Abstract:
PREMISE OF THE STUDY:Our goal was to infer the phylogenetic relationships and historical biogeography of the genus Dryopteris with a focus on taxa in sub-Saharan Africa and neighboring islands. In general, little is known about the relationships between African fern species and their congeners in other geographic regions, and our aim was to determine whether the sub-Saharan African species of Dryopteris are monophyletic and evolved within Africa or arrived there via repeated dispersals into Africa from other regions. METHODS:We obtained sequence data for five chloroplast markers from 214 species of Dryopteris and 18 outgroups. We performed phylogenetic and molecular dating analyses using a Bayesian relaxed clock method in BEAST with fossil and secondary calibration points and estimated ancestral ranges for the genus globally by comparing multiple models in BioGeoBEARS. KEY RESULTS:We found that 22 of 27 accessions of sub-Saharan African Dryopteris belong to a large clade of 31 accessions that also includes taxa from Indian and Atlantic Ocean islands. Additional accessions of taxa from our regions of interest have Asian, Hawaiian, European, or North American species as their closest relatives. CONCLUSIONS:The majority of sub-Saharan African Dryopteris species are descended from a shared common ancestor that dispersed to Africa from Asia approximately 10 Ma. There have been subsequent dispersal events from the African mainland to islands in the Atlantic and Indian Oceans, including Madagascar. Several additional species are estimated to have descended from ancestors that reached Africa via separate events over the last roughly 20 million years.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Sessa EB,Juslén A,Väre H,Chambers SMdoi
10.3732/ajb.1600392subject
Has Abstractpub_date
2017-03-01 00:00:00pages
477-486issue
3eissn
0002-9122issn
1537-2197pii
ajb.1600392journal_volume
104pub_type
杂志文章abstract:PREMISE OF THE STUDY:The apical meristem generates indeterminate apical growth of the stem and root of vascular plants. Our previous examination showed that shoot apical meristems (SAMs) can be classified into two types based on plasmodesmatal networks (PNs), which are important elements in symplasmic signaling pathway...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1153
更新日期:2018-09-01 00:00:00
abstract::Seed size and cotyledon morphology are two key juvenile traits that have evolved in response to changes in plant species life-history strategies and habitat associations. Correlations of these traits with each other and with other juvenile traits were examined for 70 species of trees and shrubs in Kibale National Park...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.6.972
更新日期:2005-06-01 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::Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the typ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.9.1485
更新日期:2002-09-01 00:00:00
abstract::Phylogenetic relationships of 38 species of the Alibertia group (Rubiaceae) and two outgroup species were investigated using the nuclear ribosomal 5S nontranscribed spacer (5S-NTS) and the internal transcribed spacers (ITS). Analysis of the data sets separately and in combination resulted in several well-supported and...
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 OF THE STUDY:Koelreuteria (Sapindaceae) has four extant deciduous tree species, disjunctly distributed in eastern Asia and the Fiji Islands. While K. paniculata is widely cultivated, the biogeographic origin and evolutionary history of Koelreuteria remain unclear. METHODS:Fruits, pollen, wood, and leaves of cl...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200415
更新日期:2013-02-01 00:00:00
abstract:PREMISE OF THE STUDY:Productivity in drylands may depend on the sensitivity of interactions between plants and biocrusts. Given future climate variability, it is essential to understand how interactions may be context-dependent with precipitation regime. Furthermore, little is known about the additional interactions of...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1120
更新日期:2018-07-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300018
更新日期:2013-06-01 00:00:00
abstract:PREMISE OF THE STUDY:Despite the strong influence of the frequency and distribution of vessel endings on both hydraulic safety and efficiency, detailed anatomical descriptions or measurements of these structures are generally lacking. METHODS:Here we used high-resolution x-ray microcomputed tomography (microCT) to ide...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700199
更新日期:2017-09-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500336
更新日期:2016-02-01 00:00:00
abstract:PREMISE OF THE STUDY:Gravity has been a major force throughout the evolution of terrestrial organisms, and plants have developed exquisitely sensitive, regulated tropisms and growth patterns that are based on the gravity vector. The nullified gravity during spaceflight allows direct assessment of gravity roles. The mic...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200343
更新日期:2013-01-01 00:00:00
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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::Microscopic structures (petrofilaments) may develop during palynological laboratory processing procedures that are superficially similar to secondary wall thickenings and elaters. These filaments form from angular bodies that resemble fungal spores and resin bodies. The angular bodies are a type of hydrocarbon called ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2000-05-01 00:00:00
