7. White seedling-1 (w1) has been known to be loosely linked with the Y1 gene of the sixth chromosome (Linkage Summary, 1935). To place w1 more accurately in the chromosome seedling counts were made of the F2 cross between w1 and pigmy (py). Seeds were taken from the Co-op stocks. The results indicate a very close linkage between py and w1.
| Genes | Phase | XY | Xy | xY | xy | Total | % Recomb. |
| Py W1 | RS | 867 | 416 | 443 | 0 | 1726 | 4.8 (if one xy) |
G. A. Lebedeff