Diosgenin can be isolated from the roots of C. speclosus. Callus from root explants also has a potential to produce diosgenin. This experi.ent was conducted to find a straint mutant callus with a higher potential to produce diosgenin than that the explant from mother plant. Calluses were irradiated with doses of 0, 250, 500, 750, 1500, 2000, 2500, 3000, 3500 and 4000 rad of gamma Co-GO rays. The effect of irradiation was studied by determining the callus growth index,diosgenin content of callus PO, PI, P2, and P3. Peroxidase isoenzymes pattern of callus PO, PB. P9. and PI0. The resul ts show that irradiation at 250 - 750 rad enhached the callus growth. The callus consisted of a small cells with a similira I form. High doses of irradiation i.e. at 3000 - 4000 rad have caused a necrotic and retarted callus growth. Most of the cells were swollen and others were broken. Diosgenin content of callus increases as irradiation doses increasing up to 750 2500 rad, however at doses higher than 3000 - 4000 rad diosgenin synthesis in callus, was ~nhibited. The highest diosgenin content (1.53 '%./g dry weight) e.g. 33.04 '%.higher than that of the parent callus. was found than the irradiation is done at 2500 rad. The growth and diosgenin content were higher and stable up to the 10th generations. Peroxidase isoenzymes patternt of the callus from B - 10 th generations were different from that of thea parent. It was found the mutan strain callus of C. Speciosus through irradiation by gammarays. The potential of the callus to produce diosgenin was higher than that of the explant from a mother plant. Norita Toruan* dan Mathius*. Pusat Penelitian perkebunan, Bogor
