Knight — 20 — Dictionary 



Buffering Genes, — A complex of polygenes controlling the 

 expression of a major gene and reducing the variability of 

 its phenotype by toning down its reaction to environmental 

 differences. See Canalized Development Hypothesis. 



Bulbil. — A modified bud capable of developing into a new 

 plant when separated from the parent plant. 



Bulk Method of Breeding. — The growing of segregating 

 generations of a hybrid of self-pollinated crops in a bulk plot, 

 with or without mass selection, followed by individual plant 

 selection in Fg or later generations (Hayes & Immer). 



Burdizzo Pincers. — Double-hinged pincers used in emascu- 

 lation for crushing the spermatic cord. 



Burdo. — A graft hybrid which arises as a result of nuclear 

 fusion as between the nuclei of stock and scion. 



