Abstract Detail

Systematics Section

Fritsch, Peter W. [1], Lu, Lu [2], Cruz, Boni C. [1], Wang, Hong [2], Li, De-Zhu [2].

Reticulate evolution, cryptic species and character convergence in the core East Asian clade of Gaultheria (Ericaceae).

The core East Asian clade of Gaultheria (Angiospermae: Ericaceae: Gaultherieae) occurs from the Sino-Himalaya and southern Hengduan Shan south to Sri Lanka, Indochina, and Malesia. Phylogenetic relationships of 84 samples representing 30 (of ca. 50) species in this clade were estimated with separate and combined DNA sequence data from five genic regions (nuclear ITS and chloroplast matK, rpl16, trnL-trnF, and trnS-trnG). Two major clades were recovered, one with leaves generally more than 1 cm long (ser. Leucothoides sensu lato), the other with leaves generally less than 1 cm long (ser. Trichophyllae). The ITS region yielded little phylogenetic resolution, whereas in the combined chloroplast analysis multiple samples from individual species in both clades often did not group together. In ser. Leucothoides s.l. this was postulated to result from reticulate evolution, particularly in two specific cases of hybridization and in a crown clade with likely chloroplast capture following localized introgression. In ser. Trichophyllae, such nonmonophyly was at least partly attributable to cryptic species and character convergence resulting from morphological reduction in high-alpine environments. In light of our molecular results, morphological reassessment supports the recognition of 17 species in ser. Trichophyllae, seven of which are new. As in other Sino-Himalayan plant groups, low overall sequence divergence and reticulate evolution among the Sino-Himalayan species of Gaultheria suggest rapid diversification.

Broader Impacts:

1 - California Academy of Sciences, Department of Botany, 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA, 94118-4503, USA
2 - Kunming Institute of Botany, Chinese Academy of Sciences, Key Laboratory of Biodiversity and Biogeography, Kunming, Yunnan, 650204, China

Keywords:
cryptic species
convergent evolution
Ericaceae
Gaultheria
Gaultherieae
reticulate evolution
Sino-Himalaya.

Presentation Type: Oral Paper:Papers for Sections
Session: 49
Location: 552B/Convention Center
Date: Wednesday, August 4th, 2010
Time: 11:30 AM
Number: 49015
Abstract ID:215