Abstract:
:We sequenced the nuclear small subunit ribosomal DNA coding region from 20 members of the Bangiophycidae and from two members of the Florideophycidae to gain insights into red algal evolution. A combined alignment of nuclear and plastid small subunit rDNA and a data set of Rubisco protein sequences were also studied to complement the understanding of bangiophyte phylogeny and to address red algal secondary symbiosis. Our results are consistent with a monophyletic origin of the Florideophycidae, which form a sister-group to the Bangiales. Bangiales monophyly is strongly supported, although Porphyra is polyphyletic within Bangia. Bangiophycidae orders such as the Porphyridiales are distributed over three independent red algal lineages. The Compsopogonales sensu stricto, consisting of two freshwater families, Compsopogonaceae and Boldiaceae, forms a well-supported monophyletic grouping. The single taxon within the Rhodochaetales, Rhodochaete parvula, is positioned within a cluster containing members of the Erythropeltidales. Analyses of Rubisco sequences show that the plastids of the heterokonts are most closely related to members of the Cyanidiales and are not directly related to cryptophyte and haptophyte plastid genomes. Our results support the independent origins of these secondary algal plastids from different members of the Bangiophycidae.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Müller KM,Oliveira MC,Sheath RG,Bhattacharya Dsubject
Has Abstractpub_date
2001-08-01 00:00:00pages
1390-400issue
8eissn
0002-9122issn
1537-2197pii
88/8/1390journal_volume
88pub_type
杂志文章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::Ontogenetic trends in the wood structure of Nepalese Rhododendron were studied in 15 specimens of two tree and four subtree species. Average growth ring width was constant from pith to bark in spite of occurrences of extremely narrow, false, or discontinuous rings. Vessel density, vessel area, vessel element length, a...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-04-01 00:00:00
abstract::• Premise of the study: Carpel closure is commonly considered as a key innovation in angiosperms; however, some families continue to exhibit a variety of forms of incomplete carpel closure. The carpel of Sagittaria species contains an unusual structure. In this study, we confirm the closure type of the carpel of Sagit...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400172
更新日期:2014-07-01 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::The geographic distribution of diploid and tetraploid cytotypes and cpDNA haplotypes throughout the entire range of Aucuba japonica was investigated. We measured relative genome size using flow cytometry and sequenced two cpDNA intergenic regions, atpB-rbcL and psbA-trnH (GUG). Two haplotypes include both diploids and...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.11.1645
更新日期:2003-11-01 00:00:00
abstract::Recent molecular phylogenetic studies of Solanaceae have identified many well-supported clades within the family and have permitted the creation of a phylogenetic system of classification. Here we estimate the phylogeny for Iochrominae, a clade of Physaleae sensu Olmstead et al. (1999), which contains 34 Andean specie...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.8.1140
更新日期:2006-08-01 00:00:00
abstract::Gaura (Onagraceae: Onagreae) is a small North American genus of 21 species consisting mostly of night-blooming, moth-pollinated annuals and perennials. The current infrageneric classification based on differences in habit, floral symmetry, and fruit morphology recognizes eight sections within the genus. We examine the...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.1.139
更新日期:2004-01-01 00:00:00
abstract:PREMISE:Closely related species occurring in sympatry may experience the negative consequences of interspecific pollen transfer if reproductive isolation (RI) barriers are not in place. We evaluated the importance of pre- and post-pollination RI barriers in three sympatric species of Achimenes (Gesneriaceae), including...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1324
更新日期:2019-07-01 00:00:00
abstract:PREMISE OF THE STUDY:Within the Hypnales-the most derived and species-rich order of pleurocarpous mosses - phylogenies at or below the family level often show poor resolution. In preparation for a phylogeny of the genus Plagiothecium, we wished to identify the DNA markers best suited for evolutionary reconstruction in ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300269
更新日期:2014-04-01 00:00:00
abstract::Biparental inbreeding is thought to be a common feature of plant populations with restricted pollen dispersal. It is generally assumed that the inbreeding depression frequently observed to accompany self-fertilization can be extrapolated to the lesser degrees of consanguinity involved in biparental inbreeding, but thi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1993.tb13838.x
更新日期:1993-05-01 00:00:00
abstract::Fitness of interspecific hybrids is sometimes high relative to their parents, despite the conventional belief that they are mostly unfit. F(1) hybrids between oilseed rape (Brassica napus) and weedy B. rapa can be significantly more fit than their weedy parents under some conditions; however, under other conditions th...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.4.571
更新日期:2003-04-01 00:00:00
abstract::Oxalate crystals are very common in angiosperms, but few descriptions of their macropattern (crystal types, their tissue distribution, and development) exist. Because unusually large prismatic crystals and druses, are known from pomegranate, we traced the development of crystal macropattern in various-aged leaf sample...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.12.1935
更新日期:2005-12-01 00:00:00
abstract::We examined the effects of size and spatial isolation of fens on the isozyme variability of 17 populations of Swertia perennis. This long-lived perennial is a locally abundant fen specialist in Switzerland, where wetlands have been strongly fragmented. Isozyme variability was comparable to other outcrossing plants (A ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.5.801
