Abstract:
PREMISE OF THE STUDY:Pollinator shifts have been implicated as a driver of divergence in angiosperms. We tested the hypothesis that there was a transition from bird- to butterfly pollination in the African genus Clivia (Amaryllidaceae) and investigated how floral traits may have been either modified or retained during this transition. METHODS:We identified pollinators using field observations, correlations between lepidopteran wing scales and pollen on stigmas, and single-visit and selective exclusion experiments. We also quantified floral rewards and advertising traits. KEY RESULTS:The upright trumpet-shaped flowers of C. miniata were found to be pollinated effectively by swallowtail butterflies during both nectar-feeding and brush visits. These butterflies transfer pollen on their wings, as evidenced by positive correlations between wing scales and pollen loads on stigmas. All other Clivia species have narrow pendulous flowers that are visited by sunbirds. Selective exclusion of birds and large butterflies from flowers of two Clivia species resulted in a significant decline in seed production. CONCLUSIONS:From the distribution of pollination systems on available phylogenies, it is apparent that a shift took place from bird- to butterfly pollination in Clivia. This shift was accompanied by the evolution of trumpet-shaped flowers, smaller nectar volume, and emission of scent, while flower color and nectar chemistry do not appear to have been substantially modified. These results are consistent with the idea that pollinator shifts can explain major floral modifications during plant diversification.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Kiepiel I,Johnson SDdoi
10.3732/ajb.1300363subject
Has Abstractpub_date
2014-01-01 00:00:00pages
190-200issue
1eissn
0002-9122issn
1537-2197pii
ajb.1300363journal_volume
101pub_type
杂志文章abstract:UNLABELLED: PREMISE OF THE STUDY:Allometric relationships among the dimensions of leaf cells, cell walls, and tissues, and whole-leaf thickness and area are likely to have key implications for leaf construction and function, but have remained virtually untested, despite the explosion of interest in allometric analysis...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200608
更新日期:2013-10-01 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
pub_type: 杂志文章
doi:10.3732/ajb.94.6.1003
更新日期:2007-06-01 00:00:00
abstract::After 120 yr of burial in moist, well-aerated sand, 23 seeds of Verbascum blattaria and two seeds of a Verbascum sp. germinated and produced normal plants (50% germination for Verbascum). After a 6-wk cold treatment, a single seed of Malva rotundifolia germinated also, producing a normal plant (2% germination). Plants...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.8.1285
更新日期:2002-08-01 00:00:00
abstract::Many foliar pathogens require free water to germinate; therefore, disease pressure should favor plants that are able to repel water. For a suite of 18 sympatric clover species (Trifolium and Medicago, Fabaceae), we evaluated leaf traits affecting leaf wetness and susceptibility to infection by the fungal pathogen Stem...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.6.857
更新日期:2003-06-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.3.441
更新日期:2002-03-01 00:00:00
abstract::Pinus rzedowskii is an endangered pine species from Michoacán (central México), which has been previously reported from only three localities. Classified within the subgenus Strobus, it exhibits intermediate morphological characters between subgenera Strobus and Pinus. We analyzed genetic aspects that could shed light...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-05-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400486
更新日期:2015-03-01 00:00:00
abstract::We investigated the possible effect of recent (1927-1995) increases in the concentration of atmospheric CO2 on the stomatal densities of leaves of a wide range of tree, shrub, and herb species (N = 60) by making new measurements for comparison with corresponding data reported by E. J. Salisbury in 1927--a time when ic...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.7.1147
更新日期:2004-07-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1428
更新日期:2020-02-01 00:00:00
abstract::The eudicot order Malpighiales contains ∼16000 species and is the most poorly resolved large rosid clade. To clarify phylogenetic relationships in the order, we used maximum likelihood, Bayesian, and parsimony analyses of DNA sequence data from 13 gene regions, totaling 15604 bp, and representing all three genomic com...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0800207
更新日期:2009-08-01 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
pub_type: 杂志文章
doi:10.3732/ajb.2007368
更新日期:2008-06-01 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
pub_type: 杂志文章
doi:10.3732/ajb.0800122
更新日期:2008-12-01 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
pub_type: 杂志文章
doi:10.3732/ajb.1100391
更新日期:2012-02-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600235
更新日期:2016-12-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900019
更新日期:2009-09-01 00:00:00
abstract::Cladistic analyses of plastid DNA sequences rbcL and trnL-F are presented separately and combined for 48 genera of Amaryllidaceae and 29 genera of related asparagalean families. The combined analysis is the most highly resolved of the three and provides good support for the monophyly of Amaryllidaceae and indicates Ag...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-09-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600339
更新日期:2017-07-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900045
更新日期:2009-07-01 00:00:00
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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
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600350
更新日期:2017-01-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200359
更新日期:2013-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000260
更新日期:2010-10-01 00:00:00
abstract::Pollinator-mediated natural selection has been shown to act on phenotypic variation in floral morphology, and this variation has often been demonstrated to be heritable, but few details are available concerning the sources of floral variation. We examined phenotypic variation in seven floral traits in wild radish (Rap...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-09-01 00:00:00
abstract::Sex allocation models predict that cosexuality is stabilized by high allocation to attractive structures in pollen-limited species or by high allocation to shared structures that contribute to both genders. High investment in unilateral fixed costs favor the evolution of dioecy or gender change. With these predictions...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-10-01 00:00:00
abstract::The boreotropical flora concept suggests that relictual tropical disjunctions between Asia and the Americas are a result of the expansion of the circumboreal tropical flora from the middle to the close of the Eocene. Subsequently, temperate species diverged at high latitudes and migrated to other continents. To test t...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-12-01 00:00:00
abstract::Lxm1-O, a dominant EMS (ethyl methanesulfonate) induced mutation in maize (Zea mays, Poaceae), was originally reported to affect the blade/sheath boundary over the midrib region of the leaf. Here we present a more extensive analysis of the Lxm phenotype in nine different inbred lines. Lxm leaves are longer and narrowe...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-04-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.10.1531
更新日期:2006-10-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Several members of Selaginella are renowned for their ability to survive extreme drought and "resurrect" when conditions improve. Many of these belong to subgenus Tetragonostachys, a group of ∼45 species primarily found in North and Central America, with substantial diversity in the Sonoran and Chi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200426
更新日期:2013-08-01 00:00:00