Phenology and demography of two species of Botrychium (Ophioglossaceae).

abstract：PREMISE OF THE STUDY:Vestigialization of traits that no longer enhance fitness is a common theme in evolution. Plants often use colorful, scented flowers to attract pollinators that mediate outcross pollination. After an evolutionary shift from outcrossing to self-fertilization, where cross-pollination is no longer nec...

journal_title：American journal of botany

authors： Doubleday LA,Raguso RA,Eckert CG

更新日期：2013-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Elucidating the factors that determine the abundance and distribution of species remains a central goal of ecology. It is well recognized that genetic differences among individual species can affect the distribution and species interactions of dependent taxa, but the ecological effects of genetic d...

journal_title：American journal of botany

authors： Adams RI,Goldberry S,Whitham TG,Zinkgraf MS,Dirzo R

更新日期：2011-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Most pollen walls are interrupted by apertures, thin areas providing access to stigmatic fluids and exit points for pollen tubes. Unexpectedly, pollen tubes of Arabidopsis thaliana are not obligated to pass through apertures and can instead take the shortest route into the stigma, passing directly ...

journal_title：American journal of botany

authors： Edlund AF,Zheng Q,Lowe N,Kuseryk S,Ainsworth KL,Lyles RH,Sibener SJ,Preuss D

更新日期：2016-06-01 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：PREMISE OF THE STUDY:Population genetic structuring over limited timescales is commonly viewed as a consequence of spatial constraints. Indirect approaches have recently revealed reproductive isolation resulting from flowering time (so-called isolation by time, IBT). Since phenological processes can be subject to selec...

journal_title：American journal of botany

authors： Daïnou K,Laurenty E,Mahy G,Hardy OJ,Brostaux Y,Tagg N,Doucet JL

更新日期：2012-09-01 00:00:00

abstract：PREMISE OF THE STUDY:The evolution of metal tolerance in plants is an important model for studies of adaptation to environment, population genetics, and speciation. Here, we investigated nickel tolerance in the North American serpentine endemic Caulanthus amplexicaulis var. barbarae in comparison with its nonserpentine...

journal_title：American journal of botany

authors： Burrell AM,Hawkins AK,Pepper AE

更新日期：2012-11-01 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：:The North American plums are a closely related group that are not easily circumscribed, have overlapping morphologies, and are known to hybridize. We previously showed that the North American plums are a closely related, monophyletic group of taxa with little to no cpDNA sequence divergence between taxa. In that study...

journal_title：American journal of botany

authors： Shaw J,Small RL

更新日期：2005-12-01 00:00:00

abstract：:A spatially explicit, reiterative algorithm (SERA) is presented and used to predict multiple aspects of plant population and community dynamics. Using simple physical principles and empirically derived relationships, SERA provides an analytical venue to test alternative hypotheses about individual functional traits go...

journal_title：American journal of botany

authors： Hammond ST,Niklas KJ

更新日期：2009-08-01 00:00:00

abstract：:Climate changes during glacial periods have had significant effects on the present geographic distribution of plant species. To elucidate the evolutionary history of a plant species with a disjunctive distribution, we investigated the geographic distribution patterns of cpDNA haplotypes in Photinia glabra (Rosaceae) g...

journal_title：American journal of botany

authors： Aoki K,Matsumura T,Hattori T,Murakami N

更新日期：2006-12-01 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：:Individual plants of Asclepias exaltata (Asclepiadaceae) typically express an unusual self-incompatibility system under single-gene control. Hand-pollinations performed in six natural populations detected occasional self-fertile plants. The frequency of self-fertile individuals ranged from 0 to 34.0% and differed sign...

journal_title：American journal of botany

authors： Lipow SR,Broyles SB,Wyatt R

更新日期：1999-08-01 00:00:00

abstract：:Self-incompatibility (SI) is an effective method for limiting self-fertilization in flowering plant species, but there are circumstances in which an otherwise functional SI system may fail. One of the most intriguing of these is the induction of selfing by mixed loads of self and heterospecific pollen (the mentor effe...

journal_title：American journal of botany

authors： Desrochers A,Rieseberg L

更新日期：1998-06-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:The question why leaf dimensions vary so much between species has long puzzled ecologists. Presumably, variation arises from selective forces acting on leaf function but which selective forces and which leaf functions? This investigation assesses the consistency of divergence in plant...

journal_title：American journal of botany

authors： Tozer WC,Rice B,Westoby M

更新日期：2015-03-01 00:00:00

abstract：:Six of 14 species of Triteleia were studied. All possess septal nectaries, raphides in the ovary wall, an anatropous and crassinucellate ovule with a micropyle formed by the inner integument only, and parietal cells. A short and thick nucellus, which is not penetrated by the embryo sac, has a one-layered apical epider...

journal_title：American journal of botany

authors： Berg RY

更新日期：2003-06-01 00:00:00

abstract：PREMISE OF THE STUDY:During the interactions between a parasitic plant and its host, the parasite affects its host morphologically, anatomically, and physiologically, yet there has been little focus on the effect of hosts on the parasite. Here, the functional interactions between the hemiparasitic mistletoe Psittacanth...

journal_title：American journal of botany

authors： Cocoletzi E,Angeles G,Ceccantini G,Patrón A,Ornelas JF

更新日期：2016-06-01 00:00:00

abstract：:Tacca, a genus of tropical herbs, possesses near black flowers, conspicuous involucral bracts and whisker-like filiform bracteoles. These features have been assumed to function as a "deceit syndrome" in which reproductive structures resemble decaying organic material attracting flies that facilitate cross-pollination ...

