Abstract:
UNLABELLED:• PREMISE OF THE STUDY:The ability to respond to environmental change via phenotypic plasticity may be important for plants experiencing disturbances such as climate change and plant invasion. Responding to belowground competition through root plasticity may allow native plants to persist in highly invaded systems such as the cold deserts of the Intermountain West, USA.• METHODS:We investigated whether Poa secunda, a native bunchgrass, could alter root morphology in response to nutrient availability and the presence of a competitive annual grass. Seeds from 20 families were grown with high and low nutrients and harvested after 50 d, and seeds from 48 families, grown with and without Bromus tectorum, were harvested after ∼2 or 6 mo. We measured total biomass, root mass fraction, specific root length (SRL), root tips, allocation to roots of varying diameter, and plasticity in allocation.• KEY RESULTS:Plants had many parallel responses to low nutrients and competition, including increased root tip production, a trait associated with tolerance to reduced resources, though families differed in almost every trait and correlations among trait changes varied among experiments, indicating flexibility in plant responses. Seedlings actively increased SRL and fine root allocation under competition, while older seedlings also increased coarse root allocation, a trait associated with increased tolerance, and increased root mass fraction.• CONCLUSIONS:The high degree of genetic variation for root plasticity within natural populations could aid in the long-term persistence of P. secunda because phenotypic plasticity may allow native species to persist in invaded and fluctuating resource environments.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Phillips AJ,Leger EAdoi
10.3732/ajb.1400234subject
Has Abstractpub_date
2015-01-01 00:00:00pages
73-84issue
1eissn
0002-9122issn
1537-2197pii
ajb.1400234journal_volume
102pub_type
杂志文章abstract:PREMISE OF THE STUDY:The ability of insect visitors to learn to manipulate complex flowers has important consequences for foraging efficiency and plant fitness. We investigated learning by two butterfly species, Danaus erippus and Heliconius erato, as they foraged on the complex flowers of Asclepias curassavica, as wel...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700040
更新日期:2017-08-01 00:00:00
abstract:PREMISE OF THE STUDY:One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season d...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400557
更新日期:2015-06-01 00:00:00
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 a...
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::Gregor Mendel was a 19(th) century priest and botanist who developed the fundamental laws of inheritance. The year 2000 marked a century since the rediscovery of those laws and the beginning of genetics. Although Mendel is now recognized as the founder of genetics, significant controversy ensued about his work through...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-05-01 00:00:00
abstract::We transplanted Nuphar variegata with submersed leaves only into natural lake sediments in pH-, [CO(2)]-, depth-, and temperature-controlled greenhouse tanks to test the hypotheses that more fertile sediment, lower free [CO(2)], and shallower depth would all stimulate the development of floating leaves. Sediment highe...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-08-01 00:00:00
abstract::Inferring basal relationships among vascular plants poses a major challenge to plant systematists. The divergence events that describe these relationships occurred long ago and considerable homoplasy has since accrued for both molecular and morphological characters. A potential solution is to examine phylogenetic anal...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-10-01 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:PREMISE OF THE STUDY:Geographic patterns of biodiversity have long inspired interest in processes that shape the assembly, diversity, and dynamics of communities at different spatial scales. To study mechanisms of community assembly, ecologists often compare spatial variation in community composition (beta-diversity) a...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500079
更新日期:2016-01-01 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:PREMISE OF THE STUDY:Both polyploidy and shifts in floral color have marked angiosperm evolution. Here, we investigate the biochemical basis of the novel and diverse floral phenotypes seen in allopolyploids in Nicotiana (Solanaceae) and examine the extent to which the merging of distinct genomes alters flavonoid pigmen...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600350
更新日期:2017-01-01 00:00:00
abstract:PREMISE OF THE STUDY:Understanding the flexibility of monocot genomes requires a phylogenetic framework, which so far is available for few of the ca. 2800 genera. Here we use a molecular tree for the South American genus Alstroemeria to place karyological information, including fluorescent in situ hybridization (FISH) ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200104
更新日期:2012-09-01 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::To investigate the relationship between the altitudinal distribution of Quercus laceyi and Q. sideroxyla and their physiological responses to drought, we measured relative water content (RWC), water potentials (Ψ(predawn) and Ψ(midday)), photosynthesis (A(max)), stomatal conductance (g), chlorophyll fluorescence (F(v)...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.5.809
