2. • WHAT ARE OUTBREEDING DEVICES??
• Devices used for pollination – Out-breeding
devices. Most of the flowering plants produce
hermaphrodite flowers.
• In such cases, pollen grains come in contact with
stigma of same flower. us self pollination result in
inbreeding depression
3. • Continued self pollination can lead to
INBREEDING DEPRESSION.
• Flowering plants have developed devices,
so that CROSS POLLINATION takes place.
4.
5. OUTBREEDING DEVICES INCLUDE
• In some plants, pollen release and stigma
receptivity are not synchronized.
• Either pollen released before stigma becomes
receptive or vice verse
6. • In other plants stigma and anther are placed
• in different positions,
• So that pollen can't come in contact with
• stigma of same flower.
• Both these devices prevent autogamy.
7. • Third device to prevent inbreeding is – self
incompatibility It's genetic mechanism,
prevents self pollen from fertilizing with
ovules by not allowing Pollen germination or
pollen tube to grow.
8. • Another device is through the
production of uni-sexual flowers. If
both male and female flowers are
present on same plant it prevents
autogamy. Example – Maize.
9. • In some plants like papaya, male and female
flowers are present on different plants. That is
the plant is either male or female.
• hence prevents autogamy.
11. COMPATIBLE/ INCOMPATIBLE
• THE PISTIL HAS THE ABILITY TO RECOGNISE
THE POLLEN. WHETHER IT IS OF THE RIGHT
TYPE
• (COMPATIBLE)
OR
• OF THE WRONG TYPE (incompatible)
