Phylogenetic studies within the Pezizales. I. 18S rRNA sequence data and classification

Abstract

The order Pezizales has been divided into two suborders. One suborder, the Sarcoscyphineae, was originally described to include members whose asci were characterized by an unusual apical structure, the suboperculum. Disagreements as to how this structure should be defined, and indeed, whether or not it exists at all, have rendered the status of the suborder controversial. The two families within this suborder are the Sarcoscyphaceae and the Sarcosomataceae. Recent ultrastructural work demonstrates that there is an apical thickening which is restricted to the Sarcoscyphaceae. In order to test the monophyly of the suborders of the Pezizales and examine the relationships within the Sarcoscyphineae, phylogenetic analyses were carried out using DNA sequence data from the 18S rRNA gene. The strict consensus tree based upon these data shows both the Sarcoscyphineae and the Pezizineae as paraphyletic. These data suggest that the subordinal taxa currently recognized within the Pezizales should be abandoned and the taxonomy revised to reflect phylogenetic relationships. Strongly supported clades (i.e., greater than 95% bootstrap value, 1500 replicates) include: the Pezizaceae, the Morchellaceae, the Sarcoscyphaceae, the Helvellaceae, and a clade that includes the Sarcosomataceae (which is paraphyletic), and the Otidiaceae (represented only by 2 taxa). The genus Pindara, formerly placed in the Sarcoscyphaceae, is nested within the Helvellaceae, and Wynnea, assigned to the Sarcosomataceae by some authors, is positioned in the Sarcoscyphaceae.

Key Words:

• cladistics
• Pezizineae
• Sarcoscyphineae