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Effect of inorganic salts and growth regulators on the meristem tip culture for virus free stock was investigated in Freesia hybrida cv. Oberon. Survival rate after 8 weeks dark culture was 70 percent in MS and modified Kano medium, and callus was formed from all survived plants. Root was formed in dark culture in 1/4MS and modified Kano medium. Shoot was formed 2 weeks after light culture in modified Kano medium, 4 weeks in MS, 6 weeks in 1/2MS, and 8 weeks in 1/4MS. Light illumination accelerated bud formation, and. the formation and growth of shoots and roots in all medium. Optimun medium for meristem tip culture was modified Kano which contains hyponex (7-6-19) 2 g/L, peptone 2 g/L, tryptone 2 g/L, myo-inositol 100 ㎎/L, and thiamin·HCL 0.4 ㎎/L. In the meristem tip culture in MS medium, NAA 5.0 ㎎/L and BA 10.0 ㎎/L combination was the best growth regulator as 75 percent survival rate, and callus and bud were formed in all survived explant. Selected medium which contained modified Kano medium, growth regulator NAA 5.0 ㎎/L and BA 10.0 ㎎/L, sucrose 30 g/L, charcoal 2 g/L and agar 8 g/L showed 92.3 percent survival rate, 100 percent callus formation rate, and shoot and root number by 1.3 and 12.7 per explant. Virus elimination of the plantlets obtained from meristem tip culture amounted to 92.9% for freesia mosaic and bean yellow mosaic potyviruses, and to 54.6% for cucumber mosaic cucumovirus respectively.
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