Abstract:
:Epiphytes are ecologically important components of tropical forests worldwide and yet they have been underrepresented in studies of reproductive biology. Given the presumed ephemeral nature of their substrates, and the importance of dispersal and colonization, epiphytes might be expected to undergo substantial inbreeding to ensure reproductive success, as in weedy terrestrial plants. While there is some evidence for inbreeding in epiphytic angiosperms, the only previous studies of fern epiphytes indicate that they are predominantly outcrossing. The present study reports on the genetic diversity and breeding system of six members of the Neotropical epiphytic fern genus Pleopeltis (Polypodiaceae). A survey of isozyme variability using starch gel electrophoresis revealed high population levels of polymorphism (P = 0.62), allelic diversity (A = 2.3), and individual heterozygosity (Ho = 0.181), but little differentiation among conspecific populations (I ³ 0.98; Gst = 0.048), and high interpopulational gene flow rates (Nm > 1). In addition, there was no indication of homozygote excess within populations that might indicate a history of selfing in these ferns: populations generally conformed to Hardy-Weinberg expected genotype frequencies, and both Wright's inbreeding coefficient (Fis) and Holsinger's intragametophytic selfing rates approached zero. Possible mechanisms limiting inbreeding in these ferns include antheridiogen activity and high levels of genetic load that would lead to inbreeding depression upon selfing.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Hooper E,Haufler Csubject
Has Abstractpub_date
1997-12-01 00:00:00pages
1664issue
12eissn
0002-9122issn
1537-2197pii
84/12/1664journal_volume
84pub_type
杂志文章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
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journal_title:American journal of botany
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journal_title:American journal of botany
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abstract::Polyploid speciation is an ongoing, important source of angiosperm diversity. However, the barriers to polyploid speciation and mechanisms of establishment remain poorly understood for all but a few species. Several factors likely to have influenced tetraploid establishment, including barriers to triploid formation, c...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.11.1827
更新日期:2005-11-01 00:00:00
abstract:UNLABELLED:• PREMISE OF THE STUDY:Polymorphic microsatellite primers were developed in the seagrass Halophila ovalis to investigate genetic variation. • METHODS AND RESULTS:Ten polymorphic microsatellite loci were developed in Halophila ovalis. The number of alleles per locus ranged from 2 to 12 across 80 H. ovalis i...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000111
更新日期:2010-06-01 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:PREMISE OF THE STUDY:The stability of the bimodal karyotype found in Agave and closely related species has long interested botanists. The origin of the bimodal karyotype has been attributed to allopolyploidy, but this hypothesis has not been tested. Next-generation transcriptome sequence data were used to test whether ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100537
更新日期:2012-02-01 00:00:00
abstract::Wood, or secondary xylem, is composed mostly of three components-cellulose, hemicelluloses, and lignin. Yet this apparent simplicity is deceiving because the sophisticated arrangement of the components on various structural levels, ranging from intricate molecular architecture to defined cellular arrangements to tissu...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.10.1433
更新日期:2006-10-01 00:00:00
abstract::In the alpine landscape most plant populations are spatially isolated due to extreme patchiness and strong natural fragmentation. We used RAPD-PCR (randomly amplified polymorphic DNA polymerase chain reaction) for a study of the genetic diversity within and among 20 populations of Geum reptans, an outcrossing clonal p...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.12.2013
更新日期:2004-12-01 00:00:00
abstract::Cleistogamous capitula formed by Centaurea melitensis display a number of morphological and functional changes with respect to chasmogamous capitula that ensure self-fertilization. Because no studies have hitherto addressed the evolution of cleistogamy in Asteraceae, it was considered useful to ascertain whether these...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2000-07-01 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
pub_type: 杂志文章
doi:10.1002/ajb2.1352
更新日期:2019-09-01 00:00:00
abstract:PREMISE:Adaptation to harsh edaphic substrates has repeatedly led to the evolution of edaphic specialists and generalists. Yet, it is unclear what factors promote specialization versus generalization. Here, we search for habitat use patterns associated with serpentine endemics (specialists) and serpentine tolerators (g...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1285
更新日期:2019-05-01 00:00:00
abstract::In an age of rapid global change, it is imperative that we continue to improve our understanding of factors that govern genetic differentiation in plants to inform biologically reasonable predictions for the future and enlighten conservation and restoration practices. In this special issue, we have assembled a set of ...
