• 제목/요약/키워드: maximum parsimony

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Phylogenetic Relationships of the Polyporaceae Based on Gene Sequences of Nuclear Small Subunit Ribosomal RNAs

  • Kim, Seon-Young;Jung, Hack-Sung
    • Mycobiology
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    • 제29권2호
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    • pp.73-79
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    • 2001
  • The Polyporaceae is a chaotic mass of genera having poroid hymenophores in the Aphyllophorales. To classify the Polyporaceae into more natural groups, phylogenetic analyses were performed using nuclear small subunit ribosomal DNA sequences. Thirty-six species from the families of the Polyporaceae, the Hymenochaetaceae, the Ganodermataceae, the Corticiaceae, the Bondarzewiaceae, the Meruliaceae, the Steccherinaceae and the Lentinaceae were phylogenetically compared. By performing maximum parsimony analysis, seven phylogenetically meaningful groups were identified and discussed. The hyphal system, presence or absence of clamps, and the type of rot were found as important characters in defining the groups. Each group was phylogenetically significant enough to be a core member of each family when the Polyporaceae was split into smaller and more natural families.

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The taxonomic status of Angelica purpuraefolia and its allies in Korea : Inferences based on ITS molecular phylogenetic analyses

  • Lee, Byoung Yoon;Kwak, Myounghai;Han, Jeong Eun;Kim, Se-Jung
    • Korean Journal of Plant Taxonomy
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    • 제41권3호
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    • pp.209-214
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    • 2011
  • The taxonomy of the umbelliferous species Angelica amurensis and its allies was reviewed on the basis of molecular phylogenies derived from sequences of nuclear ribosomal DNA internal transcribed spacer (ITS) regions. Strict consensus of six minimal length 119-step trees derived from equally weighted maximum parsimony analysis of combined nuclear rDNA ITS1 and ITS2 sequences from 29 accessions of Angelica and outgroups indicated that Angelica purpuraefolia, known to be endemic to Korea, is the same species as A. amurensis. Comparisons of sequence pairs across both spacer regions revealed identity or 1-2 bp differences between A. purpuraefolia and A. amurensis. These results indicated that the two taxa are not distinguished taxonomically. Also, nuclear rDNA ITS regions are discussed as potential barcoding loci for identifying Korean Angelica.

Monophyly of the Family Desmoscolecidae (Nematoda, Demoscolecida) and Its Phylogenetic Position Inferred from 18S rDNA Sequences

  • Hwang, Ui Wook;Choi, Eun Hwa;Kim, Dong Sung;Decraemer, Wilfrida;Chang, Cheon Young
    • Molecules and Cells
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    • 제27권5호
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    • pp.515-523
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    • 2009
  • To infer the monophyletic origin and phylogenetic relationships of the order Desmoscolecida, a unique and puzzling group of mainly free-living marine nematodes, we newly determined nearly complete 18S rDNA sequences for six marine desmoscolecid nematodes belonging to four genera (Desmoscolex, Greeffiella, Tricoma and Paratricoma). Based on the present data and those of 72 nematode species previously reported, the first molecular phylogenetic analysis focusing on Desmoscolecida was done by using neighbor joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) methods. All four resultant trees consistently and strongly supported that the family Desmoscolecidae forms a monophyletic group with very high node confidence values. The monophyletic clade of desmocolecid nematodes was placed as a sister group of the clade including some members of Monhysterida and Araeolaimida, Cyartonema elegans (Cyartonematidae) and Terschellingia Iongicaudata (Linhomoeidae) in all the analyses. However, the present phylogenetic trees do not show any direct attraction between the families Desmoscolecidae and Cyartonematidae. Within the monophyletic clade of the family Desmoscolecidae in all of the present phylogenetic trees, there were consistently observed two distinct subgroups which correspond to the subfamilies Desmoscolecinae [Greeffiella sp. + Desmoscolex sp.] and Tricominae [Paratricoma sp. + Tricoma sp].

Molecular Phylogeny of Syngnathiformes Fishes Inferred from Mitochondrial Cytochrome b DNA Sequences (실고기목 어류 (Syngnathiformes)의 분자계통학적 분류)

  • KOH Beom Seok;SONG Choon Bok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • 제37권5호
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    • pp.405-413
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    • 2004
  • The previous morphology-based taxonomic frameworks within the family Syngnathidae had emphasized the significance of the male brood pouch and reproductive biology in defining the group. However, several different hypotheses had been proposed by different investigators. This study has been carried out to determine the phylogenetic relationships among 19 species belonging to the order Syngnathiformes with three Gasterosteiformes species as outgroup taxa by using the mitochondrial cytochrome b DNA sequences. Phylogenetic analyses based on neighbor-joining distance, maximum parsimony, minimum evolution and maximum likelihood method strongly supported that the family Syngnathidae, the suborder Syngnathoidei and the order Syngnathiformes were all monophyletic group. Although much of previous morphological analyses were supported by our molecular data, there were some significant discrepancies between molecular and morphological work. Such an interesting result was that the weedy seadragon (Phyllopteryx taeniolatus) strongly grouped together with the New Zealand pot-belly seahorse (Hippocampus abdominalis). Considering the markedly different brooding structure between them, this unexpected result might be explained whether by multiple independent origins of brooding structure or by hybridization between the female Hippocampus and other syngnathid species having individual membranous egg compartment. In addition, the suborder Aulostomoidei was paraphyletic group because the shrimpfish (Aeliscus strigatus), belonging to the family Centriscidae, always grouped together with the family Syngnathidae as a sister taxon.

