The fact that ms1ms1 plants in maturity ranges I to V were producing haploids, triploids, and even higher ploidy levels along with the predominant normal diploids, indicated the female gametophyte was at least occasionally functioning abnormally. Histological sections of 92 male sterile pistils from plants about Groups III and IV, indicated only about 28% of the ovules had a normal embryo sac, by our interpretation. The remainder most commonly had extra nuclei in the regions of the secondary nucleus (endosperm mother cell) and/or the egg apparatus.
Cutter, G. L. and Bingham, E. T.
"Research Notes: Histology of the Embryo Sac of Male Sterile ms1ms1 Soybeans,"
Soybean Genetics Newsletter: Vol. 3
, Article 30.
Available at: https://lib.dr.iastate.edu/soybeangenetics/vol3/iss1/30