Effects of Different Treatments on Physiological Characteristics of <i>Cephalotaxus sinensis</i> Seeds

Abstract

Cephalotaxus sinensis seeds can't germinate even in the appropriate environment. However, numerous studies have showed that cold stratification and gibberellin acid (GA) can break the seed dormancy and promote seed germination effectively. To investigate the effect of cold stratification and different concentrations of exogenous GA 3 on dormancy breaking in seeds of Cephalotaxus sinensis, we monitored germination rates and changes in soluble sugar, starch, amylase, soluble protein, free amino acid during cold stratification. The results showed that seeds stratified for 5 months germinated to 12.7%, while those disposed with 200, 400, 600 mg/L of GA 3 germinated to 29.2%, 21.7%, and 18.4%, respectively. Free amino acid content was enhanced significantly, whereas soluble sugar content decreased during 45 days and then increased constantly. Additionally, the main reserves such as starch, protein decreased significantly during cold stratification, and cold stratification induced increases in the activities of α-amylase, (α + β)-amylase. The preliminary results show that the combination of GA 3 and cold stratification has better effect to break seed dormancy.