Geographic differentiation in the pollination system of the columnar cactus Pachycereus pecten -aboriginum.

abstract：PREMISE OF THE STUDY:Inclusion of fossils in phylogenetic analyses is necessary in order to construct a comprehensive "tree of death" and elucidate evolutionary history of taxa; however, such incorporation of fossils in phylogenetic reconstruction is dependent on the availability and interpretation of extensive morphol...

journal_title：American journal of botany

authors： Smith SY,Iles WJD,Benedict JC,Specht CD

更新日期：2018-08-01 00:00:00

abstract：PREMISE OF THE STUDY:While the effect of abiotic factors on leaf herbivory is well known, the relative importance of abiotic conditions influencing both mutualists and antagonists is less well understood. Species interactions could enhance or reduce the direct effects of abiotic factors, depending on how mutualists and...

journal_title：American journal of botany

authors： Soper Gorden NL,Adler LS

更新日期：2013-04-01 00:00:00

abstract：PREMISE:Although hybridization has played an important role in the evolution of many plant species, phylogenetic reconstructions that include hybridizing lineages have been historically constrained by the available models and data. Restriction-site-associated DNA sequencing (RADseq) has been a popular sequencing techni...

journal_title：American journal of botany

authors： Blanco-Pastor JL,Bertrand YJK,Liberal IM,Wei Y,Brummer EC,Pfeil BE

更新日期：2019-09-01 00:00:00

abstract：:Competition and herbivory are ubiquitous environmental challenges that affect most plants. We examined the influence of phenotypic responses to either competition or herbivory on the subsequent response of the plants to the other factor. The stem-elongation response of Chenopodium album to light competition attenuated...

journal_title：American journal of botany

authors： Kurashige NS,Agrawal AA

更新日期：2005-01-01 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：:The endodermis of different species of the genus Equisetum has different configurations, two or one continuous layers or a sheath only around the vascular bundles. The question whether the endodermis contributes to the mechanical stability of the aerial shoots is investigated in two ways: In a direct approach, the end...

journal_title：American journal of botany

authors： Spatz HC,Emanns A

更新日期：2004-11-01 00:00:00

abstract：:The specific shape of the relationship between plant diversity and productivity and the causal mechanism(s) behind the observed pattern(s) are still highly debated. Recent advances suggest that the relationship depends on several environmental variables and may change with the observational scale. In this study, a mul...

journal_title：American journal of botany

authors： de Lafontaine G,Houle G

更新日期：2007-01-01 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：:Patterns of biodiversity are ultimately the product of speciation and extinction. Speciation serves as the biodiversity pump while extinction serves as the agent that culls global to local levels of biodiversity. Linking these central processes to global and local patterns of biodiversity is a key challenge in both ec...

journal_title：American journal of botany

authors： Swenson NG

更新日期：2011-03-01 00:00:00

abstract：PREMISE OF THE STUDY:Expressed sequence tag (EST)-derived microsatellite markers were developed for Elaeocarpus photiniifolia, an endemic taxon of the Bonin Islands. METHODS AND RESULTS:Initially, a complementary DNA (cDNA) library was constructed by de novo pyrosequencing of total RNA extracted from a seedling. A tot...

journal_title：American journal of botany

authors： Sugai K,Setsuko S,Uchiyama K,Murakami N,Kato H,Yoshimaru H

更新日期：2012-02-01 00:00:00

abstract：PREMISE:Distylous species possess two floral morphs with reciprocal positioning of stigmas and anthers that is hypothesized to promote disassortative pollination. Theoretical models predict equal morph frequencies, but many populations depart from the expected 1:1 ratio, a pattern that often correlates with asymmetric ...

journal_title：American journal of botany

authors： Matias R,Pérez-Barrales R,Consolaro H

更新日期：2020-06-01 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：:We examined the function of floral traits associated with buzz pollination through studies of Rhexia virginica (Melastomataceae) in the Muskoka region of Ontario, Canada. Controlled pollinations demonstrated that the species is self-compatible, but dependent on insects for pollen transfer. Bumble bees made 82 and 90% ...

