Callus production from photoautotrophic soybean cell culture protoplasts

Protoplasts were prepared from a photoautotrophic (PA) cell line of Glycine max (soybean). A yield of 75 to 90% after two to three hours digestion in a mixture of 1% Cellulase R10, 0.2% Pectolyase Y23 and 2% Driselase was obtained. Cell division and colony formation occurred from approximately 18% of the plated protoplasts. The cultured protoplasts were as sensitive to the herbicide atrazine, a photosynthetic inhibitor, as the original PA cells under the same conditions. Protoplasts and cells of a heterotrophic (HT) soybean culture were not as sensitive to atrazine. The isolated protoplasts retained the PA characteristics of the parental culture in the callus and cell suspension cultures obtained from the protoplasts. The chromosome numbers in the parental cell line and in cells derived from the isolated protoplasts (both PA and HT) were found to be largely (99%) the normal diploid number of 40.