Phylogenetic position of Carex splendentissima, a Korean endemic sedge (Cyperaceae)

  • CHUNG, Kyong-Sook;YANG, Sungyu;NAM, Bo-Mi
    • Korean Journal of Plant Taxonomy
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    • 제50권3호
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    • pp.253-261
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    • 2020
  • Carex splendentissima U. Kang & J. M. Chung, endemic to the Korean peninsula, is characterized by staminate terminal spikes and glabrous elliptic perigynia. Based on its broad leaves, androgynous spikes, and tri-stigmatic features, the species has been placed in Carex sect. Siderostictae Franch. ex Ohwi, an East Asian section and a basal group in the genus. To clarify the monophyly and phylogenetic position of the species, a molecular study using the internal transcribed spacer region of nuclear ribosomal DNA and chloroplast DNA (trnL-F) data was conducted. The DNA sequence data of ten taxa in sect. Siderostictae and closely related taxa (two taxa in sect. Surculosae) with outgroups were analyzed based on maximum parsimony and maximum likelihood (ML) criteria. In the analyses, C. splendentissima was monophyletic and placed within the Siderostictae clade (sect. Siderostictae + two species of sect. Surculosae), forming a clade with C. ciliatomarginata and C. pachygyna (endemic to Japan). The clade (C. splendentissima + C. ciliatomarginata + C. pachygyna) shows evidence of diploidy. Furthermore, C. splendentissima is a sister to C. ciliatomarginata in the ML tree, and the two taxa have staminate terminal spikes. This study also updates the distribution of C. splendentissima and provides keys to the four Korean taxa in sect. Siderostictae. To conserve the endemic species C. splendentissima, further research on its genetic and ecological features should be conducted at the population level.

Systematic Relationships of the Urochordates Based on Partial 18S rDNA Sequences

  • Won, Hye-Won;Rho, Boon-Jo;Song, Jun-Im
    • Animal cells and systems
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    • 제3권4호
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    • pp.359-363
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    • 1999
  • Urochordates, the most primitive group in phylum Chordata, are mostly sessile as adults although some are free living. Presently, the ancestral stock of urochordates as weir as chordates has been the focus of interest and two conflicting hypotheses have been presented. A free swimming ancestor is one and a sessile, filter feeding ancestor is the other. To clarify the phylogenetic relationships within the urochordates, 22 urochordates and five others as outgroups were used. And we applied neighbor joining, maximum likelihood, and maximum parsimony methods to partial 18S rDNA sequences. The inferred phylogeny in all analyses indicates that order Aplousobranchia of class Ascidiacea appears to be the most ancestral group among urochordates. But it is not clear for the low bootstrap value. The remaining two orders of ascidians, Phlebobranchia and Stolidobranchia, form monophyletic groups respectively, which are well supported by high bootstrap values. These two orders are closer to classes of Thaliacea and Appendicularia than to the Aplousobranchia. While class Appendicularia is strongly supported by the monophyletic group, the phylogenetic position of class Thaliacea is unclear in this study.

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Phylogeny and systematics of Crossosomatales as inferred from chloroplast atpB, matK, and rbcL sequences

  • Oh, Sang-Hun
    • Korean Journal of Plant Taxonomy
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    • 제40권4호
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    • pp.208-217
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    • 2010
  • Crossosomatales is a recently recognized order in the rosid II clade with about 64 species in eight morphologically distinct families that have been previously classified in as many as 15 other orders. Phylogenetic relationships among the families and genera within Crossosomatales were investigated using chloroplast atpB, matK, and rbcL sequences employing maximum parsimony, maximum likelihood, and Bayesian methods. The phylogenetic framework was used to examine the patterns of morphological evolution and synapomorphies for subclades within Crossosomatales. The combined data with representative species from all genera in the order strongly supported monophyly of Crossosomatales. Strong support was found for the families in the Southern Hemisphere, in which Aphloiaceae is sister to the clade of (Geissolomataceae, (Ixerbaceae + Strasburgeriaceae)). The sister relationship between the Southern Hemisphere clade and families distributed primarily in the Northern Hemisphere was also supported. As in the previous studies, following relationships were found within the Northern Hemisphere clade: Staphyleaceae is sister to a clade of (Guamatelaceae, (Stachyuraceae + Crossosomataceae)). The pattern analysis indicates that evolutionary pattern of morphological characters is complex, requiring multiple changes within Crossosomatales. Several reproductive traits, such as inflorescence, aril, stigma, and conspicuous protrusion from pollen aperture, corroborate the molecular phylogeny.

