A condition in which F₁ plants of an interspecific cross are vigorous and fertile but their F₂ progeny is weak and sterile is called

A condition in which F₁ plants of an interspecific cross are vigorous and fertile but their F₂ progeny is weak and sterile is called Hybrid breakdown.
The hybrid breakdown is a type of reproductive failure that appears after the F₂ generation of crosses between different species or subspecies. It is caused by incompatibility between interacting genes.