Tang and Loo (1940) first reported the induction of tetraploid soybeans by soaking day-old seedlings in 0.05 to 0.1% colchicine solution for 24 or 48 h. Oinuma (1952) obtained tetraploids by soaking dry soybean seeds in 0.1% colchicine solution for 24, 48 and 72 h. His results showed that the survival of resulting plants was poor.
Cheng, S. H. and Hadley, Henry H.
"Research Notes : Studies in polyploidy in soybeans: A simple and effective colchicine technique of chromosome doubling for soybean (Glycine max (L .) Merr.) and its wild relatives.,"
Soybean Genetics Newsletter: Vol. 10
, Article 10.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol10/iss1/10