The fire ephemeral Tersonia cyathiflora (Gyrostemonaceae) germinates in response to smoke but not the butenolide 3-methyl-2H-furo[2,3-c]pyran-2-one

BACKGROUND AND AIMS: Tersonia cyathiflora (Gyrostemonaceae) is a fire ephemeral with an obligate requirement for smoke to germinate. Whether it is stimulated to germinate by 3-methyl-2H-furo[2,3-c]pyran-2-one (karrikinolide, KAR(1)), the butenolide isolated from smoke that stimulates the germination of many other smoke-responsive species, is tested. METHODS: Seeds of T. cyathiflora were buried in autumn following collection and were exhumed 1 year later, as this alleviates dormancy and enables seeds to germinate in response to smoke-water. Exhumed seeds were tested with smoke-water and KAR(1). Fresh preparations of these solutions were again tested on seeds exhumed 2 months later under a broader range of conditions. They were also tested on Grevillea eriostachya (Proteaceae) and Stylidium affine (Stylidiaceae) to confirm the activity of KAR(1). KEY RESULTS: T. cyathiflora seeds germinated in response to smoke-water but not to KAR(1). In contrast, G. eriostachya and S. affine germinated in response to both smoke-water and KAR(1). CONCLUSIONS: Although many smoke-responsive seeds germinate in the presence of KAR(1), this does not apply universally. This suggests that other chemical(s) in smoke-water may play an important role in stimulating the germination of certain species.