PHYLOGENETIC STUDIES OF THE LEPTOSPHAERIACEAE, PLEOSPORACEAE AND SOMEOTHER LOCULOASCOMYCETES BASED ON NUCLEAR RIBOSOMAL DNA-SEQUENCES

Eleven cultures representing eight genera of five families of Loculoas comycetes were obtained from ATCC and IMI. Partial 18S and 28S nuclear ribosomal DNA (rDNA) were amplified using PCR and sequenced. About 11 00 bps of 18S rDNA (NS1/NS4 region) and 459 bps of 28S rDNA (F63/R635 region) for each taxon were subject to phylogenetic analysis using par simony. The reconstructed phylogenetic trees supported the separation of two monophyletic groups, containing the type genera of the Leptosph aeriaceae and the Pleosporaceae, respectively. The members of the Lept osphaeriaceae (sensu Barr) consisted of the paraphyletic clade in the phylogenetic trees. The members of the Pleosporaceae (sensu Barr) plus Pyrenophora trichostoma formed a monophyletic clade. The results gene rally supported the separation of the Leptosphaeriaceae from Pleospora ceae and the placement of P. trichostoma, and Comoclathris baccata in the Pleosporaceae. The taxonomic position of Pleospora betae, whose co elomycetous anamorph is more closely related to Leptosphaeriaceae, was not well resolved because of low bootstrap values and decay indices. Leptosphaeria bicolor, whose ascospore morphology is not congeneric wi th the type of the genus, L. doliolum, does not belong to Leptosphaeri a based on the 18S sequence data. The taxonomic disposition of Lewia, Pyrenaphora, and Comoclathris based on the phylogenetic analyses are d iscussed.