Majority of flowering plants produce hermaphrodite flowers and pollen grains are likely to come in contact with the stigma of the same flower. Continued self-pollination result in inbreeding depression. Flowering plants have developed many devices to discourage self- pollination and to encourage cross-pollination.
The out breeding devices are as follows :
1. In some plant species pollen release and stigma receptivity are not synchronized.
2. In some plant species the anther and stigma are placed at different positions so the the pollen cannot come in cont.act with the stigma of the same flower . .
