In 1970, a part-sterile plant in Uniform Test I, entry W6-4108 (from Wisconsin), was observed at Ames, Iowa. Seven seeds from this part-sterile plant gave rise to seven plants in 1971; six were fertile and one was sterile and set no seeds. In 1972, five plant progeny rows gave all fertile plants, i.e., they did not segregate fertile and sterile plants.
Palmer, Reid G.
"Research notes: Genetics of the meiotic mutant st5,"
Soybean Genetics Newsletter: Vol. 6
, Article 30.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol6/iss1/30