Imperfect yellow hilum color in soybean is conditioned by II rr TT

Hilum color is useful for identifying soybean [Glycine max (L.) Merr.] cultivars. Tawny-pubescent yellow-hilum genotypes are sometimes described with buff, light brown, or very light brown hila in Canada. This study was conducted to determine whether the yellow hila of tawny-pubescent lines discolor more than grey-pubescent lines, and whether therefore these yellow hila may actually be classified as brown rather than yellow. Seed of tawny- and grey-pubescent yellow-hila isolines in two genetic backgrounds grown in three or four seasons were scored (1, light, to 4, dark) for hilum color by soybean breeders and also classified by the Variety Verification Unit, Canadian Food Inspection Agency. Hilum color was scored darker and non-yellow (2.9 score) for tawny-pubescent lines compared with yellow (1.4 score) for grey-pubescent lines. The effects of year and genetic background were also significant. Generally, non-yellow and yellow hila were found in tawny-pubescent lines while only yellow hila were found in grey-pubescent lines. We propose recognition of a new hilum color, imperfect yellow, conditioned by II, rr, and TT. The hilum color imperfect yellow has been approved by the Soybean Genetics Committee. The color of imperfect yellow hila ranges from yellow to brown depending on the genetic background of the line and environmental conditions