Question

What are two strategies adopted by plants to ensure cross pollination?

Answer 1

Following are the some of the strategies adopted by plants to ensure the cross pollination or to prevent self-pollination:

To happen the cross pollination mostly plants follow the criteria to prevent the self pollination:

1. Pollen grain release and stigma receptivity are not synchronised, either the anther matures first or the stigma.
2. Anther and stigma are placed at different positions, so that the pollens cannot come in contact with the stigma of same flower.
3. A genetic mechanism called self-incompatibility, which prevents self-pollen from fertilising the ovules either by inhibiting pollen germination or by retarding the growth of pollen tube in the pistil.
4. By producing unisexual flowers. Plants are dioecious and continued self-pollination may cause inbreeding depression.