abstract::Partial cambial mortality is a growth form that is characteristic of Pinus aristata trees. To better elucidate their cambial death pattern, tree size and aspect of cambial death data were gathered from three Pinus aristata forests in central Colorado, USA. Stripping frequency tended to be higher for larger diameter cl...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-04-01 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:PREMISE OF THE STUDY:Phylogenetic and morphological studies have helped clarify the systematics of large and complex groups such as the tribe Crotoneae (Euphorbiaceae). However, very little is known about the diversity, structure, and function of anatomical features in this tribe. Crotoneae comprises the species-rich p...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500017
更新日期:2015-06-01 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::Leaf habit correlates with multiple physiological traits. Understanding ecophysiology is therefore dependent on knowledge of leaf habit. A variety of leaf habits exists within forest understory plant communities. Oxalis acetosella is one such understory plant and has long been considered a wintergreen, meaning that it...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.9.1371
更新日期:2004-09-01 00:00:00
abstract::The genus Rosa has a complex evolutionary history caused by several factors, often in conjunction: extensive hybridization, recent radiation, incomplete lineage sorting, and multiple events of polyploidy. We examined the applicability of AFLP markers for reconstructing (species) relationships in Rosa, using UPGMA clus...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.95.3.353
更新日期:2008-03-01 00:00:00
abstract::Correlations were examined between habitat characters and clonal structures determined by the RAPD (random amplified polymorphic DNA) assay in five populations of Oryza rufipogon in China. Nine of 175 decameric primers were used in the study because they reproducibly amplified polymorphisms. The extent of clonality to...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-06-01 00:00:00
abstract::Phylogenetic analysis of DNA sequences of the chloroplast genes rcbL and ndhf revealed a highly supported clade composed of the families Plantaginaceae, Callitrichaceae, and Hippuridaceae in close association with the model organism Antirrhinum majus and other members of family Scrophulariaceae. Plantago has miniature...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-08-01 00:00:00
abstract::Marchantia inflexa, a dioecious thallose liverwort, is sexually dimorphic in clonal expansion traits. We used selection analyses to measure the magnitude and direction of selection on clonal fitness to uncover possible mechanisms for the maintenance of preadult sexually dimorphic characters. We planted replicates of g...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.4.592
更新日期:2002-04-01 00:00:00
abstract::We investigated patterns of fruit and seed production on inflorescences of a population of Pancratium maritimum in northwest Spain over a 2-yr period. Initial findings showed that the earliest opening flowers on an inflorescence are more likely to set fruit and produce more seeds than later opening flowers and that th...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2000-04-01 00:00:00
abstract:PREMISE OF THE STUDY:Endophytic fungi are common inhabitants of cool-season grasses that can affect host growth and reproduction. One prerequisite for the expected coevolution between symbionts is that there exist variable effects of the endosymbiont on its host in different environments. Here, the impact of endophytes...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000226
更新日期:2011-05-01 00:00:00
abstract:PREMISE:Despite the efforts to understand the processes that shape neotropical biodiversity, the complexity of certain biomes, such as the Atlantic Forest (AF), prevents the generalization of patterns. Initially, ecological niche modeling (ENM), with phylogeographic studies, identified past stable areas in the central ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1317
更新日期:2019-07-01 00:00:00
abstract:UNLABELLED:• PREMISE OF THE STUDY:The question why leaf dimensions vary so much between species has long puzzled ecologists. Presumably, variation arises from selective forces acting on leaf function but which selective forces and which leaf functions? This investigation assesses the consistency of divergence in plant...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400379
更新日期:2015-03-01 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::We analyzed the effects of temporal variation in floral display size (number of flowers open at one time on a plant) on the rate of pollen removed and receipt of individual flowers for the sequential blooming plant Narthecium asiaticum (Liliaceae). Because of the acropetal blooming of this species, the display sizes w...
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::Atriplex prostrata Boucher, a facultative halophyte, exhibits significant reduction in height and biomass and in the width of the cortex and vascular tissue under saline conditions. Therefore, the goal of this investigation was to determine the effect of salinity on plant growth as well as on the patterns of lignifica...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-09-01 00:00:00
abstract:PREMISE OF THE STUDY:The fossil record of Agathis historically has been restricted to Australasia. Recently described fossils from the Eocene of Patagonian Argentina showed a broader distribution than found previously, which is reinforced here with a new early Paleocene Agathis species from Patagonia. No previous phylo...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1127
更新日期:2018-08-01 00:00:00