Characterization and systematic implications of the diversity in timing of programmed cell death of the suspensors in Leguminosae.

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

authors： Pryer KM,Schuettpelz E,Wolf PG,Schneider H,Smith AR,Cranfill R

更新日期：2004-10-01 00:00:00

abstract：:In spite of the ecological and economic importance of temperate bamboos, relatively little is known about their population biology or evolutionary history. Recently, hybridization has emerged as a potential source of diversity in this group, as well as an underlying cause of taxonomic problems. As part of a broader ph...

journal_title：American journal of botany

authors： Triplett JK,Oltrogge KA,Clark LG

更新日期：2010-03-01 00:00:00

abstract：PREMISE OF THE STUDY:Microsatellite markers of an important medicinal plant, Eurycoma longifolia (Simaroubaceae), were developed for DNA profiling and genetic diversity studies. METHODS AND RESULTS:Eighteen polymorphic microsatellite loci were developed for E. longifolia. The primers were designed from a genomic libra...

journal_title：American journal of botany

authors： Tnah LH,Lee CT,Lee SL,Ng KK,Ng CH,Hwang SS

更新日期：2011-05-01 00:00:00

abstract：:The biogeography of plant-animal interactions is a novel topic on which many disciplines converge (e.g., reproductive biology, biogeography, and evolutionary biology). Narrative reviews have indicated that tropical columnar cacti and agaves have highly specialized pollination systems, while extratropical species have ...

journal_title：American journal of botany

authors： Munguía-Rosas MA,Sosa VJ,Ojeda MM,De-Nova JA

更新日期：2009-10-01 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

authors： Skogen KA,Jogesh T,Hilpman ET,Todd SL,Rhodes MK,Still SM,Fant JB

更新日期：2016-11-01 00:00:00

abstract：:Isozymatic data taken from 67 Guatemalan collections of maize were subjected to numerical taxonomic analyses to elucidate systematic relationships among the 19 maize races and subraces described for Guatemala by Wellhausen et al. As with Bolivian and Mexican races, isozymatic variation in Guatemalan maize was strongly...

journal_title：American journal of botany

authors： Bretting PK,Goodman MM,Stuber CW

更新日期：1990-02-01 00:00:00

abstract：:A detailed study of ascomal morphology and development in Cercophora palmicola showed that ontogeny is ascohymeniaceous, giving rise to an ostiolate perithecium. Ascomal initials consist of a coiled ascogonium surrounded by several layers of hyphae whose cells become pseudoparenchymatous. The centrum of the young asco...

journal_title：American journal of botany

authors： Hanlin RT

更新日期：1999-06-01 00:00:00

abstract：:Xylem of the orchids studied provided unusually favorable material to demonstrate how conductive tissue evolves in monocotyledons. In the end walls of tracheary elements of many Orchidaceae, remnants of pit membranes were observed with scanning electron microscopy and minimally destructive methods. The full range from...

journal_title：American journal of botany

authors： Carlquist S,Schneider EL

更新日期：2006-07-01 00:00:00

abstract：:Up to 22% of plant species are the result of breeding among species-hybridization-directly conflicting with the prediction that hybrids, compared to parental species, are intermediate in character and of low fitness and little consequence. Few studies, however, have compared the fitness of hybrids and parental species...

journal_title：American journal of botany

authors： Tierney DA,Wardle GM

更新日期：2008-02-01 00:00:00

abstract：PREMISE:Woody plants with photosynthetic stems are common in the drylands of the world; however, we know little about the origin(s) and geographical distribution of photosynthetic stems. Therefore, we set to answer the following questions: (1) Is stem photosynthesis phylogenetically conserved? (2) Do green-stemmed and ...

journal_title：American journal of botany

authors： Ávila-Lovera E,Garcillán PP

更新日期：2020-12-06 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：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：PREMISE OF THE STUDY:Elucidating the factors that determine the abundance and distribution of species remains a central goal of ecology. It is well recognized that genetic differences among individual species can affect the distribution and species interactions of dependent taxa, but the ecological effects of genetic d...

journal_title：American journal of botany

authors： Adams RI,Goldberry S,Whitham TG,Zinkgraf MS,Dirzo R

更新日期：2011-10-01 00:00:00

abstract：:We assessed the effects of local environment on survival, growth, and development in six clones (genotypes) of Vallisneria americana grown at five sites in the Huron-Erie Corridor. Detrimental effects of local environment on plant performance (rate of clonal growth, leaf and root production, surface area of leaves and...

