17. Data were obtained on a dominant or partially dominant character which we have been calling knotted leaf and designating by the symbol Kn kn. A full description has not been published. Superficial observations indicate a more rapid growth of the vascular tissue, resulting in a kinking or knotting of the veins. Plants known to be heterozygous for this character usually make normal growth with only an occasional knot on the leaf blade and a slight knotting of the leaf sheath. Other plants proven to be homozygous were so badly knotted that the tassels could not make their appearance without assistance.

Backcross data were obtained in 1933 on 531 plants and in 1936 on 252 plants involving the genes f, ts2, and Kn. The combined data for the two years are as follows:

F1 genotype 0 1 2 1,2 Total
+   +  Kn 171 125 101 161 94 31 29 71 783
ts2 f1  + 296 262 125 100  
    33.5% 16.0% 12.8%  

A marked deficiency of f1 plants in 1933 made interpretation of the data doubtful. The results in 1936, however, were very similar to those in 1933.

Backcross stocks involving the genes for br, f1, bm2, and Kn were obtained this year for classification in 1937.

A. A. Bryan