Cytotype distribution patterns, ecological differentiation, and genetic structure in a diploid-tetraploid contact zone of Cardamine amara.

abstract：:Gas exchange was measured in two subalpine herbs during alternating periods of sun and shade that simulated natural cloud patterns. Stomatal conductance (g) in the subalpine herb Helianthella quinquenervis was reduced by as much as 75% during 5-min shade periods that ranged in photosynthetic photon flux density (PPFD)...

journal_title：American journal of botany

authors： Knapp AK,Smith WK

更新日期：1990-02-01 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

authors： Fortune PM,Pourtau N,Viron N,Ainouche ML

更新日期：2008-04-01 00:00:00

abstract：PREMISE OF THE STUDY:Astragalus sect. Humillimi is distributed across the southwestern United States and contains two endangered taxa, A. cremnophylax var. cremnophylax and A. humillimus. The former was originally described from the South Rim of the Grand Canyon. Analysis of individuals discovered on the North Rim of t...

journal_title：American journal of botany

authors： Massatti R,Belus MT,Dowlatshahi S,Allan GJ

更新日期：2018-10-01 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

authors： Mokhtar IB,Houle G

更新日期：2005-03-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Microsatellite markers were developed in an alpine plant endemic to the Qinghai-Tibetan Plateau, Androsace tapete, to investigate its spatial genetic structure, gene flow, and mating patterns. • METHODS AND RESULTS:Using the combined biotin capture method, 16 microsatellite primer set...

journal_title：American journal of botany

authors： Zeng L,Li Z,Tashi T,Chen J,Zhong Y,Geng Y

更新日期：2010-10-01 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

authors： Muhaidat R,McKown AD,Al Zoubi M,Bani Domi Z,Otoum O

更新日期：2018-05-01 00:00:00

abstract：:Welwitschiaceae, a family in the Gnetales, is known today from only one extant species, Welwitschia mirabilis. This species is distributed in the Namibian desert, along the western coast of southern Africa, about 10 km inland from the coast. Very little is known about the fossil record of this family. Lower Cretaceous...

journal_title：American journal of botany

authors： Dilcher DL,Bernardes-De-Oliveira ME,Pons D,Lott TA

更新日期：2005-08-01 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

authors： Sessa EB,Juslén A,Väre H,Chambers SM

更新日期：2017-03-01 00:00:00

abstract：:The eudicot order Malpighiales contains ∼16000 species and is the most poorly resolved large rosid clade. To clarify phylogenetic relationships in the order, we used maximum likelihood, Bayesian, and parsimony analyses of DNA sequence data from 13 gene regions, totaling 15604 bp, and representing all three genomic com...

journal_title：American journal of botany

authors： Wurdack KJ,Davis CC

更新日期：2009-08-01 00:00:00

abstract：PREMISE OF THE STUDY:Inclusion of fossils in phylogenetic analyses is necessary in order to construct a comprehensive "tree of death" and elucidate evolutionary history of taxa; however, such incorporation of fossils in phylogenetic reconstruction is dependent on the availability and interpretation of extensive morphol...

journal_title：American journal of botany

authors： Smith SY,Iles WJD,Benedict JC,Specht CD

更新日期：2018-08-01 00:00:00

abstract：:Understanding the role of geography and ecology in species divergence is central to the study of evolutionary diversification. We used climatic, geographic, and biological data from nine wild Andean tomato species to describe each species' ecological niche and to evaluate the likely ecological and geographical modes o...

journal_title：American journal of botany

authors： Nakazato T,Warren DL,Moyle LC

更新日期：2010-04-01 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

authors： Houliston GJ,Chapman HM

更新日期：2004-01-01 00:00:00

abstract：PREMISE OF THE STUDY:Expressed sequence tag (EST)-derived microsatellite markers were developed for Elaeocarpus photiniifolia, an endemic taxon of the Bonin Islands. METHODS AND RESULTS:Initially, a complementary DNA (cDNA) library was constructed by de novo pyrosequencing of total RNA extracted from a seedling. A tot...

journal_title：American journal of botany

authors： Sugai K,Setsuko S,Uchiyama K,Murakami N,Kato H,Yoshimaru H

更新日期：2012-02-01 00:00:00

abstract：:We examined the effect of inbreeding on fitness (through both male and female functions) and changes in self-fertility in the partially self-incompatible species Campanula rapunculoides. Individuals in natural populations of C. rapunculoides varied extensively in their strength of self-incompatibility (SI). We crossed...

