250 



c/ 



CELL HEREDITY 



and o denote chromosomal gene 

 pair 1] and ij (iojap). 



Colorless 

 letha 



FIGURE 9.4. Nonchromosomal inheritance of striping in higher plants, so-called sfafus 

 albomaculafus. In reciprocal crosses between normal green and striped plants, when 

 the genotype of the progeny is determined by the female parent, the genetic factor 

 responsible for striping is nonchromosomal. When the female parent is normal green, 

 the striping phenotype disappears; all progeny are green, and chromosomal genes 

 segregate normally in the F,, generation. When the female parent is striped, three 

 classes of progeny appear in the F , : colorless, striped, and green with variable fre- 

 quencies. When the striped F , plants are self-pollinated, or crossed to any male, again 

 three classes of progeny are found in variable proportions with chromosomal genes 

 segregating normally (after Rhoades, 1946, C. S. H. Symp. Quanf. Biol., 1 1:202). 



eration after generation, and clearly cannot be accounted for on a 

 chromosomal basis. 



Further evidence of the nonchromosomal determination of striping 

 comes from a study of somatic segregation. In maize, for example, the 



