Nuclear rDNA phylogeny of the Sclerotiniaceae

Abstract

Recent comparative studies of morphology and developmental proteins of stromatal anamorphs suggest that the sclerotial and the substratal stromatal taxa represent two distinct lineages within the Sclerotiniaceae, a family of plant-infecting discomycetes (Leotiales). We have studied thirty-one taxa, representing 20 genera and one form genus currently placed in the Sclerotiniaceae along with three outgroup taxa. Analyses of nuclear rRNA gene sequences, including ca. 575 basepairs from the small subunit rDNA, ca. 500 basepairs from the ITS and 5.8S rDNA, and ca. 370 basepairs from the large subunit rDNA were used to infer evolutionary relationships within the family. The inferred rDNA phylogeny supports and refines the two lineage hypothesis. The sclerotial stromatal lineage representing genera of the revised, restricted concept of Sclerotiniaceae includes Botryotinia, Ciboria, Ciborinia, Coprotinia, Dumontinia, Encoelia, Grovesinia, Monilinia, Myriosclerotinia, Ovulinia, Pycnopeziza, Sclerotinia, Stromatinia, and Valdensinia. The substratal stromatal lineage includes Lambertella, Lanzia, Poculum, Rutstroemia, and Verpatinia, and are accommodated in the new family Rutstroemiaceae. The taxa Gloeotinia, Lambertella langei, Piceomphale, and Chlorociboria are excluded from the two families on the basis of nrDNA data.