authors： Valiente-Banuet A,Molina-Freaner F,Torres A,Arizmendi Mdel C,Casas A

更新日期：2004-06-01 00:00:00

abstract：:In plants, polyploidy has been a significant evolutionary force on both recent and ancient time scales. In 1950, Ownbey reported two newly formed Tragopogon allopolyploids in the northwestern United States. We have made the first synthetic lines of T. mirus and T. miscellus using T. dubius, T. porrifolius, and T. prat...

journal_title：American journal of botany

authors： Tate JA,Symonds VV,Doust AN,Buggs RJ,Mavrodiev E,Majure LC,Soltis PS,Soltis DE

更新日期：2009-05-01 00:00:00

abstract：:The last decade has witnessed a resurgence in the study of the evolution of plant development, combining investigations in systematics, developmental morphology, molecular developmental genetics, and molecular evolution. The integration of phylogenetic studies, structural analyses of fossil and extant taxa, and molecu...

journal_title：American journal of botany

authors： Friedman WE,Moore RC,Purugganan MD

更新日期：2004-10-01 00:00:00

abstract：:Maximum parsimony analysis of DNA sequence data from the internal and external transcribed spacer (ITS and ETS) regions of 18S-26S nuclear ribosomal DNA and the 3' trnK intron of chloroplast DNA from over 60 populations of Lasthenia sect. Amphiachaenia yielded a well-supported tree showing that the most common species...

journal_title：American journal of botany

authors： Chan R,Baldwin BG,Ornduff R

更新日期：2002-07-01 00:00:00

abstract：:Genetic diversity at variable-number-tandem-repeat (VNTR) loci was examined in the common cattail, Typha latifolia (Typhaceae), using three synthetic DNA probes composed of tandemly repeated "core" sequences (GACA, GATA, and GCAC). The principal objectives of this investigation were to determine whether: (1) the previ...

journal_title：American journal of botany

authors： Keane B,Pelikan S,Toth GP,Smith MK,Rogstad SH

更新日期：1999-09-01 00:00:00

abstract：:Microscopic structures (petrofilaments) may develop during palynological laboratory processing procedures that are superficially similar to secondary wall thickenings and elaters. These filaments form from angular bodies that resemble fungal spores and resin bodies. The angular bodies are a type of hydrocarbon called ...

journal_title：American journal of botany

authors： Graham A,Wood GD,Elsik WC,Speed RC

更新日期：2000-05-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Verbenaceae consist of trees, shrubs, lianas, and herbs distributed primarily in Latin America, where they occur in a wide array of ecosystems. A second center of diversity exists in Africa. Competing morphology-based classifications that rely on different traits conflict in significan...

journal_title：American journal of botany

authors： Marx HE,O'Leary N,Yuan YW,Lu-Irving P,Tank DC,Múlgura ME,Olmstead RG

更新日期：2010-10-01 00:00:00

abstract：:It is generally thought that sedimenting plastids are responsible for gravity sensing in higher plants. We directly tested the model generated by the current statolith hypothesis that the gravity sensing that leads to gravitropism results from an interaction between the plastids and actin microfilaments. We find that ...

journal_title：American journal of botany

authors： Staves MP,Wayne R,Leopold AC

更新日期：1997-11-01 00:00:00

abstract：:Seed size and germination requirements of eight (of nine) Sarracenia species, and 13 populations of S. purpurea were studied. All species except for S. purpurea are restricted to the southeastern United States, whereas S. purpurea ranges across Canada, southward along the eastern United States into Maryland and Virgin...

journal_title：American journal of botany

authors： Ellison AM

更新日期：2001-03-01 00:00:00

abstract：:The vegetative cycle of the foliicolous lichen Phyllophiale, from propagule germination to propagule production, was studied by light microscope observation of thalli colonizing plastic cover slips placed within a lowland tropical forest. Discoid propagules germinated by growth of radially arranged fungal cells and de...

journal_title：American journal of botany

authors： Sanders WB

更新日期：2002-11-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Vessels are the chief conduit for long-distance water transport in the majority of flowering plants. Vessel length is a key trait that determines plant hydraulic efficiency and safety, yet relatively little is known about this xylem feature. • METHODS:We used previously published stud...

