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. Protoplast viability was markedly decreased, probably as a result of the entrapment procedure itself. On the other hand, mitotic activity of surviving protoplasts was not influenced by the type of matrix agarose or alginate 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) cell 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.