更新日期:2007-05-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Diversification of floral traits in angiosperms is often attributed to have been driven by adaptations to pollinators. Nevertheless, phylogenetic studies on the relationships among evolutionary changes in floral traits and pollination systems are still limited. We examined the relation...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200359
更新日期:2013-03-01 00:00:00
abstract::Intensified ultraviolet-B radiation or UV-B (wavelengths between 280 and 320 nm) can delay flowering and diminish lifetime flower production in a few plants. Here we studied the effects of enhanced UV-B on floral traits crucial to pollination and pollinator reproduction. We observed simultaneous flowering responses of...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
abstract:PREMISE OF THE STUDY:Species differ in their temperature germination niche. Populations of a species may similarly differ across the distribution range of the species. Anticipating the impacts of climate variability and change requires understanding the differential sensitivity to germination temperature among and with...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600278
更新日期:2017-01-01 00:00:00
abstract::The phylogenetic structure of ferns (= monilophytes) is explored here, with a special focus on the early divergences among leptosporangiate lineages. Despite considerable progress in our understanding of fern relationships, a rigorous and comprehensive analysis of the early leptosporangiate divergences was lacking. Th...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.10.1582
更新日期:2004-10-01 00:00:00
abstract::We demonstrated that "orchid mycorrhiza," a specialized mycorrhizal type, appeared in the common ancestor of the largest plant family Orchidaceae and that the fungal partner shifted from Glomeromycota to a particular clade of Basidiomycota in association with this character evolution. Several unique mycorrhizal charac...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900101
更新日期:2009-11-01 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:UNLABELLED:• PREMISE OF THE STUDY:Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multip...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400171
更新日期:2014-08-01 00:00:00
abstract:PREMISE:The ecological implications of hyperaccumulation have been investigated at the organismal level, but are poorly understood at the plant community level. Questions addressed here were: Does the presence of selenium (Se) hyperaccumulators affect Se distribution and concentration in their native soil, and do hyper...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1500
更新日期:2020-07-01 00:00:00
abstract:PREMISE OF THE STUDY:Generic boundaries and infrageneric relationships among the charismatic temperate magnoliid Asarum sensu lato (Aristolochiaceae) have long been uncertain. Previous molecular phylogenetic analyses used either plastid or nuclear loci alone and varied greatly in their taxonomic implications for the ge...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400316
更新日期:2015-05-01 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::Chromosome numbers and karyotypes of species of Orobanche, Cistanche, and Diphelypaea (Orobanchaceae) were investigated, and 108 chromosome counts of 53 taxa, 19 counted for the first time, are presented with a thorough compilation of previously published data. Additionally, karyotypes of representatives of these gene...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.3.439
更新日期:2004-03-01 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::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::Trichomanes intricatum, the sporophyte-less filmy fern of the eastern United States, has been considered to be a species whose sporophyte generation has become extinct or is possibly still present among the many species of Trichomanes s.l. in the new world tropics but unable to grow in a temperate climate. A close rel...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0800122
更新日期:2008-12-01 00:00:00
abstract::In plants, polyploidy has been a significant evolutionary force on both recent and ancient time scales. In 1950, Ownbey reported two newly formed Tragopogon allopolyploids in the northwestern United States. We have made the first synthetic lines of T. mirus and T. miscellus using T. dubius, T. porrifolius, and T. prat...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0800299
更新日期:2009-05-01 00:00:00
abstract::The Strait of Gibraltar is the most important barrier disconnecting the landmasses of Europe and Africa on the western Mediterranean extreme. Carex helodes is a wind-pollinated species endemic to the western Mediterranean. Because molecular and cytogenetic data allow the inference of its evolutionary history, we analy...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.2007342
更新日期:2008-06-01 00:00:00
abstract:PREMISE OF THE STUDY:Large phylogenies can help shed light on macroevolutionary patterns that inform our understanding of fundamental processes that shape the tree of life. These phylogenies also serve as tools that facilitate other systematic, evolutionary, and ecological analyses. Here we combine genetic data from pu...
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