incompatibility is a natural barrier in the fusion of gametes .justify the statement.

Incompatibility means incapable. There are two forms of pollen incompatibility, interspecific (between two different species) and intraspecific (between the same species). The different conditions which lead to incompatibility are (i) when pollen grain fails to fertilize with egg (ii) when the growth of pollen tube does not occur or is incomplete (iii) when pollen fails to pass successfully through pollen tube. All these events prevents the fertilization of male gamete with the female gamete as a result no embryo formation takes place. So it is true to say that incompatibility is a natural barrier in the fusion of gametes.