Rainforest conifers of Eocene Patagonia: attached cones and foliage of the extant Southeast Asian and Australasian genus Dacrycarpus (Podocarpaceae).

abstract：:Phylogenetic analysis of DNA sequences of the chloroplast genes rcbL and ndhf revealed a highly supported clade composed of the families Plantaginaceae, Callitrichaceae, and Hippuridaceae in close association with the model organism Antirrhinum majus and other members of family Scrophulariaceae. Plantago has miniature...

journal_title：American journal of botany

authors： Reeves P,Olmstead R

更新日期：1998-08-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Flower color is one of the best-studied floral traits in terms of its genetic basis and ecological significance, yet few studies have examined the processes that shape its evolution across deep timescales. Advances in comparative methods along with larger phylogenies for floral radiat...

journal_title：American journal of botany

authors： Smith SD,Goldberg EE

更新日期：2015-07-01 00:00:00

abstract：:Floral characteristics such as morphology and flower color have been interpreted as adaptive traits that evolved through selective pressures generated by pollinators. Differences among populations in the expression of floral characters could result from natural selection for their adaptive value to local conditions. W...

journal_title：American journal of botany

authors： Silva-Montellano A,Eguiarte LE

更新日期：2003-03-01 00:00:00

abstract：:Atriplex prostrata Boucher, a facultative halophyte, exhibits significant reduction in height and biomass and in the width of the cortex and vascular tissue under saline conditions. Therefore, the goal of this investigation was to determine the effect of salinity on plant growth as well as on the patterns of lignifica...

journal_title：American journal of botany

authors： Wang L,Showalter A,Ungar I

更新日期：1997-09-01 00:00:00

abstract：:Biogeographical studies of lichens used to be complicated because of the large distribution ranges of many species. Molecular systematics has revitalized lichen biogeography by improving species delimitation and providing better information about species range limitations. This study focuses on the major clade of trop...

journal_title：American journal of botany

authors： Divakar PK,Lumbsch HT,Ferencova Z,Del Prado R,Crespo A

更新日期：2010-04-01 00:00:00

abstract：PREMISE OF THE STUDY:One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season d...

journal_title：American journal of botany

authors： Dudley LS,Hove AA,Emms SK,Verhoeven AS,Mazer SJ

更新日期：2015-06-01 00:00:00

abstract：PREMISE OF THE STUDY:Phylogenetic and morphological studies have helped clarify the systematics of large and complex groups such as the tribe Crotoneae (Euphorbiaceae). However, very little is known about the diversity, structure, and function of anatomical features in this tribe. Crotoneae comprises the species-rich p...

journal_title：American journal of botany

authors： Vitarelli NC,Riina R,Caruzo MB,Cordeiro I,Fuertes-Aguilar J,Meira RM

更新日期：2015-06-01 00:00:00

abstract：:Six of 14 species of Triteleia were studied. All possess septal nectaries, raphides in the ovary wall, an anatropous and crassinucellate ovule with a micropyle formed by the inner integument only, and parietal cells. A short and thick nucellus, which is not penetrated by the embryo sac, has a one-layered apical epider...

journal_title：American journal of botany

authors： Berg RY

更新日期：2003-06-01 00:00:00

abstract：PREMISE:Inbreeding depression is traditionally considered a major factor favoring outcrossing in hermaphrodites. Recent experiments have shown that environmental conditions can influence the magnitude of inbreeding depression, but their relevance in natural populations is unclear. To investigate this, we studied the cl...

journal_title：American journal of botany

authors： Stojanova B,Maurice S,Cheptou PO

更新日期：2020-01-01 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：PREMISE OF THE STUDY:Generic boundaries and infrageneric relationships among the charismatic temperate magnoliid Asarum sensu lato (Aristolochiaceae) have long been uncertain. Previous molecular phylogenetic analyses used either plastid or nuclear loci alone and varied greatly in their taxonomic implications for the ge...

journal_title：American journal of botany

authors： Sinn BT,Kelly LM,Freudenstein JV

更新日期：2015-05-01 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：:To determine the effects of density, genotype, and their interaction on individual seed mass in Raphanus sativus L., we replicated maternal and paternal families of seed across two planting densities in an experimental garden. Seeds were produced by a nested breeding design performed in the greenhouse. Among garden-ra...

journal_title：American journal of botany

authors： Mazer SJ,Wolfe LM

更新日期：1992-10-01 00:00:00

abstract：:The taxonomic richness of seed plants at different taxonomic levels was compared between temperate East Asia and North America at both continental and semi-continental scales. In each comparison, land area and latitude range were adjusted to a comparable level between the two continental regions. East Asia is signific...

