Methods to overcome seed dormancy in Echinacea angustifolia DC

Some factors (light, prechilling, gibberellic acid, ethylene) affecting germination of seeds of Echinacea angustifolia DC. were investigated. Without any pretreatment, the seeds germinated better in darkness than in light. however, percentages germination were low in both cases. GA,, did not increase germination in light. Prechilling for 7-15 days in light or in darkness hardly affected percentage germination but significantly increased the rate of germination. Ethephon during prechilling resulted in a large increase of percentage and rate of germination in light, but had hardly any effect on germination in darkness. The results showed that a prechilling treatment for about I I days at 5 degreesC in a 1 mM ethephon solution in continuous light, followed by a 2-week germination period in light (24 h per day) at 20/30 degreesC, can induce >90% seed germination in E. angustifolia. The prechilling treatment in ethephon also increased the rate of germination. (C) 2001 Elsevier Science B.V. All rights reserved.