Abstract Detail

Pteridology

Sirimalwatta, V.N.S. [1], Morden, C. W. [1], Ranker, T. A. [1], Sundue, M.A. [2], Chen, Chen-Wei [3], Kuo, Li-Yaung [4].

Phylogenetic Relations within the Grammitid ORT Clade (Polypodiaceae).

Grammitids are a monophyletic group of ferns within the family Polypodiaceae. It is a species-rich group with ca. 900 species (nearly a two-thirds of Polypodiaceae) among 33 genera. Species of grammitids are widely distributed in the tropics and subtropics at high elevations. Molecular phylogenetic analyses based on five chloroplast genes have found strong support for the delimitation of many grammitid clades that are recognized as previously identified or newly named genera. However, relationships among Oreogrammitis, Radiogrammitis, and Themelium (the ORT clade), however, have not been clearly resolved. The species of ORT form a large clade where Radiogrammitis and Oreogrammitis species are polyphyletic with respect to each other and Themelium is monophyletic but nested within the larger cladeRadiogrammitis. The current study was conducted to reanalyze the phylogenic relationships among species treated in ORT clade using nuclear genes. We reexamined the phylogeny of species in the ORT clade using a three-nuclear gene character matrix of 2277bp. The genes used in the study were IBR3 Short, PgiC and SQD1a. The genes are presented here as phylogenetic markers for grammitids for the first time. Phylogenetic relationships were inferred among 45 species in the ORT clade (~25% of the total known species diversity) using Maximum Likelihood (ML) and Bayesian Inference. Both ML and Bayesian optimal trees had similar topologies. ML tree had more resolved relationships with low bootstrap support. Overall the Phylogenetic relationships of the most taxa used in this study were resolved. The ingroup consisted of two clades; a small clade with two species of Radiogrammitis (R. havilandii and R. beddomeana) and large clade that included the other ORT species and that continued to show a polyphyletic relationship among genera. The majority of Oreogrammitis species formed sub-clades within the large clade of ORT but no Radiogrammitis sub-clades were resolved. Except for four accessions of Themelium yoderi, the other Themelium species formed a monophyletic group within the large clade of Oreogrammitis and Radiogrammitis. This study provided additional support for the polyphyly of the genera Oreogrammitis, Radiogrammitis, and Themelium. To further resolve the phylogenetic relationships of these closely related species of the ORT clade we are exploring rapidly evolving nuclear genes such as ITS, LEAFY, and additional chloroplast markers.

1 - University of Hawaii at Manoa, Department of Botany, 3190 Maile Way, Room 101, Honolulu, HI, 96822
2 - Pringle Herbarium, Department of Plant Biology, University of Vermont, 27 Colchester Avenue, Burlington, VT, 05405, USA
3 - Taiwan Forestry Research Institute, Taiwan
4 - Boyce Thompson Institute, USA

Keywords:
Grammitids
ORT clade
Monophyletic
Polyphyletic.

Presentation Type: Oral Paper
Session: 6, Pteridological Section/AFS
Location: Sundance 1/Omni Hotel
Date: Monday, June 26th, 2017
Time: 10:00 AM
Number: 6003
Abstract ID:346
Candidate for Awards:George R. Cooley Award