Abstract Detail



Systematics

Cho, Myong-suk [1], Mejías, José A. [2], Kim, Seung-Chul [1].

Phylogenomic data shed new light on the phylogeny of the subtribe Hyoseridinae (Asteraceae), with special emphasis on the origin of the woody Sonchus alliance in the Canary Islands.

The subtribe Hyoseridinae as recently circumscribed includes five genera, Aposeris, Hyoseris, Launaea, Reichardia, and Sonchus sensu lato. New circumscription is the result of extensive molecular phylogenetic analyses that revealed: i) the need of merging subtribes Sonchinae (a group of about 130 species arranged in 11 genera, many of which are endemic to Macaronesian Islands, forming the woody Sonchus alliance) and Dendroseridinae (which includes 12 species in the genera Dendroseris and Thamnoseris, endemic to the Pacific Juan Fernandez and Desventuradas Islands) sensu Bremer; and ii) that Aposeris and Hyoseris (formerly within the Hypochaeridinae sensu Bremer) had to be included in the Sonchinae, which was renamed as Hyoseridinae. These studies also recommended establishing a broad generic concept of Sonchus, including several species-poor or monotypic genera in the Canary Islands (Chrysoprenanthes, Babcockia, Lactucosonchus, Sventenia, Taekholmia, and Wildpretia) or Australia/New Zealand (Actites, Embergeria, and Kirkianalla). Despite such taxonomic efforts, precise phylogenetic relationships among major lineages remain poorly understood, especially for the origin and evolution of the woody Sonchus alliance in Macaronesia. In this study, we sequenced the complete chloroplast (cp) genomes of primarily Sonchinae (Launaea, Reichardia, and Sonchus s.l.) and Dendroseridinae (Dendroseris) sensu Bremer and determined phylogenetic relationships among major groups based on two outgroup genera (Taraxacum and Lactuca) and 27 ingroup taxa. Maximum likelihood tree fully resolved with strong supports, except for weedy species of Sonchus (i.e., S. asper and S. oleraceus). Our results suggest that two genera, Reichardia and Launaea, diverged first and are distantly related to the remaining members within the subtribe. However, unlike previously known nuclear phylogeny, the woody Sonchus alliance from the Macaronesian Islands diverged early within Sonchus s.l., followed by formerly Dendroseris from Juan Fernandez Islands. S. bulbosus (formerly monotypic genus Aetheorhiza) is closely related to Sonchus section Pustulati in western Mediterranean/North Africa. The recently described Sonchus section Pulvinati (S. boulosii) shares the most common ancestor with endemic species in Australia and New Zealand. The early divergence of the woody Sonchus alliance and Dendroseris may not necessarily suggest that they are ancestral to continental herbaceous and weedy lineages. Rather, it is likely that herbaceous common ancestor of Sonchus s.l. in the Mediterranean region split into two lineages, one giving rise to insular endemic woody lineage and the other responsible for remaining continental suffrutescent/herbaceous lineages. Our current new cp genome phylogeny provides new interesting relationships and some biogeographic implications.


1 - Sungkyunkwan University, Department of Biological Sciences, Seobu-ro 2066, Janan-ku, Suwon-si, Gyeonggi-do, 16419, Republic of Korea
2 - Universidad de Sevilla, Department of Plant Biology and Ecology, Seville, Spain

Keywords:
Hyoseridinae
the woody Sonchus alliance 
The complete cp genome phylogeny 
Sonchus sensu lato
Sonchinae sensu Bremer 
Dendroseridinae sensu Bremer.

Presentation Type: Poster This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PSY012
Abstract ID:338
Candidate for Awards:None


Copyright © 2000-2019, Botanical Society of America. All rights reserved