What's new?


Fern PCR and DNA Sequencing Information

This page has links to some protocols and other items that may be useful to anyone using molecular techniques on ferns, including primer sequences and a map for the gene regions rbcL and atpB of the chloroplast.




Results So Far...

1. - Phylogeny. The primary objective of this proposal - to discover a best estimate of phylogenetic relationships for basal leptosporangiate ferns - was not only accomplished, but expanded to ensure representation of all major groups of extant pteridophytes. We designed a data set to include critical basal taxa that were not included in earlier studies and concurrently reduced the number of taxa in the well-supported derived "polypodiaceous" clade. More than 5000 bp from the chloroplast (rbcL, atpB, rps4) and the nuclear (18S rDNA) genomes were sequenced for more than 70 taxa. Morphological characters were completely revised from Pryer et al. 1995 for a congruent data set, taking into account recent pertinent literature. We succeeded in resolving all the phylogenetic questions that we hoped to address with this grant (see publications page). These included: 1) the determination that Osmundaceae is the most basal leptosporangiate family, 2) filmy ferns (Hymenophyllaceae), a large and diverse basal group of mostly epiphytic ferns, form the subsequent most deeply-branching lineage, 3) gleichenioid and dipteroid ferns together with Matonia are a monophyletic basal group and not, as was once thought, a paraphyletic grade of basal ferns, 4) the heterosporous ferns (Marsileaceae and Salviniaceae) are not sister to the more basal schizaeoid or filmy ferns as previously suggested, but rather are sister group to a large clade of derived homosporous ferns that includes tree ferns and the species-rich "polypodiaceous" ferns, 5) the relationships of the enigmatic Hymenophyllopsidaceae and Lophosoriaceae, the only two fern families not included in earlier studies, are now known to be within the tree fern clade, 6) the most derived lineage of ferns including, dennstaedtioid, pteridoid, dryopteridoid, and polypodioid ferns, once thought to be polyphyletic, are now known to be monophyletic. Most importantly, our results allowed us to address one of the most important questions in plant evolution: which group of vascular plants is sister taxon to seed plants? In Pryer et al. (submitted) we have demonstrated that there are three monophyletic groups of extant vascular plants: 1) lycophytes, 2) seed plants, and 3) all non-lycophyte pteridophytes, including equisetophytes (horsetails), "psilotophytes" (whisk ferns), and all eusporangiate and leptosporangiate ferns. We have shown with unequivocal support that horsetails and ferns together are the closest relatives to seed plants, which refutes the prevailing view that they are transitional evolutionary grades between bryophytes and seed plants. We are now proposing a revised classification for ferns and related groups based on our phylogeny (Smith et al., in ms. for Ann. Missouri Bot. Gard.).

2. - Character evolution and species diversification. With a robust phylogeny now in hand, based on both molecular and morphological characters, this study will focus on assessing the evolution of selected homologous characters, especially those that may have been correlated to the radiation and diversification of ferns (work ongoing). Of particular interest to this study are causal interpretations of radiations within ferns, when they occurred, and the events leading up to them. Based on our preliminary interpretations, we can conclude that acceleration in the life cycle of derived leptosporangiate ferns has promoted their diversity and ecological success relative to other groups of plants, in particular, to non-angiospermous seed plants. We also see some evidence that the Cretaceous radiation of angiosperms, which initiated a major reorganization of terrestrial plant communities, resulted in a concurrent diversification of derived leptosporangiate ferns. Our phylogeny indicates that 80% of extant ferns result from this radiation event, with 65% of these being epiphytic on angiosperms.




Visiting Scientists

Dr. Harald Schneider arrived at The Field Museum in January 1999 to take up a position as a postdoctoral research associate collaborating on morphological and molecular phylogenetic studies of basal ferns, as well as the aquatic fern genus Marsilea.

Dr. Jean-Yves DuBuisson, Universite Pierre et Marie Curie, Paris, France, was at The Field Museum in October 1998 to initiate a molecular phylogenetic study of filmy ferns (Hymenophyllaceae) - the largest and most understudied family of the basalmost ferns.




Participation at Meetings in 2000
(Research reported at these meetings supported by DEB-9615533; DEB-9616260; DEB-9707087)

Botany 2000
August 6 - 10, 2000
Oregon Convention Center
Portland, Oregon

    Contributed Papers:
    PRYER, K.M., H. SCHNEIDER, A.R. SMITH, P. G. WOLF, R. C. CRANFILL, J. S. HUNT & S.D. SIPES. 2000. The closest living relative to seed plants: insights from four genes and morphology. American Journal of Botany 87 (Suppl): 151.

