In this work, factors that prevent or stimulate genetic variation in Sorghum bicolor (L.) were studied for in vitro propagation or variant selection, respectively. Somaclonal variation can be efficiently controlled by shortening the unorganized phase when somaclonal variation was an undesirable phenomenon. It was accomplished under light condition using high level of BAP (1- 4 mg/l) alone or in combination with 0.5 mg/l 2,4-D to promote direct shoot formation. This condition did not abolish the genetic mutation under the influence of long term culture condition due to the formation of...