Successful seed germination of the nickel hyperaccumulator Stackhousia tryonii.
OBJECTIVE
Stackhousia tryonii, a rare nickel hyperaccumulating herb, is endemic to ultramafic (serpentine) soils of central Queensland, Australia. The effects of eight dormancy-relieving treatments on germination of stored seeds of Stackhousia tryonii were investigated under controlled light and temperature conditions. *


METHODS
The treatments were: untreated (control i), leached and dehydrated (primed control ii), treating with gibberellic acid (150 and 300 microM), smoke extract (5 and 10 %, v/v) and potassium cyanide (40 and 80 mM). *


RESULTS
Freshly harvested seeds did not germinate. Germination percentage increased with time of storage for up to 18 months (38.3 %). Gibberellin, smoke extract and cyanide treatments did not significantly improve germination. Light did not affect seed germination and there was no interaction between dormancy-relieving treatments and light. A significant inhibition of germination occurred in seeds treated with 5 % (but not 10 %) aqueous smoke extract. Saturated fatty acids, predominantly tridecanoic (C13:0), constituted about 90 % of the total fatty acids in the oil of freshly harvested seeds. In contrast, there was increased accumulation (>75 %) of mono-unsaturated (oleic, c18:1) and poly-unsaturated (linoleic, c18:2; linolenic, c18:3) fatty acids in the oil of stored seeds. *


CONCLUSIONS
Seeds of S. tryonii require an after-ripening period for germination.
Bhatia
Naveen P
NP
Primary Industries Research Centre, School of Biological and Environmental Sciences, Central Queensland University, Rockhampton, Queensland 4702, Australia. naveen.bhatia@ansto.gov.au
Nkang
Ani E
AE
Walsh
Kerry B
KB
Baker
Alan J M
AJ
Ashwath
Nanjappa
N
Midmore
David J
DJ
D029753:Celastraceae / Q000254:growth & development* / Q000378:metabolism; D018525:Germination / Q000502:physiology*; D008027:Light; D009532:Nickel / Q000378:metabolism*; D012639:Seeds / Q000502:physiology*
D009532:Nickel