Abstract:
:Viability of long-distance pollen links ecological models to the genetic structure of forest tree populations, determining how forests will adapt to climate change and how far genes flow from genetically modified (GM) pine plantations. Addressing this landscape-scale inquiry is feasible when the pollen source, the delivery system, and the receiver field can be made explicit. To this end, I measured long-distance pollen germination along a 160-km transect along the North Carolina coastline, including 45000 ha of mature Pinus taeda plantations and barrier islands. Using this system, I tested three hypotheses: (1) pine pollen germinates after dispersal on meso-scale distances, (2) sodium chloride exposure reduces germination of pollen captured over open saltwater, and (3) viable pine pollen is present at high altitudes before local peak pollen shed. The experimental findings are as follows: pine pollen had germination rates of 2 to 57% after dispersal at distances from 3 to 41 km, sodium chloride solutions mildly reduced P. taeda pollen germination, and viable pine pollen grains were captured at an altitude of 610 m. GM pine plantings thus have a potential to disperse viable pollen at least 41 km from the source. Wind and rainfall, as integral parts of regional atmospheric systems, together exert a powerful influence on the genetic structure of forest tree populations.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Williams CGdoi
10.3732/ajb.0900255subject
Has Abstractpub_date
2010-05-01 00:00:00pages
846-55issue
5eissn
0002-9122issn
1537-2197pii
ajb.0900255journal_volume
97pub_type
杂志文章abstract:PREMISE OF THE STUDY:Studies of natural genetic variation can elucidate the genetic basis of phenotypic variation and the past population structure of species. Our study species, Taxodium distichum, is a unique conifer that inhabits the flood plains and swamps of North America. Morphological and ecological differences ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600046
更新日期:2016-11-01 00:00:00
abstract::We tested the hypothesis that trees growing at high elevations with occasional freezing temperatures have smaller diameter xylem vessels than trees of the same species growing at lower and warmer elevations. The young branch wood of the wide-ranging Hawaiian tree species Metrosideros polymorpha (Myrtaceae) was examine...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.5.709
更新日期:2007-05-01 00:00:00
abstract:PREMISE OF THE STUDY:Most pollen walls are interrupted by apertures, thin areas providing access to stigmatic fluids and exit points for pollen tubes. Unexpectedly, pollen tubes of Arabidopsis thaliana are not obligated to pass through apertures and can instead take the shortest route into the stigma, passing directly ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600031
更新日期:2016-06-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.4.503
更新日期:2007-04-01 00:00:00
abstract:PREMISE OF THE STUDY:Vestigialization of traits that no longer enhance fitness is a common theme in evolution. Plants often use colorful, scented flowers to attract pollinators that mediate outcross pollination. After an evolutionary shift from outcrossing to self-fertilization, where cross-pollination is no longer nec...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300159
更新日期:2013-11-01 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:PREMISE:Inbreeding depression is traditionally considered a major factor favoring outcrossing in hermaphrodites. Recent experiments have shown that environmental conditions can influence the magnitude of inbreeding depression, but their relevance in natural populations is unclear. To investigate this, we studied the cl...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1410
更新日期:2020-01-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-06-01 00:00:00
abstract::The hollow stem of Equisetum giganteum owes its mechanical stability to an outer ring of strengthening tissue, which provides stiffness and strength in the longitudinal direction, but also to an inner lining of turgid parenchyma, which lends resistance to local buckling. With a height >2.5 m isolated stems are mechani...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-03-01 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::Maximum parsimony analysis of DNA sequence data from the internal and external transcribed spacer (ITS and ETS) regions of 18S-26S nuclear ribosomal DNA and the 3' trnK intron of chloroplast DNA from over 60 populations of Lasthenia sect. Amphiachaenia yielded a well-supported tree showing that the most common species...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.7.1103
更新日期:2002-07-01 00:00:00
abstract::Pollinator-mediated natural selection has been shown to act on phenotypic variation in floral morphology, and this variation has often been demonstrated to be heritable, but few details are available concerning the sources of floral variation. We examined phenotypic variation in seven floral traits in wild radish (Rap...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-09-01 00:00:00
abstract::Perennial crops represent important fresh and processed food sources worldwide, but advancements in breeding perennials are often impeded due to their very nature. The perennial crops we rely on most for food take several years to reach production maturity and require large spaces to grow, which make breeding new cult...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400143
更新日期:2014-10-01 00:00:00
