|Author: ||G.J. Brits|
Oxygen incubation, presoaking in "Promalin" (GA4 + GA7 + benzyladenine) and sulphuric acid scarification pre-treatment were applied as a cumulative series of treatments to freshly harvested intact Leucospermum achenes.
Achenes were incubated under an alternating temperature regime optimal for L.cordifolium, which was used as a control species.
The other species, originating from widely different fynbos habitats, were L. cuneiforme, L. erubescens, L. glabrum, L. reflexum and L. vestitum. Treatment effects on germination percentage were cumulative in most species and also resulted in similar germination rate patterns, suggesting common physiological mechanisms for germination.
The promotive effect indicated for "Promalin" on L. reflexum and L. erubescens germination suggests that these species were incubated under a non-optimal temperature regime.
Acid scarification combined with the other treatments gave maximal germination percentages and rates and stimulated a significant proportion of subviable achenes to germinate, as was reflected by tetrazolium viability test results.
Seed coat qualities of the recently domesticated L. cordifolium, the "wild" species with highly viable seeds and species in which seeds were harvested prematurely (with low sinker percentages) are discussed.
Download Adobe Acrobat Reader (free software to read PDF files)
URL www.actahort.org Hosted by KU Leuven