5,513 results match your criteria American Journal Of Botany[Journal]


Highlighted articles for May 2022.

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Am J Bot 2022 May 25. Epub 2022 May 25.

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Holding on or falling off: the attachment mechanism of epiphytic Anthurium obtusum (Engl.) Grayum changes with substrate roughness.

Am J Bot 2022 May 24. Epub 2022 May 24.

Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118, Kiel, Germany.

Premise: For vascular epiphytes, secure attachment to their hosts is vital for survival. Yet studies detailing the adhesion mechanism of epiphytes to their substrate are scarce. Examination of the root hair-substrate interface is essential to understand the attachment mechanism of epiphytes to their substrate. Read More

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Multiplexed-shotgun-genotype (MSG) data resolve phylogenetic relationships within and among archipelagos in Macaronesian Tolpis.

Am J Bot 2022 May 24. Epub 2022 May 24.

Department of Ecology & Evolutionary Biology, and the Biodiversity Institute, University of Kansas, Lawrence, KS, 66045-7534, USA.

Premise Of The Study: Plants endemic to oceanic archipelagos are suitable for studying evolution, being isolated on substrates of different ages. Evolution has been recent, rendering traditionally-employed sequences insufficiently variable for resolving relationships. This study includes sampling in the genus Tolpis (Asteraceae) from the Azores, Madeira, and Cape Verde, and expands upon an earlier study demonstrating the efficacy of multiplexed shotgun genotyping (MSG) for resolving relationships in Canarian Tolpis. Read More

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Evolution of selfing syndrome and its influence on genetic diversity and inbreeding: A range-wide study in Oenothera primiveris.

Am J Bot 2022 May 21. Epub 2022 May 21.

Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois, 60035, USA.

Premise: To avoid inbreeding depression, plants have evolved diverse breeding systems to favor outcrossing, such as self-incompatibility. However, changes in biotic and abiotic conditions can result in selective pressures that lead to a breakdown in self-incompatibility. The shift to increased selfing is commonly associated with reduced floral features, lower attractiveness to pollinators, and increased inbreeding. Read More

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Architectural effects regulate resource allocation within the inflorescences with nonlinear blooming patterns.

Am J Bot 2022 May 19. Epub 2022 May 19.

Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China.

Premise: Spatial and temporal resource allocations within inflorescences have been well-studied in many plants based on flowering sequence or floral position. However, there had been few attempts to investigate architectural effects and resource competition in species where the blooming pattern does not follow a linear positional pattern within the inflorescence. Moreover, most flowering plants show female-biased sex allocation in early or basal flowers, but it is unclear in species with inherent and changeless ovule production. Read More

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Rapid-cycling Brassica rapa evolves even earlier flowering under experimental drought.

Am J Bot 2022 May 19. Epub 2022 May 19.

Department of Biological Sciences, Fordham University, Bronx, New York, 10458.

Premise: Changes in climate can impose selection on populations and may lead to rapid evolution. One such climatic stress is drought, which plant populations may respond to with escape (rapid growth and early flowering) or avoidance (slow growth and efficient water use). However, it is unclear if drought escape would be a viable strategy for populations that already flower early from prior selection. Read More

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Once more unto the breach, dear friends: Resolving the origins and relationships of the Pellaea wrightiana hybrid complex.

Am J Bot 2022 May 14. Epub 2022 May 14.

Department of Biology, Duke University, Durham, 27708, NC, USA.

Premise: The taxonomic status of Wright's cliff brake fern, Pellaea wrightiana, has been in dispute ever since it was first described by Hooker in 1858. Previously published evidence suggested that this "taxon" may represent a polyploid complex rather than a single discrete species, a hypothesis tested here using a multifaceted analytical approach.

Methods: Data derived from cytogenetics, spore analyses, leaf morphometrics, enzyme electrophoresis, and phylogenetic analyses of plastid and nuclear DNA sequences are used to elucidate the origin, relationships, and taxonomic circumscription of P. Read More

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Effects of heterospecific pollen on stigma behavior in Campsis radicans: causes and consequences.

Am J Bot 2022 May 14. Epub 2022 May 14.

Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China.

