Micropropagation of Stevia rebaudiana Bertoni. A New Sweetening Crop in Egypt

The micropropagation of Stevia rebaudiana using stem node segment explants obtained from 2 years-old shrubs were achieved. Cultures were established on Murashige and Skoog (MS) as the medium supplemented with different concentrations of 6-benzylaminopurine (BA) at concentration, 0.0, 0.1 and 0.5 mg/l individually or in combination with Kinetin (Kin) at concentration, 0.0, 0.1 and 0.5 mg/l. The highest survival percentage (90%) as well as growth percentage to survival (100%) was obtained on MS medium supplemented with 0.5 mg/L BA + 0.5 mg/l (Kin). The type of cytokinine was the most important factor affecting shoot multiplication. The highest shoot multiplication rate was obtained from single stem node segment cultured on medium supplemented with BA. Increasing BA concentration promoted shoot multiplication. The maximum number of proliferated shoots was obtained on MS medium supplemented with 2.0 mg/l BAP + 0.5 mg/l kin. However, medium supplemented with kin resulted in elongated shoots. Elongated shoots were separated and rooted on MS medium supplemented with indole butyric acid (IBA) or Naphthalene acetic acid (NAA) at concentration, 0.5, 1.0 and 2.0 mg/l. The maximum root induction (100%) was observed on medium supplemented with 1.0 or 2.0 mg/l IBA. IBA showed to be more significant and effective for rooting than NAA in all concentrations used. High survival, percentage (over 75%) was obtained when the plantlets were transferred to greenhouse conditions