Abstract:
:Dispersal is an important life history component. Seed settling velocity may be a useful surrogate for the measurement of dispersal ability in wind-dispersed plants, particularly those whose seeds have plumose dispersal structures. I measured settling velocities on seeds of eight species of Asteraceae, including annuals, biennials, and perennials, and including both native and introduced species. The species are Aster exilis, Picris echioides, Chrysopsis villosa, Heterotheca grandiflora, Conyza bonariensis, Sonchus oleraceous, Senecio vulgaris, and Taraxacum officinale. From these data I estimated components of total variation in seed settling velocities due to differences among species, among plants within species, and among inflorescences and seeds within plants. Significant amounts of variability were found at all levels. Contrasts among mean settling velocities showed that the five introduced species have lower settling velocities than the three native species; this result continues to be true when annuals are considered separately from biennials and perennials. Also, over all eight species, annuals have lower settling velocities than biennials and perennials. Variability among species apparently reflects different dispersal "strategies" employed by the species; these different strategies may be correlated with other life-history traits and with ecological characteristics. Variability within species also may have ecological consequences in that such variability may represent an example of risk-spreading.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Andersen MCdoi
10.1002/j.1537-2197.1992.tb13702.xsubject
Has Abstractpub_date
1992-10-01 00:00:00pages
1087-1091issue
10eissn
0002-9122issn
1537-2197journal_volume
79pub_type
杂志文章abstract::Evolutionary relationships among representatives of Apiaceae (Umbelliferae) subfamily Apioideae have been inferred from phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer (ITS 1 and ITS 2) and plastid rpoC1 intron sequences. High levels of nucleotide sequence variation preclude the use of the I...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-04-01 00:00:00
abstract:PREMISE OF STUDY:Sequence analyses for Pinaceae have suggested that extant genera diverged in the late Mesozoic. While the fossil record indicates that Pinaceae was highly diverse during the Cretaceous, there are few records of living genera. This description of an anatomically preserved seed cone extends the fossil re...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100568
更新日期:2012-06-01 00:00:00
abstract::Parsimony, likelihood, and Bayesian analyses of nuclear ITS and plastid trnL-F DNA sequence data are presented for the giant genus Croton (Euphorbiaceae s.s.) and related taxa. Sampling comprises 88 taxa, including 78 of the estimated 1223 species and 29 of the 40 sections previously recognized of Croton. It also incl...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.9.1520
更新日期:2005-09-01 00:00:00
abstract::The phenotype of maize plants that are homozygous recessive for the nuclear gene iojap is commonly an "anemic," grainy green appearance accompanied by white leaf stripes, white leaf margins, and reduced growth. In plants in which the iojap effect is occurring (homozygous ij/ij), we find affected tissue varies in exten...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1988.tb13486.x
更新日期:1988-05-01 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
pub_type: 杂志文章
doi:10.3732/ajb.90.12.1736
更新日期:2003-12-01 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
pub_type: 杂志文章
doi:10.3732/ajb.92.7.1085
更新日期:2005-07-01 00:00:00
abstract::Seventy-four nucleotide sequences from the ITS regions of nuclear ribosomal DNA and 76 from the trnL-trnF spacer of chloroplast DNA were used to address the origin of tetraploid Cardamine amporitana, the conspecifity of central Italian and northeastern Spanish populations, and the possible cause for such geographic di...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.8.1231
更新日期:2004-08-01 00:00:00
abstract:PREMISE OF THE STUDY:Robust markers are required (inter alia) for assessing origins of Calophyllum inophyllum populations on the Bonin Islands, Japan. Therefore, informative expressed sequence tag (EST)-based microsatellite or simple sequence repeat (SSRs) markers in the species were sought. METHODS AND RESULTS:Using ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100299
更新日期:2012-01-01 00:00:00
abstract:PREMISE OF THE STUDY:Recurrent formation of polyploid taxa is a common observation in many plant groups. Haploid, cytoplasmic genomes like the plastid genome can be used to overcome the problem of homeologous genes and recombination in polyploid taxa. Fragaria (Rosaceae) contains several octo- and decaploid species. We...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1085
更新日期:2018-05-01 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
pub_type: 杂志文章
doi:10.3732/ajb.1100465
更新日期:2012-01-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Invasive plant species threaten native plants in multiple ways, one of which is genetic assimilation through hybridization. However, information regarding hybridization between related alien and native plant species is generally lacking. In Hawaii, the invasive Central American species...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300018
更新日期:2013-06-01 00:00:00
