Actinotus helianthi (flannel flower) seed: diagrammatic cross section
Conclusions to the final Research Report to the Australian Flora Foundation on the research grant
Development, Germination and Dormancy of Actinotus helianthi (Flannel Flower) Seeds
Lynette A Lee, Dr Peter B Goodwin
Department of Crop Sciences, University of Sydney NSW 2006 Grant details Final report (279 KB)
Poor seed germination in Actinotus helianthi can be attributed
to a combination of lowered viability due to embryoless and undeveloped
seeds, and to seed dormancy. However, in the majority of cases, seed dormancy
appears to be the overriding cause of non-germinability of freshly collected
seed. The seeds of A. helianthi appear to undergo after-ripening
in dry storage at 21°C, with the optimum duration of storage lying
anywhere between 2 and 12 months. Further work to investigate the effects
of temperature, light, and humidity on afterripening are currently underway.
The optimum temperature for germination of A. helianthi is between
15 and 20°C, with some germination occurring at temperatures between
10° and 30°C. Light promotes germination only at higher temperatures.
The seed coat (testa) appears
to play an important role in the control of dormancy in this species,
but the exact nature of this role has yet to be elucidated.
In the wild, germination of flannel flower seeds would probably occur mostly during the autumn months when temperatures are lower, when more moisture is available for seedling growth, and after the seeds have had time to after-ripen following their dispersal during late spring and summer.