Phylogenetic relationships in Leptographium based on morphological and molecular characters

2001 ◽  
Vol 79 (6) ◽  
pp. 719-732 ◽  
Author(s):  
K Jacobs ◽  
M J Wingfield ◽  
B D Wingfield
Keyword(s):  
Sequence Analysis ◽  
Dna Sequence ◽  
Phylogenetic Relationships ◽  
Bark Beetles ◽  
Morphological Characters ◽  
Dna Sequence Analysis ◽  
Phylogenetic Studies ◽  
Blue Stain ◽  
Woody Substrates ◽  
Molecular Characters

Species of Leptographium Lagerberg & Melin are characterized by mononematous conidiophores with dark stipes and conidiogenous apparatuses with complex series of branches. These fungi generally inhabit woody substrates, are associated with bark beetles (Coleoptera: Scolytidae) and cause blue-stain in conifers. Few phylogenetic studies have been conducted on Leptographium species, and those that have been undertaken have been focused on a small number of species. The objective of this study was to investigate the phylogenetic relationships among species in Leptographium based on partial DNA operon sequences and to ascertain whether morphological characters are congruent with DNA-based phylogeny. Morphological characters were analyzed and compared with results from DNA sequence analysis. Results indicate that there are three groups within Leptographium based on DNA sequence analysis. There was, however, no congruence between these groups and those emerging from morphological characters. Data from this study strongly support the connection between Leptographium and Ophiostoma Sydow & Sydow. They also provide us with an objective means to confirm the identity of many Leptographium species that are difficult to distinguish based on morphological characters.Key words: Leptographium, phylogeny, morphology, Ophiostoma, rRNA.

scholarly journals Systematics of Scleranthus (Caryophyllaceae)

2021 ◽  
Author(s):  
◽  
Robin David Smissen
Keyword(s):  
Sequence Analysis ◽  
Dna Sequence ◽  
Dna Sequences ◽  
Sequence Divergence ◽  
Morphological Characters ◽  
Dna Sequence Analysis ◽  
Its Sequences ◽  
Data Sets ◽  
Nuclear Its ◽  
Floral Characters

<p>Scleranthus is a genus of about 12 species of herbaceous flowering plants or small shrubs with a disjunct Eurasian/Australasian distribution. Monophyly of the genus is supported by the close similarity of gynoecial development of all species and consistent with nuclear ITS DNA sequence analysis. Traditionally the genus had been divided into two sections, section Scleranthus and section Mniarum. Section Mniarum is exclusively Australasian while section Scleranthus has been circumscribed to contain exclusively European species or a combination of European and Australasian species. Pollen and floral characters align the species into Australasian and Eurasian groups also supported by nuclear ITS DNA sequence analysis. Section Scleranthus as more broadly defined (i.e., sensu West and Garnock-Jones, 1986) is therefore at least paraphyletic or at worst polypyhyletic. Phylogenetic reconstructions based on morphological characters differ from those based on ITS sequences in supporting different relationships within the Australasian species of Scleranthus. Hybridisation and introgression within the genus are discussed and suggested as the cause of discordance between morphology and DNA sequence based trees. Low sequence divergence among Scleranthus ITS sequences suggests that the European and Australasian clades within the genus diverged within the last l0 million years. Biogeographic implications of these dating and competing hypotheses explaining the disjunct North-South distribution of the genus are discussed. Nuclear ITS and chloroplast ndhF DNA sequences both suggest that Scleranthus belongs to a clade within the family Caryophyllaceae consisting of members of subfamilies Alsinoideae and Caryophylloideae. Phylogenetic relationships between genera belonging to the three subfamilies of Caryophyllaceae (Alsinoideae, Caryophyloideae, and Paronychioideae) are addressed in this thesis through ndhF sequence analysis, which provides no support for the monophyly of traditionally recognised groups. Morphological character data sets are likely to always encompass multiple incongruent data partitions (sensu Bull et al. 1993). It may therefore be appropriate to combine data from DNA sequence and morphology for parsimony analysis even where the two are significantly incongruent.</p>

scholarly journals Systematics of Scleranthus (Caryophyllaceae)

2021 ◽  
Author(s):  
◽  
Robin David Smissen
Keyword(s):  
Sequence Analysis ◽  
Dna Sequence ◽  
Dna Sequences ◽  
Sequence Divergence ◽  
Morphological Characters ◽  
Dna Sequence Analysis ◽  
Its Sequences ◽  
Data Sets ◽  
Nuclear Its ◽  
Floral Characters

