Effect of Soybean Male-Sterile Gene ms1 on Organization and Function of the Female Gametophyte1
- G. L. Cutter and
- E. T. Bingham2
The female gametophyte of genetic male-sterile soybeans [Glycine max (L.) Merr.] (ms1 ms1) was examined histologically to gain insight into the association of the ms1 gene with polyembryony, haploidy, and polyploidy. Embryo sacs on the day of flowering appeared normal in only 28% of 225 male-sterile ovules examined. The most common abnormality was supernumerary nuclei in the regions of the secondary nucleus and egg apparatus. It was concluded that these nuclei could arise by proliferation of nuclei during embryo sac development. Presence of supernumerary nuclei and their restitution products provides an explanation for polyembryony, haploids, and polyploids found among male-sterile progeny. Ovules without an embryo sac occurred at a frequency of 11 and 12% in male-sterile and normal fertile plants, respectively. Only one-fourth of the embryo sacs of male-sterile plants examined at 3 to 4 days post-pollination contained an embryo, which agreed with the 29% normal embryo sacs observed before pollination. This also provides an explanation for the single-seeded pods and the reduced seed set associated with the male-sterile ms1 ms1 plants.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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