- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Biosystematics of the endemic Hawaiian species of Lysimachia...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Biosystematics of the endemic Hawaiian species of Lysimachia (Primulaceae) Marr, Kendrick Lloyd
Abstract
The endemic Hawaiian species of Lysimachia were examined using a combination of analyses of metric and non—metric morphological characters, allozyme variaton and crossing studies. The purpose was to produce a taxonomic revision and to investigate the degree of genetic divergence and type of reproductive isolation that has accompanied speciation. Principal components analysis of metric characters produced an ordination of OTU’s, that was used as a first step toward understanding the range of variation. However, greater reliance was placed on non—metric characters for the taxonomic revision. Sixteen species and four subspecies, including three previously undescribed species are now recognized. Allozyme variation was analyzed in 15 taxa from 48 populations. Genetic identities ranged from 0.71-1.00, indicating high genetic similarity and supporting the hypothesis of a monophyletic origin. These values are intermediate to those of other insular genera. There is a low correlation between morphological variation and allozyme variation. Total genetic diversity, Ht, within species, ranges from 0.02-0.22. Genetic diversity within populations does not decrease in an entirely linear manner from the oldest to the youngest island. However, there is a step—wise decrease in genetic diversity among taxa within an island from the oldest through to the youngest island. All interspecific crosses that were attempted produced fertile seeds. Pollen stainability was quite variable in all species and in the F1 hybrids of most species pairs. The reduced stainability of the parents involved in the crosses makes it difficult to interpret the significance of reduced stainability of some hybrids. Approximately 80% of self pollinations within flowers failed. This appears to be due to protogyny, not to self-incompatibility. Adaptive radiation in Lysimachia has resulted in species that have diverged in corolla pigmentation, leaf size and shape, and ecological preferences. Speciation has occurred without the types of divergence between species that often accompanies speciation on continents, i.e., internal, post- zygotic barriers to reproduction and low genetic identities. This pattern of morphological and genetic variation is similar to that seen in other insular groups.
Item Metadata
Title |
Biosystematics of the endemic Hawaiian species of Lysimachia (Primulaceae)
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
1995
|
Description |
The endemic Hawaiian species of Lysimachia were examined
using a combination of analyses of metric and non—metric
morphological characters, allozyme variaton and crossing
studies. The purpose was to produce a taxonomic revision and
to investigate the degree of genetic divergence and type of
reproductive isolation that has accompanied speciation.
Principal components analysis of metric characters produced an
ordination of OTU’s, that was used as a first step toward
understanding the range of variation. However, greater
reliance was placed on non—metric characters for the taxonomic
revision. Sixteen species and four subspecies, including
three previously undescribed species are now recognized.
Allozyme variation was analyzed in 15 taxa from 48
populations. Genetic identities ranged from 0.71-1.00,
indicating high genetic similarity and supporting the
hypothesis of a monophyletic origin. These values are
intermediate to those of other insular genera. There is a low
correlation between morphological variation and allozyme
variation. Total genetic diversity, Ht, within species,
ranges from 0.02-0.22. Genetic diversity within populations
does not decrease in an entirely linear manner from the oldest
to the youngest island. However, there is a step—wise
decrease in genetic diversity among taxa within an island from
the oldest through to the youngest island. All interspecific crosses that were attempted produced
fertile seeds. Pollen stainability was quite variable in all
species and in the F1 hybrids of most species pairs. The
reduced stainability of the parents involved in the crosses
makes it difficult to interpret the significance of reduced
stainability of some hybrids. Approximately 80% of self
pollinations within flowers failed. This appears to be due to
protogyny, not to self-incompatibility.
Adaptive radiation in Lysimachia has resulted in species
that have diverged in corolla pigmentation, leaf size and
shape, and ecological preferences. Speciation has occurred
without the types of divergence between species that often
accompanies speciation on continents, i.e., internal, post-
zygotic barriers to reproduction and low genetic identities.
This pattern of morphological and genetic variation is similar
to that seen in other insular groups.
|
Extent |
4057742 bytes
|
Genre | |
Type | |
File Format |
application/pdf
|
Language |
eng
|
Date Available |
2009-04-23
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
DOI |
10.14288/1.0088322
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Graduation Date |
1995-11
|
Campus | |
Scholarly Level |
Graduate
|
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.