Phylogenetic position ofEphedra rhytidosperma, a species endemic to China: Evidence from chloroplast and ribosomal DNA sequences

Phylogenetic analysis of partial ribosomal DNA sequences was undertaken to assess the phylogenetic distribution of ophiostomatoid anamorphs with an emphasis on members of Leptographium and the generic limits of Ceratocystis sensu lato Ell. & Halst. Molecular data identified one group of Ophiostoma species with anamorphs assignable to Pesotum and Leptographium that appears to be monophyletic. This study also showed that, based on molecular characters, Pesotum pini (Hutchison & Reid) Okada and all Leptographium strains tested, including L. terebrantis Barras & Perry, L. lundbergii Lag. & Melin, and L. procerum (Kendr.) Wingf., could be placed among Ophiostoma species. With regard to the anamorphs of Ophiostoma, we determined that the separation of Leptographium from Pesotum, although convenient, is artificial. The partial ribosomal DNA sequences also confirm that Europhium should be considered a synonym of Ophiostoma. The phylogenetic position of species of Ceratocystis sensu lato with Chalara-like, Knoxdaviesia, and Gabarnaudia anamorphs is also discussed.Key words: Ceratocystis, Ophiostoma, Leptographium, partial rDNA sequences, phylogeny.

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Characterization of the Complete Nuclear Ribosomal DNA Sequences ofParamphistomum cervi

The Scientific World JOURNAL ◽

10.1155/2014/751907 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 7

Author(s):

Xu Zheng ◽

Qiao-Cheng Chang ◽

Yan Zhang ◽

Si-Qin Tian ◽

Yan Lou ◽

...

Keyword(s):

Ribosomal Dna ◽

Dna Sequences ◽

18S Rdna ◽

Internal Transcribed Spacer ◽

Interspecific Variation ◽

28S Rdna ◽

Nuclear Ribosomal Dna ◽

Phylogenetic Position ◽

Rdna Sequences ◽

Length Range

Sequences of the complete nuclear ribosomal DNA (rDNA) gene from five individualParamphistomum cerviwere determined for the first time. The five complete rDNA sequences, which included the 18S rDNA, the internal transcribed spacer 1 (ITS1), the 5.8S rDNA, the internal transcribed spacer 2 (ITS2), the 28S rDNA, and the intergenic spacer (IGS) regions, had a length range of 8,493–10,221 bp. The lengths of the investigated 18S, ITS1, 5.8S, ITS2, and 28S rDNA sequences, which were 1,994 bp, 1,293 bp, 157 bp, 286 bp, and 4,186 bp, respectively, did not vary. However, the IGS rDNA sequences had a length range of 577–2,305 bp. The 5.8S and ITS-2 rDNA sequences had 100% identity among the five investigated samples, while the identities among the IGS had a range of 53.7–99.8%. A comparative analysis revealed that different types and numbers of repeats were found within each ITS1 and IGS region, which may be related to the length polymorphism of IGS. The phylogenetic position ofP. cerviin Paramphistomatidae was analyzed based on the 18S rDNA sequences. These results will aid in studying the intra- and interspecific variation of the Paramphistomatidae and the systematics and phylogenetics of Digenea.

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