Molecular phylogeny of the Lactuca alliance (Cichorieae subtribe Lactucinae, Asteraceae) with focus on their Chinese centre of diversity detects potential events of reticulation and chloroplast capture

Ze-Huan Wang; Hua Peng; Norbert Kilian

doi:10.1371/journal.pone.0082692

Molecular phylogeny of the Lactuca alliance (Cichorieae subtribe Lactucinae, Asteraceae) with focus on their Chinese centre of diversity detects potential events of reticulation and chloroplast capture

PLoS One. 2013 Dec 20;8(12):e82692. doi: 10.1371/journal.pone.0082692. eCollection 2013.

Authors

Ze-Huan Wang¹, Hua Peng², Norbert Kilian³

Affiliations

¹ Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China ; University of Chinese Academy of Sciences, Beijing, People's Republic of China.
² Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China.
³ Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany.

Abstract

The first comprehensive molecular phylogenetic reconstruction of the Cichorieae subtribe Lactucinae is provided. Sequences for two datasets, one of the nuclear rDNA ITS region, the other of five concatenated non-coding chloroplast DNA markers including the petD region and the psbA-trnH, 5'trnL((UAA))-trnF, rpl32-trnL((UAG)) and trnQ((UUG))-5'rps16 spacers, were, with few exceptions, newly generated for 130 samples of 78 species. The sampling spans the entire subtribe Lactucinae while focusing on its Chinese centre of diversity; more than 3/4 of the Chinese Lactucinae species are represented. The nuclear and plastid phylogenies inferred from the two independent datasets show various hard topological incongruences. They concern the internal topology of major lineages, in one case the placement of taxa in major lineages, the relationships between major lineages and even the circumscription of the subtribe, indicating potential events of ancient as well as of more recent reticulation and chloroplast capture in the evolution of the subtribe. The core of the subtribe is clearly monophyletic, consisting of the six lineages, Cicerbita, Cicerbita II, Lactuca, Melanoseris, Notoseris and Paraprenanthes. The Faberia lineage and the monospecific Prenanthes purpurea lineage are part of a monophyletic subtribe Lactucinae only in the nuclear or plastid phylogeny, respectively. Morphological and karyological support for their placement is considered. In the light of the molecular phylogenetic reconstruction and of additional morphological data, the conflicting taxonomies of the Chinese Lactuca alliance are discussed and it is concluded that the major lineages revealed are best treated at generic rank. An improved species level taxonomy of the Chinese Lactucinae is outlined; new synonymies and some new combinations are provided.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Asteraceae / classification*
Asteraceae / genetics*
Bayes Theorem
China
Chloroplasts / genetics*
Databases, Genetic
Genetic Variation*
Phylogeny*
Plastids / genetics
Polymorphism, Genetic

Grants and funding

The authors thank the German Academic Exchange Service (DAAD, four months’ research stay of the first author at the Botanic Garden and Botanical Museum Berlin-Dahlem (BGBM)) and the Verein der Freunde des BGBM (lab facilities for the second author). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.