Seed morphology of modern and fossil Ampelocissus (Vitaceae) and implications for phytogeography.

abstract：:Recent discoveries of fossil reproductive structures from deposits of the Raritan Formation in New Jersey (Turonian, Upper Cretaceous, ~90 million years BP) include a previously undescribed representative of the Order Capparales. The fossils are usually charcoalified with three-dimensional structure and excellent anat...

journal_title：American journal of botany

authors： Gandolfo M,Nixon K,Crepet W

更新日期：1998-07-01 00:00:00

abstract：PREMISE OF THE STUDY:Despite being highly fertile and occupying a large geographic region, the North American heartleaf bittercress (Cardamine cordifolia; Brassicaceae) has a puzzling triploid-like chromosome number (2n = 3x = 24). As most triploids are sterile, we embarked on a detailed analysis of the C. cordifolia g...

journal_title：American journal of botany

authors： Mandáková T,Gloss AD,Whiteman NK,Lysak MA

更新日期：2016-07-01 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：PREMISE:Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerance...

journal_title：American journal of botany

authors： Martino M,Semple JC,Beck JB

更新日期：2020-11-01 00:00:00

abstract：:This paper presents the first broad overview of three main features of microsporogenesis (male meiosis) in angiosperms: cytokinesis (cell division), intersporal wall formation, and tetrad form. A phylogenetic comparative approach was used to test for correlated evolution among these characters and to make hypotheses a...

journal_title：American journal of botany

authors： Nadot S,Furness CA,Sannier J,Penet L,Triki-Teurtroy S,Albert B,Ressayre A

更新日期：2008-11-01 00:00:00

abstract：:Hybridization and introgression play important roles in plant evolution, and their occurrence on the oceanic islands provides good examples of plant speciation and diversification. Restriction fragment length polymorphisms (RFLPs) and trnL (UAA) 3'exon-trnF (GAA) intergenic spacer (IGS) sequences of chloroplast DNA (c...

journal_title：American journal of botany

authors： Setoguchi H,Watanabe I

更新日期：2000-06-01 00:00:00

abstract：:Herbivore damage is known to cause the premature loss of mature leaves. However, the effects of herbivory on abscission during the early stages of leaf development remain unexplored, even though herbivores frequently prefer unlignified, immature leaves. In a field experiment, we removed 50% of the tissue from leaves a...

journal_title：American journal of botany

authors： Blundell AG,Peart DR

更新日期：2000-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Within the Hypnales-the most derived and species-rich order of pleurocarpous mosses - phylogenies at or below the family level often show poor resolution. In preparation for a phylogeny of the genus Plagiothecium, we wished to identify the DNA markers best suited for evolutionary reconstruction in ...

journal_title：American journal of botany

authors： Wynns JT,Lange CB

更新日期：2014-04-01 00:00:00

abstract：:Multiply sired fruits provide unambiguous evidence that pollen from two or more donors was deposited on a stigma and successfully fertilized ovules. Such multiple paternity within fruits can have important consequences for both parental and offspring fitness, but little is known about the frequency of multiple paterni...

journal_title：American journal of botany

authors： Mitchell RJ,Karron JD,Holmquist KG,Bell JM

更新日期：2005-05-01 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：PREMISE OF THE STUDY:We developed simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) for Callitris columellaris sensu lato (s.l.) to elucidate population genetic structure and detect outlier loci by genome scan. METHODS AND RESULTS:mRNA from an individual seedling was subjected to cDNA synthesis ...

journal_title：American journal of botany

authors： Sakaguchi S,Uchiyama K,Ueno S,Ujino-Ihara T,Tsumura Y,Prior LD,Bowman DM,Crisp MD,Isagi Y

更新日期：2011-12-01 00:00:00

abstract：:Lxm1-O, a dominant EMS (ethyl methanesulfonate) induced mutation in maize (Zea mays, Poaceae), was originally reported to affect the blade/sheath boundary over the midrib region of the leaf. Here we present a more extensive analysis of the Lxm phenotype in nine different inbred lines. Lxm leaves are longer and narrowe...

journal_title：American journal of botany

authors： Schichnes D,Freeling M

更新日期：1998-04-01 00:00:00

abstract：:The geographic distribution of diploid and tetraploid cytotypes and cpDNA haplotypes throughout the entire range of Aucuba japonica was investigated. We measured relative genome size using flow cytometry and sequenced two cpDNA intergenic regions, atpB-rbcL and psbA-trnH (GUG). Two haplotypes include both diploids and...