journal_title：American journal of botany

authors： Jacobsen AL,Pratt RB,Tobin MF,Hacke UG,Ewers FW

更新日期：2012-10-01 00:00:00

abstract：PREMISE OF THE STUDY:The stability of the bimodal karyotype found in Agave and closely related species has long interested botanists. The origin of the bimodal karyotype has been attributed to allopolyploidy, but this hypothesis has not been tested. Next-generation transcriptome sequence data were used to test whether ...

journal_title：American journal of botany

authors： McKain MR,Wickett N,Zhang Y,Ayyampalayam S,McCombie WR,Chase MW,Pires JC,dePamphilis CW,Leebens-Mack J

更新日期：2012-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Hybridization and polyploidization (allopolyploidy) are ubiquitous in the evolution of plants, but tracing the origins and subsequent evolution of the constituent genomes of allopolyploids has been challenging. Genome doubling greatly complicates genetic analyses, and this has long hindered investi...

journal_title：American journal of botany

authors： Buggs RJ,Renny-Byfield S,Chester M,Jordon-Thaden IE,Viccini LF,Chamala S,Leitch AR,Schnable PS,Barbazuk WB,Soltis PS,Soltis DE

更新日期：2012-02-01 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:This paper investigates the occurrence and evolution of aluminum (Al) accumulation within ferns and lycophytes, which is characterized by Al concentrations above 1000 mg·kg-1 in aboveground plant tissues. We hypothesize that this feature is more common in ferns than in angiosperms, and potentially ...

journal_title：American journal of botany

authors： Schmitt M,Mehltreter K,Sundue M,Testo W,Watanabe T,Jansen S

更新日期：2017-04-01 00:00:00

abstract：:Wood, or secondary xylem, is composed mostly of three components-cellulose, hemicelluloses, and lignin. Yet this apparent simplicity is deceiving because the sophisticated arrangement of the components on various structural levels, ranging from intricate molecular architecture to defined cellular arrangements to tissu...

journal_title：American journal of botany

authors： Koehler L,Telewski FW

更新日期：2006-10-01 00:00:00

abstract：:The boreotropical flora concept suggests that relictual tropical disjunctions between Asia and the Americas are a result of the expansion of the circumboreal tropical flora from the middle to the close of the Eocene. Subsequently, temperate species diverged at high latitudes and migrated to other continents. To test t...

journal_title：American journal of botany

authors： Azuma H,García-Franco JG,Rico-Gray V,Thien LB

更新日期：2001-12-01 00:00:00

abstract：:Prior field studies have shown that populations of forest herbs on relatively nutrient poor soils have higher vesicular-arbuscular mycorrhizal (VAM) infection intensity than plants on rich soils. However, the growth responses and ability to take up P against the soil nutrient gradient are often not linearly related to...

journal_title：American journal of botany

authors： Boerner REJ

更新日期：1990-04-01 00:00:00

abstract：:Polyploid speciation is an ongoing, important source of angiosperm diversity. However, the barriers to polyploid speciation and mechanisms of establishment remain poorly understood for all but a few species. Several factors likely to have influenced tetraploid establishment, including barriers to triploid formation, c...

journal_title：American journal of botany

authors： Baack EJ

更新日期：2005-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Conifers are an important living seed plant lineage with an extensive fossil record spanning more than 300 million years. The group therefore provides an excellent opportunity to explore congruence and conflict between dated molecular phylogenies and the fossil record. METHODS:We surveyed the curr...

journal_title：American journal of botany

authors： Leslie AB,Beaulieu J,Holman G,Campbell CS,Mei W,Raubeson LR,Mathews S

更新日期：2018-09-01 00:00:00

abstract：:Multiply sired fruits provide unambiguous evidence that pollen from two or more donors was deposited on a stigma and successfully fertilized ovules. Such multiple paternity within fruits can have important consequences for both parental and offspring fitness, but little is known about the frequency of multiple paterni...

