Bryophytes and Evolution

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Bryophytes and Evolution

• John Wiley
• Winter 2008
• Plant Speciation and Evolution

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Tree of Plant Life

• Evolved from green algae
• Embryophytes
• Divergence unclear
• Earliest land plants
• Ordovician liverwort spores (Welleman et al.
  2003)
• Not thought have given rise to vascular plants
  (Qui Palmer 1999)

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Bryophytes

• Common characters (Shaw Renzaglia 2004)
• Dominant form gametophyte
• Sporophyte dependant on gametophyte
• Generally nonvascular
• Generally unistratose
• Small size
• Unique sporophyte characters

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Morphology

• Mosses
• Acrocarpus vs. Pleurocarpus
• Main parts (gametophyte)
• Rhizoids
• Stem
• Branches
• Leaves
• Exceptions

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Morphology

• Mosses
• Main parts (sporophyte)
• Seta
• Capsule
• Calyptra

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Morphology

• Liverworts
• Thalloid
• Simple
• Complex
• Leafy

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Morphology

• Hornworts
• Thalloid
• Single large chloroplast
• Sporophyte
• Long and narrow
• Splits lengthwise
• Indeterminate growth

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Selection
Taylor, et al. 2007.

• Since the dominant life form of bryophytes is
  haploid selective processes act directly on the
  genotype of and individual
• In monoecious species, high levels of inbreeding
  rapidly eliminate deleterious alleles
• In dioecious species, outcrossing can lead to a
  masking of deleterious alleles in diploid
  sporophytes
• Inbreeding depression

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Bryophyte Phylogenies

• Active area of research
• Share 66 of gametophyte genes with vascular
  sporophytes (Shaw and Renzaglia 2004)
• Ordovician
• Liverwort spores (Wellman 2003)
• Lack of macrofossils, unclear divergence
• Must look at highly conserved regions for
  examining long time periods

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Bryophyte Phylogenies

• Mitochondrial DNA introns (Dombrovska and Qiu
  2004, Groth-Malonek 2005)
• Liverworts share no introns
• Mosses and hornworts share introns
• Hornworts also have unique introns

Protein
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Bryophyte Phylogenies

• Mosses (Cox, et al. 2004)
• Presence and type of peristome define clades
• Acrocarps paraphyletic
• Pleurocarps monophyletic
• Liverworts (Crandall-Stotler, et al. 2005)
• Simple forms basal
• Complex and Leafy types diverged independently
• Hornworts(Goffinet 2000)
• Sister group to vascular plants
• Indeterminate growth of sporophyte

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Bryophyte Phylogenies
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Works Cited

• Buck, W. R., and B. Goffinet. 2000. Morphology
  and clossification of mosses. Pages 71-123 in A.
  J. Shaw and B. Goffinet, editors. Bryophyte
  Biology. Cambridge University Press, Cambridge.
• Cox, C. J., B. Goffinet, A. J. Shaw, and S. B.
  Boles. 2004. Phylogenetic relationships among the
  mosses based on heterogeneous Bayesian analysis
  of multiple genes from multiple genomic
  compartments. Systematic Botany 29234-250.
• Crandall-Stotler, B. J., L. L. Forrest, and R. E.
  Stotler. 2005. Evolutionary trends in the simple
  thalloid liverworts (Marchantiophyta,
  Jungermanniopsida subclass Metzgeriidae). Taxon
  54299-316.
• Davis, E. C. 2004. A molecular phylogeny of leafy
  liverworts (Jungermanniidae Marchantiophyta).
  Pages 61-86 in B. Goffinet, V. Hollowell, and R.
  Magill, editors. Molecular Systematics of
  bryophytes. Missouri Botanical Garden Press, St.
  Louis, Missouri.
• Dombrovska, O., and Y. L. Qiu. 2004. Distribution
  of introns in the mitochondrial gene nad1 in land
  plants phylogenetic and molecular evolutionary
  implications. Molecular Phylogenetics and
  Evolution 32246-263.
• Forrest, L. L., and B. J. Crandall-Stotler. 2004.
  A phylogeny of the simple thalloid liverworts
  (Jungermanniopsida, Metzgeriidae) as inferred
  from five chloroplast genes. Pages 119-140 in B.
  Goffinet, V. Hollowell, and R. Magill, editors.
  Molecular systematics of bryophytes. Missouri
  Botanical Garden Press, St. Louis, Missouri.
• Goffinet, B. 2000. Origin and phylogenetic
  relationships of bryophytes. Pages 124-149 in A.
  J. Shaw and B. Goffinet, editors. Bryophyte
  biology. Cambridge University Press, Cambridge.
• Groth-Malonek, M., and V. Knoop. 2005. Bryophytes
  and other basal land plants the mitochondrial
  perspective. Taxon 54293-297.
• Groth-Malonek, M., D. Pruchner, F. Grewe, and V.
  Knoop. 2005. Ancestors of trans-splicing
  mitochondrial introns support serial sister group
  relationships of hornworts and mosses with
  vascular plants. Molecular Biology and Evolution
  22117-125.
• He-Nygren, X., A. Juslen, I. Ahonen, D. Glenny,
  and S. Piippo. 2006. Illuminating the
  evolutionary history of liverworts
  (Marchantiophyta) - Towards a natural
  classification. Cladistics 221-31.
• Qiu, Y. L., and J. D. Palmer. 1999. Phylogeny of
  early land plants insights from genes and
  genomes. Trends in Plant Science 426-30.
• Shaw, J., and K. Renzaglia. 2004. Phylogeny and
  diversification of bryophytes. American Journal
  of Botany 911557-1581.
• Taylor, P. J., S. M. Eppley, and L. K. Jesson.
  2007. Sporophytic inbreeding depression in mosses
  occurs in a species with separate sexes but not
  in a species with combined sexes. American
  Journal of Botany 941853-1859.
• Wellman, C. H., P. L. Osterloff, and U.
  Mohiuddin. 2003. Fragments of the earliest land
  plants. Nature 425282-285.