Give information about compatible and incompatible pollen.

(N/A) In nature,pollination does not guarantee the transfer of the compatible or right type of pollen. Often,pollen of the wrong type,either from other species or from the same plant (if it is self-incompatible),also lands on the stigma.
The pistil has the ability to recognize the pollen,whether it is of the right type or of the wrong type.
If the pollen is of the right type (compatible),the pistil accepts the pollen and promotes post-pollination events that lead to fertilization.
If the pollen is of the wrong type (incompatible),the pistil rejects the pollen by preventing pollen germination. The ability of the pistil to recognize the pollen followed by its acceptance or rejection is the result of a continuous dialogue between the pollen grain and the pistil. This dialogue is mediated by chemical components and protein elements present in both.
It is only in recent years that botanists have been able to identify some of the pollen and pistil components and the interactions leading to recognition,followed by acceptance or rejection. In compatible pollination,the pollen grain germinates on the stigma to produce a pollen tube through one of the germ pores,and the contents of the pollen grain move into the pollen tube.