Small shoot apical meristems of Chrysanthemum morifolium ´Shin Dong Ah´ were cultured on Murashige-Skoog medium. Kinetin and NAA were added in various concentrations either individually or in combinations.
1. Differentiation of single or multiple shoots and roots, formation of friable or hard leafy callus, occurrence of shoot apex up or down, and plantlets depended on the plant growth regulator levels used.
2. The growth of callus was favored on kinetin plus NAA medium for subculture, especially at the level of 0.5㎎/ℓ kinetin plus 1.0㎎/ℓ NAA.
3. For subculture, transplanting seems to be desirable within 30 days after incubation. the ratio of survived calli was decreased in proportion to kinetin levels added.
4. Shoot formation in the kinetin plots except 2.0㎎/ℓ was more hastened than that of NAA treatments, while root formation was slightly inhibited and delayed compared with all the levels of NAA used.
5. In the combinations of NAA plus kinetin, shoot and root differentiation was unfavorable as compared with alone treatments of kinetin and NAA, while callus proliferation was increased.
6. 2.0㎎/ℓ NAA treatment, which exhibited the phenomenon of shoot apex down up to 31.3%, was good for producing multiple shoots. The occurrence of shoot apex down tends to increase in proportion to kinetin levels.
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