This experiment was carried out in order to choose the optimal basal medium and to study the seed germination of oriental orchid, Cymbidium virescens. And the effects of plant growth regulators on organogensis of the rhizome were also examined.
1. Germination was best in Kyoto II medium among 5 different kinds of basic media. In the MS medium added with 3 g/ℓ pepton, germination was better than Kyoto II medium.
2. Dipping seeds in 0.1N KOH for 1 hour was most effective for breaking the dormancy. The cold storage of seed, up to 90 days however, didn´t break the dormancy.
3. Dark condition significantly promoted the germination rate in liquid MS with 3 g/ℓ pepton compared with light condition.
4. Application of the same quantity of NAA and BA (eg. 5㎎ NAA＋5㎎ BA/ℓ) for the MS medium containing 3g/ℓ pepton not only increased fresh weight but also promoted organogenesis during rhizome culture. The higher the BA concentration relative to NAA, the more the shoot differentiation. And the higher the NAA concentration relative to BA, the more the root differentiation occurred.
5. A high level of BA in the rhizome culture resulted in browning of the medium, which was correlated to reduced growth.
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