Abstract:
:The micromorphology of pits in tracheary elements was examined in 35 species representing 29 genera of Rosaceae and related families to evaluate the assumption that angiosperm pits are largely invariant. In most Rosaceae, pit membranes between fibers and tracheids frequently appear to have amorphous thickenings with an irregular distribution. Although these structures are torus-like under the light microscope, observations by electron microscopy illustrate that they represent "pseudotori" or plasmodesmata-associated thickenings. These thickenings frequently extend from the periphery of the pit membrane and form a cap-like, hollow structure. Pseudotori are occasionally found in few Elaeagnaceae and Rhamnaceae and appear to be related to species with fiber-tracheids and/or tracheids. True tori are strongly associated with round to oval pit apertures and are consistently present in narrow tracheary elements of Cercocarpus (Rosaceae), Planera (Ulmaceae), and ring-porous species of Ulmus and Zelkova (Ulmaceae). Vestured pits with homogenous pit membranes are reported for Hemiptelea (Ulmaceae). The homoplastic nature of pit membrane characteristics may be related to functional adaptations in terms of safety and efficiency of water transport or may reflect different developmental processes of xylem elements. These observations illustrate that there is more variation in angiosperm pits than previously thought.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Jansen S,Sano Y,Choat B,Rabaey D,Lens F,Dute RRdoi
10.3732/ajb.94.4.503subject
Has Abstractpub_date
2007-04-01 00:00:00pages
503-14issue
4eissn
0002-9122issn
1537-2197pii
94/4/503journal_volume
94pub_type
杂志文章abstract::The fresh weights of suspension cultures of pear (Pyrus communis) and quince (Cydonia oblonga) increased exponentially for 30 to 40 days after subculturing. Transferring pear cultures to media in which quince cultures had grown for 10 days resulted in a 70% inhibition of callus growth. Transferring quince cultures to ...
journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:1986-01-01 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
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abstract:PREMISE OF THE STUDY:Despite being highly fertile and occupying a large geographic region, the North American heartleaf bittercress (Cardamine cordifolia; Brassicaceae) has a puzzling triploid-like chromosome number (2n = 3x = 24). As most triploids are sterile, we embarked on a detailed analysis of the C. cordifolia g...
journal_title:American journal of botany
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更新日期:2016-07-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Vessels are the chief conduit for long-distance water transport in the majority of flowering plants. Vessel length is a key trait that determines plant hydraulic efficiency and safety, yet relatively little is known about this xylem feature. • METHODS:We used previously published stud...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200140
更新日期:2012-10-01 00:00:00
abstract::Sphenobaiera huangii (Sze) Hsü is typical Early Mesozoic fossil foliage of Ginkgoales in China. It has been recorded from the Upper Triassic to the Lower Jurassic. The cuticular anatomy is investigated based on material from the type locality, Lower Jurassic Hsiangchi Formation, Zigui County, Hubei Province. The speci...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.4.709
更新日期:2005-04-01 00:00:00
abstract::Phylogenetic analyses of Meliaceae, including representatives of all four currently recognized subfamilies and all but two tribes (32 genera and 35 species, respectively), were carried out using DNA sequence data from three regions: plastid genes rbcL, matK (partial), and nuclear 26S rDNA (partial). Individual and com...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.3.471
更新日期:2003-03-01 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
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-09-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2011-05-01 00:00:00
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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::Xylem of the orchids studied provided unusually favorable material to demonstrate how conductive tissue evolves in monocotyledons. In the end walls of tracheary elements of many Orchidaceae, remnants of pit membranes were observed with scanning electron microscopy and minimally destructive methods. The full range from...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.7.963
更新日期:2006-07-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00
abstract::The origin of polyploid Bromus species of section Genea was investigated using molecular data. This group of annual species native from the Old-World is composed of three diploids, two tetraploids, one hexaploid, and one octoploid. Molecular cloning, sequencing, and phylogenetic analyses were performed on several acce...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.95.4.454
更新日期:2008-04-01 00:00:00
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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
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journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2012-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1019
更新日期:2018-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1346
更新日期:2019-09-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.8.1425
更新日期:2007-08-01 00:00:00
abstract:PREMISE OF THE STUDY:New microsatellite primers were developed for testing genetic differentiation within Nothoceros aenigmaticus and their potential use in other Nothoceros species. The microsatellites are designed to investigate partitioning of genetic variation in a taxon with a peculiar sex allopatry in the souther...
journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2012-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2006-09-01 00:00:00
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journal_title:American journal of botany
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更新日期:2009-01-01 00:00:00
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journal_title:American journal of botany
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更新日期:2002-02-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300027
更新日期:2013-08-01 00:00:00
abstract::Phylogenetic relationships among embryophytes (tracheophytes, mosses, liverworts, and hornworts) were examined using 21 newly generated mitochondrial small-subunit (19S) rDNA sequences. The "core" 19S rDNA contained more phylogenetically informative sites and lower homoplasy than either nuclear 18S or plastid 16S rDNA...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-09-01 00:00:00
abstract::It is generally thought that sedimenting plastids are responsible for gravity sensing in higher plants. We directly tested the model generated by the current statolith hypothesis that the gravity sensing that leads to gravitropism results from an interaction between the plastids and actin microfilaments. We find that ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-11-01 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
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更新日期:2016-11-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2006-08-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2016-09-01 00:00:00
abstract:PREMISE:Despite the fast pace of exploration of the patterns and processes influencing Neotropical plant hyperdiversity, the taxa explored are mostly from large groups that are widely distributed, morphologically diverse, or economically important. Vochysiaceae is an example of an undersampled taxon, providing an excel...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1502
更新日期:2020-07-01 00:00:00