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Full-Text Articles in Botany

A Gradient Of Pollination Specialization In Three Species Of Bolivian Centropogon, Laura P. Lagomarsino, Nathan Muchhala Apr 2019

A Gradient Of Pollination Specialization In Three Species Of Bolivian Centropogon, Laura P. Lagomarsino, Nathan Muchhala

Nathan Muchhala

Premise
Closely related plant species with overlapping ranges often experience competition for pollination services. Such competition can select for divergence in floral traits that attract pollinators or determine pollen placement. While most species in Centropogon(Campanulaceae: Lobelioideae) have flowers that suggest adaptation to bat or hummingbird pollination, actual pollinators are rarely documented, and a few species have a mix of traits from both pollination syndromes. We studied the pollination biology of a “mixedsyndrome” species and its cooccurring congeners to examine the relationship between floral traits and visitation patterns for Centropogon.
Methods Fieldwork at two sites in Bolivian …


Supplemental Data, Russell J. Ingram, Foster Levy, Cindy L. Barrett, James T. Donaldson Aug 2017

Supplemental Data, Russell J. Ingram, Foster Levy, Cindy L. Barrett, James T. Donaldson

Foster Levy

No abstract provided.


Evolution Of Floral Zygomorphy In Androecium And Corolla In Solanaceae, Jingbo Zhang, Peter F. Stevens, Wenheng Zhang Jan 2017

Evolution Of Floral Zygomorphy In Androecium And Corolla In Solanaceae, Jingbo Zhang, Peter F. Stevens, Wenheng Zhang

Peter Stevens

In Solanaceae, a group dominated by actinomorphic‐flowered species, floral zygomorphy is frequently observed among the early‐branching clades. Morphological studies indicated that a zygomorphic androecium is much more common than a zygomorphic corolla in the family. Ontogenic studies suggested the evolution of floral zygomorphy in these two whorls is independent. Here, we have examined the evolution of floral symmetry in the androecium and corolla in Solanaceae. The character states of floral symmetry were assembled for androecium and corolla separately, and ancestral state reconstructions were carried out at both the genus and species levels for Solanaceae and its outgroups. Correlation tests were …


Phospholipase Dζ Enhances Diacylglycerol Flux Into Triacylglycerol, Wenyu Yang, Geliang Wang, Jia Li, Philip David Bates, Xuemin Wang, Douglas K. Allen Jan 2017

Phospholipase Dζ Enhances Diacylglycerol Flux Into Triacylglycerol, Wenyu Yang, Geliang Wang, Jia Li, Philip David Bates, Xuemin Wang, Douglas K. Allen

Xuemin (Sam) Wang

Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase Dζ genes (AtPLDζ1 and AtPLDζ2) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG as a component of …


Invasive Species In An Urban Flora: History And Current Status In Indianapolis, Indiana, Rebecca W. Dolan Dec 2016

Invasive Species In An Urban Flora: History And Current Status In Indianapolis, Indiana, Rebecca W. Dolan

Rebecca W. Dolan

Invasive plant species are widely appreciated to cause significant ecologic and economic damage in agricultural fields and in natural areas. The presence and impact of invasives in cities is less well documented. This paper characterizes invasive plants in Indianapolis, Indiana. Based on historical records and contemporary accounts, 69 of the 120 species on the official Indiana state list are reported for the city. Most of these plants are native to Asia or Eurasia, with escape from cultivation as the most common mode of introduction. Most have been in the flora of Indianapolis for some time. Eighty percent of Indianapolis’ invasive …


Non-Specific Phospholipase C1 Affects Silicon Distribution And Mechanical Strength In Stem Nodes Of Rice, Huasheng Cao, Lin Zhuo, Yuan Su, Linxiao Sun, Xuemin Wang May 2016

Non-Specific Phospholipase C1 Affects Silicon Distribution And Mechanical Strength In Stem Nodes Of Rice, Huasheng Cao, Lin Zhuo, Yuan Su, Linxiao Sun, Xuemin Wang

