Morphological and genetic differentiation and reproductive isolation among closely related taxa in the Ipomoea series Batatas.

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：:Seedling establishment is central to population maintenance for nonclonal plant species. Plants with low recruitment rates are expected to have high survival rates, and life history theory indicates there should be a single curve for the trade-off between recruitment and mortality that applies to most or all plant spe...

journal_title：American journal of botany

authors： Forbis TA,Doak DF

更新日期：2004-07-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Specific leaf area (SLA) is a critical component of the leaf economics spectrum, and many functional leaf traits have been empirically demonstrated to covary with SLA. However, a complete understanding of how change in leaf size influences SLA has not yet emerged. • METHODS:To help de...

journal_title：American journal of botany

authors： Price CA,Weitz JS

更新日期：2010-11-01 00:00:00

abstract：:The micromorphology of pits in tracheary elements was examined in 35 species representing 29 genera of Rosaceae and related families to evaluate the assumption that angiosperm pits are largely invariant. In most Rosaceae, pit membranes between fibers and tracheids frequently appear to have amorphous thickenings with a...

journal_title：American journal of botany

authors： Jansen S,Sano Y,Choat B,Rabaey D,Lens F,Dute RR

更新日期：2007-04-01 00:00:00

abstract：:We examined the effect of inbreeding on fitness (through both male and female functions) and changes in self-fertility in the partially self-incompatible species Campanula rapunculoides. Individuals in natural populations of C. rapunculoides varied extensively in their strength of self-incompatibility (SI). We crossed...

journal_title：American journal of botany

authors： Good-Avila SV,Nagel T,Vogler DW,Stephenson AG

更新日期：2003-12-01 00:00:00

abstract：:The evolutionary history of maize (Zea mays subsp. mays) is of general interest because of its economic and scientific importance. Here we show that many cellular traits described previously in developing caryopses of maize are also seen in its wild progenitor teosinte (Zea mays subsp. parviglumis). These features, ea...

journal_title：American journal of botany

authors： Dermastia M,Kladnik A,Dolenc Koce J,Chourey PS

更新日期：2009-10-01 00:00:00

abstract：:Long-distance transplantation of seed material as done in restoration programs has raised concerns about the risks associated with the introduction of maladapted genotypes that may hybridize with neighboring native conspecifics and decrease local population fitness (outbreeding depression). We studied the consequences...

journal_title：American journal of botany

authors： Crémieux L,Bischoff A,Müller-Schärer H,Steinger T

更新日期：2010-01-01 00:00:00

abstract：PREMISE OF THE STUDY:Over one-third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. METHODS:...

journal_title：American journal of botany

authors： Aslan CE,Shiels AB,Haines W,Liang CT

更新日期：2019-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Previous studies have shown that polyploidy has pronounced effects on photosynthesis. Most of these studies have focused on synthetic or recently formed autopolyploids, and comparatively little is known about the integrated effects of natural allopolyploidy, which involves hybridity and genome doub...

journal_title：American journal of botany

authors： Coate JE,Luciano AK,Seralathan V,Minchew KJ,Owens TG,Doyle JJ

更新日期：2012-01-01 00:00:00

abstract：:Terrestrial plant leaves are complex structures of composite materials. Resistance to fracture is achieved by a number of mechanisms, which operate at the molecular, cell, tissue, and structural levels. Leaves of dicots have different venation patterns and cell wall volume fractions from those of grasses, and conseque...

journal_title：American journal of botany

authors： Sanson G

更新日期：2006-10-01 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 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：:Phylogenetic relationships and biogeography of the genus Cerastium were studied using sequences of three noncoding plastid DNA regions (trnL intron, trnL-trnF spacer, and psbA-trnH spacer). A total of 57 Cerastium taxa was analyzed using two species of the putative sister genus Stellaria as outgroups. Maximum parsimon...

journal_title：American journal of botany

authors： Scheen AC,Brochmann C,Brysting AK,Elven R,Morris A,Soltis DE,Soltis PS,Albert VA

更新日期：2004-06-01 00:00:00

abstract：:Megaspore and microspore massulae of Paleoazolla patagonica gen. et sp. nov. are described from the Upper Cretaceous of La Colonia Formation, Chubut Province, Argentina. The new fern possesses megaspore complexes with three to four glochidiate floats attached directly to the megaspore; a columella-like structure appea...

journal_title：American journal of botany

authors： Archangelsky A,Phipps CJ,Taylor TN,Taylor EL

更新日期：1999-08-01 00:00:00

abstract：PREMISE OF THE STUDY:Phylogenetic incongruence between "gene trees" and "species trees" has been widely acknowledged in phylogenetic research. Conflicts may emerge from several processes including paralogy, hybridization, and incomplete lineage sorting. Although phylogenetic incongruence appears common, its impact on m...

journal_title：American journal of botany

authors： Zhang Q,Feild TS,Antonelli A

更新日期：2015-04-01 00:00:00

abstract：:• Premise of the study: Tropical forests are the most species-rich terrestrial communities on Earth, and understory trees and shrubs comprise a large fraction of their plant species diversity, especially at high rainfalls. The mechanisms responsible for generating such high levels of diversity remain unknown. One hypo...

