Joongku Lee

University of California, Berkeley, Berkeley, California, United States

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Publications (4)5.21 Total impact

  • Source
    V S Ford · Joongku Lee · B G Baldwin · L D Gottlieb
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    ABSTRACT: We present a maximum likelihood tree of 41 PgiC sequences for the monophyletic Stephanomeria, with 10 perennial and six annual species, widely distributed in western North America and exemplary of different speciation processes. The phylogenetic analysis represents the first use of PgiC sequences for Compositae. The annual species were originally delimited by biosystematic studies that provided evidence of their reproductive compatibility and chromosome structural homology. The perennial species are highly distinctive in morphology and have not been examined similarly. The PgiC tree provides more resolution than our previous ITS/ETS tree and reflects both past and ongoing hybridization and/or incomplete lineage sorting. Two major PgiC clades were resolved in Stephanomeria. One clade contains the genes from the annual species plus the perennial, insular endemic S. guadalupensis, which appears closely related to a monophyletic S. virgata. Stephanomeria exigua is not monophyletic. The second clade includes the genes from all other sampled perennial species and a monophyletic subclade of four genes from two annual species. The results are compared to previous studies, also using PgiC, of Clarkia (Onagraceae). Both molecular systematic and biosystematic approaches are essential to discern the very different courses of evolution in these two, well-studied genera of western North America.
    Preview · Article · Mar 2006 · American Journal of Botany
  • Joongku Lee · Bruce G. Baldwin · L. D. Gottlieb
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    ABSTRACT: Phylogenetic analyses of internal transcribed spacer (ITS), external transcribed spacer (ETS), and 5.8S gene sequences of 18S–26S nuclear rDNA from all 23 genera of Cichorieae with centers of diversity in North America (and Picrosia from South America) show that all but three of the genera (Glyptopleura, Krigia, and Phalacroseris) belong to a series of seven clades that are well supported by bootstrap values >90%. Phalacroseris, endemic to California, with a single species (P. bolanderi), is sister to a well-supported (>95% bootstrap) clade that includes all other principally North American genera (plus Picrosia). The seven clades with major support and their component genera are: 1) the Lygodesmia Clade: Chaetadelpha, Lygodesmia, and Shinnersoseris; 2) the Pinaropappus Clade: Marshalljohnstonia and Pinaropappus; 3) the Pyrrhopappus Clade: Picrosia and Pyrrhopappus; 4) the Microseris Clade: Agoseris, Microseris, Nothocalais, Stebbinsoseris, and Uropappus; 5) the Stephanomeria Clade: Munzothamnus, Pleiacanthus, Prenanthella, Rafinesquia, and Stephanomeria; 6) the Malacothrix 1 Clade: Atrichoseris and various species of Malacothrix; and 7) the Malacothrix 2 Clade: Anisocoma, Calycoseris, and various other species of Malacothrix. The rDNA sequence data provide < 80% bootstrap support for other, larger groups that combine two or more of the seven major clades, except for one uniting all 24 ingroup genera and one uniting the Lygodesmia Clade and Pyrrhopappus Clade. The present analysis shows that Malacothrix, a genus of 22 species, is not monophyletic. None of the clades corresponds precisely to a suprageneric taxon of Cichorieae proposed previously, although taxa constituting each clade belong to a common subtribe or subgroup in classifications by Bremer, Jeffrey, and Stebbins, with two to three exceptions. As a group, the 24 genera represent a single, major radiation of Cichorieae based in North America.
    No preview · Article · Jul 2003
  • Source
    Joongku Lee · Bruce G Baldwin · L D Gottlieb
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    ABSTRACT: A phylogenetic analysis of DNA sequences from the internal transcribed spacer (ITS), the external transcribed spacer (ETS), and the 5.8S regions of 18S-26S nuclear rDNA from all diploid species of Stephanomeria and related genera shows that Stephanomeria does not include either Munzothamnus blairii (previously S. blairii) or Pleiacanthus spinosus (previously S. spinosa). Without these two taxa, Stephanomeria is a well-supported (100% bootstrap), monophyletic group of ten perennial and six annual species. Munzothamnus blairii and Pleiacanthus spinosus, both now considered members of monotypic genera, had been placed in Stephanomeria primarily because they have the same chromosome number as Stephanomeria and similar pollen surface features, but many disparities were ignored in previous classifications. Within Stephanomeria, an unsuspected sister relationship was detected between the montane S. lactucina and coastal S. cichoriacea. A second clade contained all the annual taxa and five of the perennial species. Among the annuals, strong bootstrap support was obtained for the previously recognized relationships between S. diegensis and S. exigua (98%) and between S. malheurensis and its progenitor, S. exigua subsp. coronaria (96%). Among the five perennial species that constitute a clade with the annuals, the recently described S. fluminea was shown to be sister to S. runcinata, and both of them were closely allied to S. tenuifolia and S. thurberi. The clade including the annuals (and five of the perennial species) was subtended by perennial lineages and pairwise divergence values among the annual taxa were much lower than among the perennial taxa as a group (though not too different than among the perennials in the same clade). The annuals probably originated recently within the genus.
    Preview · Article · Jan 2002 · American Journal of Botany
  • V. S. FORD · JOONGKU LEE · B. G. BALDWIN · L. D. GOTTLIEB
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a maximum likelihood tree of 41 PgiC sequences for the monophyletic Stephanomeria, with 10 perennial and six annual species, widely distributed in western North America and exemplary of different speciation processes. The phylogenetic analysis represents the first use of PgiC sequences for Compositae. The annual species were originally delimited by biosystematic studies that provided evidence of their reproductive compatibility and chromosome structural homology. The perennial species are highly distinctive in morphology and have not been examined similarly. The PgiC tree provides more resolution than our previous ITS/ETS tree and reflects both past and ongoing hybridization and/or incomplete lineage sorting. Two major PgiC clades were resolved in Stephanomeria. One clade contains the genes from the annual species plus the perennial, insular endemic S. guadalupensis, which appears closely related to a monophyletic S. virgata. Stephanomeria exigua is not monophyletic. The second clade includes the genes from all other sampled perennial species and a monophyletic subclade of four genes from two annual species. The results are compared to previous studies, also using PgiC ,o fClarkia (Onagraceae). Both molecular systematic and biosystematic approaches are essential to discern the very different courses of evolution in these two, well-studied genera of western North America.
    No preview · Article ·

Publication Stats

62 Citations
5.21 Total Impact Points

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Institutions

  • 2002-2003
    • University of California, Berkeley
      • Department of Integrative Biology
      Berkeley, California, United States