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.