Lindstrom: Heritable Characters of Maize 



13 



Normal Ear Segregating for the New Defect Segregating for Sweet Defective 



DEFECTIVE KERNEL TYPES IN INBRED GOLDEN BANTAM SWEET CORN 



Figure 19. In addition to the sweet-defective endosperm studied for two generations in 

 this inbred strain, another entirely distinct defect appeared in the third generation, remarka- 

 bly similar to that described by Mangclsdorf in another variety of sweet corn (see Figure 

 13). In this case the appearance of the defect would seem to be due to mutation, as it was 

 absent in the preceding inbred generations. (See page 130.) 



leads us to suppose that the white seed- 

 lings so closely associated with the de- 

 fective kernels are genetically identical 

 with the ordinary type and are not 

 fundamentally due to the defect in the 

 kernel itself. Scores of crosses were 

 attempted to check this, but the sterility 

 involved in this variety prevented any 

 success. 



The inheritance of this defective en- 

 dosperm character was studied by 

 means of planting the normal grains 

 of self -pollinated ears that were seg- 

 regating for normal and defective ker- 

 nels. The individual plants arising 



from such normal kernels were in turn 

 self -pollinated. This was done for 

 two growing seasons. Counts of thirty 

 ears thus produced are presented in 

 Table III. 



Of these thirty ears, six showed no 

 defective grains (from homozygous 

 normal seeds), and twenty-four had 

 both normal and defective grains on the 

 ear (from heterozygous seeds). If the 

 genetic factors governing the inherit- 

 ance of this allelomorphic pair (nor- 

 mal-defective) of characters is a simple 

 one, we should expect a proportion of 

 ten homozygous to twenty heterozygous 



