Abstract Detail

Systematics Section

Triplett, Jimmy K. [1], Clark, Lynn G. [2], Wen, Jun [3], Peterson, Paul M. [4], Li, De-Zhu [5].

Reticulate evolution in the temperate bamboos (Poaceae: Bambusoideae: Arundinarieae): evidence from low-copy nuclear gene sequences.

The temperate bamboos are a highly heterogeneous clade, with little agreement between current morphology-based taxonomy and molecular phylogenies. Recently, several lines of evidence have suggested that hybridization is an underlying cause of incongruence (a surprising result given the long flowering cycles in these plants), and intergeneric hybrids have been discovered among divergent but sympatric lineages. For example, hybridization among Phyllostachys, Pleioblastus, and Sasa in Japan produced the taxa currently classified as Hibanobambusa, Sasaella, and Semiarundinaria. In the current investigation, low-copy nuclear genes (including an endo-1,4-β glucanase and a poly-A binding protein) were used to reconstruct phylogenetic relationships in this clade. A broad survey of nuclear loci revealed two distinct classes of sequences (A and B) for any given gene, consistent with an allotetraploid origin for the clade, while four distinct sequence types (A₁, A₂, B₁, B₂) were recovered for some taxa, consistent with subsequent hybridization among divergent allotetraploids. Among numerous examples, Pseudosasa japonica was apparently derived via hybridization between Pleioblastus and Sasamorpha, while Sasaella sawadai was derived from Pleioblastus and Sasa. This new evidence, combined with recent studies using cpDNA and AFLPs, suggests that reticulate evolution has played an important and recurrent role in the diversification of the temperate bamboos.

Broader Impacts:

1 - Smithsonian Institution, Dept. of Botany, Mrc-166, National Museum of Natural History, Washington, DC, 20013-7012, USA
2 - Iowa State University, Department of Ecology, Evolution & Organismal Biology, 253 Bessey Hall, Ames, Iowa, 50011-1020, USA
3 - Smithsonian Institution, Department of Botany MRC 166, National Museum Of Natural History, Po Box 37012, Washington, DC, 20560-0166, USA
4 - Smithsonian, Department of Botany, National Museum of Natural History, P.O. Box 37012, Washington, DC, 20013, USA
5 - Kunming Institute of Botany, Chinese Academy of Sciences, Key Laboratory of Biodiversity and Biogeography, Kunming, Yunnan, 650204, China

Keywords:
Poaceae
low-copy nuclear gene
Bamboo phylogeny
intergeneric hybridization
Allopolyploidy.

Presentation Type: Oral Paper:Papers for Sections
Session: 26
Location: 556B/Convention Center
Date: Tuesday, August 3rd, 2010
Time: 8:30 AM
Number: 26003
Abstract ID:657