Premise Of The Study: Pollinator sharing of co-flowering plants may result in interspecific pollen receipt with a fitness cost. However, the underlying factors determining the effects of heterospecific pollen (HP) are not fully understood. Moreover, the cost of stigma closure induced by HP may be more severe for plants with special touch-sensitive stigma than for plants with non-touch-sensitive stigma. Read More

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Cunoniaceae infructescences from the early Eocene Laguna del Hunco flora, Patagonia, Argentina.

Am J Bot 2022 May 14. Epub 2022 May 14.

Department of Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, Pennsylvania, 16802, USA.

Premise: Two distinct types of fossil infructescences from the early Eocene Laguna del Hunco flora, Chubut Province, Patagonia, Argentina, preserve features of the family Cunoniaceae. The goal of the study is to assess their affinities within Cunoniaceae and to interpret their evolutionary and biogeographical significance.

Methods: Specimens were collected from the Tufolitas Laguna del Hunco, Huitrera Formation. Read More

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Coalescent-based species delimitation in North American pinyon pines using low-copy nuclear genes and plastomes.

Am J Bot 2022 May 8. Epub 2022 May 8.

Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.

Premise: Accurate species delimitation is essential for evolutionary biology, conservation, and biodiversity management. We studied species delimitation in North American pinyon pines, Pinus subsection Cembroides, a natural group with high levels of incomplete lineage sorting.

Methods: We used coalescent-based methods and multivariate analyses of low-copy number nuclear genes and nearly complete high-copy number plastomes generated with the Hyb-Seq method. Read More

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Identification of key regulatory genes involved in the sporophyte and gametophyte development in Ginkgo biloba ovules revealed by in situ expression analyses.

Am J Bot 2022 May 4. Epub 2022 May 4.

Botanical Garden, University of Padova, Padova, 35123, Italy.

Premise: In Arabidopsis thaliana, the role of the most important key genes that regulate ovule development is widely known. In nonmodel species, and especially in gymnosperms, the ovule developmental processes are still quite obscure. In this study, we describe the putative roles of Ginkgo biloba orthologs of regulatory genes during ovule development. Read More

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Leaf trait association in relation to herbivore defense, drought resistance, and economics in a tropical invasive plant.

Am J Bot 2022 Apr 26. Epub 2022 Apr 26.

CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China.

Premise: Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species.

Methods: We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense and drought resistance on 10 introduced populations from Asia and 12 native populations from America, selected across a broad range of climatic conditions, and grown in a common garden. Read More

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Adaptation to lower latitudes and lower elevations precedes the evolution of hummingbird pollination in western North American Penstemon.

Am J Bot 2022 Apr 26. Epub 2022 Apr 26.

Department of Biological Sciences, University of South Carolina, 715 Sumter St, Columbia, SC 29208, USA.

Premise: A switch in pollinator can occur when a plant lineage enters a new habitat where the ancestral pollinator is less common, and a novel pollinator is more common. Because pollinator communities vary according to environmental tolerances and availability of resources, there may be consistent associations between pollination mode and specific regions and habitats. Such associations can be studied in lineages that have experienced multiple pollinator transitions, representing evolutionary replicates. Read More

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Scaling relationships of leaf vein and areole traits versus leaf size for nine Magnoliaceae species differing in venation density.

Am J Bot 2022 Apr 26. Epub 2022 Apr 26.

School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.

Premise: Across species, main leaf vein density scales inversely with leaf area (A). Yet, minor vein density manifests no clear relationship with respect to A, despite having the potential to provide important insights into the trade-off among the investments in leaf mechanical support, hydraulics, and light interception.

Methods: To examine this phenomenon, the leaves of nine Magnoliaceae leaves were sampled, and the scaling relationships among A and midrib length (ML), total vein length (TVL), total vein area (TVA), total areole area (TAA), and mean areole area (MAA) were determined. Read More

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Phylogenomic analyses in Phrymaceae reveal extensive gene tree discordance in relationships among major clades.

Am J Bot 2022 Apr 24. Epub 2022 Apr 24.

Department of Plant and Microbial Biology, University of Minnesota-Twin Cities, 1445 Gortner Avenue, St. Paul, MN, 55108-1095, USA.