journal_title：American journal of botany

authors： Biernacki M,Lovett-Doust J

更新日期：1997-12-01 00:00:00

abstract：:Recruitment and mortality of Spartina alterniflora tillers and culms were estimated from measurements of live standing crops at Wallops Island, Virginia. Stands of tall and medium form grass produced from 452 to 1,227 tillers m-2 yr-1 . Those tillered in spring lengthened into culms their first year, while those tille...

journal_title：American journal of botany

authors： Reidenbaugh TG

更新日期：1983-01-01 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：PREMISE OF THE STUDY:Tea Unigene-derived MicroSatellite (TUGMS) markers were identified from the publicly available EST data in Camellia sinensis for characterization and future genome mapping studies in tea. METHODS AND RESULTS:One hundred twelve novel TUGMS markers were identified from 4356 unigenes derived by clust...

journal_title：American journal of botany

authors： Sharma H,Kumar R,Sharma V,Kumar V,Bhardwaj P,Ahuja PS,Sharma RK

更新日期：2011-06-01 00:00:00

abstract：:Contact forces are important in maintaining the twining habit of viny stems. A stem twining around a supporting pole puts itself into tension and uses a helical geometry to generate normal loads that are large relative to stem mass per unit length (Silk and Hubbard, Journal of Biomechanics 24(7):599-606, 1991). An ele...

journal_title：American journal of botany

authors： Matista A,Silk W

更新日期：1997-08-01 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：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：:The American chestnut (Castanea dentata; Fagaceae) was a dominant canopy tree in the Appalachian Mountains of North America. Since the introduction of the chestnut blight fungus (Cryphonectria parasitica; Valsaceae) in America, the American chestnut has been reduced to a predominantly clonal, understory species. Our o...

journal_title：American journal of botany

authors： Stilwell KL,Wilbur HM,Werth CR,Taylor DR

更新日期：2003-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Although our awareness of ploidy diversity has expanded with the application of flow cytometry, we still know little about the extent to which cytotypes within mixed-ploidy populations are genetically differentiated across environmental gradients. METHODS:To address this issue, we reared 14 popula...

journal_title：American journal of botany

authors： Etterson JR,Toczydlowski RH,Winkler KJ,Kirschbaum JA,McAulay TS

更新日期：2016-01-01 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：:The degree to which plants self-fertilize may impact their potential for genetic adaptation. Given that the mating system influences genetic processes within and among populations, the mating system could limit or promote local adaptation. I conducted a literature survey of published reciprocal transplant experiments ...

journal_title：American journal of botany

authors： Hereford J

更新日期：2010-02-01 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 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：:Cacti are a large and diverse group of stem succulents predominantly occurring in warm and arid North and South America. Chloroplast DNA sequences of the trnK intron, including the matK gene, were sequenced for 70 ingroup taxa and two outgroups from the Portulacaceae. In order to improve resolution in three major grou...

journal_title：American journal of botany

authors： Nyffeler R

更新日期：2002-02-01 00:00:00

abstract：:In a 3-yr study, we examined the pollinator guild and intersexual floral characteristics of the dioecious, perennial cloudberry (Rubus chamaemorus), which flowers in early spring. The findings contribute to our general understanding of pollination ecology at high latitudes and provide important information for the com...

journal_title：American journal of botany

authors： Brown AO,McNeil JN

更新日期：2009-06-01 00:00:00

abstract：:Recent surveys of seed coat morphology in Lobelioideae (Campanulaceae) have demonstrated the systematic utility of such data in the subfamily and led to a revision of the supraspecific classification of Lobelia. Expanding upon these studies, we examined via scanning electron microscopy 41 seed accessions, emphasizing ...

journal_title：American journal of botany

authors： Buss CC,Lammers TG,Wise RR

更新日期：2001-07-01 00:00:00

abstract：:Microscopic structures (petrofilaments) may develop during palynological laboratory processing procedures that are superficially similar to secondary wall thickenings and elaters. These filaments form from angular bodies that resemble fungal spores and resin bodies. The angular bodies are a type of hydrocarbon called ...

journal_title：American journal of botany

authors： Graham A,Wood GD,Elsik WC,Speed RC

更新日期：2000-05-01 00:00:00