Inheritance of Awns in Crosses Involving Sevier and Federation Wheats 1

Until the last few years awn inheritance in wheat has been regarded as extremely simple, that is, as being dependent on a single factor difference. The awns of the F1 plants have nearly al~ays been intermediate in length between the aws of the two parents, with the F2 ratios 3 :i or ~ :2 :I, awnlessness usually being regarded as dominant. Recently, however, it has become apparent that the inheritance of awns is much more complex than the original data indicated. Several workers have found two independent factors and one has found two factors segregating in such a fashion as strongly to suggest linkage between these two factors. Howard and Howard (3) 3 in India crossed a fully bearded wheat with one described as being really awnless, a fact which they emphasized ̄ as important, inasmuch as many of the so-called awnless varieties really have short-tip awns. In the F2, five awn-classes were obtained, viz., (a) entirely awnless, (b) short tips, (c) long (d) nearly full bearded, and (e) fully bearded. When the awned partially awned plants were grouped together, there was a ratio of