2002 Volume 71 Issue 6 Pages 770-776
A water soluble part of smoke derived from leaves of an endemic Australian tree, Forest oak (Allocasuarina torulosa) is effective in stimulating seeds of a native Australian plant, Goodenia scaevolina F. Muell. to germinate. The smoke solution was made by burning 25g of dried senescent or fresh leaves and dissolving the smoke in a liter of distilled water. The highest seed germination rate occurred on a 1/50 dilution of a saturated smoke solution on Murashige & Skoog (MS) medium. The components of smoke and heat are two factors considered to be involved in the smoke effects. The heat treatment of seeds at 80°C for 1 to 10min, combined with a smoke solution, was significantly effective on seed germination. However, the effect of heat treatment did not last long as germination rates became even lower than that of the untreated control seeds 8 weeks after the treatment. The smoke solution showed a similar effect to treatment with 1000ppm gibberellic acid (GA3) on seed germination at the start. The germination rate in 100 days on smoke medium was equivalent to those between 100 and 10ppm GA3. The germination rate on 1/50 smoke medium increased in the 8 months after the smoke solution was made, indicating that some changes might have occurred in the smoke solutions during their storage.