Increase induced by colchicine in the incidence of somatic crossing over in Glycine max.

The frequency of somatic crossing over in Glycine max has been significantly increased by soaking the dry seeds in aqueous solutions of 0.0025, 0.005 and 0.01% colchicine. This increase was quite consistent for several treatments involving time × concentration interaction as well as in cases where post-treatment with mitomycin C was given. Results indicate that colchicine is inefficient in disturbing the arrangements of segments of homologous chromosomes involved in the process of somatic exchanges before the onset of the process of somatic crossing over.