更新日期:2002-05-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Fuchsia (Onagraceae) anthers, pollen, and an ornithophilous Fuchsia-like flower from an earliest Miocene lacustrine diatomite deposit at Foulden Maar, southern New Zealand confirm a long record for Fuchsia in New Zealand and probably an equally long history for its distinctive honeyeat...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200643
更新日期:2013-10-01 00:00:00
abstract:PREMISE OF THE STUDY:A prevailing hypothesis in forest succession is that shade-tolerant species grow more slowly than shade-intolerant species, across light conditions, because they prioritize carbon (C) allocation to storage. We examined this hypothesis in a confamilial pair of species, including one of the fastest-g...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700057
更新日期:2017-05-01 00:00:00
abstract::Soybean partial-female-sterile mutant 1 (PS-1) was recovered from a gene-tagging study. The objectives were to study the inheritance, linkage, allelism, and certain aspects of the reproductive biology of the PS-1 mutant. For inheritance and linkage tests, PS-1 was crossed to flower color mutant Harosoy-w4 and to chlor...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract:PREMISE OF THE STUDY:Little is known about the effect of environmental conditions on seed dormancy break at the community level or how it could be affected by climate change. This study tested the effects of storage conditions on germination of 489 species from high-elevation natural grasslands on the Tibet Plateau. M...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000043
更新日期:2011-01-01 00:00:00
abstract::Floral characteristics such as morphology and flower color have been interpreted as adaptive traits that evolved through selective pressures generated by pollinators. Differences among populations in the expression of floral characters could result from natural selection for their adaptive value to local conditions. W...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.3.377
更新日期:2003-03-01 00:00:00
abstract::Extreme preformation, the initiation of leaves or inflorescences more than 1 yr before maturation and function, is common in arctic and alpine habitats. This extended pattern of development provides a potential means to alleviate an apparent asynchrony between carbon supplied by photosynthesis in the summer and carbon...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.9.1313
更新日期:2003-09-01 00:00:00
abstract:PREMISE:Within closed-canopy forests, vertical gradients of light and atmospheric CO2 drive variations in leaf carbon isotope ratios, leaf mass per area (LMA), and the micromorphology of leaf epidermal cells. Variations in traits observed in preserved or fossilized leaves could enable inferences of past forest canopy c...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1523
更新日期:2020-08-01 00:00:00
abstract::The pitchers of the tropical carnivorous plant Nepenthes alata are highly specialized organs for the attraction and capture of insects and absorption of nutrients from them. This study examined the structure and development of these pitchers, with particular focus on the nectaries and digestive glands. Immature pitche...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-10-01 00:00:00
abstract::Biogeographical patterns and diversification processes in Andean and Patagonian flora are not yet well understood. Calceolaria is a highly diversified genus of these areas, representing one of the most specialized plant-pollinator systems because flowers produce nonvolatile oils, a very unusual floral reward. Phylogen...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900165
更新日期:2009-12-01 00:00:00
abstract::The balance between clonal and sexual reproduction can vary widely among plant populations, and the extent of clonality may be influenced by the combined effects of historical land use and variation in environmental conditions. We investigated patterns of clonal spread in five Trillium cuneatum populations, two in the...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.2007159
更新日期:2008-10-01 00:00:00
abstract::Expansion of Typha domingensis into areas previously dominated by Cladium jamaicense in the Florida Everglades has been linked to anthropogenic phosphorus (P) enrichment and increased hydroperiod. The principal stress factor for plants in flooded soils is biochemical reduction, the intensity of which is measured as re...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.5.736
更新日期:2003-05-01 00:00:00
abstract::Multiply sired fruits provide unambiguous evidence that pollen from two or more donors was deposited on a stigma and successfully fertilized ovules. Such multiple paternity within fruits can have important consequences for both parental and offspring fitness, but little is known about the frequency of multiple paterni...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.5.885
更新日期:2005-05-01 00:00:00
abstract:UNLABELLED:• PREMISE OF THE STUDY:Two ovulate conifer cones, one of which is attached terminally to a short leafy shoot, reveal the presence of a new species of Hughmillerites in the Early Cretaceous Apple Bay flora of Vancouver Island, British Columbia, Canada. This ancient conifer expands the diversity of Cupressace...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400369
更新日期:2014-12-01 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:PREMISE OF THE STUDY:We developed microsatellite loci for the biomass crop Miscanthus sinensis to investigate genetic diversity and population structure of M. sinensis and its closely related species. METHODS AND RESULTS:Fourteen microsatellite loci were identified from an enriched genomic library of M. sinensis and t...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100040
更新日期:2011-07-01 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:PREMISE OF THE STUDY:The evolution of metal tolerance in plants is an important model for studies of adaptation to environment, population genetics, and speciation. Here, we investigated nickel tolerance in the North American serpentine endemic Caulanthus amplexicaulis var. barbarae in comparison with its nonserpentine...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200382
更新日期:2012-11-01 00:00:00