In:
Australian Systematic Botany, CSIRO Publishing, Vol. 15, No. 1 ( 2002), p. 49-
Abstract:
This expanded survey of ITS sequences represents the largest analysis of
molecular data ever attempted on Eucalyptus. Sequences of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA
were included in an analysis of 90 species of Eucalyptus s.s. and 28 species representing eight other
genera (Allosyncarpia, Angophora, Arillastrum, Corymbia,
Eucalyptopsis, Stockwellia, Lophostemon and Metrosideros). The
results of the study indicate that Angophora and Corymbia form a well-supported clade that is highly
differentiated from Eucalyptus s.s. Corymbia species are divided between two clades, one of which may be the sister to
Angophora. Allosyncarpia, Arillastrum, Eucalyptopsis and
‘Stockwellia’ are also highly differentiated from Eucalyptus s.s. If the genus
Eucalyptus is to be expanded to include Angophora and
Corymbia(sensu Brooker 2000), ITS data suggest that Allosyncarpia,
Eucalyptopsis, ‘Stockwellia’ and potentially
Arillastrum should also be included in Eucalyptus s.l. The ITS data suggest that subg.
Symphyomyrtus is paraphyletic and that subg. Minutifructus should be included within it. Within
subg.Symphyomyrtus, only sect. Maidenaria appears to be monophyletic. Sections
Adnataria and Dumaria are probably monophyletic; sections Exsertaria and
Latoangulatae are very close and probably should be combined in a single section. Section Bisectae is
polyphyletic and is divided into two distinct lineages. The phylogenetic groups depicted by ITS data are consistent with the frequency of natural
inter-specific hybridisations as well as data from controlled crosses within subgenus Symphyomyrtus. The ITS data illustrate that
subg. Idiogenes and western Australian monocalypts are early evolutionary lines relative to E. diversifolia,
E. rubiginosa (monotypic subg. Primitiva) and the eastern monocalypts and that subg.
Primitiva should be sunk into subg. Eucalyptus. Subgenus Eudesmia may
be monophyletic, grouping with subgenera Idiogenes and Eucalyptus. Further work is required to confirm the
phylogenetic positions of the monotypic subgenera Alveolata, Cruciformes,
Acerosae and Cuboidea.
Type of Medium:
Online Resource
ISSN:
1030-1887
Language:
English
Publisher:
CSIRO Publishing
Publication Date:
2002
SSG:
12
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