Paramyrothecium eichhorniae sp. nov., Causing Leaf Blight Disease of Water Hyacinth from Thailand

  • Pinruan, Umpawa;Unartngam, Jintana;Unartngam, Arm;Piyaboon, Orawan;Sommai, Sujinda;Khamsuntorn, Phongsawat
    • Mycobiology
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    • 제50권1호
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    • pp.12-19
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    • 2022
  • Paramyrothecium eichhorniae sp. nov. was observed and collected from Chiang Mai and Phetchaburi Provinces, Thailand. This new species is introduced based on morphological and molecular evidence. This fungus is characterized by its production of sporodochium conidiomata with a white setose fringe surrounding an olivaceous green to dark green slimy mass of conidia, penicillately branched conidiophores, and aseptate and cylindrical to ellipsoid conidia. Phylogenetic analyses of combined LSU rDNA, ITS rDNA, tef1, rpb2, tub2 and cmdA sequence data using maximum parsimony, maximum likelihood and Bayesian approaches placed the fungus in a strongly supported clade with other Paramyrothecium species in Stachybotryaceae (Hypocreales, Sordariomycetes). The descriptions of the species are accompanied by illustrations of morphological features, and a discussion of the related taxa is presented.

A Molecular Systematics of Korean Zacco Species Inferred from Mitochondrial Cytochrome b Gene Sequence (한국산 피라미속(Zacco) 어류의 미토콘드리아 cytochrome b gene 분석을 통한 분자계통)

  • Oh, Min-Ki;Park, Jong-Young
    • Korean Journal of Ichthyology
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    • 제21권4호
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    • pp.291-298
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    • 2009
  • A molecular phylogenetic relationship inferred from mitochondrial cytochrome b gene sequence was developed based on analysis of Zacco species distributed in Korea as well as China, Japan and Taiwan. A maximum parsimony (MP) tree showed that Korean Z. temminckii and Z. koreanus formed a monophyletic clade, but the populations of Z. temminckii and Z. koreanus in the 'South Korean Subdistrict' region had genetic similarity with Japanese Z. temminckii. Korean Z. platypus had a closer relationship with Japanese members of the clade than with Chinese Z. platypus, which was more closely related to Opsariichthys uncirostris amurensis. The analysis of neighbor joining (NJ) tree may support a hypothesis that the clade of Z. platypus had genetically diverged from the common ancestor of Zacco species comprising Z. koreanus, Z. temminckii, Z. sieboldii and other species; thereafter a cladogenesis of Z. koreanus and Z. temmminckii had occurred from the ancestor of Z. sieboldii. Moreover, the Chinese Z. platypus had diverged far from the Korean Z. platypus and formed a phylogenetic relationship with O. uncirostris amurensis. Therefore, a more detailed study of the taxonomy and systematics of Zacco species in regard to their zoogeographical distributions is needed.

Taxonomic status of Goodyera rosulacea (Orchidaceae): molecular evidence based on ITS and trnL sequences (로젯사철란(Goodyera rosulacea: Orchidaceae)의 분류학적 위치: ITS와 trnL 염기서열에 의한 분자적 증거)

  • Lee, Chang Shook;Eom, Sang Mi;Lee, Nam Sook
    • Korean Journal of Plant Taxonomy
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    • 제36권3호
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    • pp.189-207
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    • 2006
  • Goodyera rosulacea, which is morphologically similar to G. repens, is described recently as a new species based on its distinct morphological characters such as rosette-formed leaves, short rhizome and habitat. To verify the taxonomic identity of G. rosulacea and its taxonomic relationship within Korean Goodyera taxa, sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and the trnL region of cpDNA from 24 accessions including 1 outgroup accession were analyzed. Aligned sequences were analyzed using maximum parsimony and distance method, and the taxonomic identity and the taxonomic relationships among the related taxa were estimated by the existence of private marker gene and the phylogenetic tree of the aligned sequences. Molecular data indicate that G. rosulacea gas several private marker genes and shows monophyly in phylogenetic trees of both ITS and trnL sequences. the pairwise distance between G. rosulacea and the orher taxa of Korean Goodyera was 3.49-6.68% for ITS region and 5.05-9.53% for trnL region, indicating that G. rosulacea could be treated as an independent species. Therefore, our molecular data support the taxonomic of G. rosulacea as a distinct species of Korea. In phylogenetic trees, G. rosulacea formed same clade with G. repens, which has similar morphological characters with G. rosulacea, and showed the lowest pairwise distance with G. repens among Korean Goodyera taxa. These molecular data sugguested that G. rosulacea and G. repens are closely related taxa.