Morphologically complex plant macrofossils from the Late Silurian of Arctic Canada.

abstract：PREMISE OF THE STUDY:While the effect of abiotic factors on leaf herbivory is well known, the relative importance of abiotic conditions influencing both mutualists and antagonists is less well understood. Species interactions could enhance or reduce the direct effects of abiotic factors, depending on how mutualists and...

journal_title：American journal of botany

authors： Soper Gorden NL,Adler LS

更新日期：2013-04-01 00:00:00

abstract：:Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reporte...

journal_title：American journal of botany

authors： Taylor PJ,Eppley SM,Jesson LK

更新日期：2007-11-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Two ovulate conifer cones, one of which is attached terminally to a short leafy shoot, reveal the presence of a new species of Hughmillerites in the Early Cretaceous Apple Bay flora of Vancouver Island, British Columbia, Canada. This ancient conifer expands the diversity of Cupressace...

journal_title：American journal of botany

authors： Atkinson BA,Rothwell GW,Stockey RA

更新日期：2014-12-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Contact zones between diploids and their autopolyploid descendants represent a unique evolutionary venue for studying polyploid establishment, cytotype coexistence, and interactions. Here, we examine cytotype coexistence in a diploid-tetraploid contact zone of a perennial herb, Cardam...

journal_title：American journal of botany

authors： Zozomová-Lihová J,Malánová-Krásná I,Vít P,Urfus T,Senko D,Svitok M,Kempa M,Marhold K

更新日期：2015-08-01 00:00:00

abstract：PREMISE OF THE STUDY:Endophytic fungi are common inhabitants of cool-season grasses that can affect host growth and reproduction. One prerequisite for the expected coevolution between symbionts is that there exist variable effects of the endosymbiont on its host in different environments. Here, the impact of endophytes...

journal_title：American journal of botany

authors： Cheplick GP

更新日期：2011-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Phylogenetic incongruence between "gene trees" and "species trees" has been widely acknowledged in phylogenetic research. Conflicts may emerge from several processes including paralogy, hybridization, and incomplete lineage sorting. Although phylogenetic incongruence appears common, its impact on m...

journal_title：American journal of botany

authors： Zhang Q,Feild TS,Antonelli A

更新日期：2015-04-01 00:00:00

abstract：:The selective maintenance of gynodioecy depends on the relative fitness of the male-sterile (female) and hermaphroditic morphs. Females may compensate for their loss of male fitness by reallocating resources from male function (pollen production and pollinator attraction) to female function (seeds and fruits), thus in...

journal_title：American journal of botany

authors： Williams CF,Kuchenreuther MA,Drew A

更新日期：2000-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Fern spores are unicellular and haploid, making them a potential model system to study factors that regulate lifespan and mechanisms of aging. Aging rates of nongreen spores were measured to compare longevity characteristics among diverse fern species and test for orthodox response to storage tempe...

journal_title：American journal of botany

authors： Ballesteros D,Estrelles E,Walters C,Ibars AM

更新日期：2012-04-01 00:00:00

abstract：:Restriction fragment length polymorphism (RFLP) analysis of chloroplast (cp) DNA is a powerful tool for the study of microevolutionary processes in land plants, yet has not previously been applied to seaweed populations. We used cpDNA-RFLP, detected on Southern blots using labeled total plastid DNA, to search for intr...

journal_title：American journal of botany

authors： Wattier RA,Davidson AL,Ward BA,Maggs CA

更新日期：2001-07-01 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

authors： Molina-Freaner F,Eguiarte LE

更新日期：2003-07-01 00:00:00

abstract：PREMISE:Spiny pollen has evolved independently in multiple entomophilous lineages. Sexual selection may act on exine traits that facilitate male mating success by influencing the transfer of pollen from the anther to the body of the pollinator, while natural selection acts to increase pollen survival. We postulated tha...

journal_title：American journal of botany

authors： Lynn A,Piotter E,Harrison E,Galen C

更新日期：2020-02-01 00:00:00

abstract：:The utility of the PCR-based AFLP technique (polymerase chain reaction; amplified fragment length polymorphisms) was explored in elucidating details of polyploid evolution in the Eurasian orchid genus Dactylorhiza. We emphasized Swedish taxa but also included some material from the British Isles and elsewhere in Europ...

journal_title：American journal of botany

authors： Hedrén M,Fay MF,Chase MW

更新日期：2001-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Large genera provide remarkable opportunities to investigate patterns of morphological evolution and historical biogeography in plants. A molecular phylogeny of the species-rich and morphologically and ecologically diverse genus Mimosa was generated to evaluate its infrageneric classification, reco...

