Mature fruit of T. dregeana, T. emetica and E. capensis were harvested from trees locally, in and around Durban, South Africa. Seeds were manually removed from the fruit and surface-sterilized by soaking them in a fungicidal solution for a short period of time. Mature fruit of S. cumini were hand-harvested from trees in Tanzania, and seeds were extracted from the fruit and despatched to Durban. Fallen seeds of P. henkelii were collected from the ground below the trees in Pietermaritzburg, and transported 80 km to Durban within a few days of collection, where they were surface-sterilized.
For storage experiments, seeds were partially dried to a non-lethal water content (Table 8.1) by burying them in activated silica gel in sealed plastic bags. After partial drying, seeds were placed in pre-sterilized buckets, which were then filled with vermiculite. The contents were mixed, the buckets sealed and placed in storage at 6°C, 16°C or 25°C. Fully hydrated seeds were similarly treated. At appropriate intervals, samples were withdrawn for germination assessment. Germinating seeds were assessed daily to enable calculation of mean time to germinate (MTG):
MTG = I (t n)/I n where t is the time in days from the start of the germination trial and n is the number of seeds completing germination on day t (Bewley and Black, 1994).
Water content was measured gravimetrically. The data presented here are for embryonic axes (whole embryos in the case of P. henkelii) and are expressed on a dry mass basis.
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