Effect of warm and cold stratification, and ethanol treatment on germination of Corylopsis seeds

Abstract

Seed germination experiments with Corylopsis coreana, C. sinensis var. calvescens, and Corylopsis gotoana were conducted. Corylopsis coreana seeds were treated at 5o, 7.5o, 10o, 12.5o and 20oC to study the upper temperature limit to break dormancy. Seeds of C. sinensis var. calvescens were treated 1 mo of warm stratification (WS) at 10, 15, 20, and 25oC followed by CS at 5oC for 0, 1, 2, and 3 mo to understand the requirement of WS and CS to effectively break dormancy. Germination of Corylopsis seeds at 15o-20oC without CS suggests that dormancy is considered shallow and the upper temperature limit to break is 12.5oC. Immersing seeds in water or ethanol induced seed germination which may result from leaching of inhibitors from the seed. Observation of seed coats following treatment with water and ethanol by means of low temperature scanning electron microscopy (LT-SEM) revealed elongated and rectangular/hexagonal shaped cells in C. coreana and irregular jigsaw puzzle-piece shapes in C. gotoana. In conclusion, dormancy in Corylopsis is considered shallow and the optimum CS is suggested to be 7.5oC, while optimum WS is ranging from12.5o to 20oC.

Keywords

• corylopsis coreana
• corylopsis gotoana
• corylopsis sinensis var. calvescens
• optimum temperature
• scanning electron microscopy
• seed dormancy