<p>Scleranthus is a genus of about 12 species of herbaceous flowering plants or small shrubs with a disjunct Eurasian/Australasian distribution. Monophyly of the genus is supported by the close similarity of gynoecial development of all species and consistent with nuclear ITS DNA sequence analysis. Traditionally the genus had been divided into two sections, section Scleranthus and section Mniarum. Section Mniarum is exclusively Australasian while section Scleranthus has been circumscribed to contain exclusively European species or a combination of European and Australasian species. Pollen and floral characters align the species into Australasian and Eurasian groups also supported by nuclear ITS DNA sequence analysis. Section Scleranthus as more broadly defined (i.e., sensu West and Garnock-Jones, 1986) is therefore at least paraphyletic or at worst polypyhyletic. Phylogenetic reconstructions based on morphological characters differ from those based on ITS sequences in supporting different relationships within the Australasian species of Scleranthus. Hybridisation and introgression within the genus are discussed and suggested as the cause of discordance between morphology and DNA sequence based trees. Low sequence divergence among Scleranthus ITS sequences suggests that the European and Australasian clades within the genus diverged within the last l0 million years. Biogeographic implications of these dating and competing hypotheses explaining the disjunct North-South distribution of the genus are discussed. Nuclear ITS and chloroplast ndhF DNA sequences both suggest that Scleranthus belongs to a clade within the family Caryophyllaceae consisting of members of subfamilies Alsinoideae and Caryophylloideae. Phylogenetic relationships between genera belonging to the three subfamilies of Caryophyllaceae (Alsinoideae, Caryophyloideae, and Paronychioideae) are addressed in this thesis through ndhF sequence analysis, which provides no support for the monophyly of traditionally recognised groups. Morphological character data sets are likely to always encompass multiple incongruent data partitions (sensu Bull et al. 1993). It may therefore be appropriate to combine data from DNA sequence and morphology for parsimony analysis even where the two are significantly incongruent.</p>

Phylogenetic relationships among Malagasy lemurs as revealed by mitochondrial DNA sequence analysis

Primates ◽  
1995 ◽  
Vol 36 (3) ◽  
pp. 431-440 ◽  
Author(s):  
M. Del Pero ◽  
S. Crovella ◽  
P. Cervella ◽  
G. Ardito ◽  
Y. Rumpler
Keyword(s):  
Mitochondrial Dna ◽  
Sequence Analysis ◽  
Dna Sequence ◽  
Phylogenetic Relationships ◽  
Dna Sequence Analysis ◽  
Mitochondrial Dna Sequence

Morphological and phylogenetic relationships of the threatened geophyte Wurmbea novae-zelandiae (Colchicaceae) from New Zealand, with notes on typification

Phytotaxa ◽  
2017 ◽  
Vol 307 (2) ◽  
pp. 123
Author(s):  
PETER B. HEENAN ◽  
TERRY D. MACFARLANE ◽  
ANDREA L. CASE ◽  
SEAN W. GRAHAM ◽  
ANNIKA VINNERSTEN ◽  
...  
Keyword(s):  
New Zealand ◽  
Dna Sequence ◽  
Phylogenetic Relationships ◽  
Floral Morphology ◽  
Sequence Data ◽  
Morphological Characters ◽  
New Combination ◽  
Dna Sequence Data ◽  
Phylogenetic Studies ◽  
Generic Description

The new combination Wurmbea novae-zelandiae was recently made based on published phylogenetic studies, but little information was provided on its relationships based on morphology. This species was originally described as Anguillaria novae-zelandiae, for which a lectotype is designated. Morphological characters of W. novae-zelandiae are re-evaluated and shown to be characteristic of Wurmbea, thereby supporting the revised generic placement. However, W. novae-zelandiae differs from all other Wurmbea species in its diminutive stature, fewer tepals and stamens, and variable floral morphology, with 1–3 carpels, often leaf-like tepals, and aberrant tepal shape and number. DNA sequence data places W. novae-zelandiae as the sister species of W. uniflora, a species not included in earlier phylogenetic studies. These two species share mostly solitary flowers with white tepals, nectaries two per tepal and similar in form and position, small yellow anthers, and styles that are relatively short and recurve as flowering proceeds, with the inner style surface stigmatic for up to half of its length. A revised generic description of Wurmbea is provided to take account of the recently widened concept.

Sign in / Sign up

Export Citation Format

Share Document