Embryology of the Theaceae - anther and ovule development of Camellia, Franklinia, and Schima.

abstract：:This paper reports the frequency of spontaneous amphiploids or neopolyploids in experimental interspecific hybrids in two annual sections of Gilia (Polemoniaceae, sects. Arachnion and Gilia, x = 9). In each section the species were intercrossed in numerous hybrid combinations to obtain an array of F1 hybrid types; sev...

journal_title：American journal of botany

authors： Grant V

更新日期：2002-08-01 00:00:00

abstract：PREMISE OF THE STUDY:Geographic patterns of biodiversity have long inspired interest in processes that shape the assembly, diversity, and dynamics of communities at different spatial scales. To study mechanisms of community assembly, ecologists often compare spatial variation in community composition (beta-diversity) a...

journal_title：American journal of botany

authors： Burkle LA,Myers JA,Belote RT

更新日期：2016-01-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multip...

journal_title：American journal of botany

authors： Theis N,Barber NA,Gillespie SD,Hazzard RV,Adler LS

更新日期：2014-08-01 00:00:00

abstract：:Zeuxine gracilis, Zeuxine strateumatica, and Eulophia sinensis are wild orchids with different breeding systems and colonizing abilities. Zeuxine gracilis is an outcrosser with restricted distribution, whereas S. strateumatica is an apomictic colonizer found only in newly available open habitats. Eulophia sinensis is ...

journal_title：American journal of botany

authors： Sun M,Wong KC

更新日期：2001-12-01 00:00:00

abstract：PREMISE OF THE STUDY:Seed cone scales assigned to the genus Schizolepidopsis are widespread in Late Triassic to Cretaceous Eurasian deposits. They have been linked to the conifer family Pinaceae based on associated vegetative remains, but their exact affinities are uncertain. Recently discovered material from the Early...

journal_title：American journal of botany

authors： Leslie AB,Glasspool I,Herendeen PS,Ichinnorov N,Knopf P,Takahashi M,Crane PR

更新日期：2013-12-01 00:00:00

abstract：:Hybridization and introgression play important roles in plant evolution, and their occurrence on the oceanic islands provides good examples of plant speciation and diversification. Restriction fragment length polymorphisms (RFLPs) and trnL (UAA) 3'exon-trnF (GAA) intergenic spacer (IGS) sequences of chloroplast DNA (c...

journal_title：American journal of botany

authors： Setoguchi H,Watanabe I

更新日期：2000-06-01 00:00:00

abstract：:Seeds are useful in distinguishing among extant genera of Vitaceae and provide a good basis for interpretation of fossil remains in reconstructing the evolutionary and phytogeographic history of this putatively basal Rosid family. Seeds of Ampelocissus s.l. including Pterisanthes and Nothocissus are distinguished from...

journal_title：American journal of botany

authors： Chen I,Manchester SR

更新日期：2007-09-01 00:00:00

abstract：:We investigated patterns of fruit and seed production on inflorescences of a population of Pancratium maritimum in northwest Spain over a 2-yr period. Initial findings showed that the earliest opening flowers on an inflorescence are more likely to set fruit and produce more seeds than later opening flowers and that th...

journal_title：American journal of botany

authors： Medrano M,Guitián P,Guitián J

更新日期：2000-04-01 00:00:00

abstract：:Temporal and demographic aspects of the growth of Botrychium gallicomontanum and B. mormo were studied for 2 yr. A total of 219 B. gallicomontanum and 412 B. mormo plants were monitored in a prairie and maple-basswood forest, respectively. Growth events were divided into four stages: leaf emergence, leaf separation, s...

journal_title：American journal of botany

authors： Johnson-Groh CL,Lee JM

更新日期：2002-10-01 00:00:00

abstract：:Scaling relationships among photosynthetic rate, foliar nutrient concentration, and leaf mass per unit area (LMA) have been observed for a broad range of plants. Leaf traits of the carnivorous pitcher plant Darlingtonia californica, endemic to southern Oregon and northern California, USA, differ substantially from the...

journal_title：American journal of botany

authors： Ellison AM,Farnsworth EJ

更新日期：2005-07-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Taxonomic groups have often been recognized on the basis of geographic distinctions rather than accurately representing evolutionary relationships. This has been particularly true for temperate and tropical members from the same family. Polygonaceae exemplifies this problem, wherein th...

journal_title：American journal of botany

authors： Burke JM,Sanchez A,Kron K,Luckow M

更新日期：2010-08-01 00:00:00

abstract：:The degree to which plants self-fertilize may impact their potential for genetic adaptation. Given that the mating system influences genetic processes within and among populations, the mating system could limit or promote local adaptation. I conducted a literature survey of published reciprocal transplant experiments ...

journal_title：American journal of botany

authors： Hereford J

更新日期：2010-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Virtually nothing is known about what actually happens during prolonged dormancy, the period during which significant proportions of geophyte populations do not sprout after seasonal dormancy but remain alive underground, to emerge again 1 or more years later. This study investigated the fate of pe...

journal_title：American journal of botany

authors： Gregg KB

更新日期：2011-02-01 00:00:00

abstract：PREMISE:Outcomes of species interactions, especially mutualisms, are notoriously dependent on environmental context, and environments are changing rapidly. Studies have investigated how mutualisms respond to or ameliorate anthropogenic environmental changes, but most have focused on nutrient pollution or climate change...

