Phylogeny of Rosellinia capetribulensis sp. nov. and its allies (Xylariaceae)

Abstract

A new Rosellinia species, R. capetribulensis isolated from Calamus sp. in Australia is described. R. capetribulensis is characterized by perithecia immersed within a carbonaceous stroma surrounded by subiculum-like hyphae, asci with large, barrel-shaped amyloid apical apparatus and large dark brown spores. Morphologically, R. capetribulensis appears to be similar to R. bunodes, R. markhamiae and R. megalospora. To gain further insights into the phylogeny of this new taxon we analyzed the ITS-5.8S rDNA using maximum parsimony and likelihood methods. In addition, a morphological dataset also was analyzed phylogenetically to investigate possible affinities. ITS rDNA based phylogenies reveal that R. capetribulensis is closely related to other Rosellinia species showing closest affinity to R. arcuata, R. necatrix and R. pepo. However, analysis of R. capetribulensis forms an unsupported branch sister to these taxa. Results from the morphological matrix indicate a close morphological affinity to members of Rosellinia subgenus Rosellinia. Despite that ITS rDNA and morphological analyses present difficulties in constructing a proper phylogenetic framework among Rosellinia and allied genera, there is sufficient evidence to support the establishment of the new taxon in the genus Rosellinia. The morphological similarities and differences between R. capetribulensis and allied genera such as Astrocystis and Entoleuca are also briefly discussed.

• Astrocystis
• Entoleuca
• Nemania
• phylogeny
• rDNA
• taxonomy
• Xylariaceae
• Xylariales

J. Bahl would like to thank the University of Hong Kong for a postgraduate studentship, The Hong Kong Research Grants Council (grant no. HKU 7320/02 M) and the Committee on Research and Conference Grants (grant no. 100205773) for financial support. Michelle Nissen with the Environmental Protection Agency, Queensland, Australia is acknowledged to facilitate issue of permits required for collection, Ceri Pierce and Barbara Paulus for collection assistance and suggestions. G.J. Smith is acknowledged for providing sequence data for Astrocystis bambusae, A. cocoes, A. mirabilis and Rosellinia aquila. Cai Lei and Vijaykrishna Dhanasekaran are thanked for comments on the draft manuscript and J-M. Moncalvo for advice on phylogenetic analysis.