The experiment was carried out at the Department of Horticulture. Kasetsart University. Tissue culture plants of K.Khai were cultured on MS media supplementing with 4mg/l BA for each treatment. One hundred of K.Khai plantlets were soaked in 0.5. , 0.75 colchicines and 15 M. 30 M. 4 M of oryzaline containing DMSO for 2.5 , 5.0 and 7.5 hours while the control was soaked in distilled water The explants were washed after soaked in distilled water and then cultured in modified MS medium with 4 mg/l BA. Subcultures of selected plants were prepared every month.