Characteristics of Hosta plantaginea mutants derived from γ-ray treatment

Hosta (Hosta plantaginea) is a flowering plant with excellent fragrance, which has been widely used as a bedding and pot plant worldwide. However, its flower and leaf color is simple and leaf shapes are monotonous, which hinders customers' choice. To increase plant's diversity in morphology and color, Hosta seeds were treated with a γ-ray in the dose ranges of 10, 15, 20, 25, and 30Gy in 2003. A preliminary result indicated that LD50 at which 50 % of the treated plants are lethal was around 30Gy for the Hosta. A first screening of variants was obtained among the survived plants treated with doses around the LD50 level. In the following M1V1 generation, 12 mutants were selected, which had characteristics of short plant height and leaf variations in color and shapes. Based on observation up to a M1V4 generation, 8 mutants out of the selected 12 variants were found to maintain their mutated traits Those 8 mutants include one from each 15 or 20 Gy, four from 25 Gy, and two from 30 Gy treatments. Leaf length and width were 15 and 12 cm, respectively for the non-irradiated plant, while the selected mutants exhibited relatively narrow leaf width and long leaf length. In order to verify their genetic modification, a random amplification of polymorphic DNA (RAPD) approach is being applied by using the selected mutants and original plant materials, which will be reported and updated. This work was supported by a grant (Code No. 20070301034033) from BioGreen 21 Program, Rural Development Administration, Republic of Korea. (author)