Thesis (M.Sc.(Systematics and Biodiversity Science))-- Stellenbosch University, 2001. / ENGLISH ABSTRACT: Sequence data from the intron and the spacer of the trnL-F chloroplast DNA region were
used to study the phylogenetic relationships of the genus Zygophyllum L. (Zygophylloideae:
Zygophyllaceae) in the southern African region. The chloroplast DNA was extracted from
both herbarium and silica-gel dried material. Closely related genera, i.e. Augea Thunb.,
Fagonia L. and Tetraena Maxim. within the subfamily Zygophylloideae and more distantly
related genera Seetzenia R.Br. ex Decne and Tribulus L. were used as outgroups. Sequences
revealed length variation mainly due to the presence of indels (insertions and deletions).
Phylogenetic analysis using parsimony revealed two distinct lineages for southern African
members of Zygophyllum, corresponding to the proposed subgeneric classification (Van
Huysteen 1937; Van Zyl 2000). There is a strong monophyly support for the sections within
the subgenus Agrophyllum (Neck.) Endl. However, the transference of the monotypic section
Grandifolia Engl. from subgenus Zygophyllum to Agrophyllum is not confirmed, because
material of Z. stapffii Schinz. was not available. Despite the morphological evidence for the
subdivision of the subgenus Zygophyllum, the molecular data did not confirm the monophyly
for its sections. This could be the result of biased sampling, since all the species used in the
analyses, except Z. cordifolium L.f. and Z. morgsana L., belong to section Capensia Engl.
The trnL region data support the transfer of the mono typic section Morgsana Huysst. from
subgenus Agrophyllum to subgenus Zygophyllum. The molecular data also seem to have
implications for the biogeography of Zygophyllum. The southern African Agrophyllum
representatives are related to East African and Middle East Zygophyllum species, whereas the
southern African subgenus Zygophyllum members are closely related to Australian
Zygophyllum species. / AFRIKAANSE OPSOMMING: Die volgorde-data van die trnL-F chloroplas-DNA gebied is gebruik om die filogenetiese
verwantskappe van die genus Zygophyllum L. (Zygophylloideae: Zygophyllaceae) in suider
Afrika te bestudeer. Die chloroplas-DNA is geëkstraheer van beide herbaria en silica-gel
gedroogde materiaal. Naverwante genera binne die subfamilie Zygophylloideae bv. Augea
Thunb., Fagonia L. en Tetraena Maxim., sowel as verder verwante genera, soos Seetzenia
R.Br. ex Decne en Tribulus L., was as buite-groepe gebruik. Die lengte-variasie in die
volgorde-data kan toegeskryf word aan indels (insertions and deletions). Filogenetiese analise
deur die gebruik van parsimonie het twee duidelike ontwikkelingslyne vir suider-Afrikaanse
Zygophyllum taksa aangedui. Dit stem goed ooreen met die voorgestelde subgeneriese
klassifikasiesisteem vir die genus (Van Huysteen1937; Van Zyl 2000). Daar is 'n sterk
ondersteuning vir monofilie van die seksies binne die subgenus Agrophyllum (Neck.) Endl.
Die oorplasing van die monotipiese seksie Grandifolia Engl. vanaf subgenus Zygophyllum na
subgenus Agrophyllum is nie bevestig nie, want materiaal van Z. stapffii Schinz. was nie
beskikbaar nie. Ten spyte van morfologiese bewyse vir die subdivisie van die subgenus
Zygophyllum het die molekulêre data nie die monofilie van die seksies bevestig nie. Dit is
moontlik as gevolg van eensydige data-insameling, aangesien al die spesies wat in die analise
gebruik word (behalwe Z. cordifolium L.f. en Z. morgsana L.) aan die seksie Capensia Engl.
behoort. Die trnL-gebied data ondersteun die oordra van die monotipiese seksie Morgsana
Huysst. van die subgenus Agrophyllum na die subgenus Zygophyllum. Die molekulêre data
bied ode inligting oor die biogeografie van Zygophyllum. Die suider-Afrikaanse Agrophyllum
taksa is verwant aan Oos-Afrika en Midde-Oosterse Zygophyllum spesies, terwyl lede van die
Suid-Afrikaanse subgenus Zygophyllum nouverwant is aan Zygophyllum spesies in Australië.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52099 |
| Date | 04 1900 |
| Creators | Makwarela, Azwimpheleli M. |
| Contributors | Bellstedt, D. U., Dreyer, L. L., Marais, E. M., Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 56 p. : ill. |
| Rights | Stellenbosch University |
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