Backcross

Definition
verb
To cross a hybrid (i.e. offspring of the F1 generation) with its parent
noun
(1) The offspring produced from such a cross
(2) The process of crossing a hybrid with its parent or with another individual with genotype similar to its parent
Supplement
This method has long been used in horticulture, e.g. to incorporate desirable traits to the elite line of crops. At present, the deliberate back-crossing is carried out to breed and produce gene knockouts used in genetics research.
See also:

• test cross