abstract：:In a 3-yr study, we examined the pollinator guild and intersexual floral characteristics of the dioecious, perennial cloudberry (Rubus chamaemorus), which flowers in early spring. The findings contribute to our general understanding of pollination ecology at high latitudes and provide important information for the com...

journal_title：American journal of botany

authors： Brown AO,McNeil JN

更新日期：2009-06-01 00:00:00

abstract：:Many characteristics of plants and animals scale with body size as described by allometric equations of the form Y = βM(α), where Y is an attribute of the organism, β is a coefficient that varies with attribute, M is a measure of organism size, and α is another constant, the scaling exponent. In current models, the fr...

journal_title：American journal of botany

authors： Koontz TL,Petroff A,West GB,Brown JH

更新日期：2009-05-01 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：: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：: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：:Traditional farming communities frequently maintain high levels of agrobiodiversity, so understanding their agricultural practices is a priority for biodiversity conservation. The cultural origin of agave spirits (mezcals) from west-central Mexico is in the southern part of the state of Jalisco where traditional farme...

journal_title：American journal of botany

authors： Vargas-Ponce O,Zizumbo-Villarreal D,Martínez-Castillo J,Coello-Coello J,Colunga-Garcíamarín P

更新日期：2009-02-01 00:00:00

abstract：:Koch et al. (Nature 428: 851-854) measured various parameters that were thought to limit the height of Sequoia sempervirens from northern California and concluded that the maximum height for this species is 122-130 m because within this range: (1) Irreversible embolism formation was proposed to occur when the xylem pr...

journal_title：American journal of botany

authors： Netting AG

更新日期：2009-02-01 00:00:00

abstract：:For more than a century, the common ancestor of flowering plants was thought to have had a seven-celled, eight-nucleate Polygonum-type female gametophyte. It is now evident that not one, but in fact three, patterns of female gametophyte development and mature structure characterize the common ancestors of the four mos...

journal_title：American journal of botany

authors： Friedman WE,Ryerson KC

更新日期：2009-01-01 00:00:00

abstract：:Bennettitales is an extinct group of seed plants with reproductive structures that are similar in some respects to both Gnetales and angiosperms, but systematic relationships among the three clades remain controversial. This study summarizes characters of bennettitalean plants and presents new evidence for the structu...

journal_title：American journal of botany

authors： Rothwell GW,Crepet WL,Stockey RA

更新日期：2009-01-01 00:00:00

abstract：:Wind is a major ecological factor for plants and a major economical factor for forestry. Mechanical analyses have revealed that the multimodal dynamic behavior of trees is central to wind-tree interactions. Moreover, the trunk and branches influence dynamic modes, both in frequency and location. Because of the complex...

journal_title：American journal of botany

authors： Rodriguez M,Langre Ed,Moulia B

更新日期：2008-12-01 00:00:00

abstract：:Trichomanes intricatum, the sporophyte-less filmy fern of the eastern United States, has been considered to be a species whose sporophyte generation has become extinct or is possibly still present among the many species of Trichomanes s.l. in the new world tropics but unable to grow in a temperate climate. A close rel...

journal_title：American journal of botany

authors： Ebihara A,Farrar DR,Ito M

更新日期：2008-12-01 00:00:00

abstract：:This paper presents the first broad overview of three main features of microsporogenesis (male meiosis) in angiosperms: cytokinesis (cell division), intersporal wall formation, and tetrad form. A phylogenetic comparative approach was used to test for correlated evolution among these characters and to make hypotheses a...

journal_title：American journal of botany

authors： Nadot S,Furness CA,Sannier J,Penet L,Triki-Teurtroy S,Albert B,Ressayre A

更新日期：2008-11-01 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：:Interspecific hybridization is considered a possible mechanism of plant diversification. The Andes are a hotspot of biodiversity, but hybridization in Andean taxa has so far not been investigated intensively. The current study investigates crossability in Caiophora (Loasaceae subfam. Loasoideae) by experimental inters...

