RAPD (random amplified polymorphic DNA) analysis was examined to detect variation of in vitro cultured 30 rhizomes of Cymbidium goeringii and Cymbidium kanran, with long-term subculture, respectively. Out of 105 DNA bands detected, the 38 were polymorphic with a polymorphic rate 36.1% in the C. goeringii. Out of 126 DNA bands detected, the 58 were polymorphic with a polymorphic rate 46.0% in the C. kanran. The size of the amplified fragments of the two species ranged from about 200bp to 3,000bp. Genetic similarity matrix (GSM) shows from 0.810 to 1.00 with an average of 0.929 in the rhizomes of C. goeringii and 0.786 to 0.984 with an average of 0.915 in the C. kanran. The result indicate that the long-term in vitro cultured C. goeringii and C. kanran supplemented with growth regulators might be promoted in higher polymorphism and increased GSM. Thus, the higher polymorphism rate of in vitro cultured rhizomes might be resulted in long-term subculture and the plant growth regulators supplemented with the culture medium. The results provide as fundamental data to develop a new materials for plant breeding and resources plant.

• Jaihyunk Ryu(Division of Bioresources Science, Sunchon National University)
• Chang-Hyu Bae(Division of Bioresources Science, Sunchon National University) Corresponding author