journal_title：American journal of botany

authors： Theim TJ,Shirk RY,Givnish TJ

更新日期：2014-07-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Microsatellite markers were isolated and characterized in Mimulus ringens (Phrymaceae), a herbaceous wetland perennial, to facilitate studies of mating patterns and population genetic structure. • METHODS AND RESULTS:A total of 42 polymorphic loci were identified from a sample of 24 i...

journal_title：American journal of botany

authors： Nunziata SO,Karron JD,Mitchell RJ,Lance SL,Jones KL,Trapnell DW

更新日期：2012-12-01 00:00:00

abstract：:Iris cristata and I. lacustris differ markedly in geographic distribution, glacial history of current ranges, and ecology. We hypothesized that I. cristata, a widespread species of unglaciated regions of eastern North America, would exhibit genetic diversity typical of other widespread plant species, whereas the threa...

journal_title：American journal of botany

authors： Hannan GL,Orick MW

更新日期：2000-03-01 00:00:00

abstract：:The mode of chloroplast DNA (cpDNA) inheritance was investigated in the genus Larrea (Zygophyllaceae) by polymerase chain reaction (PCR) amplification of cpDNA fragments using three pairs of chloroplast universal primers. A total of 20 F(1)s from interspecific crosses among five different taxa in the section Bifolium ...

journal_title：American journal of botany

authors： Yang TW,Yang YA,Xiong Z

更新日期：2000-10-01 00:00:00

abstract：:Tribe Macadamieae (91 spp., 16 genera; Proteaceae) is widespread across the southern hemisphere on all major fragments of Gondwana except New Zealand and India. Macadamia is cultivated outside its natural range as a "nut" crop (notably in Hawaii, where it is the principal orchard crop). We sampled seven DNA regions an...

journal_title：American journal of botany

authors： Mast AR,Willis CL,Jones EH,Downs KM,Weston PH

更新日期：2008-07-01 00:00:00

abstract：PREMISE:Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerance...

journal_title：American journal of botany

authors： Martino M,Semple JC,Beck JB

更新日期：2020-11-01 00:00:00

abstract：:Fitness of interspecific hybrids is sometimes high relative to their parents, despite the conventional belief that they are mostly unfit. F(1) hybrids between oilseed rape (Brassica napus) and weedy B. rapa can be significantly more fit than their weedy parents under some conditions; however, under other conditions th...

journal_title：American journal of botany

authors： Hauser TP,Damgaard C,Jørgensen RB

更新日期：2003-04-01 00:00:00

abstract：:Partial cambial mortality is a growth form that is characteristic of Pinus aristata trees. To better elucidate their cambial death pattern, tree size and aspect of cambial death data were gathered from three Pinus aristata forests in central Colorado, USA. Stripping frequency tended to be higher for larger diameter cl...

journal_title：American journal of botany

authors： Schauer AJ,Schoettle AW,Boyce RL

更新日期：2001-04-01 00:00:00

abstract：PREMISE OF THE STUDY:Plant communities may be influenced by toxic secondary metabolites or enhanced plant growth from plant-symbiont interactions. The C:N hypothesis predicts that carbon or nitrogen constrains plant secondary metabolite production, but it does not consider compounds produced by plant symbionts. Locowee...

journal_title：American journal of botany

authors： Delaney KJ,Klypina N,Maruthavanan J,Lange C,Sterling TM

更新日期：2011-12-01 00:00:00

abstract：PREMISE:The Eocene-Oligocene transition (EOT; 34-33 Ma) was marked by global cooling and increased seasonality and aridity, leading to a shift in North American floras from subtropical forests to deciduous hardwood forests similar to today. This shift is well documented taxonomically and biogeographically, but its ecol...

journal_title：American journal of botany

authors： Butrim MJ,Royer DL

更新日期：2020-12-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Despite the ecological, economic, and cultural importance of the palm Mauritia flexuosa in Amazonia, knowledge of its reproductive biology is scarce. Previous observations of this species suggested beetles as the probable pollinator, but experimental work to confirm this hypothesis was...

journal_title：American journal of botany

authors： Khorsand Rosa R,Koptur S

更新日期：2013-03-01 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：: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：:Chrysothamnus nauseosus (Asteraceae) is a complex polymorphic shrub species widely distributed in western North America. In a study of 86 populations belonging to 15 subspecies, achene mass varied among populations over a sevenfold range. Achene mass was closely correlated with capitulum size at the subspecies level, ...

journal_title：American journal of botany

authors： Meyer S

更新日期：1997-04-01 00:00:00

abstract：:Developmental and physiological studies of roots are frequently limited to a post-germination stage. In Arabidopsis, a developmental change in the root meristem architecture during plant ontogenesis has not previously been studied and is addressed presently. Arabidopsis thaliana have closed root apical organization, i...

journal_title：American journal of botany

authors： Baum SF,Dubrovsky JG,Rost TL

更新日期：2002-06-01 00:00:00