Breaking of seed dormancy in Hypericum leptophyllum Hochst., an endemic Turkish species

Abstract

Seed germination requirements of the endemic Turkish species of Hypericum, Hypericum leptophyllum Hochst. were studied by performing some pre-soaking treatments with the aim of describing suitable germination protocols for use in ex situ conservation. Before placing the seeds in Petri dishes, they were soaked in 50, 100 or 150 ppm GA; 0.5, 1 or 1.5% H2SO4; 150 ppm GA + 0.5% H2SO4 solutions, tap water and 40, 50 or 60 degrees C hot water for 30 min. To evaluate the effect of light on germination rate, the study was performed under both continuous illumination and darkness in a growth chamber. Light was found to be the most important factor in seed germination. In the presence of light, gibberellic acid (GA) and sulphuric acid (H2SO4) treatments in different doses increased germination rate significantly. The germination response to the pre-soaking treatments was discussed as a possible result of double dormancy involving partially dormant embryo and hard seed coat. This is the first report on the endemic species.