Inability of functional pollen of one species or genera to effect fertilisation of the female of related species or genus is called

The inability of functional pollen of one species or genera to affect the fertilisation of the female of a related species or genus is called Cross-incompatibility.
CI has been defined as any relationship (or its absence) between pollen and pistil which prevents hybrid zygote formation in crosses between two fertile species.
Incompatibility is a common means of controlling breeding behaviour among plants, and has been an important factor in evolution.