Allometry of cells and tissues within leaves.

abstract：:Phloem, as a major tissue mediating long-distance communication, has been an object of extensive research ever since its structure was first reported in 1837. Functional phloem consists of sieve elements (SEs) and companion cells (CCs). While SEs are enucleated conducting cells in the phloem, CCs are cells with intact...

journal_title：American journal of botany

authors： Heo JO,Roszak P,Furuta KM,Helariutta Y

更新日期：2014-09-01 00:00:00

abstract：:We present here the first molecular phylogeny of tribe Diseae (Orchidoideae: Orchidaceae). Nuclear ribosomal ITS1, 5.8S rDNA, and ITS2 sequences were compared for 30 Diseae, 20 Orchideae, and four Cranichideae and Diurideae outgroups. ITS - rDNA sequences exhibited a transition:transversion ratio of 1.3 and extensive ...

journal_title：American journal of botany

authors： Douzery EJ,Pridgeon AM,Kores P,Linder HP,Kurzweil H,Chase MW

更新日期：1999-06-01 00:00:00

abstract：:The evolutionary history of maize (Zea mays subsp. mays) is of general interest because of its economic and scientific importance. Here we show that many cellular traits described previously in developing caryopses of maize are also seen in its wild progenitor teosinte (Zea mays subsp. parviglumis). These features, ea...

journal_title：American journal of botany

authors： Dermastia M,Kladnik A,Dolenc Koce J,Chourey PS

更新日期：2009-10-01 00:00:00

abstract：:Inferring basal relationships among vascular plants poses a major challenge to plant systematists. The divergence events that describe these relationships occurred long ago and considerable homoplasy has since accrued for both molecular and morphological characters. A potential solution is to examine phylogenetic anal...

journal_title：American journal of botany

authors： Wolf P

更新日期：1997-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Species differ in their temperature germination niche. Populations of a species may similarly differ across the distribution range of the species. Anticipating the impacts of climate variability and change requires understanding the differential sensitivity to germination temperature among and with...

journal_title：American journal of botany

authors： Chamorro D,Luna B,Moreno JM

更新日期：2017-01-01 00:00:00

abstract：PREMISE OF THE STUDY:A prevailing hypothesis in forest succession is that shade-tolerant species grow more slowly than shade-intolerant species, across light conditions, because they prioritize carbon (C) allocation to storage. We examined this hypothesis in a confamilial pair of species, including one of the fastest-g...

journal_title：American journal of botany

authors： Piper FI,Sepúlveda P,Bustos-Salazar A,Zúñiga-Feest A

更新日期：2017-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Uplift of the tropical Andes had a significant impact on the diversification of South American flora and fauna. Recent biogeographic inquiries have established patterns of Andean divergence, but investigations on ferns are scant. The fern genus Polystichum Roth (Dryopteridaceae) combines widespread...

journal_title：American journal of botany

authors： McHenry MA,Barrington DS

更新日期：2014-02-01 00:00:00

abstract：:We examined the function of floral traits associated with buzz pollination through studies of Rhexia virginica (Melastomataceae) in the Muskoka region of Ontario, Canada. Controlled pollinations demonstrated that the species is self-compatible, but dependent on insects for pollen transfer. Bumble bees made 82 and 90% ...

journal_title：American journal of botany

authors： Larson BM,Barrett SC

更新日期：1999-04-01 00:00:00

abstract：PREMISE OF THE STUDY:The species boundaries of wild and cultivated potatoes are controversial, with most of the taxonomic problems in the cultivated potato clade. We here provide the first in-depth phylogenetic study of the cultivated potato clade to explore possible causes of these problems. METHODS:We examined 131 d...

journal_title：American journal of botany

authors： Spooner DM,Ruess H,Arbizu CI,Rodríguez F,Solís-Lemus C

更新日期：2018-01-01 00:00:00

abstract：:The specific shape of the relationship between plant diversity and productivity and the causal mechanism(s) behind the observed pattern(s) are still highly debated. Recent advances suggest that the relationship depends on several environmental variables and may change with the observational scale. In this study, a mul...

journal_title：American journal of botany

authors： de Lafontaine G,Houle G

更新日期：2007-01-01 00:00:00

abstract：:We developed an improved cytological protocol for producing high quality, light microscope images of plant meiotic chromosomes. Because the technique works on species with small genomes and thick microsporocyte cell walls, it should be useful for studying the wild relatives of Arabidopsis and other eudicots with small...

journal_title：American journal of botany

authors： Stronghill PE,Hasenkampf CA

更新日期：2007-12-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Verbenaceae consist of trees, shrubs, lianas, and herbs distributed primarily in Latin America, where they occur in a wide array of ecosystems. A second center of diversity exists in Africa. Competing morphology-based classifications that rely on different traits conflict in significan...

journal_title：American journal of botany

authors： Marx HE,O'Leary N,Yuan YW,Lu-Irving P,Tank DC,Múlgura ME,Olmstead RG

更新日期：2010-10-01 00:00:00

abstract：:Senna (Leguminosae) is a large, widespread genus that includes species with enantiostylous, asymmetric flowers and species with extrafloral nectaries. Clarification of phylogenetic relationships within Senna based on parsimony analyses of three chloroplast regions (rpS16, rpL16, and matK) provides new insights on the ...

