332 POMOLOGY 



It so happens, however, that it makes no practical difference 

 whether fruit varieties are homozygous or heterozygous since 

 a valuable new kind is propagated asexually and hence has 

 little opportunity to break up, or lose its type. Therefore, it 

 is unnecessary in breeding fruits to take this into considera- 

 tion and in crosses between heterozygous parents the re- 

 combination of characters takes place in the Fi. This being 

 the case, new combinations can be obtained from which to 

 select desirable fruiting types without selfing individuals and 

 encountering sterility or the great reduction in vigor which 

 so often happens. 



293. Pedigreed nursery stock. — Following the usage of 

 the animal-breeders, certain nurserymen have adopted the 

 term "pedigreed" to designate fruit-trees which have been 

 propagated from a tree of known behavior or superior worth. 

 This, of course, carries with it the idea that such trees will 

 be better producers, have better color and quality, or have 

 some other merit which individuals of the same variety 

 selected at random would not possess. 



It must be remembered that animal-breeders always refer 

 to a new individual produced by the union of sex cells while 

 the nurseiyman refers to the same identical tree which has 

 been increased by asexual propagation. Therefore, unless a 

 true mutation occurs, the varying forms of a fruit variety 

 will not be transmitted by vegetative propagation. Owing 

 to the failure of practically all the experiments in the eastern 

 United States to secure a superior strain of trees by prop- 

 agating from a high producer or othenvise superior plant, 

 there is a distinct prejudice among horticulturists to the 

 use of the term ''pedigreed" trees. On the other hand, the 

 cases cited from California show that many true bud-sports 

 do occur in that state, and Coit has adopted the use of a 

 better term to designate trees propagated from these mutants 

 in the phrase "recorded trees." 



