ABSTRACT
The genus Bipolaris includes important plant pathogens with worldwide distribution. Species recognition in the genus has been uncertain due to the lack of molecular data from ex-type cultures as well as overlapping morphological characteristics. In this study, we revise the genus Bipolaris based on DNA sequence data derived from living cultures of fresh isolates, available ex-type cultures from worldwide collections and observation of type and additional specimens. Combined analyses of ITS, GPDH and TEF gene sequences were used to reconstruct the molecular phylogeny of the genus Bipolaris for species with living cultures. The GPDH gene is determined to be the best single marker for species of Bipolaris. Generic boundaries between Bipolaris and Curvularia are revised and presented in an updated combined ITS and GPDH phylogenetic tree. We accept 47 species in the genus Bipolaris and clarify the taxonomy, host associations, geographic distributions and species' synonymies. Modern descriptions and illustrations are provided for 38 species in the genus with notes provided for the other taxa when recent descriptions are available. Bipolaris cynodontis, B. oryzae, B. victoriae, B. yamadae and B. zeicola are epi- or neotypified and a lectotype is designated for B. stenospila. Excluded and doubtful species are listed with notes on taxonomy and phylogeny. Seven new combinations are introduced in the genus Curvularia to accomodate the species of Bipolaris transferred based on the phylogenetic analysis. A taxonomic key is provided for the morphological identification of species within the genus.
ABSTRACT
Phyllosticta is a geographically widespread genus of plant pathogenic fungi with a diverse host range. This study redefines Phyllosticta, and shows that it clusters sister to the Botryosphaeriaceae (Botryosphaeriales, Dothideomycetes), for which the older family name Phyllostictaceae is resurrected. In moving to a unit nomenclature for fungi, the generic name Phyllosticta was chosen over Guignardia in previous studies, an approach that we support here. We use a multigene DNA dataset of the ITS, LSU, ACT, TEF and GPDH gene regions to investigate 129 isolates of Phyllosticta, representing about 170 species names, many of which are shown to be synonyms of the ubiquitous endophyte P. capitalensis. Based on the data generated here, 12 new species are introduced, while epitype and neotype specimens are designated for a further seven species. One species of interest is P. citrimaxima associated with tan spot of Citrus maxima fruit in Thailand, which adds a fifth species to the citrus black spot complex. Previous morphological studies lumped many taxa under single names that represent complexes. In spite of this Phyllosticta is a species-rich genus, and many of these taxa need to be recollected in order to resolve their phylogeny and taxonomy. TAXONOMIC NOVELTIES: New species - Phyllosticta abieticola Wikee & Crous, P. aloeicola Wikee & Crous, P. citrimaxima Wikee, Crous, K.D. Hyde & McKenzie, P. leucothoicola Wikee, Motohashi & Crous, P. mangifera-indica Wikee, Crous, K.D. Hyde & McKenzie, P. neopyrolae Wikee, Motohashi, Crous, K.D. Hyde & McKenzie, P. pachysandricola Wikee, Motohashi & Crous, P. paxistimae Wikee & Crous, P. podocarpicola Wikee, Crous, K.D. Hyde & McKenzie, P. rhaphiolepidis Wikee, C. Nakash. & Crous, P. rubra Wikee & Crous, P. vacciniicola Wikee, Crous, K.D. Hyde & McKenzie; New combinations - P. foliorum (Sacc.) Wikee & Crous, P. philoprina (Berk. & M.A. Curtis) Wikee & Crous; Epitypifications (basionyms) - P. concentrica Sacc., P. cussoniae Cejp, P. owaniana G. Winter; Neotypifications (basionyms) - Phyllosticta cordylinophila P.A. Young, Physalospora gregaria var. foliorum Sacc., Sphaeropsis hypoglossi Mont., Sphaeropsis minima Berk. & M.A. Curtis.
