Abstract：
:Reproductive traits of tropical tree species vary predictably in relation to successional stage, but this variation may be due to the species' phylogenetic histories rather than selective pressures imposed by regeneration requirements. Reproductive phenology, tree size at the onset of reproduction, and fecundity of 11 sympatric, closely related Macaranga species were studied to investigate within-species variation in reproductive traits in relation to resource availability, and among-species variation in relation to other life-history traits (shade tolerance, seed size and maximum tree size, H(max)) and consequently the requirements for forest-gap colonization. Nine species reproduced in synchronous episodes, and two species reproduced continuously over 32 mo. Episodic reproduction was most intense in 1992 following a severe drought. For several species, reproductive trees had greater light availability, lower fecundity in lower light levels, and lower growth rates than nonreproductive trees, reflecting resource-limited reproduction. Among species, H(max) was negatively correlated with shade tolerance and seed size. Tree size at the onset of reproduction and fecundity was strongly linked to this axis of life-history variation, but phenological pattern was not. Absolute tree size at the onset of reproduction was positively correlated with H(max) and negatively correlated with shade tolerance. Relative size at reproductive onset was not correlated with shade tolerance or H(max). Fecundity ranged four orders of magnitude among species and was correlated positively with H(max) and negatively with seed size and shade tolerance. The interrelationships among these reproductive and other life-history traits are strongly correlated with the species' requirements for gap colonization.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Davies SJ,Ashton PSsubject
Has Abstractpub_date
1999-12-01 00:00:00pages
1786-95issue
12eissn
0002-9122issn
1537-2197pii
86/12/1786journal_volume
86pub_type
杂志文章abstract：UNLABELLED: PREMISE OF THE STUDY:Most studies on orchid hybrids examine separately the effects of hybridization on interactions with pollinators or with mycorrhizal fungi. Here, we simultaneously investigated both interactions in the mediterranean food-deceptive Orchis simia, O. anthropophora, and their hybrid (O. ×be...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.0900303
更新日期：2010-08-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:Adansonia digitata L. is one of the most important indigenous fruit trees of mainland Africa. Despite its significance for subsistence and income generation of local communities, little is known about the genetic and morphological variability of East African populations of A. digitata...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1400198
更新日期：2014-09-01 00:00:00
abstract：:This paper reports the frequency of spontaneous amphiploids or neopolyploids in experimental interspecific hybrids in two annual sections of Gilia (Polemoniaceae, sects. Arachnion and Gilia, x = 9). In each section the species were intercrossed in numerous hybrid combinations to obtain an array of F1 hybrid types; sev...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.89.8.1197
更新日期：2002-08-01 00:00:00
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 annua...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/j.1537-2197.1992.tb13702.x
更新日期：1992-10-01 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
pub_type： 杂志文章
doi：10.3732/ajb.1100137
更新日期：2011-10-01 00:00:00
abstract：:Very little is known regarding how repetitive elements evolve inpolyploid organisms. Here we address this subject by fluorescent insitu hybridization (FISH) of 20 interspersed repetitive elements tometaphase chromosomes of the cotton AD-genome tetraploid Gossypiumhirsutum and its putative A- and D-genome diploid ances...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1998-10-01 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
pub_type： 杂志文章
doi：10.1002/j.1537-2197.1990.tb13548.x
更新日期：1990-02-01 00:00:00
abstract：PREMISE:Medullary bundles, i.e., vascular units in the pith, have evolved multiple times in vascular plants. However, no study has ever explored their anatomical diversity and evolution within a phylogenetic framework. Here, we investigated the development of the primary vascular system within Nyctaginaceae showing how...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1471
更新日期：2020-05-01 00:00:00
abstract：PREMISE OF THE STUDY:Miscanthus, a nonfood plant with high potential as a biofuel, has been used in Europe and the United States. The selection of a cultivar with high biomass, photosynthetic efficiency, and stress resistance from wild populations has become an important issue. New genic microsatellite markers will aid...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1100071
更新日期：2011-08-01 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
pub_type： 杂志文章
doi：10.3732/ajb.95.1.98
更新日期：2008-01-01 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
pub_type： 杂志文章
doi：10.3732/ajb.94.5.709
更新日期：2007-05-01 00:00:00
abstract：PREMISE OF THE STUDY:Documented fossil floras in the neotropics are sparse, yet their records provide evidence on the spatial and temporal occurrence of taxa, allowing for testing of biogeographical and diversification scenarios on individual lineages. A new fossil Piper from the Late Cretaceous of Colombia is describe...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1400427