journal_title：American journal of botany

authors： Ohi T,Kajita T,Murata J

更新日期：2003-11-01 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：:Leaf habit correlates with multiple physiological traits. Understanding ecophysiology is therefore dependent on knowledge of leaf habit. A variety of leaf habits exists within forest understory plant communities. Oxalis acetosella is one such understory plant and has long been considered a wintergreen, meaning that it...

journal_title：American journal of botany

authors： Tessier JT

更新日期：2004-09-01 00:00:00

abstract：:Phylogenetic relationships were inferred using nucleotide sequence variation of the nuclear-encoded chalcone synthase gene (Chs) and the chloroplast gene matK for members of five tribes from the family Brassicaceae to analyze tribal and subtribal structures. Phylogenetic trees from individual data sets are mostly in c...

journal_title：American journal of botany

authors： Koch M,Haubold B,Mitchell-Olds T

更新日期：2001-03-01 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：:The relationship between near-infrared reflectance at 800 nm (NIRR) from leaves and characteristics of leaf structure known to affect photosynthesis was investigated in 48 species of alpine angiosperms. This wavelength was selected to discriminate the effects of leaf structure vs. chemical or water content on leaf ref...

journal_title：American journal of botany

authors： Slaton MR,Raymond Hunt E Jr,Smith WK

更新日期：2001-02-01 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: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：UNLABELLED: PREMISE OF THE STUDY:An anatomical examination of dry and fleshy fruits within the Solanaceae was carried out to identify comparable stages throughout development as well as features exclusive to each type of fruit. We studied fruit development of Nicotiana and Petunia, which have the plesiomorphic capsula...

journal_title：American journal of botany

authors： Pabón-Mora N,Litt A

更新日期：2011-09-01 00:00:00

abstract：PREMISE:Closely related species occurring in sympatry may experience the negative consequences of interspecific pollen transfer if reproductive isolation (RI) barriers are not in place. We evaluated the importance of pre- and post-pollination RI barriers in three sympatric species of Achimenes (Gesneriaceae), including...

journal_title：American journal of botany

authors： Ramírez-Aguirre E,Martén-Rodríguez S,Quesada-Avila G,Quesada M,Martínez-Díaz Y,Oyama K,Espinosa-García FJ

更新日期：2019-07-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Island plants are over-exploited and "under-explored." Understanding the reproductive biology of plants, especially rare species, is fundamental to clarifying their evolution, estimating potential for change, and for creating effective conservation plans. Clarification of sexual syste...

journal_title：American journal of botany

authors： Anderson GJ,Anderson MK,Patel N

更新日期：2015-03-01 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：PREMISE OF THE STUDY:Fossilized seeds similar to Cissus (Vitaceae) have been recognized from the Miocene of Kenya, though some were previously assigned to the Menispermaceae. We undertook a comparative survey of extant African Cissus seeds to identify the fossils and consider their implications for the evolution and bi...

journal_title：American journal of botany

authors： Adams NF,Collinson ME,Smith SY,Bamford MK,Forest F,Malakasi P,Marone F,Sykes D

更新日期：2016-09-01 00:00:00

abstract：:The ultrastructure of Typha latifolia pollen was examined as a function of pollen moisture content and incubation temperature, in order to identify possible lesions induced by imbibitional chilling. A syndrome of structural traits was found which characterizes damaged grains. Compared to viable grains, the protoplas...

journal_title：American journal of botany

authors： Sack FD,Leopold AC,Hoekstra FA

更新日期：1988-01-01 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：:We studied 15 riparian and upland Sonoran desert species to evaluate how the limitation of xylem pressure (Ψ(x)) by cavitation corresponded with plant distribution along a moisture gradient. Riparian species were obligate riparian trees (Fraxinus velutina, Populus fremontii, and Salix gooddingii), native shrubs (Bacch...

journal_title：American journal of botany

authors： Pockman WT,Sperry JS

更新日期：2000-09-01 00:00:00

abstract：:The relationship between pollen and progeny performance has been a subject of many studies but the evidence for pollen-tube growth rate as an indicator of progeny fitness is equivocal. We used an anemophilous tree, Betula pendula, to examine the relationship between pollen-tube growth rate and seed and seedling perfor...

journal_title：American journal of botany

authors： Pasonen HL,Pulkkinen P,Käpylä M

更新日期：2001-05-01 00:00:00

abstract：PREMISE:Outcomes of species interactions, especially mutualisms, are notoriously dependent on environmental context, and environments are changing rapidly. Studies have investigated how mutualisms respond to or ameliorate anthropogenic environmental changes, but most have focused on nutrient pollution or climate change...

journal_title：American journal of botany

authors： O'Brien AM,Yu ZH,Luo DY,Laurich J,Passeport E,Frederickson ME

更新日期：2020-02-01 00:00:00