SUPPORTING MATRIX INFLUENCES PROTOPLAST-DERIVED COLONY FORMATION - STRUCTURAL-ANALYSIS

Flax (Linum usitatissimum) protoplasts were immobilized in agarose and in Ca-alginate, medium (MV) and high viscosity (HV) grades. Protoplas t viability was markedly decreased, probably as a result of the entrap ment procedure itself. On the other hand, mitotic activity of survivin g protoplasts was not influenced by the type of matrix agarose or algi nate HV grade. Light and electron microscopical observations revealed compact heterogeneous cell colonies in agarose surrounded by cells in a more or less advanced state of lysis. In Ca-alginate (MV and HV) cel l colonies were compact and spherical with poorly vacuolated cells. In this matrix, cell walls were intensely stained and sinuous, separated from the plasma membrane by a large periplasmic space.