journal_title：American journal of botany

authors： Qian H

更新日期：2002-11-01 00:00:00

abstract：:Phylogenetic relationships of eight species of Saintpaulia H. Wendl., 19 species of Streptocarpus Lindl. (representing all major growth forms within the genus), and two outgroups (Haberlea rhodopensis Friv., Chirita spadiciformis W. T. Wang) were examined using comparative nucleotide sequences from the two internal tr...

journal_title：American journal of botany

authors： Moller M,Cronk Q

更新日期：1997-07-01 00:00:00

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：: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:Hyperaccumulation of heavy metals in plants has never been documented from Central America or Mexico. Psychotria grandis, P. costivenia, and P. glomerata (Rubiaceae) have been reported to hyperaccumulate nickel in the Greater Antilles, but they also occur widely across the neotropics. The goals of this research...

journal_title：American journal of botany

authors： McCartha GL,Taylor CM,van der Ent A,Echevarria G,Navarrete Gutiérrez DM,Pollard AJ

更新日期：2019-10-01 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：: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：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

abstract：PREMISE OF THE STUDY:Permineralization provides the most faithful known mode of three-dimensional preservation of the morphology and cellular anatomy of fossil plants. Standard optical microscopic documentation of such structures can provide only an approximation of their true three-dimensional form and is incapable of...

journal_title：American journal of botany

authors： Shi CS,Schopf JW,Kudryavtsev AB

更新日期：2013-08-01 00:00:00

abstract：:Soybean partial-female-sterile mutant 1 (PS-1) was recovered from a gene-tagging study. The objectives were to study the inheritance, linkage, allelism, and certain aspects of the reproductive biology of the PS-1 mutant. For inheritance and linkage tests, PS-1 was crossed to flower color mutant Harosoy-w4 and to chlor...

journal_title：American journal of botany

authors： Pereira T,Lersten N,Palmer R

更新日期：1997-06-01 00:00:00

abstract：:Much of the ultraviolet-B radiation (UV-B) research on plants has concentrated on vegetative plant parts, and only a small fraction has dealt with the reproductive system. The present study analyzed pollen grains of 34 taxa germinated and grown under two levels of UV-B radiation (187 and 460 mW/m2) or no UV-B (control...

journal_title：American journal of botany

authors： Torabinejad J,Caldwell M,Flint S,Durham S

更新日期：1998-03-01 00:00:00

abstract：:Nuclear and chloroplast DNA variation was assayed for two populations of Louisiana irises (Bayou Teche and Young's Coulee) that demonstrated extreme morphological variation and for a sample of the putative hybrid species, Iris nelsonii. The genetic markers examined in this analysis were diagnostic for either Iris fulv...

journal_title：American journal of botany

authors： Arnold ML

更新日期：1993-05-01 00:00:00

abstract：:Responses to photoperiod and temperature were compared for hybrids between Asiatic plants in the indigenous strumarium morphological complex and plants in five American complexes: oviforme, italicum, chinense, cavanillesii, and pennsylvancium. The F1 hybrids between Hong Kong plants and various American plants showed ...

journal_title：American journal of botany

authors： McMillan C

更新日期：1975-01-01 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：PREMISE OF THE STUDY:The classification of the genus Salix has historically been intrinsically difficult due to its propensity toward plasticity and high variation in diagnostic morphological characters. We investigated leaf epidermal characteristics, focusing on the stomatal apparatus because it may provide critical i...

journal_title：American journal of botany

authors： Ghahremaninejad F,Khalili Z,Maassoumi AA,Mirzaie-Nodoushan H,Riahi M

更新日期：2012-04-01 00:00:00

abstract：:We used isozymes (16 loci in 11 enzymatic systems) from Laelia speciosa, an endemic and endangered epiphytic orchid of Mexico, to assess the genetic diversity and population genetic structure in nine populations distributed along its geographic range, as well as to detect those populations that are genetically unique ...

journal_title：American journal of botany

authors： Avila-Díaz I,Oyama K

更新日期：2007-02-01 00:00:00

abstract：:Ontogenetic trends in the wood structure of Nepalese Rhododendron were studied in 15 specimens of two tree and four subtree species. Average growth ring width was constant from pith to bark in spite of occurrences of extremely narrow, false, or discontinuous rings. Vessel density, vessel area, vessel element length, a...

journal_title：American journal of botany

authors： Noshiro S,Suzuki M

更新日期：2001-04-01 00:00:00