View/Open - ResearchSpace - University of KwaZulu-Natal
View/Open - ResearchSpace - University of KwaZulu-Natal
View/Open - ResearchSpace - University of KwaZulu-Natal
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2.7 PROPAGATION OF ROMULEA SPECIES<br />
Literature review<br />
There are very few publications on the propagation <strong>of</strong> Romulea species. In a book by<br />
DENO (1993), it was reported that R. bulbocdium and R. luthicii geminated at 10°C,<br />
with no germination at 20°C. It also stated that 96% germination was obtained during<br />
winter in Tauranga, New Zealand with fresh R. hantamnensis seeds, whereas seeds<br />
which had been in dry storage for an unknown time showed no germination (DENO,<br />
1993). The only scientific paper that could be found on this topic is a study on the<br />
seed dispersal and germination <strong>of</strong> R. rosea by EDDY & SMITH (1975). Some<br />
preliminary tests done by EDDY & SMITH (1975) suggests that application <strong>of</strong> KNO3<br />
and prechilling for 5 days at 2°C does not increase the germination <strong>of</strong> this species.<br />
These experiments indicated an optimum temperature <strong>of</strong> 10 to 11°C. This was<br />
confirmed by larger experiments, which showed that its germination has an optimum<br />
in the range <strong>of</strong> 9.5 to 15°C and is inhibited by temperatures exceeding 16.5°C. They<br />
found that germination <strong>of</strong> this species is quite slow relative to other species occurring<br />
in the pastures which they studied (EDDY & SMITH, 1975). They also showed that<br />
seed collected in 1969 had a higher percentage germination and shorter time to<br />
germination than seed collected in 1968 (EDDY & SMITH, 1975). This and the<br />
experiments on R. hantamnensis seeds described by DENO (1993) suggest that<br />
fresh seeds <strong>of</strong> species <strong>of</strong> this genus should be used for germination.<br />
2.8 GERMINATION PHYSIOLOGY<br />
2.8.1 Seed structure<br />
An angiosperm seed is typically comprised <strong>of</strong> the embryo, which is the result <strong>of</strong><br />
fertilization <strong>of</strong> the egg cell in the embryo sac by a male pollen tube nucleus; the<br />
endosperm, which arises from the fusion <strong>of</strong> two nuclei in the embryo sac with the<br />
other pollen tube nucleus; the perisperm, which is developed from the nucellus; and<br />
the protective testa or seed coat, which is formed from one or both the integuments<br />
around the ovule (HARTMANN & KESTER, 1965; BEWLEY & BLACK, 1994).<br />
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