Effects of 5-azacytidine on somatic mutation in a soybean test system.

The mutagenic activity of 5-azacytidine (azaC) was assayed in heterozygous soybean plants (Y11y11), according to the appearance of mutational spots (yellow, dark green and twin) on the leaves. When soybean seeds were treated with azaC at 10-100 micrograms/ml, azaC was found to be significantly mutagenic and to exert heritable effects in the soybean test system. Treatment with azaC increased the frequency of twin spots on the leaves. AzaC would thus appear to cause somatic crossing over as its major effect.