journal_title：American journal of botany

authors： Ackermann M,Achatz M,Weigend M

更新日期：2008-09-01 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：: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：: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：:The Strait of Gibraltar is the most important barrier disconnecting the landmasses of Europe and Africa on the western Mediterranean extreme. Carex helodes is a wind-pollinated species endemic to the western Mediterranean. Because molecular and cytogenetic data allow the inference of its evolutionary history, we analy...

journal_title：American journal of botany

authors： Escudero M,Vargas P,Valcárcel V,Luceño M

更新日期：2008-06-01 00:00:00

abstract：:Propagule banks are assumed to be able to store considerable genetic variability. Bryophyte populations are expected to rely more heavily on stored propagules than those of seed plants due to the vulnerability of the haploid gametophyte. This reliance has important implications for the genetic structure and evolutiona...

journal_title：American journal of botany

authors： Hock Z,Szövényi P,Schneller JJ,Tóth Z,Urmi E

更新日期：2008-05-01 00:00:00

abstract：:The origin of polyploid Bromus species of section Genea was investigated using molecular data. This group of annual species native from the Old-World is composed of three diploids, two tetraploids, one hexaploid, and one octoploid. Molecular cloning, sequencing, and phylogenetic analyses were performed on several acce...

journal_title：American journal of botany

authors： Fortune PM,Pourtau N,Viron N,Ainouche ML

更新日期：2008-04-01 00:00:00

abstract：:The genus Rosa has a complex evolutionary history caused by several factors, often in conjunction: extensive hybridization, recent radiation, incomplete lineage sorting, and multiple events of polyploidy. We examined the applicability of AFLP markers for reconstructing (species) relationships in Rosa, using UPGMA clus...

journal_title：American journal of botany

authors： Koopman WJ,Wissemann V,De Cock K,Van Huylenbroeck J,De Riek J,Sabatino GJ,Visser D,Vosman B,Ritz CM,Maes B,Werlemark G,Nybom H,Debener T,Linde M,Smulders MJ

更新日期：2008-03-01 00:00:00

abstract：:Up to 22% of plant species are the result of breeding among species-hybridization-directly conflicting with the prediction that hybrids, compared to parental species, are intermediate in character and of low fitness and little consequence. Few studies, however, have compared the fitness of hybrids and parental species...

journal_title：American journal of botany

authors： Tierney DA,Wardle GM

更新日期：2008-02-01 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：:The tribe Genisteae includes genera of great ecological importance in Mediterranean countries because they are dominant elements of many plant communities. Genetic variation and diversification patterns in Stauracanthus (Genisteae) provide information relevant for the study of the processes of diversification in relat...

journal_title：American journal of botany

authors： Pardo C,Cubas P,Tahiri H

更新日期：2008-01-01 00:00:00

abstract：:In rainforests, trunk size, strength, crown position, and geometry of a tree affect light interception and the likelihood of mechanical failure. Allometric relationships of tree diameter, wood density, and crown architecture vs. height are described for a diverse range of rainforest trees in Brunei, northern Borneo. T...

journal_title：American journal of botany

authors： Osunkoya OO,Omar-Ali K,Amit N,Dayan J,Daud DS,Sheng TK

更新日期：2007-12-01 00:00:00

abstract：:We developed an improved cytological protocol for producing high quality, light microscope images of plant meiotic chromosomes. Because the technique works on species with small genomes and thick microsporocyte cell walls, it should be useful for studying the wild relatives of Arabidopsis and other eudicots with small...

journal_title：American journal of botany

authors： Stronghill PE,Hasenkampf CA

更新日期：2007-12-01 00:00:00

abstract：:Axillary meristems play a fundamental role in inflorescence architecture. Maize (Zea mays) inflorescences are highly branched panicles because of the production of multiple types of axillary meristems. We used auxin transport inhibitors to show that auxin transport is required for axillary meristem initiation in the m...

journal_title：American journal of botany

authors： Wu X,McSteen P

更新日期：2007-11-01 00:00:00

abstract：:Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reporte...

