Taxonomic classification of an endemic Bermudian fern, using molecular and morphological data
Advisor Information
Roxanne Kellar
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
6-3-2015 9:00 AM
End Date
6-3-2015 10:30 AM
Abstract
Diplazium is a genus in the Athyriaceae family of ferns. One specimen of Diplazium laffanianum wascollected in Bermuda in 1905, and this species is believed to be endemic to Bermuda. Because fewindividuals remain, it is not very well studied. In this study, I used morphological and molecularmethodology to determine the exact taxonomic placement of this species. The government of Bermudawants to know if Diplazium laffanianum (D. laffanianum) should remain its own species and if so, what isits phylogenetic placement. Diplazium is an immense and diverse genus. In order to properly place thisfern into its correct family, phylogenetic and morphological analysis was completed. Nucleotidesequences from six plastid markers (atpA, atpB, matK, rbcL, rps4-trnS, and trnL-F) were used toconstruct a phylogenetic tree for D. laffanianum. Upon completion of the tree, D. laffanianum fell sister toDiplazium cristatum which is found in Mexico, the Caribbean, and South America. From review of thephylogenetic tree, I borrowed several herbarium specimens of D. laffanianum, Diplazium cristatum,Diplazium plantaginifolium, and Diplazium bombonasae. All these species were in the same clade as D.laffanianum. With these samples, I investigated 20 different morphological characteristics of Diplaziumand developed a character matrix which included a wide range of descriptors such as color, size, andother metrics. With this information, I was able to determine that D. laffanianum is its own distinct speciesand it can now be properly protected.
Taxonomic classification of an endemic Bermudian fern, using molecular and morphological data
Dr. C.C. and Mabel L. Criss Library
Diplazium is a genus in the Athyriaceae family of ferns. One specimen of Diplazium laffanianum wascollected in Bermuda in 1905, and this species is believed to be endemic to Bermuda. Because fewindividuals remain, it is not very well studied. In this study, I used morphological and molecularmethodology to determine the exact taxonomic placement of this species. The government of Bermudawants to know if Diplazium laffanianum (D. laffanianum) should remain its own species and if so, what isits phylogenetic placement. Diplazium is an immense and diverse genus. In order to properly place thisfern into its correct family, phylogenetic and morphological analysis was completed. Nucleotidesequences from six plastid markers (atpA, atpB, matK, rbcL, rps4-trnS, and trnL-F) were used toconstruct a phylogenetic tree for D. laffanianum. Upon completion of the tree, D. laffanianum fell sister toDiplazium cristatum which is found in Mexico, the Caribbean, and South America. From review of thephylogenetic tree, I borrowed several herbarium specimens of D. laffanianum, Diplazium cristatum,Diplazium plantaginifolium, and Diplazium bombonasae. All these species were in the same clade as D.laffanianum. With these samples, I investigated 20 different morphological characteristics of Diplaziumand developed a character matrix which included a wide range of descriptors such as color, size, andother metrics. With this information, I was able to determine that D. laffanianum is its own distinct speciesand it can now be properly protected.