Premise Of The Study: Phylogenomic datasets using genomes and transcriptomes provide rich opportunities beyond resolving bifurcating phylogenetic relationships. Monkeyflower (Phrymaceae) is a model system for evolutionary ecology. However, it lacks a well-supported phylogeny as a basis for a stable taxonomy and for macroevolutionary comparisons. Read More

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Diversification in the Rosales is influenced by dispersal, geographic range size, and pre-existing species richness.

Am J Bot 2022 Apr 21. Epub 2022 Apr 21.

Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota.

Premise Of The Study: Biodiversity results from origination and extinction, justifying interest in identifying traits that influence this balance. Traits implicated in the success or failure of lineages include dispersal, colonization ability, and geographic range size. We investigate the impact of dispersal and range size on contemporary diversity in the Rosales. Read More

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As above so below: Recent and future advances in plant-mediated above- and belowground interactions.

Authors:
Sergio Rasmann

Am J Bot 2022 Apr 20. Epub 2022 Apr 20.

Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland.

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The Vessel Wall Thickness-Vessel Diameter Relationship Across Woody Angiosperms.

Am J Bot 2022 Apr 18. Epub 2022 Apr 18.

Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510, México.

Premise: Comparative anatomy is necessary to identify the extremes of combinations of functionally relevant structural traits, to ensure that physiological data cover xylem anatomical diversity adequately, together achieving a global understanding of xylem structure-function relations. A key trait relationship is that between xylem vessel diameter and wall thickness, both the single vessel wall as well as the double vessel+adjacent imperforate tracheary element (ITE) wall.

Methods: We compiled a comparative dataset with 1093 samples, 858 species, 350 genera, 86 families, and 33 orders. Read More

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Population-specific responses of floral volatiles to abiotic factors in changing environments.

Am J Bot 2022 Apr 18. Epub 2022 Apr 18.

Vegetable Crops Research Unit, United States Department of Agriculture, Agricultural Research Service, Madison, 53706, WI, USA.

Premise: Shifts in abiotic factors can affect many plant traits, including floral volatiles. This study examined the response of floral volatiles to water availability and whether phenotypic plasticity to water availability differs among populations. It also investigated genetic differentiation in floral volatiles, determined the effect of temperature on phenotypic plasticity to water availability, and assessed temporal variation in floral scent emission between day and evening, since pollinator visitation differs at those times. Read More

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A novel cupulate seed plant, Xadzigacalix quatsinoensis gen. et sp. nov., provides new insight into the Mesozoic radiation of gymnosperms.

Am J Bot 2022 Apr 18. Epub 2022 Apr 18.

Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, 97331-2902, USA.

Premise Of Study: Anatomically preserved evidence for a novel clade of gymnosperms emphasizes diversity of seed plants immediately prior to the appearance of angiosperm fossils in the paleontological record.

Methods: Cupulate seeds from the Early Cretaceous Apple Bay locality (Vancouver Island) are described from serial cellulose acetate peels and 3D reconstruction. Phylogenetic context is assessed through the comparative analysis of gymnosperm seed producing fructifications and maximum parsimony analysis of a revised morphological dataset for seed plant phylogeny. Read More

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Evidence of floral rewards in Brasiliorchis supports the convergent evolution of food-hairs in Maxillariinae.

Am J Bot 2022 Apr 18. Epub 2022 Apr 18.

University of Warsaw, Faculty of Biology, Botanic Garden, Al. Ujazdowskie 4, 00-478, Warszawa, Poland.

Premise: Angiosperms distributed over a large geographical area may display considerable phenotypic variation that can be recognized at morphological and micromorphological levels. Here, we investigate the pollination biology and the presence of floral rewards in Brazilian populations of the widely distributed orchid, Brasiliorchis picta. Based on the new data presented here this study investigates the evolution of floral rewards in Maxillariinae, and tests for the occurrence of convergent evolution of food-hairs in this subtribe. Read More

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Digitized collections elucidate invasion history and patterns of awn polymorphism in Microstegium vimineum.

Am J Bot 2022 Apr 18. Epub 2022 Apr 18.