更新日期：2015-02-01 00:00:00
abstract：PREMISE OF THE STUDY:Self-incompatibility (SI) is a mechanism that prevents inbreeding in many plant species. The mutational breakdown of SI occurs frequently, yet relatively little is known about the evolutionary steps involved in the progressive loss of pistil and pollen SI function. METHODS:In Solanaceae, SI is the...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1600208
更新日期：2016-10-01 00:00:00
abstract：PREMISE OF THE STUDY:Microsatellite primers were developed in the traditional Tibetan medicinal plant Halenia elliptica D. Don to investigate its genetic diversity and population genetic structure. METHODS AND RESULTS:Using the Fast Isolation by AFLP of Sequences Containing (FIASCO) repeats protocol, 24 primer sets we...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1000534
更新日期：2011-07-01 00:00:00
abstract：PREMISE OF THE STUDY:The lycophyte family Selaginellaceae includes approximately 750 herbaceous species worldwide, with the main species richness in the tropics and subtropics. We recently presented a phylogenetic analysis of Selaginellaceae based on DNA sequence data and, with the phylogeny as a framework, the study d...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1600288
更新日期：2016-12-01 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
pub_type： 杂志文章
doi：10.3732/ajb.2007283
更新日期：2008-05-01 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
pub_type： 杂志文章
doi：10.3732/ajb.0800318
更新日期：2009-03-01 00:00:00
abstract：PREMISE:Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerance...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1556
更新日期：2020-11-01 00:00:00
abstract：:Genetic diversity at variable-number-tandem-repeat (VNTR) loci was examined in the common cattail, Typha latifolia (Typhaceae), using three synthetic DNA probes composed of tandemly repeated "core" sequences (GACA, GATA, and GCAC). The principal objectives of this investigation were to determine whether: (1) the previ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1999-09-01 00:00:00
abstract：:Sex ratio and sexual dimorphism in physiology and growth were studied in the dioecious tree Ilex aquifolium at two localities in northern Spain. Genet sex ratio was significantly male biased in one locality but not in the other. However, ramet and flowering ramet sex ratios were male biased at both study sites. Males ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1998-11-01 00:00:00
abstract：:Although theory has demonstrated rather low levels of gene flow are sufficient to counteract opposing mutation, drift, and selection, widespread recognition of the evolutionary importance of gene flow has come slowly. The perceived role of gene flow as an evolutionary force has vacillated over the last century. In the...
journal_title：American journal of botany
pub_type： 杂志文章,评审
doi：10.3732/ajb.1400024
更新日期：2014-05-01 00:00:00
abstract：:The shoot apical meristem (SAM) produces stem and initiates leaves. Its structure is maintained despite a continuous flow of cells basipetally from the distal portion of the meristem. The apoplasm and symplasm are the obvious means of cell integration, and their role in chemical cell-to-cell signaling is known. Howeve...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.9.1277
更新日期：2004-09-01 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: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：PREMISE OF THE STUDY:Discovery of cupulate ovules of Doylea tetrahedrasperma within a compact, compound seed cone highlights the rich diversity of fructification morphologies, pollination biologies, postpollination enclosure of seeds, and systematic diversity of Early Cretaceous gymnosperms. METHODS:Specimens were stu...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1600030
更新日期：2016-05-01 00:00:00
abstract：:The desert moss Syntrichia caninervis exhibits one of the most skewed sex ratios in the plant kingdom, with female individuals far outnumbering male individuals (exceeding 14♀:1♂). The "cost of sex hypothesis" derives from allocational theory and predicts that the sex which is most expensive should be the rarer sex. T...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-11-01 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
pub_type： 杂志文章
doi：10.3732/ajb.92.3.517
更新日期：2005-03-01 00:00:00
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 THE STUDY:Microsatellite markers were developed for the common wetland plant Juncus effusus to assess levels of within- and among-population genetic diversity. METHODS AND RESULTS:Using a next-generation sequencing approach we identified new microsatellite loci, from which 23 were further characterized in a...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1100322
更新日期：2012-02-01 00:00:00
abstract：:Fluorescence in situ hybridization (FISH) of a large-insert genomic clone, BAC 22B2, previously suggested that Sorghum bicolor (2n = 20) has the tetraploid architecture A(b)A(b)B(b)B(b). Here, we report on BAC 22B2 subclone pCEN38 (1047-bp insert) as related to sorghum and sugarcane. Mitotic FISH of six different subc...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-12-01 00:00:00
