3 research outputs found
Re-evaluation of Cryptosporiopsis eucalypti and Cryptosporiopsis-like species occurring on Eucalyptus
No full textCryptosporiopsis eucalypti is a common follicolous pathogen of Eucalyptus species in tropical and temperate regions where these trees are grown in plantations. The taxonomy of C. eucalypti is confused by the fact that it is phylogenetically unrelated to the type species of Cryptosporiopsis (Cryptosporiopsis nigra = C. scutellata, Helotiales). The aim of this study was to resolve the taxonomic position of C. eucalypti based on morphology and phylogenetic inference. Thirty-two Eucalyptus leaf samples with symptoms typical of C. eucalypti infection were collected from 10 tropical and temperate countries across four continents. Cultures were established from single conidia, as well as from ascospores of a previously unreported teleomorph state. DNA sequences were obtained for the 28 S nrDNA, the internal transcribed spacers of the nrDNA operon, and beta-tubulin regions to determine generic and species-level relationships. DNA-sequence analysis showed that conidial and ascospore isolates of C. eucalypti have low intraspecific variation, although two collections from Australia and one from Uruguay represented two novel taxa. Based on the newly collected teleomorph stage, as well as the phylogenetic data, C. eucalypti is shown to represent a new genus closely related to Plagiostoma (Gnomoniaceae, Diaporthales) for which the names Pseudoplagiostoma gen. nov. and Pseudoplagiostomaceae fam. nov. (Diaporthales) are introduced. Two new species of Cryptosporiopsis (Dermateaceae, Helotiales) on Eucalyptus from Australia and California (USA) are also described
Mycoparasitic species of Sphaerellopsis, and allied lichenicolous and other genera
No full textSpecies of Sphaerellopsis (sexual morph Eudarluca) are well-known cosmopolitan mycoparasites occurring on a wide range of rusts. Although their potential role as biocontrol agents has received some attention, the molecular phylogeny of the genus has never been resolved. Based on morphology and DNA sequence data of the large subunit nuclear ribosomal RNA gene (LSU, 28S) and the internal transcribed spacers (ITS) and 5.8S rRNA gene of the nrDNA operon, the genus Sphaerellopsis is shown to belong to Leptosphaeriaceae in Dothideomycetes. Sphaerellopsis is circumscribed, and the sexually typified generic name Eudarluca treated as a synonym on the basis that Sphaerellopsis is more commonly used in literature, is the older generic name, and is the morph commonly encountered by plant pathologists in the field. A neotype is designated for Sphaerellopsis filum, and two new species are introduced, S. macroconidialis and S. paraphysata spp. nov. Species previously incorrectly placed in Sphaerellopsis are allocated to Neosphaerellopsis gen. nov. as N. thailandica, and to the genus Acrocalymma, as A. fici. The genus Rhizopycnis is nestled among species of Acrocalymma, and reduced to synonymy based on its morphology and DNA phylogeny, while Acrocalymmaceae is introduced as novel family to accommodate members of this genus in the Dothideomycetes. Furthermore, Sphaerellopsis proved to be phylogenetically closely allied to a lichenicolous complex of phoma-like taxa, for which the new genera Diederichomyces and Xenophoma are established. Several new combinations are introduced, namely D. xanthomendozae, D. ficuzzae, D. caloplacae, D. cladoniicola, D. foliaceiphila, and X. puncteliae combs. nov, while Paraphaeosphaeria parmeliae sp. nov. is newly described
Caulicolous Botryosphaeriales from Thailand
No full text<p>Members of Botryosphaeriales are commonly encountered as endophytes or pathogens of various plant hosts. The Botryosphaeriaceae represents the predominant family within this order, containing numerous species associated with canker and dieback disease on a wide range of woody hosts. During the course of routine surveys from various plant hosts in Thailand, numerous isolates of Botryosphaeriaceae, including Aplosporellaceae were collected. Isolates were subsequently identified based on a combination of morphological characteristics and phylogenetic analysis of a combined dataset of the ITS and EF1-α gene regions. The resulting phylogenetic tree revealed 11 well-supported clades, correlating with different members of Botryosphaeriales. Other than confirming the presence of taxa such as Lasiodiplodia theobromae, L. pseudotheobromae and Neofusicoccum parvum, new records for Thailand include Pseudofusicoccum adansoniae and P. ardesiacum. Furthermore, four novel species are described, namely Diplodia neojuniperi from Juniperus chinensis, Lasiodiplodia thailandica from Mangifera indica, Pseudofusicoccum artocarpi and Aplosporella artocarpi from Artocarpus heterophyllus, while a sexual morph is also newly reported for L. gonubiensis. Further research is presently underway to determine the pathogenicity and relative importance of these species on different woody hosts in Thailand.</p
