84 BREEDING CROP PLANTS 



nuclei, there may be a range of from to 6 factors for starchiness 

 of the endosperm. This assumption was shown to explain results 

 quite satisfactorily. The above starchiness is believed by Free- 

 man to be quite different from the well-known "yellow berry" of 

 wheat. Numerous workers have shown that varieties and strains 

 differ widely in the amount of "yellow berry" when grown under 

 the same environmental conditions. Texture of seed is, however, 

 a character which is quite easily modified by unfavorable environ- 

 mental conditions. 



Chaff Characters. There are a number of different intensities 

 of the chaff color. In some cases a deep brownish red color is 

 present, in other cases a light brownish-red, and frequently the 

 outer glumes have dark brownish red striations on a slightly 

 colored or colorless background. Biff en (1905) studied crosses 

 between so-called red and colorless and obtained red or reddish 

 color in FI and a 3:1 segregation of colored to colorless in F 2 . 

 Kezer and Boyack (1918), in winter wheat crosses in which the 

 parents differed in chaff color, obtained intermediate color in FI 

 and segregation in a 3:1 ratio in F 2 . Simple ratios in varietal 

 crosses have been reported by others for this color character. 

 As there are different intensities which are quite uniform in in- 

 heritance it seems reasonable to conclude that there are different 

 factors in different varieties for brownish-red color. In a durum- 

 vulgare cross, Love and Craig (1918a) obtained in F 2 an indica- 

 tion of a 15: 1 ratio for brownish red and colorless chaff. 



Besides the chaff colors there are awn colors. The Howards 

 (1915), in India, obtained a ratio in F 2 of 3.45 black-awned to 1 

 colorless in a cross between Indian wheats. 



Hairy chaff is a varietal character of considerable' classification 

 value. The Howards have made extensive studies of this 

 character. Under linkage relations a number of cases were 

 given in which hairy chaff was correlated with glume color. 

 Henkemeyer (1915) reports different crosses, one in which hairy 

 chaff is correlated with white chaff and another in which these 

 characters are independently inherited. This leads one to sus- 

 pect that there are two kinds, either of hairy chaff or of chaff color. 

 The Howards have been able to demonstrate two kinds of hairs 

 on the glumes of Rivet wheat. Two Indian varieties were like- 

 wise studied. Each produced hairy chaff, but differed in the 

 sort of hairs produced. In crosses between these varieties, 

 ratios of 15 pubescent to 1 smooth were obtained in F 2 . 