    SCHNEIDER,H. & K.M. PRYER, 2000. Spore morphology of heterosporous ferns and its possible implications for understanding the evolution of the seed habit. American Journal of Botany 87 (Suppl): 31-32.


Developmental Genetics and Plant Evolution
September 20-22, 2000
Natural History Museum, London, UK.

    Contributed Paper:
    SCHNEIDER,H., K.M. PRYER, A.R. SMITH, P. G. WOLF, R. C. CRANFILL. 2000. Phylogeny of vascular plants and the evolution of their body plans.




Participation at Meetings in 1999
(Research reported at these meetings supported by DEB-9615533; DEB-9616260; DEB-9707087)

Symposium on the Phylogeny of Green Plants and International Workshop on Advances on the Phylogeny of Bryophytes
Xalapa, Veracruz, Mexico
8-12 March 1999.
Efrain De Luna & Brent D. Mishler, organizers.
Invited symposium paper: K.M. Pryer*, H. Schneider, J.S. Hunt, P.G. Wolf, & A.R. Smith. Basal tracheophytes and the phylogeny of "pteridophyte" lineages.
This public symposium presentation was videotaped and will be distributed as educational material by the Mexican Botanical Society.

The International Botanical Congress (IBC)
St. Louis, MO
1-7 August 1999

General symposium organized by Kathleen M. Pryer and Jean-Yves DuBuisson:
"Fern phylogeny with emphasis on relationships of basal lineages"
K.M. Pryer, H. Schneider, J.S. Hunt, L. Sappelsa, P.G. Wolf, S.D. Sipes, & A.R. Smith. Phylogeny of basal tracheophytes and ferns inferred from four large data sets: morphology, 18S nrDNA, rbcL, and atpB.
J.-Y. Dubuisson, J. S. Hunt, K. M. Pryer, and A. R. Smith. Phylogeny of filmy ferns (Hymenophyllaceae).

Poster Session
J.S. Hunt, K.M. Pryer, A. Vaghani, A.R. Smith, & P.G. Wolf. "Fern DNA Database": Using FileMaker Pro to coordinate DNA availability, DNA sequence data, voucher and source information for large-scale and collaborative phylogenetic studies.

G.M. Moeser, R. Lupia, H. Schneider, K.M. Pryer, and P.R. Crane. Marsileaceae sporocarps and spores from the Late Cretaceous of Georgia, USA.





Participation at Meetings in 1998
(Research reported at these meetings supported by DEB-9615533; DEB-9616260; DEB-9707087)

Green Plant Phylogeny Research Coordination Group
Chicago GPPRCG Fern Mini-Workshop
October 6, 1998
Department of Botany
The Field Museum of Natural History
The Green Plant Phylogeny Research Coordination Group (GPPRCG) sponsored a fern mini-workshop in Chicago on October 6, 1998. A small group of participants working primarily on basal tracheophyte and basal fern relationships was invited. This provided an opportunity for discussions and interactions on topics related to the general goals of the GPPRCG as well as to upcoming meetings. Specific topics addressed included:

  • confirmation of exemplar "pteridophyte" taxa
  • confirmation of morphological and molecular data availability for these exemplar taxa
  • discussion on the importance of databasing and a mechanism to ensure that all members of the GPPRCG fern sub-group have ready access to and can continually upgrade a comprehensive data availability matrix (DAM)
  • areas of future focus for GPPRCG




Participation at Meetings in 1997
(Research reported at these meetings supported by DEB-9615533; DEB-9616260; DEB-9707087)

AIBS Meetings - Montreal 1997

SYMPOSIUM: Relationships and Fossil History of Ferns.
PRYER, K.M., A.R. SMITH, G. ROTHWELL, & P. KENRICK. 1997. Symposium: Relationships and fossil history of ferns. American Journal of Botany 84: 157-158.
WOLF, P.G., K.M. PRYER & J.A. IRWIN. 1997. Multiple gene approaches to fern phylogeny. American Journal of Botany 84: 160.
PRYER, K.M. & A.R. SMITH. 1997. Character evolution and fern phylogeny. American Journal of Botany 84: 159.