ABSTRACT Corn (Zea mays L.) in the second important after rice in Indonesia. The experiment to know plant about the genetic validity of the mutan which has been treated with Gavana-Ray (Co-60), with a combination of colchicine concentration, was held in July 30, 1992 until September 22, 1992 in Kedunganri Regency, the North Magelang Dis- trict, Kotamadya Magelang, Central Java. At…