abstract:PREMISE OF THE STUDY:Populations of heterostylous species are characterized by two or three floral morphs with reciprocal positioning of stigmas and anthers. Theoretical models predict equal morph frequencies (isoplethy) when disassortative mating is prevalent in populations, but biased morph ratios may occur when vari...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600345
更新日期:2017-01-01 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
pub_type: 杂志文章
doi:10.3732/ajb.1400527
更新日期:2015-04-01 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
pub_type: 杂志文章
doi:10.3732/ajb.0900063
更新日期:2009-08-01 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
pub_type: 杂志文章
doi:10.3732/ajb.0700006
更新日期:2008-07-01 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
pub_type: 杂志文章
doi:10.3732/ajb.1100133
更新日期:2011-12-01 00:00:00
abstract::Perennial crops represent important fresh and processed food sources worldwide, but advancements in breeding perennials are often impeded due to their very nature. The perennial crops we rely on most for food take several years to reach production maturity and require large spaces to grow, which make breeding new cult...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400143
更新日期:2014-10-01 00:00:00
abstract::The American chestnut (Castanea dentata; Fagaceae) was a dominant canopy tree in the Appalachian Mountains of North America. Since the introduction of the chestnut blight fungus (Cryphonectria parasitica; Valsaceae) in America, the American chestnut has been reduced to a predominantly clonal, understory species. Our o...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.2.207
更新日期:2003-02-01 00:00:00
abstract::Phylogenetic relationships were determined in the Araucariaceae, which are now found mainly in the Southern Hemisphere. This conifer family was well diversified and widely distributed in both hemispheres during the Mesozoic era. The sequence of 1322 bases of the rbcL gene of cpDNA was determined from 29 species of Ara...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-11-01 00:00:00
abstract::A well-integrated plant shows extensive carbohydrate translocation through the plant body. Even in highly integrated plants, however, translocation patterns will be sectorial if vascular tissue restricts carbon movement to sectors along stems. Both integration and sectorial translocation patterns are sensitive to plan...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-12-01 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
pub_type: 杂志文章
doi:10.1002/ajb2.1404
更新日期:2020-02-01 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
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1983.tb12430.x
更新日期:1983-01-01 00:00:00
abstract:PREMISE OF THE STUDY:The genus Hoya (Apocynaceae; Asclepiadoideae) is characterized by a set of complex floral characters unique among the asclepiads, but their role in pollination is poorly understood. Here, we report a new mechanism of asclepiad pollination in the wax plant Hoya carnosa: the pollinaria are transferre...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700078
更新日期:2017-06-01 00:00:00
abstract:PREMISE OF THE STUDY:Chloroplast microsatellites were developed in Theobroma cacao to examine the genetic diversity of cacao cultivars in Trinidad and Tobago. METHODS AND RESULTS:Nine polymorphic microsatellites were designed from the chloroplast genomes of two T. cacao accessions. These microsatellites were tested in...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100306
更新日期:2011-12-01 00:00:00
abstract::The ultrastructure of Typha latifolia pollen was examined as a function of pollen moisture content and incubation temperature, in order to identify possible lesions induced by imbibitional chilling. A syndrome of structural traits was found which characterizes damaged grains. Compared to viable grains, the protoplas...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1988-01-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Microsatellite primers were developed in the introduced shrub Rhamnus cathartica L., to investigate potential hybridization events with related taxa as a stimulus of invasive spread. • METHODS AND RESULTS:Using a non-radioactive protocol, 15 primer sets were identified in North Americ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900394
更新日期:2010-03-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Polyploid speciation has been important in plant evolution. However, the conditions that favor the origination and persistence of polyploids are still not well understood. Here, we examine origins of 16 polyploid species in Mentzelia section Trachyphytum. • METHODS:We used phylogeny r...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900388
更新日期:2010-09-01 00:00:00
abstract:PREMISE OF THE STUDY:Conifers are an important living seed plant lineage with an extensive fossil record spanning more than 300 million years. The group therefore provides an excellent opportunity to explore congruence and conflict between dated molecular phylogenies and the fossil record. METHODS:We surveyed the curr...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1143
更新日期:2018-09-01 00:00:00
abstract:PREMISE OF THE STUDY:Land-use change is cited as a primary driver of global biodiversity loss, with myriad consequences for species, populations, and ecosystems. However, few studies have examined its impact on species interactions, particularly pollination. Furthermore, when the effects of land-use change on pollinati...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600302
更新日期:2016-11-01 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
pub_type: 杂志文章
doi:10.3732/ajb.2007313
更新日期:2008-08-01 00:00:00