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Abstract

Chemical characters in the majority of the Tasmanian
species of Eucalypts have been investigated to determine their
value to the taxonomy of the genus.
The investigation has included three classes of chemicals.

1. The leaf and twig bark anthocyanins of each of twenty-two
species were isolated and identified; it was found that
anthocyanin distribution generally paralleled the split of
the Tasmanian Eucalypts into two sections, namely, Sections
Macrantherae and Renantherae. Cyanidin compounds containing
glucose are the most widespread in the genus, other anthocyanidins
found being delphinidin, malvidin and peonidin. The anthocyanin
pattern of the Macrantherae is generally simple, and is
based on the 3-glucoside and 3,5-diglucoside of cyanidin. The
Section Renantherae,
is further subdivided into two groups on the basis of the distribution
both of the galactosides of cyanidin and delphinidin
and of the methylated anthocyanins ~ this division parallels
that based on morphological characters. The anthocyanin patterns
of some renantherous species, (E. coccifera, E. risdoni
and E. tasmanica) reflects the simplicity of the patterns
found in macrantherous species.

2. Other flavonoids in leaf and twig bark were classified
according to their Rf values in different solvent systems.
Certain aglycones and alcohol-soluble polyphenols were restricted
to either section or to groups within these sections.
Again, these divisions agreed with morphological classification
excepting for E. coccifera.

3. Protein and isoenzyme patterns of seedlings of the
twenty-two species were obtained. Peroxidase and esterase
patterns were useful in showing taxa relationships. All
macrantherous species, except E. aggregata showed similar
peroxidase patterns, while E. aggregata showed a typically
renantherous pattern. Quantitative differences in peroxidase
bands reflect intra-section variation. Qualitative
and quantitative variations in esterase patterns also provide
useful taxonomic markers in the two sections.
Chemical characters were also used in an investigation
of the E. viminalis/E. dalrympleana complex in Tasmania. Macro-molecular
characters of seedlings did not aid in distinguishing
the two species, but differences in the phenolic compounds
of the seedling leaves enabled positive identification of a
"viminalis-type" or a "dalrympleana-type" tree.

Item Type:	Thesis - PhD
Authors/Creators:	Sharma, PJ
Keywords:	Eucalyptus
Copyright Information:	Copyright 1974 the Author - The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s).
Additional Information:	Thesis (Ph.D.)--University of Tasmania, 1974. Bibliography: l. 87-94
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