<Original>Callus Formation, and Effects of Applied Pressure to the Cultured Cambial Explant of Sugi (Cryptomeria japonica D. Don)

Abstract

The callus formation was investigated with the cultured cambial explants of Sugi (Cryptomeria japonica D. Don). Cell proliferation was vigorous in the surface area of the explant comparing with the inner area. Phloem parenchyma cells, ray cells and a few of fusiform cells contributed to the callus formation. In order to simulate the in vitro system of the cambial explant to the inner environment of the growing stem, the culture with radially applied pressure was also attempted. The applied pressure suppressed the cell proliferation in the inner area of the explant. The proliferated tissues under the pressure maintained their ordered cell arrangement. Therefore, the applied pressure was effective to the maintenance of the tissue structure in culture.