XVI International Botanical Congess
To establish a suitable alternative to the widely-used 18S rRNA system for molecular systematics of fungi, we initiated similar studies using a nuclear gene, RPB2, encoding the second-largest subunit of RNA polymerase II. While the RPB2 phylogenetic analyses gave trees similar to those from 18S rDNA sequences, the RPB2 phylogeny has much stronger statistical support for all the branches within the orders and for several branches between orders of the Ascomycota. This study provides a large body of fungal RPB2 sequence data, and the analyses show that such a slowly-evolving structural gene is effective for determining evolutionary relationships amongst fungi. The phylogeny between ascomycetes based on their RPB2 sequences will be presented, and inferences regarding the evolution of morphological characters will be discussed.