journal_title：American journal of botany

authors： Good-Avila SV,Nagel T,Vogler DW,Stephenson AG

更新日期：2003-12-01 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

authors： Burkle LA,Myers JA,Belote RT

更新日期：2016-01-01 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：:Many plant species are characterized by a life cycle with a long-lived, subterranean phase that is completely dependent on mycorrhizal fungal symbionts for fixed carbon. This type of life cycle is both phylogenetically and ecologically widespread and is found in diverse vascular plant lineages from the tropics to suba...

journal_title：American journal of botany

authors： Winther JL,Friedman WE

更新日期：2007-07-01 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

authors： Wang Y,Guignard G,Thévenard F,Dilcher D,Barale G,Mosbrugger V,Yang X,Mei S

更新日期：2005-04-01 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

authors： Hoggard GD,Kores PJ,Molvray M,Hoggard RK

更新日期：2004-01-01 00:00:00

abstract：PREMISE OF THE STUDY:To enhance our knowledge of the diversity of microalgae, a phycological survey of the Canary Islands (Spain) was undertaken. Here we report the discovery of a (semi)terrestrial green filamentous alga isolated from a steep volcanic canyon on La Palma. This alga is continually exposed to changing wea...

journal_title：American journal of botany

authors： Caisová L,Reyes CP,Álamo VC,Quintana AM,Surek B,Melkonian M

更新日期：2015-09-01 00:00:00

abstract：PREMISE OF THE STUDY:The fossil record of Agathis historically has been restricted to Australasia. Recently described fossils from the Eocene of Patagonian Argentina showed a broader distribution than found previously, which is reinforced here with a new early Paleocene Agathis species from Patagonia. No previous phylo...

journal_title：American journal of botany

authors： Escapa IH,Iglesias A,Wilf P,Catalano SA,Caraballo-Ortiz MA,Rubén Cúneo N

更新日期：2018-08-01 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

authors： Chacón J,Sousa A,Baeza CM,Renner SS

更新日期：2012-09-01 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

authors： Sampson BJ,Cane JH

更新日期：1999-01-01 00:00:00

abstract：:Biparental inbreeding is thought to be a common feature of plant populations with restricted pollen dispersal. It is generally assumed that the inbreeding depression frequently observed to accompany self-fertilization can be extrapolated to the lesser degrees of consanguinity involved in biparental inbreeding, but thi...

journal_title：American journal of botany

authors： Heywood JS

更新日期：1993-05-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Despite the ecological, economic, and cultural importance of the palm Mauritia flexuosa in Amazonia, knowledge of its reproductive biology is scarce. Previous observations of this species suggested beetles as the probable pollinator, but experimental work to confirm this hypothesis was...

journal_title：American journal of botany

authors： Khorsand Rosa R,Koptur S

更新日期：2013-03-01 00:00:00

abstract：:Phylogenetic relationships and biogeography of the genus Cerastium were studied using sequences of three noncoding plastid DNA regions (trnL intron, trnL-trnF spacer, and psbA-trnH spacer). A total of 57 Cerastium taxa was analyzed using two species of the putative sister genus Stellaria as outgroups. Maximum parsimon...

journal_title：American journal of botany

authors： Scheen AC,Brochmann C,Brysting AK,Elven R,Morris A,Soltis DE,Soltis PS,Albert VA

更新日期：2004-06-01 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

authors： Fisher JB,Goldstein G,Jones TJ,Cordell S

更新日期：2007-05-01 00:00:00

abstract：:Size, allometry, and mechanical design were measured for trees of three canopy species in a tropical rain forest in French Guiana. Mechanical design was expressed as the safety factor, using the elastic-stability model, and the wind resistance factor, using the constant-stress model. Changes with ontogeny were describ...

journal_title：American journal of botany

authors： Sterck F,Bongers F

更新日期：1998-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Intertidal macroalgae must resist extreme hydrodynamic forces imposed by crashing waves. How does frond flexibility mitigate drag, and how does flexibility affect predictions of drag and dislodgement in the field? METHODS:We characterized flexible reconfiguration of six seaweed species in a recirc...

journal_title：American journal of botany

authors： Martone PT,Kost L,Boller M

更新日期：2012-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Little is known about the effect of environmental conditions on seed dormancy break at the community level or how it could be affected by climate change. This study tested the effects of storage conditions on germination of 489 species from high-elevation natural grasslands on the Tibet Plateau. M...

journal_title：American journal of botany

authors： Liu K,Baskin JM,Baskin CC,Bu H,Liu M,Liu W,Du G

更新日期：2011-01-01 00:00:00