解剖学和形态学
麻醉学
听力与言语-语言病理学
行为科学
心脏和心血管系统
细胞和组织工程学
临床神经病学
危重症监护医学
牙科,口腔外科和医学
皮肤病学
急诊医学
内分泌学和新陈代谢
肠胃学和肝脏学
老人病学和老年医学
卫生保健科学和服务
血液学
免疫学
传染病
综合和补充性医学
医学伦理学
医学信息学
医学实验室技术
医学,全科和内科
医学,法律
医学,研究和试验
神经系统科学
护理
营养学和饮食学
产科医学和妇科医学
肿瘤学
眼科学
整形外科学
耳鼻喉科学
病理学
儿科学
周围血管疾病
药理学和药剂学
生理学
基本医疗保健
精神病学
公共、环境和职业卫生
放射学,核医学和医学成像
康复学
生殖生物学
呼吸系统
风湿病学
运动科学
外科学
毒理学
热带医学
泌尿学和肾脏学
病毒学
老年医学
健康政策和服务
心理学,临床
abstract:PREMISE OF THE STUDY:Recurrent formation of polyploid taxa is a common observation in many plant groups. Haploid, cytoplasmic genomes like the plastid genome can be used to overcome the problem of homeologous genes and recombination in polyploid taxa. Fragaria (Rosaceae) contains several octo- and decaploid species. We...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1085
更新日期:2018-05-01 00:00:00
abstract:PREMISE OF THE STUDY:Tetraena simplex is an independently evolved C4 species in the Zygophylloideae (Zygophyllaceae) and a characteristic forb of saline flats in hot and sandy desert habitats. During early ontogeny, the species had a morphological shift from planar cotyledons (dorsiventral symmetry) to terete, succulen...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1087
更新日期:2018-05-01 00:00:00
abstract:PREMISE OF THE STUDY:The ecological and evolutionary significance of natural epigenetic variation (i.e., not based on DNA sequence variants) variation will depend critically on whether epigenetic states are transmitted from parents to offspring, but little is known on epigenetic inheritance in nonmodel plants. METHODS...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1074
更新日期:2018-04-01 00:00:00
abstract:PREMISE OF THE STUDY:Evolutionary and biogeographic history, including past environmental change and diversification processes, are likely to have influenced the expansion, migration, and extinction of populations, creating evolutionary legacy effects that influence regional species pools and the composition of communi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1049
更新日期:2018-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Species formation is an intuitive endpoint of reproductive isolation, but circumscribing taxa that arise during speciation can be difficult because of gene flow, morphological continuity, hybridization or polyploidization, and low sequence variation among newly diverged lineages. Nonetheless, speci...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1061
更新日期:2018-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Many ecological and evolutionary processes shape the assembly of organisms into local communities from a regional pool of species. We analyzed phylogenetic and functional diversity to understand community assembly of the ferns of Florida at two spatial scales. METHODS:We built a phylogeny for 125 ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1073
更新日期:2018-03-01 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
abstract:PREMISE OF THE STUDY:Pollen dispersal is a key process that influences ecological and evolutionary dynamics of plant populations by facilitating sexual reproduction and gene flow. Habitat loss and fragmentation have the potential to reduce pollen dispersal within and among habitat patches. We assessed aquatic pollen di...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1031
更新日期:2018-02-01 00:00:00
abstract:PREMISE OF THE STUDY:The species boundaries of wild and cultivated potatoes are controversial, with most of the taxonomic problems in the cultivated potato clade. We here provide the first in-depth phylogenetic study of the cultivated potato clade to explore possible causes of these problems. METHODS:We examined 131 d...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1008
更新日期:2018-01-01 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:Bignoniaceae is an important component of neotropical forests and a model for evolutionary and biogeographical studies. A previous combination of molecular markers and morphological traits improved the phylogeny of the group. Here we demonstrate the value of next-generation sequencing (NGS) to asse...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700302
更新日期:2017-10-01 00:00:00
abstract:PREMISE OF THE STUDY:Despite the strong influence of the frequency and distribution of vessel endings on both hydraulic safety and efficiency, detailed anatomical descriptions or measurements of these structures are generally lacking. METHODS:Here we used high-resolution x-ray microcomputed tomography (microCT) to ide...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700199
更新日期:2017-09-01 00:00:00
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:Global change in temperature and soil nitrogen availability could affect plant community composition, potentially giving an advantage to invasive species compared to native species. We addressed how high temperatures affected CO2 assimilation parameters for invasive Phalaris arundinacea and a sedge...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600339
更新日期:2017-07-01 00:00:00
abstract:PREMISE OF THE STUDY:Direct tests of a species distribution model (SDM) were used to evaluate the hypothesis that the northern and southern edges of Mimulus bicolor's geographical range are limited by temperature and precipitation. METHODS:Climatic suitability was predicted using an SDM informed only by temperature an...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600414
更新日期:2017-06-01 00:00:00
abstract:PREMISE OF THE STUDY:The genus Hoya (Apocynaceae; Asclepiadoideae) is characterized by a set of complex floral characters unique among the asclepiads, but their role in pollination is poorly understood. Here, we report a new mechanism of asclepiad pollination in the wax plant Hoya carnosa: the pollinaria are transferre...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1700078
更新日期:2017-06-01 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:PREMISE OF THE STUDY:Plants adjust their phenology in response to seasonal cues experienced both by their parents and by themselves, and coordinating responses to these cues is necessary for expressing adaptive phenology. We investigated how cues are integrated across time to influence an important progeny phenotype, i...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600389