Xuemin (Sam) Wang

Silicon, the second abundant element in the crust, is beneficial for plant growth, mechanical strength, and stress responses. Here we show that manipulation of the non‐specific phospholipase C1, NPC1, alters silicon content in nodes and husks of rice (Oryza sativa). Silicon content in NPC1‐overexpressing (OE) plants was decreased in nodes but increased in husks compared to wild‐type, whereas RNAi suppression of NPC1 resulted in the opposite changes to those of NPC1‐OE plants. NPC1 from rice hydrolyzed phospholipids and galactolipids to generate diacylglycerol that can be phosphorylated to phosphatidic acid. Phosphatidic acid interacts with Lsi6, a silicon transporter that is expressed …


Membrane Glycerolipidome Of Soybean Root Hairs And Its Response To Nitrogen And Phosphate Availability, Fang Wei, Brian Fanella, Liang Guo, Xuemin Wang Jan 2016

Membrane Glycerolipidome Of Soybean Root Hairs And Its Response To Nitrogen And Phosphate Availability, Fang Wei, Brian Fanella, Liang Guo, Xuemin Wang

Xuemin (Sam) Wang

Root hairs are tubular extensions of specific root epidermal cells important in plant nutrition and water absorption. To determine membrane glycerolipids in root hairs and roots may differ, as well as their respective response to nutrient availability, this study analyzed the membrane glycerolipid species in soybean root hairs and in roots stripped of root hairs, and their response to nitrogen (N) and phosphate (Pi) supplementation. The ratio of phospholipids to galactolipids was 1.5 fold higher in root hairs than in stripped roots. Under Pi deficiency, the ratio of phospholipids to galactolipids in stripped roots decreased with the greatest decrease found …


Bacon's Swamp- Ghost Of A Central Indiana Natural Area Past, Rebecca W. Dolan Jan 2016

Bacon's Swamp- Ghost Of A Central Indiana Natural Area Past, Rebecca W. Dolan

Rebecca W. Dolan

Bacon’s Swamp was identified in the 1920s as a ca. 12 ha glacial kettle lake bog system at the southernmost limits of these habitats in Indiana. Located just 9.6 km from the center of Indianapolis, the site was all but destroyed in the mid-20th century by urban expansion. Prior to habitat conversion at the site, Bacon’s Swamp was a frequent location for Butler University ecology class field trips and student research projects. Herbarium specimens and published inventory records allow for analysis of the historical vegetation of Bacon’s Swamp using modern techniques. Floristic Quality Assessment applied to these historical records reveals …


Lineage Sorting In Multihost Parasites: Eidmanniella Albescens And Fregatiella Aurifasciata On Seabirds From The Galapagos Islands, Jose L. Rivera-Parra, Iris I. Levin, Kevin P. Johnson, Patricia G. Parker Jan 2015

Lineage Sorting In Multihost Parasites: Eidmanniella Albescens And Fregatiella Aurifasciata On Seabirds From The Galapagos Islands, Jose L. Rivera-Parra, Iris I. Levin, Kevin P. Johnson, Patricia G. Parker

Patricia Parker

Parasites comprise a significant percentage of the biodiversity of the planet and are useful systems to test evolutionary and ecological hypotheses. In this study, we analyze the effect of host species identity and the immediate local species assemblage within mixed species colonies of nesting seabirds on patterns of genetic clustering within two species of multihost ectoparasitic lice. We use three genetic markers (one mitochondrial, COI, and two nuclear, EF1‐α and wingless) and maximum likelihood phylogenetic trees to test whether (1) parasites show lineage sorting based on their host species; and (2) switching of lineages to the alternate host species depends …


Next-Generation Field Guides, Elizabeth J. Farnsworth, Miyoko Chu, W. John Kress, Amanda K. Neill, Jason H. Best, John Pickering, Robert D. Stevenson, Gregory W. Courtney, John K. Vandyk, Aaron M. Ellison Oct 2014

Next-Generation Field Guides, Elizabeth J. Farnsworth, Miyoko Chu, W. John Kress, Amanda K. Neill, Jason H. Best, John Pickering, Robert D. Stevenson, Gregory W. Courtney, John K. Vandyk, Aaron M. Ellison

