Familial relationships of the monocot order Liliales based on a molecular phylogenetic analysis using four plastid loci: matK, rbcL, atpB and atpF-H

Abstract

Many molecular studies have shown the monocot order Liliales to be well supported; morphologically, it is defined by synapomorphies of tepalar nectaries and extrorse anthers, in contrast with septal nectaries and introrse anthers commonly found in other monocots, especially Asparagales, with which it was often confused in the past. It comprises c. 1500 species, 67 genera and 911 families. Although monophyly is clear, the phylogenetic relationships among some of the families are still unclear. In this study, we examine the inter- and infrafamilial relationships among Liliales in phylogenetic analyses based on four plastid loci (matK, rbcL, atpB and atpF-H). We performed phylogenetic analyses and constructed maximum parsimony and Bayesian trees for 49 genera and 148 taxa in ten families of Liliales sensuAngiosperm Phylogeny Group (APG) III using the combined DNA data. The monophyly of Liliales, except for Corsiaceae (Arachnitis), was strongly supported by both analyses. Campynemataceae were sister to the rest of the order, excluding Corsiaceae. The other families formed two well-defined clades, (Colchicaceae+Alstroemeriaceae) and (Liliaceae, Smilacaceae, (Rhipogonaceae+Philesiaceae)), and one weakly supported clade with Melanthiaceae and Petermanniaceae. Subfamilial and tribal circumscriptions for the three larger families, Colchicaceae, Melanthiaceae and Liliaceae, agreed well with the results of this study, except for the subfamily Calochortoideae of Liliaceae, which was split into two separate clades of Calochortus and Tricyrtis. In addition, we found several taxa with a 10-bp inversion in matK, which could contribute additional homoplasy to these analyses if included without re-coding. Phylogenetic relationships among families of Liliales were better defined here than in a previous molecular analysis, although the placement of Corsiaceae with plastid data remains problematic. Based on these results, reconsideration of the circumscriptions of Rhipogonaceae+Philesiaceae and the subfamilial circumscription for Calochortoideae of Liliaceae is suggested.(c) 2013 The Linnean Society of London