更新日期:2017-04-01 00:00:00
abstract:PREMISE OF THE STUDY:This paper investigates the occurrence and evolution of aluminum (Al) accumulation within ferns and lycophytes, which is characterized by Al concentrations above 1000 mg·kg-1 in aboveground plant tissues. We hypothesize that this feature is more common in ferns than in angiosperms, and potentially ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600381
更新日期:2017-04-01 00:00:00
abstract:PREMISE OF THE STUDY:Our goal was to infer the phylogenetic relationships and historical biogeography of the genus Dryopteris with a focus on taxa in sub-Saharan Africa and neighboring islands. In general, little is known about the relationships between African fern species and their congeners in other geographic regio...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600392
更新日期:2017-03-01 00:00:00
abstract:PREMISE OF THE STUDY:It has been hypothesized that two flower types permit flexible allocation of resources to female and male functions, yet empirical evidence for the sex-allocation hypothesis remains scarce in gynomonoecious species. To characterize resource allocation to pistillate and perfect flowers and allocatio...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600397
更新日期:2017-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Populations of heterostylous species are characterized by two or three floral morphs with reciprocal positioning of stigmas and anthers. Theoretical models predict equal morph frequencies (isoplethy) when disassortative mating is prevalent in populations, but biased morph ratios may occur when vari...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600345
更新日期:2017-01-01 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: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: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:PREMISE OF THE STUDY:Functional trait plasticity in resource capture traits has been suggested as an underlying mechanism promoting invasive species establishment and spread. Earlier studies on this mechanism treat invasiveness as a discrete characteristic (i.e., invasive vs. noninvasive) and do not consider the potent...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600235
更新日期:2016-12-01 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:Sex lability (i.e., gender diphasy) in plants is classically linked to the larger resource needs associated with the female sexual function (i.e., seed production) compared to the male function (i.e., pollen production). Sex lability in response to the environment is extensively documented in dioec...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600158
更新日期:2016-11-01 00:00:00
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:PREMISE OF THE STUDY:Self-incompatibility (SI) is a mechanism that prevents inbreeding in many plant species. The mutational breakdown of SI occurs frequently, yet relatively little is known about the evolutionary steps involved in the progressive loss of pistil and pollen SI function. METHODS:In Solanaceae, SI is the...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600208
更新日期:2016-10-01 00:00:00
abstract:PREMISE OF STUDY:Although there is increasing recognition of the effects of plant intraspecific diversity on consumers, the mechanisms by which such effects cascade-up to higher trophic levels remain elusive. METHODS:We evaluated the effects of plant (lima bean, Phaseolus lunatus) intraspecific diversity on a suite of...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600234
更新日期:2016-10-01 00:00:00
abstract:PREMISE OF THE STUDY:Fossilized seeds similar to Cissus (Vitaceae) have been recognized from the Miocene of Kenya, though some were previously assigned to the Menispermaceae. We undertook a comparative survey of extant African Cissus seeds to identify the fossils and consider their implications for the evolution and bi...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600177
更新日期:2016-09-01 00:00:00
abstract:PREMISE OF THE STUDY:The phenotype of an individual can be modified by the environment experienced by its predecessors, a phenomenon called transgenerational or maternal effects. These effects are studied mostly across sexual generations and are thought to be mediated also by epigenetic variation. However, we do not kn...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500526
更新日期:2016-09-01 00:00:00
abstract:PREMISE OF THE STUDY:Plant-herbivore networks are highly specialized in their interactions, yet they are highly variable with regard to the relative importance of specific host species for herbivores. How host species traits determine specialization and species strength in this antagonistic network is still an unanswer...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600045
更新日期:2016-08-01 00:00:00
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
pub_type: 杂志文章
doi:10.3732/ajb.1500452
更新日期:2016-07-01 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
abstract:PREMISE OF THE STUDY:During the interactions between a parasitic plant and its host, the parasite affects its host morphologically, anatomically, and physiologically, yet there has been little focus on the effect of hosts on the parasite. Here, the functional interactions between the hemiparasitic mistletoe Psittacanth...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600166
更新日期:2016-06-01 00:00:00
abstract:PREMISE OF THE STUDY:Discovery of cupulate ovules of Doylea tetrahedrasperma within a compact, compound seed cone highlights the rich diversity of fructification morphologies, pollination biologies, postpollination enclosure of seeds, and systematic diversity of Early Cretaceous gymnosperms. METHODS:Specimens were stu...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600030
更新日期:2016-05-01 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 OF THE STUDY:Geographic differences in flower visitor assemblages might lead to among-population differences in the magnitude and pattern of floral integration. However, the role of current pollinator visitation in shaping the magnitude and pattern of floral trait correlations is still controversial. METHODS:W...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500336
更新日期:2016-02-01 00:00:00