journal_title：American journal of botany

authors： Simon MF,Grether R,de Queiroz LP,Särkinen TE,Dutra VF,Hughes CE

更新日期：2011-07-01 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

authors： López-Carretero A,Boege K,Díaz-Castelazo C,Domínguez Z,Rico-Gray V

更新日期：2016-08-01 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

authors： Muellner AN,Samuel R,Johnson SA,Cheek M,Pennington TD,Chase MW

更新日期：2003-03-01 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

authors： Ramos BCM,Rodríguez-Gironés MA,Rodrigues D

更新日期：2017-08-01 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

authors： Gonzales E,Hamrick JL,Smouse PE

更新日期：2008-10-01 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

authors： McClure KA,Sawler J,Gardner KM,Money D,Myles S

更新日期：2014-10-01 00:00:00

abstract：:Caryophyllaceae is a principally holarctic family including around 2200 species often classified into the three subfamilies Alsinoideae, Caryophylloideae, and Paronychioideae. Complex and possibly homoplasious morphological characters within the family make taxa difficult to delimit and diagnose. To explore part of th...

journal_title：American journal of botany

authors： Fior S,Karis PO,Casazza G,Minuto L,Sala F

更新日期：2006-03-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Mountainous regions support high plant productivity, diversity, and endemism, yet are highly vulnerable to climate change. Historical records and model predictions show increasing temperatures across high elevation regions including the Southern Rocky Mountains, which can have a stron...

journal_title：American journal of botany

authors： Munson SM,Sher AA

更新日期：2015-08-01 00:00:00

abstract：:The boreotropical flora concept suggests that relictual tropical disjunctions between Asia and the Americas are a result of the expansion of the circumboreal tropical flora from the middle to the close of the Eocene. Subsequently, temperate species diverged at high latitudes and migrated to other continents. To test t...

journal_title：American journal of botany

authors： Azuma H,García-Franco JG,Rico-Gray V,Thien LB

更新日期：2001-12-01 00:00:00

abstract：:Exotic plant species can threaten closely related native congeners through asymmetric hybridization and subsequent backcrossing, the process known as genetic assimilation. I explore the initial stages of this process in Taraxacum ceratophorum (Asteraceae), the native alpine dandelion, and the invasive apomict T. offic...

journal_title：American journal of botany

authors： Brock MT

更新日期：2004-05-01 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

authors： Mandáková T,Gloss AD,Whiteman NK,Lysak MA

更新日期：2016-07-01 00:00:00

abstract：:Many characteristics of plants and animals scale with body size as described by allometric equations of the form Y = βM(α), where Y is an attribute of the organism, β is a coefficient that varies with attribute, M is a measure of organism size, and α is another constant, the scaling exponent. In current models, the fr...

journal_title：American journal of botany

authors： Koontz TL,Petroff A,West GB,Brown JH

更新日期：2009-05-01 00:00:00

abstract：PREMISE:Adaptation to harsh edaphic substrates has repeatedly led to the evolution of edaphic specialists and generalists. Yet, it is unclear what factors promote specialization versus generalization. Here, we search for habitat use patterns associated with serpentine endemics (specialists) and serpentine tolerators (g...

journal_title：American journal of botany

authors： Sianta SA,Kay KM

更新日期：2019-05-01 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

authors： Lomelí-Sención JA,Sahagún-Godínez E

更新日期：2002-09-01 00:00:00

abstract：:A well-integrated plant shows extensive carbohydrate translocation through the plant body. Even in highly integrated plants, however, translocation patterns will be sectorial if vascular tissue restricts carbon movement to sectors along stems. Both integration and sectorial translocation patterns are sensitive to plan...

journal_title：American journal of botany

authors： Preston KA

更新日期：1998-12-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Allometric relationships among the dimensions of leaf cells, cell walls, and tissues, and whole-leaf thickness and area are likely to have key implications for leaf construction and function, but have remained virtually untested, despite the explosion of interest in allometric analysis...

journal_title：American journal of botany

authors： John GP,Scoffoni C,Sack L

更新日期：2013-10-01 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

authors： Matias R,Pérez-Barrales R,Consolaro H

更新日期：2020-06-01 00:00:00

abstract：:Seed size and germination requirements of eight (of nine) Sarracenia species, and 13 populations of S. purpurea were studied. All species except for S. purpurea are restricted to the southeastern United States, whereas S. purpurea ranges across Canada, southward along the eastern United States into Maryland and Virgin...

journal_title：American journal of botany

authors： Ellison AM

更新日期：2001-03-01 00:00:00