In this study, testtube plantlets of O.Violaceus were cultured on MS media and treated with low temperature, phytohormones, etc. The following results were obtained: 1. The cold treatment of 5～7℃ for more than 7 days was needed for flower initiation of the testtube plantlets originated from germinated seeds. 2. When cultured on the MS media supplemented with 2mg/L gibberellin (GA3), the testtube plantlets could initiate flowers without cold treatment. 3. When the MS media was supplemented with a reduced amount of NH4NO3, flower initiation of the testtube plantlets could be accelerated. The results of the study on flower development of O.Violaceus may be useful for the production of testtube flowers of this ornamental plant species.
