Abstract Detail

Systematics

Kim, Seon-Hee [1], Kim, Seung-Chul [2].

New insight into the evolutionary and biogeographic history of golden bells (Forsythia; Oleaceae).

The genus Forsythia comprises of 13 species and is restricted to the temperate region of Eurasia, especially northeastern Asia and eastern Europe. It represents one of the most popular shrubby spring flowers and many wild species and several cultivars are widely cultivated in this region. All but one species, F. europaea, occur in east Asia and the northeastern Asia is considered as the center of diversity. Despite of its horticultural importance, very little is known about phylogenetic relationships among wild species within the genus. In addition, the delimitation of several species is controversial due to highly variable vegetative and reproductive characters. In this study, we sampled all but one species of Forsythia (i.e., total 86 accessions) and sequenced for both nuclear ITS and four chloroplast noncoding regions (rps16-trnQ, rpl32-trnL, rpl32-ndhF, and psbJ-petA). For phylogenetic analysis, we conducted maximum parsimony (MP), maximum likelihood (ML), and Bayesian Inference (BI) analyses. Furthermore, molecular dating using BEAST program was performed to estimate the age of genus Forsythia and major lineages within the genus. The ITS phylogeny is somewhat poorly resolved with weak supports. Nevertheless, it suggests that Abeliophyllum, a monotypic and endemic genus in Korea, and Forsythia are reciprocally monophyletic and two major lineages were identified in genus Forsythia. Non-monophyly of several species is apparent, requiring careful evaluation of their morphological characters. The cpDNA phylogeny based on four combined regions suggested that the species from China diverged first followed by the divergence of two lineages; one lineage with lanceolate-leaved species and other with ovate-leaved species. Although two major lineages within Forsythia correspond to their vegetative and floral morphology, species relationships within each lineage were poorly resolved. The combined analysis of ITS and cpDNA data sets provided somewhat better resolutions than separate analysis. The molecular dating based on the combined data sets suggested that the split between Fontanesieae (Fontanesia) and Forsythieae (Abeliophyllum and Forsythia) occurred during Eocene. However, the crown age of Forsythieae is relatively young (i.e., late Miocene) and subsequent divergence of major lineages within Forsythia occurred recently during the late Miocene and early Pliocene. The results of biogeographic analysis and some species delimitation problems within Forsythia will be presented in detail.

1 - Sungkyunkwan University, Biological Sciences, 2066 Seobu-ro, Suwon, Gyeonggi, 440-746, Korea
2 - Sungkyunkwan University, Biological Sciences, 2066 Seobu-ro, Suwon, 16419, Korea

Keywords:
Oleaceae
Forsythieae
Forsythia
species boundaries.

Presentation Type: Oral Paper
Session: 17, Asterids I part B
Location: 204/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 8:45 AM
Number: 17004
Abstract ID:587
Candidate for Awards:None