journal_title:American journal of botany
pub_type:
doi:10.3732/ajb.1500515
更新日期:2016-01-01 00:00:00
abstract::The temperature dependence of freezing-induced xylem cavitation was studied in a Chihuahuan desert population of Larrea tridentata (Zygophyllaceae). Field measurements of wood temperature and xylem embolism were combined with anatomical studies and laboratory measurements of embolism in stem and root samples frozen un...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.12.1916
更新日期:2002-12-01 00:00:00
abstract:PREMISE OF THE STUDY:Microsatellite markers were isolated and characterized from Dacryodes edulis (Burseraceae), a tropical rainforests fruit tree of central Africa. METHODS AND RESULTS:Using an enrichment protocol, six microsatellites loci were developed from Dacryodes edulis. We investigated polymorphism using 45 tr...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000463
更新日期:2011-04-01 00:00:00
abstract::Exotic plant species can threaten closely related native congeners through asymmetric hybridization and subsequent backcrossing, the process known as genetic assimilation. I explore the initial stages of this process in Taraxacum ceratophorum (Asteraceae), the native alpine dandelion, and the invasive apomict T. offic...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.5.656
更新日期:2004-05-01 00:00:00
abstract::Members of tribe Vandeae (Orchidaceae) form a large, pantropical clade of horticulturally important epiphytes. Monopodial leafless members of Vandeae have undergone extreme reduction in habit and represent a novel adaptation to the canopy environment in tropical Africa, Asia, and America. To study the evolution of mon...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.5.770
更新日期:2006-05-01 00:00:00
abstract:PREMISE OF THE STUDY:We developed the first set of microsatellite markers for the passion fruit, Passiflora cincinnata, to provide tools for further study of its genetic diversity and to support current conservation and genetic studies. METHODS AND RESULTS:We used a microsatellite-enriched library approach to isolate ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100477
更新日期:2012-04-01 00:00:00
abstract::The anther and ovule development of Camellia, Franklinia, and Schima (Theaceae, Camellioideae) were observed. The three genera share the following embryological traits: anther wall formation of basic type, tapetum of glandular type, walls of endothecial cells with secondary thickening, and production of pseudopollen g...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-03-01 00:00:00
abstract::Restriction fragment length polymorphism (RFLP) analysis of chloroplast (cp) DNA is a powerful tool for the study of microevolutionary processes in land plants, yet has not previously been applied to seaweed populations. We used cpDNA-RFLP, detected on Southern blots using labeled total plastid DNA, to search for intr...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-07-01 00:00:00
abstract:PREMISE OF THE STUDY:Microsatellite primers were developed in the native legume tree Anadenanthera colubrina var. cebil to study the genetic diversity and genetic structure in natural populations in Argentina. METHODS AND RESULTS:Nine microsatellite markers were identified using a genomic library enriched for tandemly...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200078
更新日期:2012-09-01 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:The study of scaling examines the relative dimensions of diverse organismal traits. Understanding whether global scaling patterns are paralleled within species is key to identify causal factors of universal scaling. I examined whether the foliage-stem (Corner's rules), the leaf size-number, and the...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500439
更新日期:2016-05-01 00:00:00
abstract::Inferring basal relationships among vascular plants poses a major challenge to plant systematists. The divergence events that describe these relationships occurred long ago and considerable homoplasy has since accrued for both molecular and morphological characters. A potential solution is to examine phylogenetic anal...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-10-01 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::Molecular phylogenetic studies of seven plastid DNA regions were used to resolve circumscriptions at generic and infrageneric levels in subfamily Tillandsioideae of Bromeliaceae. One hundred and ten tillandsioid samples were analyzed, encompassing 10 genera, 104 species, and two cultivars. Two species of Bromelioideae...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.2.337
更新日期:2005-02-01 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: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::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
pub_type: 杂志文章,评审
doi:10.3732/ajb.1000289
更新日期:2011-03-01 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
pub_type: 杂志文章
doi:10.3732/ajb.94.8.1333
更新日期:2007-08-01 00:00:00