dc.description.abstract | The aim of this reseach was to select mutant plantlets of Spathoglottis plicata orchid prodeced by gamma irradiation based of morfology characterization specially form and color of leaf and flower at green house. This experiment was arranged by Completely Randomized Design (CRD) with 9 doses of irradiation of Gamma Ray were 0, 50, 100, 150, 200, 250, 300, 350, and 400 Gray, with 50 lini clone of plantlets per doses gamma irradiation. Irradiation by gamma ray have done at Centre of Aplication Technology Isotop and Radiation (PATIR), Badan Tenaga Nuklir Nasional (BATAN) Pasar Jumat, Jakarta. Source of irradiation is Gamma Ray produces from Cobalt 60 (60Co) ionization through out Irradiator Gamma Chamber 4000A Irpasena type. Lethal Dose 50 (LD50) for lini clone of S. plicata orchid was 141.33 Gy. Morphological characters of S. plicata orchid have changed after plantlets were hit by 50-150 Gy of Gamma irradiation dose. All of plantlets were died irradiated by gamma ray dose more than 150 Gy. Effect of Gamma irradition made plant shorter and leaf smaller than wild type, flower sprout faster, and number of flower fewer than wild type. The bigest changed after 10 months observation was color changed of flower from light purple to soft pink | en |