Abstract
In examining the influence of various substances on protoplasts it was found that high molecules of dextran sulfate had the effect of causing protoplast aggregation like gelatin. In order to distinguish one protoplast from another, the vacuoles of the protoplasts were stained with neutral red. When protoplasts of two different species were mixed in the dextran sulfate solution, they aggregated with each other at random. In the aggregated protoplasts between different species, they made cell walls and showed cell division at several times, but then they stoped their cell division and did not grow as colonies. It was thought their specificity appeared gradually in the process of cell division and development of cells into colonies, though it did not at early stages. Using dextran sulfate and gelatin, hybrid plants were induced from the aggregated protoplasts between green leaf and albino callus of haploid tobacco.
