科研之友
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摘要
The smoke-derived chemical karrikinolide commonly triggers seeds in the Brassicaceae, Solanaceae and Asteraceae families to germinate, yet species in the Poaceae-another major understorey and weed family-have responded to the chemical with mixed results. This study aimed to understand why some grass species respond to karrikinolide while others do not. Using a field-based seed-burial trial, dose-response experiment, and stratification experiment, we investigated whether karrikinolide could alleviate dormancy and trigger seeds to germinate for seven global agronomic weeds: Avena fatua L., Lolium rigidum Gaudin, Eragrostis curvula (Schrad.) Nees, Phalaris minor Retz., Hordeum glaucum Steud., Ehrharta calycina Sm. and Bromus diandrus Roth. Seeds of A. fatua were consistently stimulated to germinate with karrikinolide in all experiments, whether seeds were freshly collected or dormancy had been partially alleviated. In contrast, seeds of L. rigidum failed to respond to karrikinolide when the seeds were fresh, after-ripened in the laboratory, and even during natural dormancy loss in the field. Interestingly, although karrikinolide did not stimulate freshly collected E. curvula seeds to germinate, it hastened dormancy loss when applied during stratification. These findings are helpful for understanding the responses of grass species following fire. They also contribute to a growing body of research aimed at using karrikinolide as a tool for triggering uniform germination of seeds for enhancing restoration efforts and depleting the weed seed bank.
- 出版日期2011
