what is fertilization/pollen germination/pollen tube growth and guidance

1. FERTILIZATION
Presented by :- Patel Rinku D .
CBO :- 404
M.Sc sem :- 2
Department of life sciences ,
H.N.G.U., Patan

2. CONTENTS
• What is Fertilization ?
• Pollen germination
• Pollen tube growth and guidance

3. What is fertilization ?
• When the male sex cells fuse with the female sex cells
within the ovule .
• The resulting embryo then develops into a seed .
• Unfertilised ovules cannot become seeds .

5. Pollen germination
Definition :-
• The growth of the root through the seed coat .
• When a seed lands on a place with sufficient warmth ,
water and air ,it starts to germinate .
• Sunlight is not necessary for germination .
• First , the root of the baby plant grows out of the seed to
form a seedling .

6. • During this stage , the seedling cannot make its own food.
• It gets its energy from the food stored in its seed leaves .
• The small tubular structure also known as pollen tube
continues to elongate , and makes its way down the tissue of
the stigma and style .

7. • The stigma plays an important role in the germination of pollen
grain . The stigma , secretes fluid containing liquids , gums ,
sugar and resins .
• The germination of pollen grains depends upon several factors
both in vitro and in vivo .
• By absorbing water they swell and become activated . This
purpose high (RH) is required both in vitro and in vivo
conditions .

9. Pollen tube growth and guidance
• Pollen germination started immediately after pollination .
• A compatible combination was characterized by a rapid
germination ,a high number of germinating pollen grains ,
and after 24 h most of the pollen grains had germinated .
• At the same time , in an incompatible combination only a
small number of the pollen grains had germinated .

10. • After in the emergence of the pollen tube from the pollen
grain , it makes its way between the stigmatic papillae into
the tissues of the style .
• The styles have been classified into three main types : Open
, half closed and closed .

11. • After arriving in the wall of the ovary , the pollen tube may enter
the ovule either through the micropyle or by some other route .
• Most of pollen grains are monosiphonous . But the condition
may be polysiphonous as found in the members of malvaceae .

12. REFERENCES
• A textbook of botany :
by - B.P. Pandey
 https://en.m.Wikipedia.org

13. THANK YOU