Romero Fredy R, Delate Kathleen, Hannapel David J
Department of Horticulture, Iowa State University, Ames, IA 50011-1100.
HortScience. 2005 Oct;40(6):1751-1754.
Organic production of one of the most popular botanical supplements, Echinacea, continues to expand in the U.S. Echinacea seeds typically show a high degree of dormancy that can be broken by ethephon or gibberelic acid (GA), but these methods are currently disallowed in organic production. In order to determine the efficacy of non-chemical seed treatments, we evaluated the effect of varying seed source and supplying light, with and without cold-moist stratification, on seed germination of the three most important medicinal species of Echinacea, E. angustifolia DC, E. purpurea (L) Moench, and E. pallida (Nutt.) Nutt. Treatments included cold-moist stratification under 24 h light, 24 h dark, and 16/8 h light/dark to break seed dormancy. We found that germination was greater in the E. purpurea and E. pallida seeds from a commercial organic seed source compared to a public germplasm source. When seeds were not cold-moist stratified, 16-24 h light increased germination in E. angustifolia only. Echinacea angustifolia, E. purpurea, and E. pallida seeds that were cold-moist stratified under 16-24 h of light for 4 wk had a significantly greater percentage and rate of germination compared to seeds germinated in the dark. Therefore, cold-moist stratification under light conditions is recommended as a method to break seed dormancy and increase germination rates in organic production of Echinacea.
紫锥菊是美国最受欢迎的植物性补充剂之一，其有机生产规模持续扩大。紫锥菊种子通常具有高度休眠性，可用乙烯利或赤霉素打破休眠，但这些方法目前在有机生产中不被允许。为了确定非化学种子处理方法的效果，我们评估了不同种子来源以及有无冷湿层积处理并提供光照对紫锥菊三种最重要药用品种狭叶紫锥菊、紫花紫锥菊和淡紫紫锥菊种子萌发的影响。处理方法包括在24小时光照、24小时黑暗以及16/8小时光/暗条件下进行冷湿层积处理以打破种子休眠。我们发现，与公共种质资源来源的种子相比，商业有机种子来源的紫花紫锥菊和淡紫紫锥菊种子发芽率更高。当种子未进行冷湿层积处理时，16 - 24小时光照仅能提高狭叶紫锥菊的发芽率。与在黑暗中发芽的种子相比，在16 - 24小时光照下进行4周冷湿层积处理的狭叶紫锥菊、紫花紫锥菊和淡紫紫锥菊种子发芽率和发芽速率显著更高。因此，建议在光照条件下进行冷湿层积处理，作为打破紫锥菊种子休眠并提高其在有机生产中发芽率的一种方法。
