pollination is the transfer of pollen grain from anther to the stigma.

1. Pollination in flower
Dambar Singh Khatri

2. Behavioral objectives
• At the end of season, students will be able to-
• Describe what must occur for plant fertilization
• Explain cross-pollination and the ways in which it takes place.
• Explain the self pollination in plants
• Differentiate among the non-insect methods of pollination

3. Types

4. Self- pollination
This type of pollination deals with only one flower and hence it is quite a
basic type of pollination.
When pollen grain from the male part of the flower (anther) falls directly on
the stigma which is the female part of the same flower and fertilization
occurs, such type of pollination is called self-pollination.
The plants that undergo self pollination are referred to as self pollinating
plants.
Some examples of self-pollinating plants are: wheat, rice, peanut etc.

5. Types of self pollination
• Types of Self-Pollination
• Self-pollination can be of two types.
•Autogamy
•Geitonogamy

6. Autogamy
• This type of self-pollination occurs where the transfer of sperm cells from the
pollen grain to the stigma takes place within the same flower.
• Autogamy is possible under some circumstances like
• Both the anther and the stigma of the same flower should be open
• Stigma should be prepared to receive the pollen when released from the anther
• Anther and stigma should be close enough.

7. Geitonogamy
• This type of self-pollination occurs when transfer of pollen grains from
the male part of the plant to the female part of the plant takes place in
different flowers but of the same plant.
• Geitonogamy seems more of a cross-pollination and requires pollination
agent but since it occurs in the same plant is called self-pollination.

8. Cross-Pollination
• This type of pollination is more complex as here the transfer of pollen grain occurs from the
anther of one flower to the stigma of a different flower.
• Cross-pollination is also called xenogamy.
• The movement of pollen grains in cross-pollination is possible through pollinating agents.
• Pollinating agents can be anything like animals, insects, winds and some other abiotic and
biotic things.
• Generally, cross-pollination occurs in bright colour flowers as their colour and odour attracts
the insects like bees.
• Some of the cross-pollination plants are strawberry, apple, etc.

9. Types of Cross-Pollination
• Pollination through biotic factors like animals,
insects, birds etc.
• Pollination through abiotic factors like wind,
water etc.

10. Pollination through biotic factors like animals,
insects, birds etc.
• Entomophily:
• Entomophily or insect pollination is a form of pollination whereby pollen of plants,
especially distributed by insects.
• Flowers pollinated by insects typically advertise themselves with bright colors,
sometimes with conspicuous patterns (honey guides) leading to rewards of pollen and
nectar.
• They may also have an attractive scent which in some cases mimics insect pheromones.
• Insect pollinators such as bees have adaptations for their role, such as lapping or sucking
mouthparts to take in nectar, and in some species also pollen baskets on their hind legs.

11. Ornithophily
• Ornithophily is a form of pollination whereby pollen is transferred by birds.
• The flowers species frequently have evolved mechanisms to make themselves
more appealing to the particular type of pollinator, e.g. brightly colored or
scented flowers, nectar, and appealing shapes and patterns.
• Other methods of pollination are-
• Malacophily
• Chiroptophily

12. Huming bird taking
nector from flower
Snail. an example of malacophily
Bat feedind on nector. An
example of chiroptophily

13. Pollination through abiotic factors like wind,
water etc.
• If pollination takes place through air, it is called anemophily.
• The characteristics of anemophilus flowers are:
• No bright colors, special odors, or nectar
• Small
• Most have no petals
• Stamens and stigmas exposed to air currents

14. • Large amount of pollen
• Pollen smooth, light, easily airborne
• Stigma feathery to catch pollen from wind
• May have staminate and pistillate flowers, may be monoecious or dioecious
• Usually single-seeded fruits, such as oak, grass, birch, poplar, hazel, dock, cat-
tail, plantain, and papyrus

15. Hydrophily
• Water pollinated plants are aquatic.
• Pollen floats on the water’s surface drifting until it contacts flowers.
• This is called surface hydrophily, but is relatively rare (only 2% of pollination
is hydrophily). This water-aided pollination occurs in waterweeds and
pondweeds.

16. Advantages of self pollination:
• It does not depend upon external agency , so it is called sure method of
pollination.
• Pollen grains are not wasted.
• Parental characters can be preserved by self pollination.
• It causes no genetic variations.

17. Disadvantages of polination
• 1.It produces weak progenies, generation after generation, which cannot
adopt to the changing environment.
• 2.It does not help in evolution of new species.
• 3.It does not cause any variability.
• 4.The undesirable or defect characters do not get eliminated from a plant.

18. Advantages of Cross pollination
• Useful characters can be introduces by it.
• It leads to the production of genetic diversity, as a result , new characters are evolved.
• It is utilized in the production of new, strong healthy, disease resistant varieties of crops.
• Disadvantages:
• The plants fully depend upon external agencies for pollination.
• A larger number of pollen grains are wasted.
• Sometimes it introduces harmful characters to the organisms.
• Cross pollination is not a sure method.
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19. Thank you