Phylogenetic studies of Saprolegniomycetidae and related groups based on nuclear large subunit ribosomal DNA sequences

1999 ◽  
Vol 77 (12) ◽  
pp. 1790-1800 ◽  
Author(s):  
Ale×andra Riethmüller ◽  
Michael Weiß ◽  
Franz Oberwinkler
1997 ◽  
Vol 75 (12) ◽  
pp. 2045-2056 ◽  
Author(s):  
Dominik Begerow ◽  
Robert Bauer ◽  
Franz Oberwinkler

To show phylogenetic relationships among the smut fungi and their relatives, we sequenced a part of the nuclear LSU rDNA from 43 different species of smut fungi and related taxa. Our data were combined with the existing sequences of seven further smut fungi and 17 other basidiomycetes. Two sets of sequences were analyzed. The first set with a representative number of simple septate basidiomycetes, complex septate basidiomycetes, and smut fungi was analyzed with the neighbor-joining method to estimate the general topology of the basidiomycetes phylogeny and the positions of the smut fungi. The tripartite subclassification of the basidiomycetes into the Urediniomycetes, Ustilaginomycetes, and Hymenomycetes was confirmed and two groups of smut fungi appeared. The smut genera Aurantiosporium, Microbotryum, Fulvisporium, and Ustilentyloma are members of the Urediniomycetes, whereas the other smut species tested are members of the Ustilaginomycetes with Entorrhiza as a basal taxon. The second set of 46 Ustilaginomycetes was analyzed using the neighbor-joining and the maximum parsimony methods to show the inner topology of the Ustilaginomycetes. The results indicated three major lineages among Ustilaginomycetes corresponding to the Entorrhizomycetidae, Exobasidiomycetidae, and Ustilaginomycetidae. The Entorrhizomycetidae are represented by Entorrhiza species. The Ustilaginomycetidae contain at least two groups, the Urocystales and Ustilaginales. The Exobasidiomycetidae include five orders, i.e., Doassansiales, Entylomatales, Exobasidiales, Georgefischeriales, and Tilletiales, and Graphiola phoenicis and Microstroma juglandis. Our results support a classification mainly based on ultrastructure. The description of the Glomosporiaceae is emended. The Doassansiopsaceae, Melanotaeniaceae, and Urocystaceae are proposed as new taxa. Key words: basidiomycete systematics, LSU rDNA, Microbotryales, molecular phylogeny, smut fungi, Ustilaginomycetes.


1993 ◽  
Vol 71 (1) ◽  
pp. 52-63 ◽  
Author(s):  
G. Hausner ◽  
J. Reid ◽  
G. R. Klassen

Analyses of partial rDNA sequences from both the small and large subunit genes of species of Ceratocystis s.l. support the contention that species that lack Chalara anamorphs, are resistant to cycloheximide, and have rhamnose in their cell walls should be assigned to Ophiostoma, whereas only species with Chalara anamorphs should be accommodated in Ceratocystis s.s. The data also show that Ceratocystiopsis is polyphyletic, and Sphaeronaemella fimicola appears to have little relation to either Ceratocystis or Ophiostoma. Key words: Ceratocystis, Ophiostoma, phylogeny, partial rDNA sequences.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Yi-Fan Cao ◽  
Hui-Xia Chen ◽  
Yang Li ◽  
Dang-Wei Zhou ◽  
Shi-Long Chen ◽  
...  

Abstract Background The Tibetan antelope Pantholops hodgsonii (Abel) (Artiodactyla: Bovidae) is an endangered species of mammal endemic to the Qinghai-Tibetan Plateau. Parasites and parasitic diseases are considered to be important threats in the conservation of the Tibetan antelope. However, our present knowledge of the composition of the parasites of the Tibetan antelope remains limited. Methods Large numbers of nematode parasites were collected from a dead Tibetan antelope. The morphology of these nematode specimens was observed using light and scanning electron microscopy. The nuclear and mitochondrial DNA sequences, i.e. small subunit ribosomal DNA (18S), large subunit ribosomal DNA (28S), internal transcribed spacer (ITS) and cytochrome c oxidase subunit 1 (cox1), were amplified and sequenced for molecular identification. Moreover, phylogenetic analyses were performed using maximum likelihood (ML) inference based on 28S and 18S + 28S + cox1 sequence data, respectively, in order to clarify the systematic status of these nematodes. Results Integrated morphological and genetic evidence reveals these nematode specimens to be a new species of pinworm Skrjabinema longicaudatum (Oxyurida: Oxyuridae). There was no intraspecific nucleotide variation between different individuals of S. longicaudatum n. sp. in the partial 18S, 28S, ITS and cox1 sequences. However, a high level of nucleotide divergence was revealed between the new species and its congeners in 28S (8.36%) and ITS (20.3–23.7%) regions, respectively. Molecular phylogenetic results suggest that the genus Skrjabinema should belong to the subfamily Oxyurinae (Oxyuroidea: Oxyuridae), instead of the subfamily Syphaciidae or Skrjabinemiinae in the traditional classification, as it formed a sister relationship to the genus Oxyuris. Conclusions A new species of pinworm Skrjabinema longicaudatum n. sp. (Oxyurida: Oxyuridae) is described. Skrjabinema longicaudatum n. sp. represents the first species of Oxyurida (pinworm) and the fourth nematode species reported from the Tibetan antelope. Our results contribute to the knowledge of the species diversity of parasites from the Tibetan antelope, and clarify the systematic position of the genus Skrjabinema.


