Double Fertilization

Double Fertilization :-

- these Type of Pollination occur only in Angiosperms

- Role Of Recognition Factor :-

These are the factor which decide acception & Rejection of pollen grain
* If it is Accepted , Then inner intine form hydrolytic enzyme, Which eat cell of style & make passage for intine
* In Angiosperms , Siphonogamy (Pollen tube carried male gamete to the egg ) type pollination found
- Pollen tube entery from Micropylar side is of Three type :-

i) Progamy =

 Here, pollen tube enter from micropylar side

ii) Chalazogamy = 

Here, Pollen tube enter from chalazal side

iii) Meizogamy =

 Here, pollen tube enter from lateral side

- Process Of Double Fertilization :-

These process is described by Mausachain in 1818 in fritillaria & lilium type plant
According to double fertilization , two male gamete , one synergids dis-organise at time of entry of pollen tube & provide site for entry of pollen grain, Now 1st male nucleus fuse with egg Called generative ferilization & Syngamy & after Symgamy Zygote is produced which further developed into embryo
Now 2nd male nucleus fuse with secondary Nucleus (polar Nuclei) , These process called vegetative fertilization , which is triploid (3n) in nature , these process is called fertilization