Please use this identifier to cite or link to this item:
Type: Thesis
Title: Molecular systematics of the Lomandra Labill. Complex (Asparagales: Laxmanniaceae).
Author: Donnon, Matthew J.
Issue Date: 2010
School/Discipline: School of Earth and Environmental Sciences
Abstract: The “Lomandra complex” (or Lomandra grouping) is an informally recognised grade resulting from the subdivision of the Laxmanniaceae into two groups (Conran, 1998); the ‘Lomandra complex” (Acanthocarpus, Chamaexeros, Lomandra, Romnalda and Xerolirion), and the remainder as the Arthropodoids (Arthropodium, Chamaescilla, Cordyline, Eustrephus, Laxmannia, Murchisonia, Sowerbaea, Thysanotus and Trichopetalum). Laxmanniaceae are an Australiacentred, tropical to temperate family of 14 genera with around 180 species from Australasia, SE Asia, the Mascarenes, New Caledonia, New Guinea, New Zealand, North and South America and the Pacific Islands. There have been no detailed phylogenetic studies in Laxmanniaceae and the relationships within and between the genera is poorly understood. This study utilised molecular data from chloroplast trnL-F and nuclear ribosomal ITS2 regions analysed with maximum parsimony and bayesian inference methods to reconstruct the phylogeny of the genera of the ‘Lomandra complex’, using species of Arthropodium, Eustrephus, Laxmannia and Thysanotus as outgroups. The molecular phylogeny shows that Lomandra forms four primary clades; with members from the classical anatomy, inflorescence-defined section and series distributed amongst these, typically in large islands. The monotypic genus Xerolirion resides deeply within Lomandra, raising questions about the appropriateness of this genus. Additionally, the other genera of the Lomandra complex (Acanthocarpus, Chamaexeros and Romnalda) form a clade positioned sister to one of four primary Lomandra clades, but nested inside Lomandra sens. lat., indicating a closer relationship between these genera than previously thought. The affiliation of these bisexual, hermaphroditic genera within the otherwise unisexual, dioecious Lomandra clade supports the recognition of the ‘Lomandra complex’ as an expanded genus, Lomandra; and represents either an example of the evolution of unisexuality followed by reversion, or else multiple losses of hermaphrodite flowers. Morphological and anatomical data were obtained for leaf and floral macroscopic characters, mid-leaf section anatomy and cuticle microscopic features and analysed with maximum parsimony and bayesian inference methods to reconstruct the anatomical phylogeny. These data were also utilised to generate a DELTA key for identifying species of Lomandra from a combination of macroscopic morphological and microscopic leaf anatomical features.
Advisor: Conran, John Godfrey
Hill, Bob
Dissertation Note: Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2010
Keywords: Lomandra; Molecular systematic; ITS, trnL; PAUP*; MrBayes; Leaf anatomy; Inflorescence anatomy
Provenance: Copyright material removed from digital thesis. See print copy in University of Adelaide Library for full text.
Appears in Collections:Research Theses

Files in This Item:
File Description SizeFormat 
01front.pdf33.82 kBAdobe PDFView/Open
02chapters1-2.pdf2.85 MBAdobe PDFView/Open
03chapter3.pdf3.79 MBAdobe PDFView/Open
04chapters4-6.pdf1.34 MBAdobe PDFView/Open
05appendixA-PartA.pdf3.33 MBAdobe PDFView/Open
06appendixA-PartB.pdf3.15 MBAdobe PDFView/Open
07appendixA-PartC.pdf3.23 MBAdobe PDFView/Open
08appendixA-PartD.pdf3.25 MBAdobe PDFView/Open
09appendixB-C.pdf202.91 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.