John K. VanDyk

To conserve species, we must first identify them. Field researchers, land managers, educators, and citizen scientists need up-to-date and accessible tools to identify organisms, organize data, and share observations. Emerging technologies complement traditional, book-form field guides by providing users with a wealth of multimedia data. We review technical innovations of next-generation field guides, including Web-based and stand-alone applications, interactive multiple-access keys, visual-recognition software adapted to identify organisms, species checklists that can be customized to particular sites, online communities in which people share species observations, and the use of crowdsourced data to refine machine-based identification algorithms. Next-generation field guides are user …


Weed Seed Germplasm Collection 1964-2014 Of The Weed Biology Laboratory, Jack Dekker Mar 2014

Weed Seed Germplasm Collection 1964-2014 Of The Weed Biology Laboratory, Jack Dekker

Jack Dekker

J. Dekker weed seed germplasm collection; including: Lots 1-3974: 1964-2014; main seed library listed by lot numbers. Lots 649-1457: 1989 all-Iowa Setaria transect study. Lots 1762-1812: 1981; Diane Manthey, North Dakota St. Univ., Setaria collection at Bob Anderson's (USDA, Univ. of Minn) 1960's wild oat study sites. Lots 2389-2595: 1992 north temperate world collection (Japan, Russia, Europe) by J. Dekker. Lots 3270-3685: 1993 Brent Reschly transect study of eastern Iowa conventional and Amish farmers. Lots 3786-3962: 2000 J. Dekker 2000 salt-tolerant Setaria of southern Japan collection. All seed in all these collections belong, and were collected and archived by Jack …


Maine's Kelp Highway, Catherine Schmitt Mar 2014

Maine's Kelp Highway, Catherine Schmitt

Catherine Schmitt

No abstract provided.


Another Look At The Root Of The Angiosperms Reveals A Familiar Tale, Bryan Drew, Brad Ruhfel, Stephen Smith, Michael Moore, Barbara Briggs, Matthew Gitzendanner, Pamela Soltis, Douglas Soltis Feb 2014

Another Look At The Root Of The Angiosperms Reveals A Familiar Tale, Bryan Drew, Brad Ruhfel, Stephen Smith, Michael Moore, Barbara Briggs, Matthew Gitzendanner, Pamela Soltis, Douglas Soltis

Brad R. Ruhfel

Since the advent of molecular phylogenetics more than 25 years ago, a major goal of plant systematists has been to discern the root of the angiosperms. Although most studies indicate that Amborella trichopoda is sister to all remaining extant flowering plants, support for this position has varied with respect to both the sequence data sets and analyses employed. Recently, Goremykin et al. (2013) questioned the “Amborella-sister hypothesis” using a “noise-reduction” approach and reported a topology with Amborella + Nymphaeales (water lilies) sister to all remaining angiosperms. Through a series of analyses of both plastid genomes and mitochondrial genes, we continue …


Different Meal, Same Flavor: Cospeciation And Host Switching Of Haemosporidian Parasites In Some Non-Passerine Birds, Diego Santiago-Alarcon, Adriana Rodríguez-Ferraro, Patricia G. Parker, Robert E. Ricklefs Dec 2013

Different Meal, Same Flavor: Cospeciation And Host Switching Of Haemosporidian Parasites In Some Non-Passerine Birds, Diego Santiago-Alarcon, Adriana Rodríguez-Ferraro, Patricia G. Parker, Robert E. Ricklefs

Robert Ricklefs

Background
Previous studies have shown that haemosporidian parasites (Haemoproteus(Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with …


Different Meal, Same Flavor: Cospeciation And Host Switching Of Haemosporidian Parasites In Some Non-Passerine Birds, Diego Santiago-Alarcon, Adriana Rodríguez-Ferraro, Patricia G. Parker, Robert E. Ricklefs Dec 2013

Different Meal, Same Flavor: Cospeciation And Host Switching Of Haemosporidian Parasites In Some Non-Passerine Birds, Diego Santiago-Alarcon, Adriana Rodríguez-Ferraro, Patricia G. Parker, Robert E. Ricklefs

Patricia Parker

Background
Previous studies have shown that haemosporidian parasites (Haemoproteus (Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with their non-passerine hosts.

