Ultrastructural Analysis of Electrofused Protoplasts from Pansy and Wild Viola by Scanning Electron Microscopy

Abstract

Ultrastructural changes during the fusion of the protoplasts isolated from wild viola callus(without chloroplasts)and pansy mesophyll cells(with chloroplasts)were examined by scanning electron microscopy(SEM)and transmission electron microscopy(TEM). The presence of pansy protoplasts in the fusion products was proved by the presence of chloroplasts lying beneath the plasma membrane identified by SEM. Involvement of pansy chloroplasts in the fusion products was confirmed by TEM. Thus it was possible to distinguish between viola protoplasts and pansy protoplasts by SEM. During the process of protoplast fusion, adhesion of two protoplasts, the rupture and recovery of the membrane between them, and a single-paired spherical fusion body were clearly observed by SEM using our preparation method. Fused protoplasts divided and a microcolony was produced.