전자빔 조사 기내 배양 양란 심비디움(Cymbidium spp.)의 유전적 다양성

Genetic Diversity of in vitro Cultured Cymbidium spp. Irradiated with Electron Beam

The study was carried out to evaluate growth and genetic diversity among in vitro cultured protocorms of Cymbidium spp. that irradiated with 10 Gy～300 Gy of electron beam. Shoot induction and shoot length were decreased by an increase of intensity of electron beam, and shoot induction was significantly decreased over 200 Gy of electron beam irradiation in 10 weeks culture. As a result of ISSR (inter-simple sequence repeats) analysis, out of 80 bands detected overall, 10 bands were identified to be polymorphic with a rate of 12.5% at control group, and 90 bands detected overall, 38 bands were identified to be polymorphic with a rate of 42.2% at electron beam treatment. According to the RAPD (random amplified polymorphic DNA) analysis, out of 92 bands detected overall, 12 bands were identified to be polymorphic with a rate of 13.0% at control group, and 121 bands detected overall, 53 bands were identified to be polymorphic with a rate of 43.8% at electron beam treatment. Genetic similarity matrix (GSM) of electron beam treatment was lower than that of control. The result indicates that the beam treatment accelerated genetic diversity by promoting polymorphism of DNA. According to the cluster analysis by using both ISSR and RAPD markers, individuals of C. spp. were divided into control and electron beam treatment group. Our results indicate that the electron beam irradiated in vitro cultured C. spp. might be resulted in promoting higher polymorphism but decreasing GSM.