Methods
We sequenced the mtDNA cyt b gene of both haemosporidian parasites and their …


Combined Morphological And Molecular Phylogeny Of The Clusioid Clade (Malpighiales) And The Placement Of The Ancient Rosid Macrofossil Paleoclusia, Brad Ruhfel, Peter Stevens, Charles Davis Dec 2012

Combined Morphological And Molecular Phylogeny Of The Clusioid Clade (Malpighiales) And The Placement Of The Ancient Rosid Macrofossil Paleoclusia, Brad Ruhfel, Peter Stevens, Charles Davis

Brad R. Ruhfel

Premise of research. The clusioid clade is a member of the large rosid order Malpighiales and contains∼1900 species in five families: Bonnetiaceae, Calophyllaceae, Clusiaceae sensu stricto (s.s.), Hypericaceae, and Podostemaceae. Despite recent efforts to clarify their phylogenetic relationships using molecular data, no such data are available for several critical taxa, including especially Hypericum ellipticifolium (previously recognized in Lianthus), Lebrunia, Neotatea, Thysanostemon, and the second-oldest rosid fossil (∼90 Ma), Paleoclusia chevalieri. Here, we (i) assess congruence between phylogenies inferred from morphological and molecular data, (ii) analyze morphological and molecular data simultaneously to place taxa lacking molecular data, and (iii) use ancestral …


The Role Of Olfactory Cues In The Sequential Radiation Of A Gall-Boring Beetle, Mordellistena Convicta, Bradley Rhodes, Catherine Blair, Mizuki Takahashi, Warren Abrahamson Nov 2012

The Role Of Olfactory Cues In The Sequential Radiation Of A Gall-Boring Beetle, Mordellistena Convicta, Bradley Rhodes, Catherine Blair, Mizuki Takahashi, Warren Abrahamson

Warren G. Abrahamson, II

1. Herbivorous insects often have close associations with specific host plants, and their preferences for mating and ovipositing on a specific host-plant species can reproductively isolate populations, facilitating ecological speciation. Volatile emissions from host plants can play a major role in assisting herbivores to locate their natal host plants and thus facilitate assortative mating and host-specific oviposition. 2. The present study investigated the role of host-plant volatiles in host fidelity and oviposition preference of the gall-boring, inquiline beetle, Mordellistena convicta, using Y-tube olfactometers. Previous studies suggest that the gall-boring beetle is undergoing sequential host-associated divergence by utilizing the resources that …


Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Peter Stevens, Sarah Mathews, Charles Davis Oct 2012

Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Peter Stevens, Sarah Mathews, Charles Davis

Brad R. Ruhfel

The angiosperm order Malpighiales includes ∼16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas …


The Spatial Signature Of Biotic Interactions Of A Clonal And A Non-Clonal Palmetto In A Subtropical Plant Community, Mizuki Takahashi, Toshiro Kubota, Liana Horner, Nathan Keller, Warren Abrahamson Jun 2012

The Spatial Signature Of Biotic Interactions Of A Clonal And A Non-Clonal Palmetto In A Subtropical Plant Community, Mizuki Takahashi, Toshiro Kubota, Liana Horner, Nathan Keller, Warren Abrahamson

Warren G. Abrahamson, II

Spatial analyses of plant-distribution patterns can provide inferences about intra- and interspecific biotic interactions. Yet, such analyses are rare for clonal plants because effective tools (i.e., molecular markers) needed to map naturally occurring clonal individuals have only become available recently. Clonal plants are unique in that a single genotype has a potential to spatially place new individuals (i.e., ramets) in response to intra- and interspecific biotic interactions. Laboratory and greenhouse studies suggest that some clonal plants can avoid intra-genet, inter-genet, and inter-specific competition via rootplacement patterns. An intriguing and yet to be explored question is whether a spatial signature of …


Phylogenetics Of Morus (Moraceae) Inferred From Its And Trnl-Trnf Sequence Data., Madhav Nepal Mar 2012

Phylogenetics Of Morus (Moraceae) Inferred From Its And Trnl-Trnf Sequence Data., Madhav Nepal