journal_title：American journal of botany

authors： Larson BM,Barrett SC

更新日期：1999-04-01 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

abstract：PREMISE OF THE STUDY:Species differ in their temperature germination niche. Populations of a species may similarly differ across the distribution range of the species. Anticipating the impacts of climate variability and change requires understanding the differential sensitivity to germination temperature among and with...

journal_title：American journal of botany

authors： Chamorro D,Luna B,Moreno JM

更新日期：2017-01-01 00:00:00

abstract：:Clarkia (Onagraceae) is a genus of 42 annual species, mostly native to California, that has served as a model for many studies of plant evolutionary biology, particularly morphological, cytological, and genetic divergence; reproductive isolation; and speciation. Section Sympherica is the largest section with eight dip...

journal_title：American journal of botany

authors： Ford VS,Gottlieb LD

更新日期：2003-02-01 00:00:00

abstract：:The genus Caltha (Ranunculaceae) consists of 10 species of low-growing, perennial herbs distributed throughout the moist temperate and cold regions of both the Northern and Southern Hemispheres. Traditionally, the species have been divided into two sections: section Psychrophila in the Southern Hemisphere with diploph...

journal_title：American journal of botany

authors： Schuettpelz E,Hoot SB

更新日期：2004-02-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Sphagnum dominates vast expanses of wetland habitats throughout the northern hemisphere and species delimitation within the genus is important because floristic changes associated with a warming global climate may have measureable impacts on large-scale ecological processes. Most north...

journal_title：American journal of botany

authors： Shaw AJ,Shaw B,Johnson MG,Higuchi M,Arikawa T,Ueno T,Devos N

更新日期：2013-06-01 00:00:00

abstract：:Floral organogenesis and development of the tropical legume trees Haematoxylum campechianum (logwood) and H. brasiletto (brazilwood) were studied using scanning electron microscopy. The aims were to compare ontogenies, and to elucidate the relationships of Haematoxylum with other genera of Caesalpinieae, the basal tri...

journal_title：American journal of botany

authors： Tucker S,Kantz K

更新日期：1997-08-01 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：:Contact forces are important in maintaining the twining habit of viny stems. A stem twining around a supporting pole puts itself into tension and uses a helical geometry to generate normal loads that are large relative to stem mass per unit length (Silk and Hubbard, Journal of Biomechanics 24(7):599-606, 1991). An ele...

journal_title：American journal of botany

authors： Matista A,Silk W

更新日期：1997-08-01 00:00:00

abstract：:We present here the first molecular phylogeny of tribe Diseae (Orchidoideae: Orchidaceae). Nuclear ribosomal ITS1, 5.8S rDNA, and ITS2 sequences were compared for 30 Diseae, 20 Orchideae, and four Cranichideae and Diurideae outgroups. ITS - rDNA sequences exhibited a transition:transversion ratio of 1.3 and extensive ...

journal_title：American journal of botany

authors： Douzery EJ,Pridgeon AM,Kores P,Linder HP,Kurzweil H,Chase MW

更新日期：1999-06-01 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：:In spite of the ecological and economic importance of temperate bamboos, relatively little is known about their population biology or evolutionary history. Recently, hybridization has emerged as a potential source of diversity in this group, as well as an underlying cause of taxonomic problems. As part of a broader ph...

journal_title：American journal of botany

authors： Triplett JK,Oltrogge KA,Clark LG

更新日期：2010-03-01 00:00:00

abstract：:Madagasikaria andersonii is described here as a new genus and species of Malpighiaceae from Madagascar. The phylogenetic placement of Madagasikaria was estimated by using combined data from ndhF and trnL-F chloroplast sequences and phytochrome (PHYC) and ITS nuclear sequences. It forms a strongly supported clade with ...

journal_title：American journal of botany

authors： Davis CC

更新日期：2002-04-01 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：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：:Recruitment and mortality of Spartina alterniflora tillers and culms were estimated from measurements of live standing crops at Wallops Island, Virginia. Stands of tall and medium form grass produced from 452 to 1,227 tillers m-2 yr-1 . Those tillered in spring lengthened into culms their first year, while those tille...

journal_title：American journal of botany

authors： Reidenbaugh TG

更新日期：1983-01-01 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：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