journal_title：American journal of botany

authors： Taylor PJ,Eppley SM,Jesson LK

更新日期：2007-11-01 00:00:00

abstract：:Taxonomical classification of higher fungi remains an important challenge and can benefit from the application of molecular analysis. We propose that the ectomycorrhizal (EM) fungal taxa might include a number of cryptic species because there are few morphological characteristics useful for distinguishing among these ...

journal_title：American journal of botany

authors： Sato H,Yumoto T,Murakami N

更新日期：2007-10-01 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：:Chloroplast DNA (cpDNA) is maternally inherited in the majority, but not all, of angiosperm species. The mode of inheritance of cpDNA is a critical determinant of its molecular evolution and of its population genetic structure. Here, we present the results of investigations of the inheritance of cpDNA in Silene vulgar...

journal_title：American journal of botany

authors： McCauley DE,Sundby AK,Bailey MF,Welch ME

更新日期：2007-08-01 00:00:00

abstract：:We used the chloroplast gene ndhF to reconstruct the phylogeny of the moonseed family (Menispermaceae), a morphologically diverse and poorly known cosmopolitan family of dioecious, primarily climbing plants. This study includes a worldwide sample of DNA sequences for 88 species representing 49 of the 70 genera of all ...

journal_title：American journal of botany

authors： Ortiz Rdel C,Kellogg EA,Werff HV

更新日期：2007-08-01 00:00:00

abstract：:Bamboo is considered useful for controlling landslides, but we observed numerous shallow-slope failures in forests of big node bamboo (Phyllostachys nidularia) in Sichuan, China. Therefore, we inventoried landslide occurrence and vegetation type along one valley. To quantify bamboo root anchorage, we performed uprooti...

journal_title：American journal of botany

authors： Stokes A,Lucas A,Jouneau L

更新日期：2007-07-01 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：:To our knowledge, xylary reaction tissue has never been reported in a forage crop species. Here we report the discovery of reaction tissue in a transgenic line of Medicago sativa (pC3H, for the gene for p-coumarate-3-hydroxylase) with reduced lignin content and in the wild-type (WT) line. Based on microscopy and biome...

journal_title：American journal of botany

authors： Patten AM,Jourdes M,Brown EE,Laborie MP,Davin LB,Lewis NG

更新日期：2007-06-01 00:00:00

abstract：:The plastid trnL-F region has proved useful in molecular phylogenetic studies addressing diverse evolutionary questions from biogeographic history to character evolution in a broad range of plant groups. An important assumption for phylogenetic reconstruction is that data used in combined analyses contain the same phy...

journal_title：American journal of botany

authors： Pirie MD,Vargas MP,Botermans M,Bakker FT,Chatrou LW

更新日期：2007-06-01 00:00:00

abstract：:We tested the hypothesis that trees growing at high elevations with occasional freezing temperatures have smaller diameter xylem vessels than trees of the same species growing at lower and warmer elevations. The young branch wood of the wide-ranging Hawaiian tree species Metrosideros polymorpha (Myrtaceae) was examine...

journal_title：American journal of botany

authors： Fisher JB,Goldstein G,Jones TJ,Cordell S

更新日期：2007-05-01 00:00:00

abstract：:To investigate the relationship between the altitudinal distribution of Quercus laceyi and Q. sideroxyla and their physiological responses to drought, we measured relative water content (RWC), water potentials (Ψ(predawn) and Ψ(midday)), photosynthesis (A(max)), stomatal conductance (g), chlorophyll fluorescence (F(v)...

journal_title：American journal of botany

authors： Poulos HM,Goodale UM,Berlyn GP

更新日期：2007-05-01 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：:The fossil record of aquatic flowering plants broadens our understanding of their former diversity and origins from terrestrial ancestors. This paper describes a floating aquatic monocot from 71 whole plants and several isolated leaf fragments from Upper Cretaceous oxbow lake sediments in the Dinosaur Park Formation, ...

journal_title：American journal of botany

authors： Stockey RA,Rothwell GW,Johnson KR

更新日期：2007-04-01 00:00:00