Madhav Nepal

Morus (Tribe Moreae, Moraceae) consists of ca. 13 species of trees distributed in Asia, Africa, Europe, and North, Central, and South America. The broad geographical distribution of the genus, overlapping ranges of many taxa, and documented hybridization between some species present interesting questions of taxonomy, phylogeny, and biogeography. Phylogenetic data for Morus also contribute to higher level taxonomic work in the family. We used sequence data from ITS of the nrDNA and the chloroplast trnL-trnF intergenic spacer to study phylogenetic relationships of Morus. Phylogenies based on separate data sets were not statistically incongruent, and the combined tree …


Rapid Diversification Of Tragopogon And Ecological Associates In Eurasia, Charles Bell Dec 2011

Rapid Diversification Of Tragopogon And Ecological Associates In Eurasia, Charles Bell

Charles D. Bell

No abstract provided.


Phylogeny And Diversification Of Valerianaceae (Dipsacales) In The Southern Andes, Charles D. Bell Dec 2011

Phylogeny And Diversification Of Valerianaceae (Dipsacales) In The Southern Andes, Charles D. Bell

Charles D. Bell

No abstract provided.


Extensive Clonal Spread And Extreme Longevity In Saw Palmetto, A Foundation Clonal Plant, Mizuki K. Takahashi, Liana M. Horner, Toshiro Kubota, Nathan A. Keller, Warren G. Abrahamson Ii Aug 2011

Extensive Clonal Spread And Extreme Longevity In Saw Palmetto, A Foundation Clonal Plant, Mizuki K. Takahashi, Liana M. Horner, Toshiro Kubota, Nathan A. Keller, Warren G. Abrahamson Ii

Warren G. Abrahamson, II

The lack of effective tools has hampered our ability to assess the size, growth and ages of clonal plants. With Serenoa repens (saw palmetto) as a model, we introduce a novel analytical frame work that integrates DNA fingerprinting and mathematical modelling to simulate growth and estimate ages of clonal plants. We also demonstrate the application of such life-history information of clonal plants to provide insight into management plans. Serenoa is an ecologically important foundation species in many Southeastern United States ecosystems; yet, many land managers consider Serenoa a troublesome invasive plant. Accordingly, management plans have been developed to reduce or …


Comparative Transcriptome And Metabolite Analysis Of Oil Palm And Date Palm Mesocarp That Differ Dramatically In Carbon Partitioning, Fabienne Bourgis, Aruna Kilaru, Xia Cao, Georges Frank Ngando-Ebongue, Noureddine Drira, John B. Ohlrogge, Vincent Arondel Jul 2011

Comparative Transcriptome And Metabolite Analysis Of Oil Palm And Date Palm Mesocarp That Differ Dramatically In Carbon Partitioning, Fabienne Bourgis, Aruna Kilaru, Xia Cao, Georges Frank Ngando-Ebongue, Noureddine Drira, John B. Ohlrogge, Vincent Arondel

Aruna Kilaru

Oil palm can accumulate up to 90% oil in its mesocarp, the highest level observed in the plant kingdom. In contrast, the closely related date palm accumulates almost exclusively sugars. To gain insight into the mechanisms that lead to such an extreme difference in carbon partitioning, the transcriptome and metabolite content of oil palm and date palm were compared during mesocarp development. Compared with date palm, the high oil content in oil palm was associated with much higher transcript levels for all fatty acid synthesis enzymes, specific plastid transporters, and key enzymes of plastidial carbon metabolism, including phosphofructokinase, pyruvate kinase, …


Plant-Animal Interactions, W. Abrahamson, T. Taylor Dec 2010

Plant-Animal Interactions, W. Abrahamson, T. Taylor

Warren G. Abrahamson, II

No abstract provided.


Nomenclatural Changes For Some Grasses In California. Ii, James Payne Smith Jr., J. Travis Columbus Dec 2010

Nomenclatural Changes For Some Grasses In California. Ii, James Payne Smith Jr., J. Travis Columbus

James Payne Smith

Two additional nomenclatural changes are required for Poaceae treatments that will appear in the second edition of The Jepson Manual: Higher Plants of California. They are Elymus 3 gouldii and Festuca temulenta. The former corrects a violation of the rule in the International Code of Botanical Nomenclature involving the naming of hybrids, and the latter involves a widely occurring non-native grass in California traditionally assigned to Lolium. Key words: California, Elymus, Festuca, Leymus, Lolium, nomenclature, Poaceae.


