Return to search

Systematic study on Davalliaceae in Peninsular Malaysia

The results presented in this thesis show moderate to strong support for the paraphyly of genera in Davalliaceae, especially in Peninsular Malaysia. The results were incongruent with the latest classification based on morphology but congruent with a preliminary study based on molecular data. the phylogeny showed that <i>Leucostegia </i>should not be in Davalliaceae. Six clades were recognised in Davalliaceae, namely the <i>Ariaostegia </i>clade (AC); <i>Davallia </i>with four clades: denticulate clade (DC1), dimorpha-divaricata clade (DCII), scyphularia-solida clade (DCIII), trichomanoides clade (DCIV); and the <i>Humata </i>clade (HC). Maximum parsimony and Bayesian analyses of <i>rps4-trnS </i>and combined three regions produced congruent topologies, but the topologies of <i>rbcL </i>and <i>trnL-F </i>produced only slight differences. The combined <i>rbcL</i> data also showed that all species were fully resolved without having a separated/regional clade. In general the molecular phylogenetic reconstruction of Davalliaceae based on <i>trnL-F </i>and <i>rps4-trnS </i>regions showed additional support that no genera in this family are monophyletic. However, the results produced could have been interpreted with more confidence if species from <i>Davallodes </i>(not reported in Peninsular Malaysia) and species from other parts of the world were included in the study. Most genera of Davalliaceae in the study area were characterized by having a single base chromosome number, x = 40, except for <i>Leucostegia </i>which has x = 41. All plants studied were diploids except for <i>Humata vestita </i>which was polyploid (hexaploid). Spores of Davallioid ferns are monolete (ellipsoid) and have verruculate ornamentation. Davalliaceae in Peninsular Malaysia comprises fifteen species in two genera, <i>Araiostegia </i>(1 species) and <i>Davallia </i>(14 species).
Date January 2008
CreatorsKader Maideen, Haja Maideen
PublisherUniversity of Edinburgh
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation

Page generated in 0.0114 seconds