The presence or absence, homozygosity or heterozygosity, as well as the linkage relationships of the se gene continue to baffle many sweet corn breeders who try with varying success to use this basic gene for quality improvement. Chemical tests for se are virtually impossible to use in a breeding program because the breeder is seldom an experienced chemist who has the necessary laboratory equipment and chemicals. There is, however, a simple genetic test for se that the breeder can make if he will grow some Ill677a for this purpose.
The test cross for se is based on the super sensitivity of the 677a background to the fine wrinkling phenotype of se expression. Any pollen from a heterozygous se plant will result in obvious differences in xenia effects, yielding two different kernel types. The finely wrinkled se kernels will stand out in bold contrast to the kinky kernels of Se (non-se). To the initiated, the differences between se and Se expression on 677a are just as obvious as those of sugary vs. starchy.
Probably the great sensitivity of 677a to se wrinkling was a major factor in the recognition and selection of the se gene by Dusty Rhodes.
David W. Galinat and Walton C. Galinat
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