Table 1. Genotypes and phenotypes of soybean cultivars and mutant isolines used in this study.
| Lab name | Genotype | Seed Coat Phenotype | Cultivar/origin PI number | PI number |
| RM55 | i,rm,T | Black-brown striped | Clark isoline L72-2040 | PI547559 |
| RM30 | i,R*,T | Black | Revertant in L72-2040 | NA |
| RM38 | i,r,T | Brown | Clark isoline L67-3484 | PI547494 |
| PI91073 | i,rm,T | Black-brown striped | Source of rmallele | PI91073 |
| Wm43 | ii,R,T | Black hilum | Williams | PI548631 |
| UC55 | i,R,T | Black | Mutation in Williams | PI518670 |
| Sooty | i,R,T | Black | Sooty | PI548415 |
| Peking | i,R,T | Black | Peking | PI417243 |
| Jack | I,r,T | Yellow | Jack | PI540556 |
| UC501 | I,r,T | Yellow | Harosoy | PI548575 |
| T157 | i,R,t | Imperfect black | Mutation in Richland | PI548182 |
All cultivars are homozygous for the alleles indicated. The varieties are searchable by the PI number in the USDA Germplasm Resources Information Network (GRIN). NA, not applicable.
L numbers are isoline number designations. The rm allele from PI91073 that specifies a variegated phenotype had been repetitively backcrossed into the Clark brown seeded isoline L67-3484 (here designated as RM38 with the r allele) to create the variegated Clark isoline L72-2040 (here designated as RM55 with the rm) by R.L. Bernard of the USDA. The L72-2040 line demonstrated somatic and germinal instability to yield fully black seed. One of these lines is here designated as RM30 and the gene symbol R* is used to designated this revertants of the rm line from the standard R allele that specifics black seed coats.