Cell division patterns in the apices of subterranean axis and aerial shoot of Psilotum nudum (Psilotaceae): morphological and phylogenetic implications for the subterranean axis.

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

authors： Lázaro A,Santamaría L

更新日期：2016-02-01 00:00:00

abstract：:It is generally thought that sedimenting plastids are responsible for gravity sensing in higher plants. We directly tested the model generated by the current statolith hypothesis that the gravity sensing that leads to gravitropism results from an interaction between the plastids and actin microfilaments. We find that ...

journal_title：American journal of botany

authors： Staves MP,Wayne R,Leopold AC

更新日期：1997-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Cryptic species are superficially morphologically indistinguishable and therefore erroneously classified under one single name. The identification and delimitation of these species is usually a difficult task. The main aim of this study is to provide an inclusive methodology that combines standard ...

journal_title：American journal of botany

authors： Abdelaziz M,Lorite J,Muñoz-Pajares AJ,Herrador MB,Perfectti F,Gómez JM

更新日期：2011-06-01 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

authors： Schmitt M,Mehltreter K,Sundue M,Testo W,Watanabe T,Jansen S

更新日期：2017-04-01 00:00:00

abstract：:Despite their ecological significance, parasitic plants face more conservation challenges than do autotrophic plants. This is especially true for the groups that include weedy or invasive species such as Cuscuta. While approximately half of the Cuscuta (dodders) species may require conservation measures, the genus as ...

journal_title：American journal of botany

authors： Costea M,Stefanovic S

更新日期：2009-09-01 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 OF THE STUDY:In angiosperm seeds, the developing embryo acquires nutrients via a suspensor that typically undergoes programmed cell death (PCD) at the early cotyledon stage. However, in Leguminosae (the third largest angiosperm family), the suspensors can disappear at the heart-shaped stage (i.e., prior to the ...

journal_title：American journal of botany

authors： Endo Y

更新日期：2012-08-01 00:00:00

abstract：:The biological nature of some symbioses is unclear because it is often not easy to discern whether the symbionts obtain any benefits from the association. Mastodia tessellata, a symbiosis between a leafy green alga and a fungus of uncertain phylogenetic position, is among the most investigated, controversial, and poor...

journal_title：American journal of botany

authors： Pérez-Ortega S,Ríos Ade L,Crespo A,Sancho LG

更新日期：2010-05-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:The Malpighiaceae include ∼1300 tropical flowering plant species in which generic definitions and intergeneric relationships have long been problematic. The goals of our study were to resolve relationships among the 11 generic segregates from the New World genus Mascagnia, test the mon...

journal_title：American journal of botany

authors： Davis CC,Anderson WR

更新日期：2010-12-01 00:00:00

abstract：:The direct and indirect effects of vegetative herbivory on the mating system of Impatiens capensis were analyzed through a survey of herbivory in natural I. capensis populations and manipulation of leaf damage in the field. Across 10 wild populations of I. capensis proportion of cleistogamous flowers had a significant...

journal_title：American journal of botany

authors： Steets JA,Ashman TL

更新日期：2004-07-01 00:00:00

abstract：:We investigated patterns of fruit and seed production on inflorescences of a population of Pancratium maritimum in northwest Spain over a 2-yr period. Initial findings showed that the earliest opening flowers on an inflorescence are more likely to set fruit and produce more seeds than later opening flowers and that th...

journal_title：American journal of botany

authors： Medrano M,Guitián P,Guitián J

更新日期：2000-04-01 00:00:00

abstract：:Additional information on the morphology of the vegetative ultimate branches of Archaeopteris roemeriana was obtained by uncovering compression specimens collected in Upper Devonian deposits in Belgium. For the first time, anisophylly, previously inferred from anatomical studies, is demonstrated on one species of the ...

journal_title：American journal of botany

authors： Fairon-Demaret M,Leponce I

更新日期：2001-04-01 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

authors： Yukawa T,Ogura-Tsujita Y,Shefferson RP,Yokoyama J

更新日期：2009-11-01 00:00:00

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

authors： Dillenberger MS,Wei N,Tennessen JA,Ashman TL,Liston A

更新日期：2018-05-01 00:00:00

abstract：:The shoot apical meristem (SAM) produces stem and initiates leaves. Its structure is maintained despite a continuous flow of cells basipetally from the distal portion of the meristem. The apoplasm and symplasm are the obvious means of cell integration, and their role in chemical cell-to-cell signaling is known. Howeve...

journal_title：American journal of botany

authors： Kwiatkowska D

更新日期：2004-09-01 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

authors： Abdala-Roberts L,Hernández-Cumplido J,Chel-Guerrero L,Betancur-Ancona D,Benrey B,Moreira X

