Double Fertilization: S.G.Nawaschin 1898was the first to show that both the sperms released by a pollen tube are involved in fertilization. They fertilize two different components of the embryo sac. The phenomenon is unique to angiosperms and is called double fertilization. The nucleus of one of the sperm fuses with the egg nucleus thus completing syngamy. This result in the formation of a diploid cell, the zygote. The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce triploid endosperm nucleus.As this involves the fusion of three haploid nuclei, it is termed as triple fusion. Since two types of fusion, syngamy and triple fusion takes place in an embryo sac, the phenomenon is termed double fertilization, an event unique to flowering plants.The central cell after triple fusion becomes the primary endosperm cell PEC develops into endosperm while the zygote develops into an embryo.
Posted on: Tue, 07 Oct 2014 12:40:52 +0000
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