Kilen and Hartwig (1975) have described a short internode character found in PI 227.224 which causes a zigzag stem appearance. They indicated that the short internode character was probably determined by a single recessive gene pair based on classification of the presence or absence of the zigzag stem appearance. In the F2 generations of the crosses, PI 227.224 x 'Coker 338' and PI 227.224 x 'Davis,' we observed two different ratios.
Boerma, H. R. and Jones, B. G.
"Research Notes: Evidence of a Second Gene Controlling a Short Internode (Zigzag Stem) Character,"
Soybean Genetics Newsletter: Vol. 3
, Article 11.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol3/iss1/11