ORIGIN AND IMPROVEMENT OF FRUIT 317 



being by the use of vegetative parts such as bulbs, tubers, 

 buds, grafts, cuttings, runners, and the hke. The various 

 sorts of apples, . . . commonly denominated varieties in a 

 more restricted sense would be clons. Clons of apples, pears, 

 strawberries, and the like, do not propagate true to seed, 

 while this is one of the most importaat characters of races 

 and strains of wheat, corn and others." (Webber.) 



Hence, any selection for propagation of superior trees of 

 any of the fruits would properly be termed "clonal-selection." 

 Thus, a tree which appears different from others in a planta- 

 tion or is superior to them, as being a regular or heavj^ bearer, 

 having better color, quality, or size of fruit, or being particu- 

 larly hardy , might be selected for the purpose of propagating 

 a desirable variation within the clone. The temi "strain" 

 is commonly used in referring to such differences.^ 



282. Bud-selection, as commonly used in horticultural 

 literature, refers to the selection of a bud or branch which 

 shows a superiority over or difference from the remainder of 

 the tree. Instead of the whole tree being the unit of variation, 

 the individual bud is the unit atid is so selected. Before dis- 

 cussing the improvement of fruits by clonal- or bud-selection, 

 it should be determined whether such variations occur 

 within the tree-fruits. The data refer to deciduous fruit- 

 trees for the most part, although the bud variations which 

 have been reported for citrus fruits are so conspicuous that 

 they are mentioned in this connection. 



283. Individuality of fruit-trees. — It is well known that 

 many plants have given rise to bud-sports or mutations, 

 particularly under high cultivation, such as greenhouse roses 

 and carnations. Here such variations as the occurrence of 

 a pink rose on a plant producing white ones or a change in 

 form of the flower have been so distinct as to be unmistak- 



^ Babcock and Clausen. Genetics in Relation to Agriculture. 

 McGraw-Hill Co., New York. 1916. 



