nybom: vegetatively propagated species 



271 



Normal Williams pears 



"Seedless" mutant 



Figure 6. — X-ray-induced mutation in Williams pear with "seedless" 

 elongated fruits. 



recombinations similar to those found in other plants (4, 58, 74, 87, 

 91, 94). 



These tissue recombinations may still be of considerable interest, 

 however, and a deliberate production of such changes is also on our 

 irradiation program. As should be clear, most somatic mutants are 



\ 



■ 



Figure 7. — Cross-sections of "seedless" fruits at both sides of a normal pear. 



