30 



of various plants from different seed origin are necessary to <le- 

 termine this. 



Apple trees growing wild arc, except perhaps for origin 

 through root suckers, each from a dilTerent seed and unless 

 there is isolation there is opportunity for cross-pollinations. 

 Under such conditions incompatibilities and also cross-incom- 

 patibilities between imhvichials from different seed are not at 

 all ol)vi(jus in the setting of fruit. 



Fli.UKE 4. 'ilic fruits shown above arc from the sclf-pollinat.ion of 

 flowers enclosed within a pajicr bap; on a l)ranch of a tree of Mains 

 Mains. The plant is fully sclf-frnit ful but souu' i.f its seed progeny 

 niiiy be enlirily sclf-inc()ni]>atible. 



In culli\ated ap])Ies, all the trees of a variet\' are from branches 

 derived by vegetative propagation from one seedling or bud 

 sport. It is a '^ clonal" \ariel\ in conlrast to a \aiiet}' grown 

 from seed. Pollination between two plants of a clonal \ariety 

 is the same as pollination from llower to flower on a single tree. 

 This is not cross-pollination but close-pollination. When there 

 is com])lcte self-incompalibilit\- in a seedling ap])le ])lant the 



