A flower structure mutant was found segregating within the original heterogeneous PI 339,868 population in 1970. This mutant is characterized by having cleistogamous flowers with an exposed stigma and is sterile. The flowers of sterile plants have been observed by dissections, serial paraffin sections and the scanning electron microscope (SEM).
Winger, Carol L. and Palmer, Reid G.
"Research notes: A flower structure mutant,"
Soybean Genetics Newsletter: Vol. 6
, Article 29.
Available at: https://lib.dr.iastate.edu/soybeangenetics/vol6/iss1/29