abstract:PREMISE OF THE STUDY:Variation in demographic parameters reflects the life-history strategies of plants in response to specific environments. We aimed to investigate the intraspecific variation in life-history traits of a clonal alpine herb, Gentiana nipponica, in various snowmelt conditions. METHODS:Individual ramets...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1186
更新日期:2018-11-01 00:00:00
abstract::Gelatinous fibers (G-fibers) are the active component of tension wood. G-fibers are unlike traditional fiber cells in that they possess a thick, nonlignified gelatinous layer (G-layer) internal to the normal secondary cell wall layers. For the past several decades, the G-layer has generally been presumed to be compose...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.2007368
更新日期:2008-06-01 00:00:00
abstract::Wind is a major ecological factor for plants and a major economical factor for forestry. Mechanical analyses have revealed that the multimodal dynamic behavior of trees is central to wind-tree interactions. Moreover, the trunk and branches influence dynamic modes, both in frequency and location. Because of the complex...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0800161
更新日期:2008-12-01 00:00:00
abstract::In monocarpic plants, reproduction is closely associated with senescence, which is itself often correlated to specific environmental signals. Floerkea proserpinacoides (Limnanthaceae) is a spring ephemeral annual of the deciduous forests of eastern North America. The phenology of its growth and reproduction is conside...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.3.438
更新日期:2005-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Areas lacking dominant plants, or gaps, can support high diversity and specialist species. Previous chronosequence research in Florida rosemary scrub showed indistinct gap area patterns with fire and the dependence of certain species on gaps. We hypothesized that fire and gap size would affect exti...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700175
更新日期:2017-12-01 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:PREMISE:Distylous species possess two floral morphs with reciprocal positioning of stigmas and anthers that is hypothesized to promote disassortative pollination. Theoretical models predict equal morph frequencies, but many populations depart from the expected 1:1 ratio, a pattern that often correlates with asymmetric ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1478
更新日期:2020-06-01 00:00:00
abstract::To our knowledge, xylary reaction tissue has never been reported in a forage crop species. Here we report the discovery of reaction tissue in a transgenic line of Medicago sativa (pC3H, for the gene for p-coumarate-3-hydroxylase) with reduced lignin content and in the wild-type (WT) line. Based on microscopy and biome...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.6.912
更新日期:2007-06-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:The role of hybridization in plant evolution remains a source of intense debate. Potential consequences range from genetic dead-ends to species fusion or hybrid speciation. While much has been learned from model systems such as Populus, Iris, and Helianthus, many questions remain. Cons...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300038
更新日期:2013-10-01 00:00:00
abstract::Molecular studies of apomictic plant species often detect more genotypic variation than predicted from their assumed reproductive mode. The two most commonly invoked mechanisms to explain these high levels of variation are recombination, via facultative sexuality, and mutation. The potential for sexual reproduction in...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.1.37
更新日期:2004-01-01 00:00:00
abstract::The relationship between pollen and progeny performance has been a subject of many studies but the evidence for pollen-tube growth rate as an indicator of progeny fitness is equivocal. We used an anemophilous tree, Betula pendula, to examine the relationship between pollen-tube growth rate and seed and seedling perfor...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-05-01 00:00:00
abstract::Floral morphology of the 13 species of Moringa ranges from actinomorphic flowers with little hypanthium to highly zygomorphic flowers with well-developed hypanthia. Scanning electron and light microscopy were used to identify ontogenetic differences among two actinomorphic and eight zygomorphic species. All species sh...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.1.49
更新日期:2003-01-01 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::Phylogenetic relationships were determined in the Araucariaceae, which are now found mainly in the Southern Hemisphere. This conifer family was well diversified and widely distributed in both hemispheres during the Mesozoic era. The sequence of 1322 bases of the rbcL gene of cpDNA was determined from 29 species of Ara...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1998-11-01 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::The relationship between near-infrared reflectance at 800 nm (NIRR) from leaves and characteristics of leaf structure known to affect photosynthesis was investigated in 48 species of alpine angiosperms. This wavelength was selected to discriminate the effects of leaf structure vs. chemical or water content on leaf ref...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-02-01 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