Uwebraunia and Dissoconium, two morphologically similar anamorph genera with distinct teleomorph affinity

Crous, P. W., L. Hong, M. J. Wingfield, B. Wingfield & J. C. Kang (1999). Uwebraunia and Dissoconium, two morphologically similar anamorph genera with different teleomorph affinities. Sydowia 51(2): 155-166. More than 20 anamorph form genera, including Uwebraunia, have been linked to Mycosphaerella. The diversity of anamorphs associated with Mycosphaerella has led to hypotheses that the genus is either polyphyletic, or that the features used to separate anamorphs are indicative of natural lineages within Mycosphaerella. Uwebraunia is morphologically similar to Dissoconium, a genus suspected to include species hyperparasitic on other fungi. Phylogenetic analysis of 5.8S, ITS! and ITS2 rDNA operon of several Mycosphaerella spp. with Uwebraunia, Dissoconium and other anamorphs, as well as species of Ramulispora (Tapesia teleomorph), using Mycocentrospora (teleomorph unknown) as the outgroup taxon, identified three clades. One major clade represented species of Mycosphaerella sensu stricto, comprising several subclades that correlate with the various anamorph form-genera. The other two clades were distinct from the larger Mycosphaerella clade, and represented a smaller clade with Dissoconium anamorphs, and a Tapesia clade with Ramulispora anamorphs. Uwebraunia was shown to include two species representing Mycosphaerella anamorphs. A third species was synonymous with Dissoconium dekkeri, forming a clade separate from Mycosphaerella sensu stricto. Species of Dissoconium are thought to be hyperparasitic on other fungi, whereas species of Uwebraunia are apparent plant pathogens. These findings suggest that divergence occurred in the Mycosphaerella lineage, followed by convergent evolution of morphological form, which accounts for the similar anamorphs.