journal_title：American journal of botany

authors： Mitchell RJ,Karron JD,Holmquist KG,Bell JM

更新日期：2005-05-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Polyploid speciation has been important in plant evolution. However, the conditions that favor the origination and persistence of polyploids are still not well understood. Here, we examine origins of 16 polyploid species in Mentzelia section Trachyphytum. • METHODS:We used phylogeny r...

journal_title：American journal of botany

authors： Brokaw JM,Hufford L

更新日期：2010-09-01 00:00:00

abstract：:The utility of the PCR-based AFLP technique (polymerase chain reaction; amplified fragment length polymorphisms) was explored in elucidating details of polyploid evolution in the Eurasian orchid genus Dactylorhiza. We emphasized Swedish taxa but also included some material from the British Isles and elsewhere in Europ...

journal_title：American journal of botany

authors： Hedrén M,Fay MF,Chase MW

更新日期：2001-10-01 00:00:00

abstract：:The phylogenetic structure of ferns (= monilophytes) is explored here, with a special focus on the early divergences among leptosporangiate lineages. Despite considerable progress in our understanding of fern relationships, a rigorous and comprehensive analysis of the early leptosporangiate divergences was lacking. Th...

journal_title：American journal of botany

authors： Pryer KM,Schuettpelz E,Wolf PG,Schneider H,Smith AR,Cranfill R

更新日期：2004-10-01 00:00:00

abstract：:Cladistic parsimony analyses of rbcL nucleotide sequence data from 171 taxa representing nearly all tribes and subtribes of Orchidaceae are presented here. These analyses divide the family into five primary monophyletic clades: apostasioid, cypripedioid, vanilloid, orchidoid, and epidendroid orchids, arranged in that ...

journal_title：American journal of botany

authors： Cameron KM,Chase MW,Whitten WM,Kores PJ,Jarrell DC,Albert VA,Yukawa T,Hills HG,Goldman DH

更新日期：1999-02-01 00:00:00

abstract：:This study shows that structural data, when carefully examined, can provide valuable characters for delimiting monophyletic groups and can complement DNA with observable features to recognize and circumscribe taxa. In the angiosperm order Apiales, traditional classification has relied heavily (often exclusively) on fr...

journal_title：American journal of botany

authors： Liu MR,Plunkett GM,Lowry PP 2nd,Wyk BE,Tilney PM

更新日期：2006-09-01 00:00:00

abstract：:The geographic distribution of diploid and tetraploid cytotypes and cpDNA haplotypes throughout the entire range of Aucuba japonica was investigated. We measured relative genome size using flow cytometry and sequenced two cpDNA intergenic regions, atpB-rbcL and psbA-trnH (GUG). Two haplotypes include both diploids and...

journal_title：American journal of botany

authors： Ohi T,Kajita T,Murata J

更新日期：2003-11-01 00:00:00

abstract：:Primarily known only by the edible fruits of Citrus, Rutaceae comprise a large (c. 160 genera and 1900 species), morphologically diverse, cosmopolitan family. Of its extraordinary array of secondary chemical compounds, many have medicinal, antimicrobial, insecticidal, or herbicidal properties. To assist with the much-...

journal_title：American journal of botany

authors： Groppo M,Pirani JR,Salatino ML,Blanco SR,Kallunki JA

更新日期：2008-08-01 00:00:00

abstract：:Polyploids have significantly influenced angiosperm evolution. Understanding the genetic consequences of polyploidy is advanced by studies on synthetic allopolyploids that mimic natural species. In Nicotiana, Burk (1973) and Kostoff (1938) generated synthetic tobacco (N. tabacum) using the parents ♀N. sylvestris × ♂N....

journal_title：American journal of botany

authors： Lim KY,Souckova-Skalicka K,Sarasan V,Clarkson JJ,Chase MW,Kovarik A,Leitch AR

更新日期：2006-06-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Microsatellite primers were developed in the introduced shrub Rhamnus cathartica L., to investigate potential hybridization events with related taxa as a stimulus of invasive spread. • METHODS AND RESULTS:Using a non-radioactive protocol, 15 primer sets were identified in North Americ...

journal_title：American journal of botany

authors： Culley TM,Stewart JR

更新日期：2010-03-01 00:00:00