HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Henk, D. A. Articles by Vilgalys, R. Search for Related Content PubMed Articles by Henk, D. A. Articles by Vilgalys, R. Agricola Articles by Henk, D. A. Articles by Vilgalys, R.

Molecular phylogeny suggests a single origin of insect symbiosis in the Pucciniomycetes with support for some relationships within the genus Septobasidium¹

²10300 Baltimore Avenue, Room 304, Building 011A, Beltsville, Maryland 20705 USA; ³Box 90338, Department of Biology, Duke University, Durham, North Carolina 27708 USA

ABSTRACT

In the Pucciniomycetes, a class of fungi that includes the plant pathogenic rust fungi, insect parasitism is restricted to a single family, the Septobasidiaceae. The Septobasidiaceae form a variety of symbioses with scale insects and have remained largely unstudied since the 1930s. Transitions between plant and animal parasitism and between mutualism and parasitism cannot be fully addressed in the Basidiomycota without a clear phylogenetic hypothesis for the Septobasidiales. Here, molecular phylogenetic methods were applied to understand the origin of scale insect parasitism, test the monophyly of the order Septobasidiales, and evaluate the infrageneric concepts in the largest genus of scale insect parasites, Septobasidium. DNA sequence data from rRNA genes were used to infer higher-level relationships within the Pucciniomycetes, and data from translation elongation factor 1-alpha (tef1) were added for phylogenetic inference within the Septobasidiaceae. Data from tef1 revealed different intron arrangements within Septobasidium, but the molecule did not provide much additional phylogenetically informative data. Likelihood-model-based phylogenetic analyses of 44 Pucciniomycotina taxa provided moderate support for a single origin of insect parasitism. Within the Septobasidiaceae, there was little or no support for a monophyletic Septobasidium, and well-resolved subclades of Septobasidium species contradict previous morphological delimitations of groups within the genus.

Key Words: Auriculoscypha • Coccoidea • mutualism • parasitism • Pucciniomycetes • rDNA • scale insect • tef1 • Uredinella