Linda Watson

Linda Watson

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 October 2020 in Journal of Systematics and Evolution
Verified
Journal Article
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LWLinda Watson
Linda Watson
CSCarolina M. Siniscalchi
Carolina M. Siniscalchi
JMJennifer Mandel
Jennifer Mandel
Asteraceae account for 10% of all flowering plant species, and 35%–40% of these are in five closely related tribes that total over 10 000 species. These tribes include Anthemideae, Astereae, Calenduleae, Gnaphalieae, and Senecioneae, which form one of two enormous clades within Subfamily Asteroideae. We took a phylogenomics approach to resolve evolutionary relationships among these five tribes. We sampled the nuclear and plastid genomes via HybSeq target enrichment and genome skimming, and recovered 74 plastid genes and nearly 1000 nuclear loci, known as Conserved Orthologous Sequences. We tested for conflicting support in both data sets and used network analyses to assess patterns of reticulation to explain the early evolutionary history of this lineage, which has experienced whole‐genome duplications and rapid radiations. We found concordance and conflicting support in both data sets and documented four ancient hybridization events. Due to the timing of the early radiation of this five‐tribe lineage, shortly before the Eocene–Oligocene extinction event (34 MYA), early lineages were likely lost, obscuring some details of their early evolutionary history.

25 October 2019 in Applications in Plant Sciences
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Journal Article
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KJKaty E. Jones
Katy E. Jones
TFTomáš Fér
Tomáš Fér
RSRoswitha E. Schmickl
Roswitha E. Schmickl
RDRebecca B. Dikow
Rebecca B. Dikow
VFVicki A. Funk
Vicki A. Funk
JMJennifer Mandel
Jennifer Mandel
Premise: Hybrid capture with high‐throughput sequencing (Hyb‐Seq) is a powerful tool for evolutionary studies. The applicability of an Asteraceae family‐specific Hyb‐Seq probe set and the outcomes of different phylogenetic analyses are investigated here.Methods: Hyb‐Seq data from 112 Asteraceae samples were organized into groups at different taxonomic levels (tribe, genus, and species). For each group, data sets of non‐paralogous loci were built and proportions of parsimony informative characters estimated. The impacts of analyzing alternative data sets, removing long branches, and type of analysis on tree resolution and inferred topologies were investigated in tribe Cichorieae.Results: Alignments of the Asteraceae family‐wide Hyb‐Seq locus set were parsimony informative at all taxonomic levels. Levels of resolution and topologies inferred at shallower nodes differed depending on the locus data set and the type of analysis, and were affected by the presence of long branches.Discussion: The approach used to build a Hyb‐Seq locus data set influenced resolution and topologies inferred in phylogenetic analyses. Removal of long branches improved the reliability of topological inferences in maximum likelihood analyses. The Astereaceae Hyb‐Seq probe set is applicable at multiple taxonomic depths, which demonstrates that probe sets do not necessarily need to be lineage‐specific.

15 November 2018 in Diversity
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SJSusannah Johnson-Fulton
Susannah Johnson-Fulton
LWLinda Watson
Linda Watson
Species of the Cochlospermaceae, a small mostly pantropical plant family, were evaluated at a continental scale for medicinal uses in traditional medicine. This ethnobotanical information was placed in a phylogenetic framework to make informed predictions in the search for new medicines and bioactive compounds. Medicinal plant-use data were mapped onto a molecular phylogeny based on DNA sequences of nuclear and chloroplast markers. Associations of medicinal uses among closely related species occurring in different geographic regions and among diverse cultures were evaluated. The most common medicinal uses for these species are those used to treat skin ailments, gastro-intestinal problems, malaria, and liver issues. The plant species with the most numerous uses is Cochlospermum tinctorium, which occurs primarily in West Africa. Closely related species being used by cultural groups in different geographic regions to treat the same illnesses suggests the presence of bioactive compounds with potential biomedical value, since they may represent independent discoveries of similar medicinally-active compounds. This leads to the speculation that those closely related species not currently being used to treat these ailments may also contain identical or similar medicinally-active compounds and are worthy of laboratory investigations.

23 September 2021 in Plants
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HAHanan Ibrahim Sayed Ahmed
Hanan Ibrahim Sayed Ahmed
ABAbdelfattah Badr
Abdelfattah Badr
HEHanaa H. El-Shazly
Hanaa H. El-Shazly
LWLinda Watson
Linda Watson
Ahmed FouadAhmed Fouad
Ahmed Fouad
FEFaten Y. Ellmouni
Faten Y. Ellmouni
The genus Trifolium is one of the largest genera of the legume family Fabaceae with ca. 255 species. The genus is divided into eight sections; the section Trifolium is a major section of the genus, comprising 73 species mainly distributed in the Mediterranean region. We used nuclear ribosomal DNA internal transcribed spacer (ITS) and morphological variation to reconsider the delimitation and phylogenetic relationships of species in the section Trifolium with reference to chromosomal variations. Bayesian analysis of ITS data delimited the species as three clades based on the analysis of ITS sequence and informative indels in combination with morphological variation. The phylogeny of the species by different analyses methods does not support their current delimitation in 17 subsections. The basic chromosome number x = 8 is the number for the genus Trifolium, from which x = 7, 6 and 5 were derived through successive aneuploidy events. With reference to the distribution of these numbers in the species of the section Trifolium, species in clade III and clade II are more evolved than species in clade I.

1 May 2026 in Applications in Plant Sciences
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Journal Article
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PEPaige Ellestad
Paige Ellestad
EMErika R. Moore‐Pollard
Erika R. Moore‐Pollard
CSCarolina M. Siniscalchi
Carolina M. Siniscalchi
RTRamhari Thapa
Ramhari Thapa
LWLinda Watson
Linda Watson
JMJennifer Mandel
Jennifer Mandel
Premise: Conflicting phylogenetic signals are common in plant phylogenomics and often reflect evolutionary histories shaped by processes like hybridization, incomplete lineage sorting, and whole‐genome duplication (WGD). We aimed to identify and assess these complex processes in the hyper‐diverse family Asteraceae to offer insight into the underlying causes of phylogenetic discordance. Methods: We used new and existing Hyb‐Seq and transcriptome data to explore phylogenetic discordance by testing for nuclear/plastid incongruences, WGD, and reticulation. We present a tutorial detailing the execution of complex bioinformatic analyses to increase transparency, facilitate reproducibility, and support advancements in the field of plant evolution ( https://github.com/erika-r-moore/Ellestad_etal_2025_APPS_Hybridizations ). Results: We uncovered extensive discordance among nuclear gene trees and deep reticulation events, particularly among South American lineages. Signals of WGD were found across the family but were often difficult to interpret, likely due to variation in data completeness, the complexity of the events, and their ancient origins. Discussion: Our study and tutorial, along with a growing body of phylogenomic research, emphasize the role of reticulation and WGD in the evolution of large, diverse clades, while also underscoring the challenges. We anticipate continued advancements in theoretical approaches that will further enhance empirical studies in reticulate evolution.

25 February 2020 in Systematic Botany
Verified
Journal Article
Closed access
LWLinda Watson
Linda Watson