274 



MUTATION AND PLANT BREEDING 



Growth of the 

 mutated tissue. 



n 



primary sectors, unstable, stable. i ntiti n f */> p 



fading to: tV;^ or ?f^o/ or ^Itatn 



cnimazra chimazra 



Ty pes of 



periclinal mutations: 



primary 

 mutants 



secondary 

 changes 



Epidermal 

 mutant 



ecto- 

 chim&ra 



diecto- 

 chimasra 



Subepidermal 

 mutants 



meso- 

 chimcera 



endo- 

 chimcera 



solid 

 mutant 



reversion 

 to normal 



Figure 12. — Schematic presentation of mode of origin and chimaerical 

 structure of somatic mutations. 



no way has been found to use these thornless sports in breeding for 

 thornlessnesss". 