journal_title：American journal of botany

authors： O'Brien AM,Yu ZH,Luo DY,Laurich J,Passeport E,Frederickson ME

更新日期：2020-02-01 00:00:00

abstract：:Natural recruitment of oaks appears to be declining throughout the northern hemisphere. Summer drought poses a potentially important barrier to oak recruitment in southern California. To evaluate this barrier, we grew evergreen Quercus agrifolia and deciduous Q. lobata from seeds near parental trees. We measured water...

journal_title：American journal of botany

authors： Mahall BE,Tyler CM,Cole ES,Mata C

更新日期：2009-04-01 00:00:00

abstract：PREMISE:The genus Arisaema (Araceae) has rapidly diversified in Japan, and multiple species often coexist in the field. Although Japanese Arisaema species hybridize from artificial crossing, hybrid individuals are rare in mixed populations; suggesting the presence of effective pre-pollination barriers. We examined the ...

journal_title：American journal of botany

authors： Matsumoto TK,Miyazaki Y,Sueyoshi M,Senda Y,Yamada K,Hirobe M

更新日期：2019-12-01 00:00:00

abstract：:Restriction fragment length polymorphism (RFLP) analysis of chloroplast (cp) DNA is a powerful tool for the study of microevolutionary processes in land plants, yet has not previously been applied to seaweed populations. We used cpDNA-RFLP, detected on Southern blots using labeled total plastid DNA, to search for intr...

journal_title：American journal of botany

authors： Wattier RA,Davidson AL,Ward BA,Maggs CA

更新日期：2001-07-01 00:00:00

abstract：:Multicellularity has evolved at least once in every major eukaryotic clade (in all ploidy levels) and numerous times among the prokaryotes. According to a standard multilevel selection (MLS) model, in each case, the evolution of multicellularity required the acquisition of cell-cell adhesion, communication, cooperatio...

journal_title：American journal of botany

authors： Niklas KJ

更新日期：2014-01-01 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：:Exotic plant species can threaten closely related native congeners through asymmetric hybridization and subsequent backcrossing, the process known as genetic assimilation. I explore the initial stages of this process in Taraxacum ceratophorum (Asteraceae), the native alpine dandelion, and the invasive apomict T. offic...

journal_title：American journal of botany

authors： Brock MT

更新日期：2004-05-01 00:00:00

abstract：:Tropical forest plants are known to be pollinated by a diverse array of animals. Here we report on the pollination of a woody climber species, Uvaria elmeri (Annonaceae), by cockroaches in a lowland mixed-dipterocarp forest in Sarawak, Malaysia. To the best of our knowledge, this is the first report of pollination by ...

journal_title：American journal of botany

authors： Nagamitsu T,Inoue T

更新日期：1997-02-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Accurate assessments of biodiversity are paramount for understanding ecosystem processes and adaptation to change. Invasive species often contribute substantially to local biodiversity; correctly identifying and distinguishing invaders is thus necessary to assess their potential impac...

journal_title：American journal of botany

authors： Moffat CE,Ensing DJ,Gaskin JF,De Clerck-Floate RA,Pither J

更新日期：2015-07-01 00:00:00

abstract：:Deciphering species relationships and hybrid origins in polyploid agamic species complexes is notoriously difficult. In this study of cheilanthoid ferns, we demonstrate increased resolving power for clarifying the origins of polyploid lineages by integrating evidence from a diverse selection of biosystematic methods. ...

journal_title：American journal of botany

authors： Grusz AL,Windham MD,Pryer KM

更新日期：2009-09-01 00:00:00

abstract：PREMISE:Inbreeding depression is traditionally considered a major factor favoring outcrossing in hermaphrodites. Recent experiments have shown that environmental conditions can influence the magnitude of inbreeding depression, but their relevance in natural populations is unclear. To investigate this, we studied the cl...

journal_title：American journal of botany

authors： Stojanova B,Maurice S,Cheptou PO

更新日期：2020-01-01 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：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 eudicot order Malpighiales contains ∼16000 species and is the most poorly resolved large rosid clade. To clarify phylogenetic relationships in the order, we used maximum likelihood, Bayesian, and parsimony analyses of DNA sequence data from 13 gene regions, totaling 15604 bp, and representing all three genomic com...

journal_title：American journal of botany

authors： Wurdack KJ,Davis CC

更新日期：2009-08-01 00:00:00

abstract：:A detailed study of ascomal morphology and development in Cercophora palmicola showed that ontogeny is ascohymeniaceous, giving rise to an ostiolate perithecium. Ascomal initials consist of a coiled ascogonium surrounded by several layers of hyphae whose cells become pseudoparenchymatous. The centrum of the young asco...

journal_title：American journal of botany

authors： Hanlin RT

更新日期：1999-06-01 00:00:00

abstract：:Phylogenetic relationships were inferred using nucleotide sequence variation of the nuclear-encoded chalcone synthase gene (Chs) and the chloroplast gene matK for members of five tribes from the family Brassicaceae to analyze tribal and subtribal structures. Phylogenetic trees from individual data sets are mostly in c...

journal_title：American journal of botany

authors： Koch M,Haubold B,Mitchell-Olds T

更新日期：2001-03-01 00:00:00

abstract：PREMISE:Spiny pollen has evolved independently in multiple entomophilous lineages. Sexual selection may act on exine traits that facilitate male mating success by influencing the transfer of pollen from the anther to the body of the pollinator, while natural selection acts to increase pollen survival. We postulated tha...

journal_title：American journal of botany

authors： Lynn A,Piotter E,Harrison E,Galen C

更新日期：2020-02-01 00:00:00