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 asphaltene and extrude the filaments when compounds in the bodies react with solvents in the mounting medium. They may be misinterpreted as fossils and so are illustrated here for the first time in the published literature.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Graham A,Wood GD,Elsik WC,Speed RCsubject
Has Abstractpub_date
2000-05-01 00:00:00pages
752-3issue
5eissn
0002-9122issn
1537-2197pii
87/5/752journal_volume
87pub_type
杂志文章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: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::Accurate estimates of inbreeding depression are necessary in order to predict the evolutionary dynamics of a population, but many studies estimate inbreeding depression based solely on components of female function such as fruit set, seed set, and seed quality. Because total fitness is achieved through both male and f...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.1.107
更新日期:2005-01-01 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::Seeds are useful in distinguishing among extant genera of Vitaceae and provide a good basis for interpretation of fossil remains in reconstructing the evolutionary and phytogeographic history of this putatively basal Rosid family. Seeds of Ampelocissus s.l. including Pterisanthes and Nothocissus are distinguished from...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.9.1534
更新日期:2007-09-01 00:00:00
abstract::Breakdown of genetically enforced self-incompatibility (SI), an extremely common and important evolutionary transition in plants, has conventionally been conceived as a qualitative rather than a quantitative change. We evaluated qualitative and quantitative variation in SI for four populations of Witheringia solanacea...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.4.592
更新日期:2006-04-01 00:00:00
abstract::Temporal and demographic aspects of the growth of Botrychium gallicomontanum and B. mormo were studied for 2 yr. A total of 219 B. gallicomontanum and 412 B. mormo plants were monitored in a prairie and maple-basswood forest, respectively. Growth events were divided into four stages: leaf emergence, leaf separation, s...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.10.1624
更新日期:2002-10-01 00:00:00
abstract:PREMISE OF THE STUDY:Hybridization and polyploidization (allopolyploidy) are ubiquitous in the evolution of plants, but tracing the origins and subsequent evolution of the constituent genomes of allopolyploids has been challenging. Genome doubling greatly complicates genetic analyses, and this has long hindered investi...
journal_title:American journal of botany
pub_type: 杂志文章,评审
doi:10.3732/ajb.1100395
更新日期:2012-02-01 00:00:00
abstract::Paniculate agaves from tropical deserts depend on nectar-feeding bats for their reproduction, while species from extratropical areas near the northern limit of Leptonycteris curasoae are pollinated by diurnal and nocturnal insects and birds. Agave angustifolia is a paniculate agave with a broad distribution in Mexico ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.7.1016
更新日期:2003-07-01 00:00:00
abstract:PREMISE OF THE STUDY:Inclusion of fossils in phylogenetic analyses is necessary in order to construct a comprehensive "tree of death" and elucidate evolutionary history of taxa; however, such incorporation of fossils in phylogenetic reconstruction is dependent on the availability and interpretation of extensive morphol...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1123
更新日期:2018-08-01 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
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:PREMISE OF THE STUDY:Reintroductions may be essential to prevent extinction of many critically endangered species. Ideally, reintroduction efforts rely on adjacent source populations, but limited source material may necessitate crossing individuals from different and possibly distant populations. To determine the conse...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400271
更新日期:2014-11-01 00:00:00
abstract::Five plant communities in Western Australia, as well as selected desert and Rocky Mountain species of the western USA, were surveyed to evaluate associations among leaf structure, orientational properties, and the sunlight exposure and precipitation characteristic of each community. Selected leaf structural features h...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-01-01 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: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
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
abstract:PREMISE OF THE STUDY:To enhance our knowledge of the diversity of microalgae, a phycological survey of the Canary Islands (Spain) was undertaken. Here we report the discovery of a (semi)terrestrial green filamentous alga isolated from a steep volcanic canyon on La Palma. This alga is continually exposed to changing wea...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500199
更新日期:2015-09-01 00:00:00
abstract:PREMISE OF THE STUDY:Collinsia was the subject of classic biosystematic studies by Garber and colleagues and is increasingly investigated to address major evolutionary questions. Lack of phylogenetic data from more than one gene region and one taxonomic exemplar has left relationships, diversity, and phytogeography of ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000346
更新日期:2011-04-01 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::Because leaf pubescence of the desert shrub Encelia farinosa increases in response to drought and influences photosynthesis and transpiration, we hypothesized that differences in water availability across the range of this species may result in genetic differentiation for pubescence and associated productivity traits....
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.10.1481
更新日期:2003-10-01 00:00:00
abstract::Seed and pollen morphology were studied by light microscopy and scanning electron microscopy in 39 North and Central American species of Houstonia (including Hedyotis, but excluding Oldenlandia). Chromosome counts were obtained for eight taxa, of which five lacked previous chromosome data. A chromosome number of n = 1...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1986.tb09686.x
更新日期:1986-01-01 00:00:00
abstract::We launched imbibed seeds and seedlings of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on 1) root-cap regeneration, and 2) the distribution of amyloplasts and endoplasmic reticulum (ER) in the putative statocytes (i.e., columella cells) of roots. Decapped roo...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1987-01-01 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 used isozymes (16 loci in 11 enzymatic systems) from Laelia speciosa, an endemic and endangered epiphytic orchid of Mexico, to assess the genetic diversity and population genetic structure in nine populations distributed along its geographic range, as well as to detect those populations that are genetically unique ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.2.184
更新日期:2007-02-01 00:00:00
abstract::Microelectrodes were used to study the oxygen concentration within Myrica gale L. nodules. Low oxygen concentrations were found only in the region of the mature, nitrogen-fixing endophyte, and appeared to correspond to clusters of infected host cells. The oxygen concentration in the remainder of the nodule was much hi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1983.tb12432.x
更新日期:1983-01-01 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::We present here the first molecular phylogeny of tribe Diseae (Orchidoideae: Orchidaceae). Nuclear ribosomal ITS1, 5.8S rDNA, and ITS2 sequences were compared for 30 Diseae, 20 Orchideae, and four Cranichideae and Diurideae outgroups. ITS - rDNA sequences exhibited a transition:transversion ratio of 1.3 and extensive ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-06-01 00:00:00
abstract:PREMISE:Most plants interact with mycorrhizal fungi and animal pollinators simultaneously. Yet, whether mycorrhizae affect traits important to pollination remains poorly understood and may depend on the match between host and fungal genotypes. Here, we examined how ericoid mycorrhizal fungi affected flowering phenology...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1372
更新日期:2019-11-01 00:00:00
abstract::In turnip mitochondria the cox2 gene is partially contained within a 2-kb (kilobase) direct repeat that is the site of homologous recombination events that generate subgenomic molecules. Because of its partial presence within the direct repeat, the turnip cox2 gene exists in four genomic contexts, two on the master ch...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-02-01 00:00:00