Abstract: On various mediums with different variety and level of phytohormone, cotyledon callus of Longshan common buckwheat showed different differentiation states: (1) no differentiation took place; (2) root differentiation; (3) bud differentiation and (4) plantlet differentiation. The ratio of peroxidase activity in 4 kinds of calli is 1:1.47:5.95:7.78. There appeared also significant difference among their zymogram of peroxidase isoenzyme. Band 4' in zymogram is characteristic for the differentiated callus; band 2' is common for the undifferentiated and the differentiated; band 1' is of shortage for the differentiated root and the undifferentiated; band 3' is an extra for the undifferentiated.

Key words: Common buckwheat, Tissue culture, Peroxidase, Peroxidase isoenzyme