更新日期：2016-10-01 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

authors： Edlund AF,Zheng Q,Lowe N,Kuseryk S,Ainsworth KL,Lyles RH,Sibener SJ,Preuss D

更新日期：2016-06-01 00:00:00

abstract：:Incarvillea is a herbaceous and temperate member of Bignoniaceae, previously divided into four subgenera, Niedzwedzkia, Amphicome, Incarvillea, and Pteroscleris. Niedzwedzkia and Amphicome have in the past been treated as independent genera. Different relationships have been proposed for the four subgenera. Here, maxi...

journal_title：American journal of botany

authors： Chen S,Guan K,Zhou Z,Olmstead R,Cronk Q

更新日期：2005-04-01 00:00:00

abstract：:The genus Rosa has a complex evolutionary history caused by several factors, often in conjunction: extensive hybridization, recent radiation, incomplete lineage sorting, and multiple events of polyploidy. We examined the applicability of AFLP markers for reconstructing (species) relationships in Rosa, using UPGMA clus...

journal_title：American journal of botany

authors： Koopman WJ,Wissemann V,De Cock K,Van Huylenbroeck J,De Riek J,Sabatino GJ,Visser D,Vosman B,Ritz CM,Maes B,Werlemark G,Nybom H,Debener T,Linde M,Smulders MJ

更新日期：2008-03-01 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：:Seed mass is considered to be the least plastic component of reproductive yield. Yet, in invasive populations of garlic mustard, Alliaria petiolata, seed mass was highly variable (eightfold among populations, 2.5-7.5 fold within populations, two-threefold within individuals, and 1.4-1.8 fold within fruits). Variation ...

journal_title：American journal of botany

authors： Susko DJ,Lovett-Doust L

更新日期：2000-01-01 00:00:00

abstract：:Megaspore and microspore massulae of Paleoazolla patagonica gen. et sp. nov. are described from the Upper Cretaceous of La Colonia Formation, Chubut Province, Argentina. The new fern possesses megaspore complexes with three to four glochidiate floats attached directly to the megaspore; a columella-like structure appea...

journal_title：American journal of botany

authors： Archangelsky A,Phipps CJ,Taylor TN,Taylor EL

更新日期：1999-08-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Taxonomic groups have often been recognized on the basis of geographic distinctions rather than accurately representing evolutionary relationships. This has been particularly true for temperate and tropical members from the same family. Polygonaceae exemplifies this problem, wherein th...

journal_title：American journal of botany

authors： Burke JM,Sanchez A,Kron K,Luckow M

更新日期：2010-08-01 00:00:00

abstract：PREMISE OF THE STUDY:New microsatellite primers were developed for testing genetic differentiation within Nothoceros aenigmaticus and their potential use in other Nothoceros species. The microsatellites are designed to investigate partitioning of genetic variation in a taxon with a peculiar sex allopatry in the souther...

journal_title：American journal of botany

authors： Villarreal JC,Forrest LL,McFarland K,Goffinet B

更新日期：2012-03-01 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

authors： Escudero M,Vargas P,Valcárcel V,Luceño M

更新日期：2008-06-01 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

authors： Chan R,Baldwin BG,Ornduff R

更新日期：2002-07-01 00:00:00

abstract：:Climate changes during glacial periods have had significant effects on the present geographic distribution of plant species. To elucidate the evolutionary history of a plant species with a disjunctive distribution, we investigated the geographic distribution patterns of cpDNA haplotypes in Photinia glabra (Rosaceae) g...

journal_title：American journal of botany

authors： Aoki K,Matsumura T,Hattori T,Murakami N

更新日期：2006-12-01 00:00:00

abstract：:Aralia sect. Aralia (Araliaceae) consists of approximately eight species disjunctly distributed in Asia and North America. Phylogenetic and biogeographic analyses were conducted using sequences of the internal transcribed spacer regions of the nuclear ribosomal DNA. Aralia racemosa from eastern North America was siste...

journal_title：American journal of botany

authors： Wen J,Shi S,Jansen R,Zimmer E

更新日期：1998-06-01 00:00:00

abstract：:In a detailed analysis of how limited seed dispersal can create spatial structuring of genetic variation, several nuclear microsatellites were assayed in seedlings from two forests of Pinus strobus, one old growth (OG) and the other (second site, SS) logged in ca. 1900. By using loci with a large number of alleles and...

journal_title：American journal of botany

authors： Walter R,Epperson BK

更新日期：2004-04-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Sphagnum dominates vast expanses of wetland habitats throughout the northern hemisphere and species delimitation within the genus is important because floristic changes associated with a warming global climate may have measureable impacts on large-scale ecological processes. Most north...

journal_title：American journal of botany

authors： Shaw AJ,Shaw B,Johnson MG,Higuchi M,Arikawa T,Ueno T,Devos N

更新日期：2013-06-01 00:00:00