Original paper

Can molecular systematics provide insights into aspects of the reproductive biology of Trachymene Rudge (Araliaceae)?

Henwood, Murray J.; Lu-Irving, Patricia; Perkins, Andrew J.

Abstract

The phylogenetic relationships of 23 Australian species of Trachymene Rudge plus Uldinia ceratocarpa (W.Fitzg.) N.T.Burb. are estimated using separate and combined analyses of nucleotide sequences derived from the trnT-trnF region of the chloroplast genome and the External Transcribed Spacer (ETS) region of the nuclear genome. Maximum parsimony and Maximum Likelihood analyses produce congruent topologies that resolve a monophyletic Trachymene (inclusive of U. ceratocarpa) comprising four subclades matching the currently recognized infrageneric classification of the genus. A formal synopsis of section Trachymene is provided. The resultant phylogeny is used to provide insights into the evolution of various aspects of the reproductive biology of Trachymene including; palynological characters, life-history attributes and breeding system data. Andromonoecy and a perennial life-history are plesiomorphic in Trachymene. From these we propose the independent origin of a number of different breeding system and life-history attributes. We describe the co-variation of several reproductive character states with each other, and we explore their possible functional significance.

Keywords

trachymeneapialesandromonoecysexual systemsbreeding system