journal_title：American journal of botany

authors： Marazzi B,Endress PK,Queiroz LP,Conti E

更新日期：2006-02-01 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 THE STUDY:Direct tests of a species distribution model (SDM) were used to evaluate the hypothesis that the northern and southern edges of Mimulus bicolor's geographical range are limited by temperature and precipitation. METHODS:Climatic suitability was predicted using an SDM informed only by temperature an...

journal_title：American journal of botany

authors： Dixon AL,Busch JW

更新日期：2017-06-01 00:00:00

abstract：:Several alpine species have outlying populations in the lowlands and lower mountains north of the Alps. These small, isolated populations are usually described as either (1) glacial relics, (2) descendants from populations living on forelands and moraines during the ice ages, or (3) populations founded by long-distanc...

journal_title：American journal of botany

authors： Lutz E,Schneller JJ,Holderegger R

更新日期：2000-04-01 00:00:00

abstract：:Many plant species contain populations with more than one polyploid cytotype, but little is known of the mechanisms maintaining several cytotypes in a population. Andropogon gerardii cytotypes were compared to evaluate different models of autopolyploid cytotype coexistence. The enneaploid (90 chromosome, 9x) cytotype ...

journal_title：American journal of botany

authors： Keeler KH,Davis GA

更新日期：1999-07-01 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：PREMISE OF THE STUDY:In animal-pollinated plants, autonomous selfing may provide reproductive assurance when pollinators or reproductive partners are limited. Under such circumstances, the contribution of pollinator-mediated seed set to total seed production also may be more variable compared with situations in which p...

journal_title：American journal of botany

authors： Brys R,de Crop E,Hoffmann M,Jacquemyn H

更新日期：2011-11-01 00:00:00

abstract：:The fossil record of aquatic flowering plants broadens our understanding of their former diversity and origins from terrestrial ancestors. This paper describes a floating aquatic monocot from 71 whole plants and several isolated leaf fragments from Upper Cretaceous oxbow lake sediments in the Dinosaur Park Formation, ...

journal_title：American journal of botany

authors： Stockey RA,Rothwell GW,Johnson KR

更新日期：2007-04-01 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：: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：PREMISE OF THE STUDY:Variation in demographic parameters reflects the life-history strategies of plants in response to specific environments. We aimed to investigate the intraspecific variation in life-history traits of a clonal alpine herb, Gentiana nipponica, in various snowmelt conditions. METHODS:Individual ramets...

journal_title：American journal of botany

authors： Kawai Y,Kudo G

更新日期：2018-11-01 00:00:00

abstract：:Tropical forest plants are known to be pollinated by a diverse array of animals. Here we report on the pollination of a woody climber species, Uvaria elmeri (Annonaceae), by cockroaches in a lowland mixed-dipterocarp forest in Sarawak, Malaysia. To the best of our knowledge, this is the first report of pollination by ...

journal_title：American journal of botany

authors： Nagamitsu T,Inoue T

更新日期：1997-02-01 00:00:00

abstract：:Taxonomical classification of higher fungi remains an important challenge and can benefit from the application of molecular analysis. We propose that the ectomycorrhizal (EM) fungal taxa might include a number of cryptic species because there are few morphological characteristics useful for distinguishing among these ...

journal_title：American journal of botany

authors： Sato H,Yumoto T,Murakami N

更新日期：2007-10-01 00:00:00

abstract：PREMISE:Variation in seedling emergence timing is considered adaptive over the long term in wild populations, but early emergence can result in a fitness advantage. To explore the adaptive significance of seedling emergence timing, it should be studied under realistic conditions and in the context of other traits that ...

journal_title：American journal of botany

authors： Mercer KL,Alexander HM,Snow AA

更新日期：2011-06-01 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：UNLABELLED: PREMISE OF THE STUDY:Microsatellite primers were developed in the introduced shrub Rhamnus cathartica L., to investigate potential hybridization events with related taxa as a stimulus of invasive spread. • METHODS AND RESULTS:Using a non-radioactive protocol, 15 primer sets were identified in North Americ...

journal_title：American journal of botany

authors： Culley TM,Stewart JR

更新日期：2010-03-01 00:00:00

abstract：:Biogeographical patterns and diversification processes in Andean and Patagonian flora are not yet well understood. Calceolaria is a highly diversified genus of these areas, representing one of the most specialized plant-pollinator systems because flowers produce nonvolatile oils, a very unusual floral reward. Phylogen...

journal_title：American journal of botany

authors： Cosacov A,Sérsic AN,Sosa V,De-Nova JA,Nylinder S,Cocucci AA

更新日期：2009-12-01 00:00:00

abstract：PREMISE OF THE STUDY:Large phylogenies can help shed light on macroevolutionary patterns that inform our understanding of fundamental processes that shape the tree of life. These phylogenies also serve as tools that facilitate other systematic, evolutionary, and ecological analyses. Here we combine genetic data from pu...

journal_title：American journal of botany

authors： Smith SA,Brown JW

更新日期：2018-03-01 00:00:00