Abstract: The peroxidase activity increases during the processes of both dedifferentiation and differentiation of Brasisca oleracea var.italic.The emergencce of calli 12 days after the initiation of dedifferentiation culture, coinsides with the abrupt increase of the enzyme activity. The appearance of buds 21 days after the initiation of differentiation on culture is accompanied by an apparent increase of peroxidase activity. The isoperoxidase band c and band e appear before the callus, indicating that they must be part of the reason for dedifferentiation. The reappearance of band c before the emergence of buds indicates that it must be related to the trigger-on of differentiation.The IAA-oxidase activity increases during dedifferentiation, but shows no significant changes during differntiation.

Key words: Brassica oleracea var. italic, Peroxidase, Isoperoxidase, IAA-oxidase, Differentiation, Dedifferentiation