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4.3 RESULTS
4.3.1 Viability tests
Germination physiology
The results of the TTC and embryo excision tests are shown in Table 4.1. According
to the TTC test, seed embryo and endosperm of R. camerooniana and R. flava
showed < 61% staining indicating low to moderate viability respectively. All other
tested species of Romulea exhibited over 90% staining of embryo and endosperm
indicating high seed viability. The embryo excision test of R. camerooniana and R.
rosea did not show any in vitro response. An in vitro response was however
observed for all other species. Excised embryos of R. diversiformis and R. leipoldtii
showed the highest percentage in vitro response. TTC and embryo excision tests
were comparable for species R. diversiformis, R. leipoldtii and R. monadelpha (Table
4.1). The results of both tests differed for R. flava, R. minutiflora and R. sabulosa.
Table 4.1: Seed viability tests of different Romulea species.
Species
TTC (embryo + endosperm)
(% staining )
Embryo excision
(% response)
R. camerooniana 45 ± 19 0 ± 0
R. diversiformis 100 ± 0 100 ± 0
R. flava 60 ± 13 95 ± 5
R. leipoldtii 95 ± 6 100 ± 0
R. minutiflora 92 ± 12 70 ± 30
R. monadelpha 100 ± 0 90 ± 10
R. rosea 90 ± 6 0 ± 0
R. sabulosa 95 ± 5 54 ± 11
4.3.2. Water content and imbibition rate
R. leipoldtii seed had the highest initial water content (37 ± 1.4%) followed by R. flava
(30 ± 2.1%). The lowest seed water content was determined for R. camerooniana
and R. diversiformis (23%). Overall the range of seed water content was between 23
and 37% in the studied Romulea species (Figure 4.1). In most of the species the rate
of imbibition sharply increased in the first three hours and was gradual up to 6 h,
followed by a sharp increase in water uptake up to 48 h, after which it was slow. R.
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