Phylogeny Of The Clusioid Clade (Malpighiales): Evidence From The Plastid And Mitochonrial Genomes, Brad R. Ruhfel, Volker Bittrich, Claudia A. Bove, Mats H.G. Gustafsson, C. Thomas Philbrick, Rolf Rutsihauser, Zhenxiang Xi, Charles C. Davis Dec 2010

Phylogeny Of The Clusioid Clade (Malpighiales): Evidence From The Plastid And Mitochonrial Genomes, Brad R. Ruhfel, Volker Bittrich, Claudia A. Bove, Mats H.G. Gustafsson, C. Thomas Philbrick, Rolf Rutsihauser, Zhenxiang Xi, Charles C. Davis

Brad R. Ruhfel

• Premise of the study : The clusioid clade includes five families (i.e., Bonnetiaceae, Calophyllaceae, Clusiaceae s.s., Hypericaceae, and Podostemaceae) represented by 94 genera and ~1900 species. Species in this clade form a conspicuous element of tropical forests worldwide and are important in horticulture, timber production, and pharmacology. We conducted a taxon-rich multigene phylogenetic analysis of the clusioids to clarify phylogenetic relationships in this clade.

• Methods : We analyzed plastid ( matK , ndhF , and rbcL ) and mitochondrial ( matR ) nucleotide sequence data using parsimony, maximum likelihood, and Bayesian inference. Our combined data set included 194 …


The Rare, Serpentine Endemic Streptanthus Morrisonii (Brassicaceae) Species Complex, Revisited Using Isozyme Analysis, Rebecca W. Dolan Mar 2010

The Rare, Serpentine Endemic Streptanthus Morrisonii (Brassicaceae) Species Complex, Revisited Using Isozyme Analysis, Rebecca W. Dolan

Rebecca W. Dolan

The Streptanthus morrisonii (Brassicaceae) complex is a group of six narrowly-distributed obligate serpentine endemic taxa whose habitat is threatened by geothermal development. Isozyme analysis of this little-studied complex supports the delineation of two species, S. morrisonii and S. brachiatus, but is at odds with the treatment of two subspecies based on morphology. These results may be influenced by small sample sizes but genetic studies of other Streptanthus taxa have shown patterns of relatedness that often transgress subspecies boundaries based on morphology. The present study further shows that members of the S. morrisonii complex share high genetic identity values (mean = …


Population Genetic Structure In Nolina Brittoniana (Agavaceae), A Plant Endemic To The Central Ridges Of Florida, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges Mar 2010

Population Genetic Structure In Nolina Brittoniana (Agavaceae), A Plant Endemic To The Central Ridges Of Florida, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges

Rebecca W. Dolan

Nolina brittoniana is endemic to the central ridges of peninsular Florida. Its scrub and sandhill habitats have suffered extensive anthropogenic modification. Analysis of isozymes from populations throughout its range revealed less genetic variation than generally reported for endemic plants. Populations were well differentiated, with significant clines in allele frequency along the north-south axis of distribution. Pair-wise F-statistics calculated at four levels of population geographic substructure revealed that current and inferred historical habitat patches had similar genetic structure. We found no evidence of recent bottlenecks or changes in genetic structure due to habitat loss and fragmentation, consistent with populations having always …


The Effects Of Seed Size And Maternal Origin On The Distribution Of Individual Plant Size In Ludwigia Leptocarpa (Onagraceae), Rebecca W. Dolan Mar 2010

The Effects Of Seed Size And Maternal Origin On The Distribution Of Individual Plant Size In Ludwigia Leptocarpa (Onagraceae), Rebecca W. Dolan

Rebecca W. Dolan

Seed size is normally distributed for many annual species, while mature plant size is frequently positively skewed. A study was conducted to determine the influence of seed size and the role of genetic differences in determining relative seedling size for Ludwigia leptocarpa. Seed size had a significant effect on percentage germination and time of seed germination but no effect on dry weight or leaf area of seedlings. Seed size and spacing had a significant effect on seedling dry weight for plants grown under competition, while relative day of emergence had no effect. Familial (genetic) differences were found in average seed …