A preliminary study on the phylogeny of the genus Melanelia using nuclear large subunit ribosomal DNA sequences

2003 ◽  
Vol 35 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Beata Guzow-Krzemińska ◽  
Grzegorz Wegrzyn
Keyword(s):  
Ribosomal Dna ◽  
Dna Sequences ◽  
Large Subunit ◽  
Preliminary Study

On the subdivision of Ceratocystis s.l., based on partial ribosomal DNA sequences

1993 ◽  
Vol 71 (1) ◽  
pp. 52-63 ◽  
Author(s):  
G. Hausner ◽  
J. Reid ◽  
G. R. Klassen
Keyword(s):  
Key Words ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
Cell Walls ◽  
Large Subunit ◽  
Rdna Sequences

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.

scholarly journals Morphology, genetic characterization and molecular phylogeny of pinworm Skrjabinema longicaudatum n. sp. (Oxyurida: Oxyuridae) from the endangered Tibetan antelope Pantholops hodgsonii (Abel) (Artiodactyla: Bovidae)

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Yi-Fan Cao ◽  
Hui-Xia Chen ◽  
Yang Li ◽  
Dang-Wei Zhou ◽  
Shi-Long Chen ◽  
...  
Keyword(s):  
New Species ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Small Subunit ◽  
Sister Relationship ◽  
Tibetan Antelope ◽  
A New Species

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.

scholarly journals Phylogenetic Relationships of Agaric Fungi Based on Nuclear Large Subunit Ribosomal DNA Sequences

2000 ◽  
Vol 49 (2) ◽  
pp. 278-305 ◽  
Author(s):  
Jean-Marc Moncalvo ◽  
François M. Lutzoni ◽  
Stephen A. Rehner ◽  
Jacqui Johnson ◽  
Rytas Vilgalys
Keyword(s):  
Ribosomal Dna ◽  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Large Subunit

A preliminary overview of the Diaporthales based on large subunit nuclear ribosomal DNA sequences

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

scholarly journals Cryphonectriaceae on Myrtales in China: phylogeny, host range, and pathogenicity

2020 ◽  
Vol 45 (1) ◽  
pp. 101-131 ◽  
Author(s):  
W. Wang ◽  
G.Q. Li ◽  
Q.L. Liu ◽  
S.F. Chen
Keyword(s):  
New Species ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
Fungal Pathogens ◽  
Southern China ◽  
Large Subunit ◽  
Morphological Characteristics ◽  
Psidium Guajava ◽  
Fungal Species ◽  
Canker Disease

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.

A phylogeny inferred from large-subunit (26S) ribosomal DNA sequences suggests that Burmanniales are polyphyletic

2002 ◽  
Vol 15 (1) ◽  
pp. 19 ◽  
Author(s):  
Ray Neyland
Keyword(s):  
Ribosomal Dna ◽  
Dna Sequences ◽  
Large Subunit ◽  
Monophyletic Group

According to several authors, the Burmanniales are an order that includes the families Burmanniaceae, Thismiaceae and Corsiaceae. At present, there is no consensus concerning the circumscription of Burmanniales. All members of Thismiaceae and Corsiaceae are mycoheterotrophic; Burmanniaceae are composed of both mycoheterotrophic and autotrophic species. Other than mycoheterotrophy, there are few characters that unite members of the order. Because mycoheterotrophy has resulted in extreme vegetative reduction that may have contributed to homoplasy in the form of character convergence, the systematics of Burmanniales is problematic. A phylogeny inferred from large-subunit (26S) ribosome-DNA sequences suggests that the order Burmanniales is polyphyletic. Specifically, the Burmanniaceae appears as strongly supported monophyletic group with Thismia as sister. Corsia is distinct and may be associated with the Liliales.

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