Freeman: Bread Making Wheats for Warm Climates 



Table X. — Inheritance of Percentage of Yellow Berry in Hard Wheats 



225 



Percent- 

 age of 

 yellow 

 berry in 

 parents 



Average percentages of yellow berry in offspring 



1 1- 5- 



14 



9-13-17-21-25-29- 

 12 :i6 20 24 28 32 



3i- 

 36 



37-41- 



40 44 



49- 



52 



53- 

 56 



57-'61- 

 60 164 



No. of 

 races 



Average - 

 percent- 

 age of 

 yellow 

 berry 



145 pure races of Turkey wheat; crop of 1914 compared with that of 1915 



145 pure races of Turkey wheat; crop of 1914 compared with that of 1916 



0-24 



25-49 

 50-100 



145 pure races of Turkey wheat; crop of 1915 compared with that of 1916 



0-19 

 20-39 

 40-100 



65 homozygous hard wheats of hybrid origin (Macaroni-Sonora) 







1-13 

 14-91 



4 



5 



11 



is sufficient!}^ high, the entire cell con- 

 tents are cemented together solidly as 

 the grain dries out in ripening. It, 

 therefore, takes on a hard, glassy, semi- 

 translucent texture. In the absence of 

 a sufficient proportion of gluten to hold 

 the cell contents together, the shrink- 

 age in drying does not fully compensate 

 for the loss of water, and air spaces 

 appear within the cells. These open 

 spaces render the grain soft and, also, 

 since they serve as refracting surfaces, 

 make it opaque. We are, therefore, 

 accustomed to associate softness, 

 opaqueness and low gluten content in 

 wheats. 



3. There are two types of soft grains 

 among the wheats included in these 

 experiments. 



(a) A type designated by the writer 

 as "true softness" in which the air 

 spaces in the endosperm are diffuse and 

 finely scattered. This type of softness 

 is only slightly affected by environic 

 conditions. 



(&) A type commonly called "yellow 



berry" in which the air spaces within 

 the endosperm occur in flake-like groups 

 with quite definite margins. The 

 opaqueness thus arising may be con- 

 fined to a small spot only or may in- 

 clude the entire endosperm. This type 

 of softness is very sensitive to environic 

 conditions. 



4. The genetic behavior of "true soft- 

 ness" in the wheats crossed by the 

 writer may be explained by two inde- 

 pendent factors governing the relative 

 proportion of gluten and starch. These 

 factors show incomplete dominance 

 over their absence, and appear to be 

 accumulative in their action, i. c, the 

 intensity of their action depends upon 

 the number of times the factors appear 

 in the endosperm. Thus (assuming 

 double fertilization) the presence of 

 none to six factors in the endosperm 

 cells gives rise to a series of types grad- 

 ing from hard (translucent) through 

 almost insensible degrees to completely 

 soft (opaque) grains. 



