108. Introduction
Plant cells frequently have been used for
cell-fusion experiments as a result of the development of a technique
for enzymatic digestion of the cell wall (Cocking, 1960). With
this technique, a variety of new genetic manipulations have become
possible, such as protoplast fusion, uptake of organelles, and
uptake of DNA. With the enzymatic digestion procedure,
large populations of genetically and physiologically homogeneous
protoplasts are now available (Chaleff, 1981).The most unique
experimental area introduced by the ability to fuse protoplasts
is the hybridization of widely divergent taxa that are normally
isolated genetically by morphological, developmental, or sexual
incompatibility barriers (Salhani et al., 1985). By a
method of cell fusion, which involves PEG (polyethylene
glycol) and high concentrations of Ca2+, it is possible
to construct new and otherwise impossible genetic combinations
that can be used for studying the genetic characterization of
the plant as well as improving crop quantity and quality.