Viability of and germination test conditions for Schoenocaulon officinale seeds

摘要

Schoenocaulon officinale, commonly known as Sabadilla, is a new world species, which has been an important medicinal plant for Native Americans, and it is currently economically important for the production of some homeopathic medicines. At present, research regarding Sabadilla has mainly been focused on systematics, quantitative analysis of alkaloid fraction, and its insecticidal and medicinal properties. A search in academic databases produced no literature on seed germination of S. officinale. Therefore, the main objectives of this research were to determine suitable germination test conditions and to assess the storability of S. officinale seeds. Triphenyl tetrazolium chloride method was used to determine the viability of the seeds. Owing to thelack of methodology for this species, the International Seed Testing Association (ISTA)'s rules for Allium cepa were used as the starting point. Seeds were stored at 6°C, and germination tests were carried out at 20°C, with permanent light. A thermo-gradient table was used to identify the optimum temperature for germination. Sabadilla seeds started to germinate 18 days after planting, and complete germination was achieved in 42 days. Best germination rates were achieved using constant temperatures between 19.2°C and 30.7°C and alternating temperatures between 10.0°C and 28.4°C. Results of the storability assessment indicated that loss of total viability was expected to occur in 2.5 years. We recommend a temperature of 25°C and permanent light and first and final count after 15 and 45 days to determine, respectively, germination and viability with the ISTA method described for A. cepa using longitudinally dissected seeds.