Department of Biology, West Virginia University, 53 Campus Drive, Morgantown, West Virginia, 26506, USA.

Premise: Digitized collections can help illuminate the mechanisms behind the establishment and spread of invasive plants. These databases provide a record of traits in space and time that allows for investigation of abiotic and biotic factors that influence invasive species.

Methods: Over 1100 digitized herbarium records were examined to investigate the invasion history and trait variation of Microstegium vimineum. Read More

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Spatial phylogenetics of Japanese ferns: Patterns, processes, and implications for conservation.

Am J Bot 2022 Apr 18. Epub 2022 Apr 18.

Department of Botany, National Museum of Nature and Science, Tsukuba, Japan.

Premise: Biodiversity is often only measured with species richness; however, this metric ignores evolutionary history and is not sufficient for making conservation decisions. Here, we characterize multiple facets and drivers of biodiversity to understand how these relate to bioregions and conservation status in the ferns of Japan.

Methods: We compiled a community data set of 1239 grid cells (20 × 20 km each) including 672 taxa based on >300,000 specimen records. Read More

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A missing link: Connecting plant and pollinator population structure.

Am J Bot 2022 Apr 14. Epub 2022 Apr 14.

Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA.

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Glacial vicariance and oceanic circulation shape population structure of the coastal legume Derris trifoliata in the Indo-West Pacific.

Am J Bot 2022 Apr 13. Epub 2022 Apr 13.

State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, Guangdong, China.

Premise Of The Study: The phylogeography of coastal plant species is shaped by contemporary and historical biogeographic processes. In this study, we aim to decipher the phylogeography of Derris trifoliata, a woody legume of relatively recent origin and wide distribution, in coastal areas in the Indo-West Pacific (IWP) region.

Methods: Genetic diversity and population structure were assessed by analyzing six nuclear and three chloroplast DNA sequences from 30 populations across the species' range. Read More

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Highlighted articles for April 2022.

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Am J Bot 2022 04 11;109(4):495-496. Epub 2022 Apr 11.

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Decoding family-level features for modern and fossil leaves from computer-vision heat maps.

Am J Bot 2022 Mar 23. Epub 2022 Mar 23.

Department of Cognitive, Linguistic and Psychological Sciences, Carney Institute for Brain Science, Brown University, Providence, Rhode Island, 02912, USA.

Premise: Angiosperm leaves present a classic identification problem due to their morphological complexity. Computer-vision algorithms can identify diagnostic regions in images, and heat map outputs illustrate those regions for identification, providing novel insights through visual feedback. We investigate the potential of analyzing leaf heat maps to reveal novel, human-friendly botanical information with applications for extant- and fossil-leaf identification. Read More

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Contrasting effects of nectar yeasts on the reproduction of Mediterranean plant species.

Am J Bot 2022 03 22;109(3):393-405. Epub 2022 Mar 22.

Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas, Avenida Américo Vespucio 26, E-41092, Sevilla, Spain.

Premise: Yeasts are often present in floral nectar and can influence plant fitness directly (independently of pollinators) or indirectly by influencing pollinator visitation and behavior. However, few studies have assessed the effect of nectar yeasts on plant reproductive success or compared effects across different plant species, limiting our understanding of the relative impact of direct vs. indirect effects. Read More

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Highlighted articles for March 2022.

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Am J Bot 2022 03 17;109(3):361-362. Epub 2022 Mar 17.

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Evolution and conservation genetics of an insular hemiparasitic plant lineage at the limit of survival: the case of Thesium sect. Kunkeliella in the Canary Islands.

Am J Bot 2022 03 15;109(3):419-436. Epub 2022 Mar 15.

Instituto Universitario de Estudios Ambientales y Recursos Naturales (IUNAT), Universidad de Las Palmas de Gran Canaria, Campus Universitario de Tafira, 35017 Las Palmas de Gran Canaria, Canary Islands, Spain.

Premise: The diversification of island flora has been widely studied. However, the role of environmental niches in insular radiation processes has been less investigated. We combined population genetic analyses with species distribution modelling to clarify the genetic relationships, diversification patterns, species niche requirements, and conservation of Thesium sect. Read More

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