What do you understand by Double Fertilization? Give its significance.

Explanation

It is fusion of two male gametes brought by a pollen tube with two different structures i.e., egg and diploid secondary nucleus) in the same embryo sac to produce two different structures zygote and primary endosperm cell). Double fertilization was discovered by Nawaschin, 1898 in fritillaria and Liliuin.
Significance. It ensures formation of endosperm only when egg has been fertilised and embryo evelopment has started.