Characteristics of Seed Germination of the Protected Medicinal Plant Coptis chinensis

The medicinal plant Coptis chinnesis is a third-class state protected plant species in China.In the present study,several physiological indexes of seed germination of the plant were determined to reveal its germination physiology and the mechanisms for its vulnerability.Seed vigor,tested by TTC dyeing,showed a relatively low seed vigor(56%),empty seeds and seeds without vitality accounting for 28% and 16% of the total,respectively Water absorption experiment indicated that the water permeability of the seed coat was high,and complete water absorption was achieved within 24h only,which showed that the seed coat is not a limiting factor of low seed germination rate.In the germination experiment,22 ℃ was the optimum temperature for seed germination,with a germination rate of 52.9%.GA3 treatment at a concentration of 5.0 mg·L-1 had highly significant stimulating effect,the rate of germination being 71.2%.Higher concentration(7.5 mg·L-1)of GA3 inhibited germination,however.It is thus concluded that the most suitable parameters for seed germination are 22℃ and 5.0 mg·L-1 GA3 and that low seed vigor and seed dormancy may be the main causes for the vulnerability of C.chinensis.