|Suh, Jeung keun|
Submitted to: Scientific Horticulture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/13/2009
Publication Date: 5/18/2009
Citation: Roh, M.S., Lee, A.K., Suh, J.K., Bordelon, C.M. 2009. Interspecific variations in seed germination of Corylopsis. Scient. Hort. 118:347-350. Interpretive Summary: Seeds of many trees and shrubs require several months of warm stratification (WS) at approximately 20oC followed by cold stratification (CS) at approximately 5oC. Seeds can be prevented from germination due to a mechanical constraint imposed by the seed coat or a dormant embryo. After completion of proper WS and CS that removes the inhibitor of seed germination, seeds can germinate when placed under favorable environment conditions. Corylopsis are shrubs or small trees, and there are about 29 species native to China, Japan, and Korea with 19 species endemic in China. The nature of dormancy in Corylopsis whether attributed to the seed coat or the embryo alone or a combination of the two constraints has not been investigated extensively. Generally, it has been suggested that Corylopsis glabrescens seeds require 5M WS and 3M CS. No information on the interspecific variations of seed germination of Corylopsis responding to WS and CS is available at present. It is concluded that C. coreana exhibited partial seed germination at 10oC and that this temperature could be considered the upper limit of CS for C. coreana. Only 2M CS were was required for more than 90 seeds to germinate. However, C. sinensis var. calvescens required longer than 3M CS for more than 29 seeds to germinate. This clearly shows that there is an interspecific variation in optimum seed germination temperatures. It is clear that the requirement for WS and CS differs by species and more investigations on seed germination depending on different taxa are required.
Technical Abstract: This study was initiated to investigate the difference in germination pattern between C. coreana Uyeki and C. sinensis var. calvescens Rehder & E. H. Wilson responding to a warm (WS) and cold stratification (CS), and to study the effect of different WS temperatures interacting with different durations of CS. Warm stratification at 10o, 15o, 20o, and 25oC were given for one month (1M 10 oC, 15 oC, 20 oC, and 25oC WS) followed by 0, 1, 2, and 3M of CS at 5oC (0, 1, 2, 3M CS). On average, less than 1.3 seeds of Corylopsis coreana germinated when seeds were sown without any WS and CS or with 1M 15 oC, 20 oC, and 25 oC WS without CS treatment. However, 26.3 C. coreana seeds germinated after IM 10 oC WS without any CS treatment. Germination was not affected by WS temperatures when followed by 2M 5 oC CS. It is concluded that C. coreana exhibited partial seed germination at 10oC and that this temperature could be considered the upper limit of CS for C. coreana. Only 2M CS were was required for more than 90 seeds to germinate. However, C. sinensis var. calvescens required longer than 3M CS for more than 29 seeds to germinate. This clearly shows that there is an interspecific variation in optimum seed germination temperatures.