Return to ContentsKings Park scientists have found a way to stop plants from being endangered. Some of the ways are listed down below.
The Effects of Smoke on Germination
Why was the research started?
Since the time of the first fleet in the
1780s, many Australian species could not be germinated reliably from seed. This
baffled many horticulturalists and plant lovers who marvelled at the diversity
of wildflowers in Australia but were unable to grow them by the conventional
seed propagation means.
Although sophisticated tissue culture methods
often involving complex hormone treatments may have resulted in germination for
many species, these methods were hardly applicable to the home garden or for
nursery production in a commercial sense. Following the discovery in 1991 by
South African scientists that smoke may aid seed germination in African species,
Kings Park staff were quick to research the impacts of smoke on germination of
Australian species.
Smoke provides one of the most important cues for breaking dormancy in many
species and opens up new horizons for the horticulture appreciation and
conservation of Australian plants.
Germination after a fire
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Its been commonly held that its the heat and the ash of fire that is important in germination. It is now clear that it is the smoke from the fire that plays one of the most crucial roles in aiding germination in a wide range of native species. This effect is most apparent in those species which shed their seeds into the soil seed bank. For those species that retain their seed in capsules on the plant for long periods, there appears to be less of a requirement for smoke. |
Experiments
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Experiments were conducted under nursery conditions and in disturbed bushland, using seed selected from the natural soil seed bank. In most instances where smoke is not applied, the control, that is, without smoke treatment, will often have no, or very little germination. |
Current research into smoke
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Liquid smoke,
aerosol smoke and concentrated forms of smoke are currently being
developed for application to horticulture and land management. Research is
also attempting to understand what is the key chemical in smoke
responsible for promoting germination. |
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The search for the active chemical in smoke
What is clear so far, is that whatever the agent is in smoke, it is likely to be very effective at extraordinary low levels, and that only small quantities will be needed to treat hectares of bushland; eliciting a germination response from the dormant seed bank. For horticulture, resolution of the active chemical will allow the commercial application of smoke to a broader range of species, and may help in the commercialisation of native species for bedding plants and landscaping.
Tissue Culture
The Tissue Culture Process
Propagation material for tissue culture
can be established from growing shoots, leaves or stem tissues and even embryos
taken from seeds.
These tissues are placed on agar media after sterilising to rid the material of
surface contaminants.This gelled medium contains growth regulators which cause
the plant tissues to grow and proliferate.
Once healthy rooted plants are produced, the plantlets are transferred to soil
and nursery culture.
Tissue Culture at Kings Park & Botanic Garden
The development of plant tissue culture
and micropropagation for research and commercial nursery production has
demonstrated the value of these techniques for mass propagation of plants. In
addition, use of tissue culture techniques may provide solutions to breeding
barriers, allow long term preservation of a species where seed is not available
or difficult to germinate, and permit multiplication of plants which cannot be
readily propagated by seed, cuttings or division.
The laboratory specializes in micropropagation and in vitro conservation of the rare and threatened flora of Western Australia.
In many cases the selection of plant material and media for in vitro propagation
requires considerable empirical research. Many specialised formulations have now
been developed for micropropagation of nearly 200 species representing 33
families of Western Australian plants.