2000 ◽  
Vol 77 (12) ◽  
pp. 1790-1800 ◽  
Author(s):  
Alexandra Riethmüller ◽  
Michael Weiß ◽  
Franz Oberwinkler

To reveal phylogenetic relationships within the Peronosporomycetes (Oomycetes), we sequenced a part of the nuclear rDNA coding for the ribosomal large subunit of 46 Peronosporomycetes species and one representative of the Xanthophyta. The main emphasis of our study was put on the phylogenetic relationships within the Saprolegniomycetidae. We supplemented our data with a sequence of Phytophthora megasperma Drechsler from GenBank. Two sets of sequences were analysed using the neighbor-joining method, statistically supported by the bootstrap method, as well as the maximum parsimony method. Our results are well compatible with the tripartite subclassification of the Peronosporomycetes into Saprolegniomycetidae, Rhipidiomycetidae and Peronosporomycetidae, as well as with the placement of the orders Saprolegniales and Leptomitales in the Saprolegniomycetidae. Pachymetra chaunorhiza Croft & Dick, which has been placed in the Sclerosporales, was grouped within the Saprolegniales. Within the Peronosporomycetidae, the orders Peronosporales and Pythiales could not be separated. There are indications that Phytophthora de Bary and the Peronosporales form a common natural group. The genus Achlya Nees proved to be a heterogeneous group.


2000 ◽  
Vol 49 (2) ◽  
pp. 278-305 ◽  
Author(s):  
Jean-Marc Moncalvo ◽  
François M. Lutzoni ◽  
Stephen A. Rehner ◽  
Jacqui Johnson ◽  
Rytas Vilgalys

Mycologia ◽  
2002 ◽  
Vol 94 (6) ◽  
pp. 1017-1031 ◽  
Author(s):  
Lisa A. Castlebury ◽  
Amy Y. Rossman ◽  
Walter J. Jaklitsch ◽  
Larissa N. Vasilyeva

2020 ◽  
Vol 45 (1) ◽  
pp. 101-131 ◽  
Author(s):  
W. Wang ◽  
G.Q. Li ◽  
Q.L. Liu ◽  
S.F. Chen

Plantation-grown Eucalyptus (Myrtaceae) and other trees residing in the Myrtales have been widely planted in southern China. These fungal pathogens include species of Cryphonectriaceae that are well-known to cause stem and branch canker disease on Myrtales trees. During recent disease surveys in southern China, sporocarps with typical characteristics of Cryphonectriaceae were observed on the surfaces of cankers on the stems and branches of Myrtales trees. In this study, a total of 164 Cryphonectriaceae isolates were identified based on comparisons of DNA sequences of the partial conserved nuclear large subunit (LSU) ribosomal DNA, internal transcribed spacer (ITS) regions including the 5.8S gene of the ribosomal DNA operon, two regions of the β-tubulin (tub2/tub1) gene, and the translation elongation factor1-alpha (tef1) gene region, as well as their morphological characteristics. The results showed that eight species reside in four genera of Cryphonectriaceae occurring on the genera Eucalyptus, Melastoma (Melastomataceae), Psidium (Myrtaceae), Syzygium (Myrtaceae), and Terminalia (Combretaceae) in Myrtales. These fungal species include Chrysoporthe deuterocubensis, Celoporthe syzygii, Cel. eucalypti, Cel. guang-dongensis, Cel. cerciana, a new genus and two new species, as well as one new species of Aurifilum. These new taxa are hereby described as Parvosmorbus gen. nov., Par. eucalypti sp. nov., Par. guangdongensis sp. nov., and Aurifilum terminali sp. nov. Pathogenicity tests showed that the eight species of Cryphonectriaceae are pathogenic to two Eucalyptus hybrid seedlings, Melastoma sanguineum branches, and Psidium guajava and Syzygium jambos seedlings. Theoveralldatashowedthat Chr. deuterocubensis is the most aggressive, followed by Par. eucalypti. Significant differences in tolerance were observed between the two tested Eucalyptus hybrid genotypes, suggesting that disease-tolerant genotypes can be selected for disease management in the Eucalyptus industry.


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