journal_title：American journal of botany

authors： Zhang L,Barrett SC,Gao JY,Chen J,Cole WW,Liu Y,Bai ZL,Li QJ

更新日期：2005-03-01 00:00:00

abstract：:Correlations were examined between habitat characters and clonal structures determined by the RAPD (random amplified polymorphic DNA) assay in five populations of Oryza rufipogon in China. Nine of 175 decameric primers were used in the study because they reproducibly amplified polymorphisms. The extent of clonality to...

journal_title：American journal of botany

authors： Xie ZW,Lu YQ,Ge S,Hong DY,Li FZ

更新日期：2001-06-01 00:00:00

abstract：PREMISE OF THE STUDY:Both polyploidy and shifts in floral color have marked angiosperm evolution. Here, we investigate the biochemical basis of the novel and diverse floral phenotypes seen in allopolyploids in Nicotiana (Solanaceae) and examine the extent to which the merging of distinct genomes alters flavonoid pigmen...

journal_title：American journal of botany

authors： McCarthy EW,Berardi AE,Smith SD,Litt A

更新日期：2017-01-01 00:00:00

abstract：:The biogeography of plant-animal interactions is a novel topic on which many disciplines converge (e.g., reproductive biology, biogeography, and evolutionary biology). Narrative reviews have indicated that tropical columnar cacti and agaves have highly specialized pollination systems, while extratropical species have ...

journal_title：American journal of botany

authors： Munguía-Rosas MA,Sosa VJ,Ojeda MM,De-Nova JA

更新日期：2009-10-01 00:00:00

abstract：PREMISE OF THE STUDY:New microsatellite primers were developed for testing genetic differentiation within Nothoceros aenigmaticus and their potential use in other Nothoceros species. The microsatellites are designed to investigate partitioning of genetic variation in a taxon with a peculiar sex allopatry in the souther...

journal_title：American journal of botany

authors： Villarreal JC,Forrest LL,McFarland K,Goffinet B

更新日期：2012-03-01 00:00:00

abstract：:We examined the effects of size and spatial isolation of fens on the isozyme variability of 17 populations of Swertia perennis. This long-lived perennial is a locally abundant fen specialist in Switzerland, where wetlands have been strongly fragmented. Isozyme variability was comparable to other outcrossing plants (A ...

journal_title：American journal of botany

authors： Lienert J,Fischer M,Schneller J,Diemer M

更新日期：2002-05-01 00:00:00

abstract：PREMISE OF THE STUDY:We developed simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) for Callitris columellaris sensu lato (s.l.) to elucidate population genetic structure and detect outlier loci by genome scan. METHODS AND RESULTS:mRNA from an individual seedling was subjected to cDNA synthesis ...

journal_title：American journal of botany

authors： Sakaguchi S,Uchiyama K,Ueno S,Ujino-Ihara T,Tsumura Y,Prior LD,Bowman DM,Crisp MD,Isagi Y

更新日期：2011-12-01 00:00:00

abstract：:Based on positive results for 11 of 17 species included in an anatomical survey of tree roots, we concluded that the origin of adventitious branch roots (ABR) on established, undisturbed woody parental root axes is a widespread occurrence. ABR were morphologically indistinguishable from branch roots formed in primary ...

journal_title：American journal of botany

authors： Paolillo DJ Jr,Bassuk NL

更新日期：2005-05-01 00:00:00

abstract：:We analyzed the effects of temporal variation in floral display size (number of flowers open at one time on a plant) on the rate of pollen removed and receipt of individual flowers for the sequential blooming plant Narthecium asiaticum (Liliaceae). Because of the acropetal blooming of this species, the display sizes w...

journal_title：American journal of botany

authors： Ishii HS,Sakai S

更新日期：2002-03-01 00:00:00

abstract：:Gelatinous fibers (G-fibers) are the active component of tension wood. G-fibers are unlike traditional fiber cells in that they possess a thick, nonlignified gelatinous layer (G-layer) internal to the normal secondary cell wall layers. For the past several decades, the G-layer has generally been presumed to be compose...

journal_title：American journal of botany

authors： Bowling AJ,Vaughn KC

更新日期：2008-06-01 00:00:00

abstract：PREMISE OF THE STUDY:Productivity in drylands may depend on the sensitivity of interactions between plants and biocrusts. Given future climate variability, it is essential to understand how interactions may be context-dependent with precipitation regime. Furthermore, little is known about the additional interactions of...

journal_title：American journal of botany

authors： Dettweiler-Robinson E,Sinsabaugh RL,Rudgers JA

更新日期：2018-07-01 00:00:00

abstract：:Investigations of the Middle Eocene Princeton Chert reveal evidence for the connection of lauraceous flowers to fruits through a developmental series. Youngest fruits are found with attached floral remnants. Later stages show receptacle enlargement, fruit wall thickening, and the development of abundant sclereid clust...

journal_title：American journal of botany

authors： Little SA,Stockey RA,Penner B

更新日期：2009-03-01 00:00:00

abstract：PREMISE OF THE STUDY:The perennial feather moss Hylocomium splendens is one of the most widely distributed and common bryophytes in the Northern Hemisphere and has, because of its capacity to grow under a wide range of environmental conditions, been used as a biomonitor for atmospheric metal deposition in Europe. METH...

journal_title：American journal of botany

authors： Vik U,Halvorsen R,Ohlson M,Rydgren K,Carlsen T,Korpelainen H,Kauserud H

更新日期：2012-09-01 00:00:00

abstract：:Serpentine soils are a model system for the study of plant adaptation, speciation, and species interactions. Serpentine soil is an edaphically stressful, low productivity soil type that hosts stunted vegetation and a spectacular level of plant endemism. One of the first papers on serpentine plant endemism was by Arthu...

journal_title：American journal of botany

authors： Anacker BL

更新日期：2014-02-01 00:00:00