Abstract Detail

Systematics Section / ASPT

Samuel, Rosabelle [1], Stuessy, Tod F. [1], Gutermann, Walter [1], Zidorn, Christian [2], Hermanowski, Barbara [1], Ehrendorfer, Friedrich [1].

Nuclear and plastid DNA sequences suggest generic segregation of subgenus Oporinia from Leontodon (Asteraceae, Lactuceae).

Nuclear ITS and plastid, matK, trnL intron, trnL /F spacer sequences suggest that Leontodon in its present circumscription is paraphyletic. It belongs to the well supported major clade of Lactuceae-Hypochaeridinae which consists of two subclades, one including Leontodon subg. Oporinia, and the other subg. Leontodon with Hypochaeris as sister. Subgenus Leontodon, in turn, can be divided with strong support into sect. Leontodon and sect. Thrincia, the latter being sister to the closely related genera Picris and Helminthotheca. In general, infrageneric classification of Leontodon is not only supported by molecular data, but also by patterns of chromosomal differentiation and epidermal hair characters. Sesquiterpenoids are also reliable phytochemical markers for delimiting sections of Leontodon, with hypocretenolides restricted to section Leontodon and lactucin-type compounds to subgenus Oporinia. All these data recommend the re-establishment of Oporinia as a distinct genus. The relationships of Picris and Helminthotheca to subgenus Leontodon, however, require further analysis.

1 - University of Vienna, Institute for Botany, Dept. of Higher Plant Systematics and Evolution, Rennweg 14, Vienna, A-1030, Austria
2 - Institute of Pharmacy, Dept. of Pharmacognosy, University of Innsbruck, Innsbruck, A 6020, Austria

Keywords:
Leontodon
Asteraceae
ITS
matK
trnL/F
Oporinia.

Presentation Type: Paper
Session: 3-7
Location: Cottonwood B (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 9:30 AM
Abstract ID:169