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Introduction
The subgenera Romulea and Spatulanthus were expected to have differentially
suitable conditions for ex vitro and in vitro development and growth.
1.3 GENERAL OVERVIEW OF THESIS CONTENT
Chapter 2 is a review of literature available on aspects relative to this study. It firstly
covers the distribution, morphology, life-cycle, habitat and conservation status of
species in the genus Romulea. It then discusses other studies performed on
ecophysiology and propagation of this genus with descriptions of phylogeny and
taxonomy. It further reviews the ecophysiological techniques of soil sampling and
analysis. A review of seed physiology and techniques applicable to this study is
included in this chapter. It also gives a review on micropropagation in general,
discusses some in vitro techniques applicable to the study, placing emphasis on
explant selection, culture initiation and multiplication, embryogenesis, in vitro corm
formation, in vitro flowering and ex vitro acclimatization. A summary of the
micropropagation of species in the family Iridaceae is included.
In Chapter 3 the habitat of some Romulea species is investigated further through
ecophysiological techniques of soil sampling and analysis.
Chapter 4 is an examination of the germination physiology of some Romulea
species. This was done firstly by examining the physical properties and viability of the
seeds, and then investigating the effect of an array of physical and chemical stimuli
on germination. The physical properties of the seeds; imbibition rate, moisture
content and viability of seeds were determined. The seed coat and micropylar
regions were examined using scanning electron microscopy. To test for suitable
stimuli for germination, the effect of temperature and light, cold and warm
stratification, acid and sand paper scarification, plant growth promoting substances,
deficiency of nitrogen, phosphorous and potassium, and different light spectra
(phytochromes) on germination were examined.
Chapter 5 is an examination of the suitability of various explant types and media
supplementations for culture initiation. Two explant types were used; seedling organs
and embryos. It also investigates the effect of various physical and chemical
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