Abstract Detail

Systematics Section/ASPT

Shen, Hsien-Hui [1], Chiang, Yu-Chung [1], Liao, Pei-Chun  [2].

Reconstruction the phylogeny and speciation history among species in Section Asiorientales and Stangeroides of Cycads based on multilcous analysis.

The genus Cycas is the ancestral lineage in the seed plant. Within Cycas, the sections Asiorientales and Stangerioide are the basal clade with three and eleven species in the cycad lineage. In the section Asiorientales, there are three species distributed on islands Taiwan, Kyushu, Ryukyu, and mainland China. In section Stangerioide, there are eleven species, including two island species restricted on Hainan Island and nine inland species, with parapatric or allopatric distribution. Recently, reconstruction of the phylogeny and speciation history based on hung sequence data of multilocus is a powerful tool to evaluate the species divergence and coalescence. In this study, we use multilocus methods to evaluate the species divergence, speciation history and coalescence of disjunctive, inter-island, parapatric, or allopatric species of cycad, including 12 species of section Asiorientales and Stangerioide. In the preliminary data, we selected 40 different nuclear genes and direct sequence cycad samples for 12 species belong to section Asiorientales and Stangerioide. Totally, the nucleotide diversity and divergence were ranged from 0.00533 to 0.09156 and 0.00813 to 0.04831. Within section Asiorientales and Stangerioide, the nucleotide diversity was stretched from 0.00309 to 0.02020 and 0.00488 to 0.02990, respectively. Between two sections, average number of nucleotide substitute per site was ranged from 0.00685 to 0.16482. Divergent times are estimated based on the test of isolation-with-migration model and the speciation analysis in Bayesian evolutionary analysis by sampling trees. The genome-wide light of divergence pattern and speciation modes of Cycas section Asiorientales and Stangerioide provide clear resolution for reconstructing the evolutionary history of these Laurasian species.

Broader Impacts:

1 - National Sun Yat-sen University, Department of Biological Sciences, No. 70, Lienhai Road, , Kaohsiung, 80424, Taiwan
2 - National Pingtung University of Science and Technology, Department of Biological Science and Technology, Pingtung, 91201, Taiwan

Keywords:
Cycas
multilocus
Section Asiorientales
Section Stangerioide
speciation history
divergence.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM
Number: PSY049
Abstract ID:555