Dormancy characteristics and germination requirements of Phoebe bournei seed

In order to determine the dormant type, and improve germination of Phoebe bournei seeds, some measures, including stratification and GA 3 solution soaking, had been taken, and the germination percentage, water permeability, respiration rate and germination inhibitory substance of Phoebe bournei seeds were investigated. The results showed that although the testa was water permeable, the fresh seed testa had some effect for the low respiration rate and low germination percentage of the seeds. In addition, the Phoebe bournei seeds contained some germination inhibitory substance which retarded seed germination. These indicated that the dormancy type of Phoebe bournei seeds belongs to physiological dormancy (PD). The respiration rate of the Phoebe bournei seeds was improved continuously with prolonging wet sand stratification at 4 +/- 1 degrees C, and the dormancy of the Phoebe bournei seeds was released gradually thus the germination was early and quick, and germination percentage increased steadly (the germination percentage increased from 23.3% to 91.3% for the seeds stratification from 0 to 60 days). The dormancy was also released and the germination percentage increased while the Phoebe bournei seeds were treated with GA(3) solution of different concentrations, and the 800 mg.L-1 solution had the best effect.