What is the pollen tube nucleus and the generative nucleus? what are its functions?

Inside a pollen grain--





There are two nuclei





1 ) Tube nucleus or Pollen tube nucleus = It forms a pollen tube when a pollen germinates on the stigma . The pollen tube then passes through the style to reach the ovary and the ovule towards the female gamete / gametophyte / Ovum.





2 ) Generative nucleus == It forms TWO Male gametes or the sperms or the sperm nuclei by division.





Both of them travel through the pollen tube till they reach the Ovum .





One of them fuses with the female gamete to form diploid OOSPORE OR ZYGOTE (It form embryo or the future plant )





The remaining one fuses with diploid secondary nucleus to form the endosperm nucleus ( The Nourishing tissue for the germinating seed / embryo.





http://www.biologie.uni-hamburg.de/b-onl...





http://www.uq.edu.au/_School_Science_Les...





http://www.ualr.edu/botany/doublefert4.g...





http://www.botany.hawaii.edu/faculty/web...