Pollen tube through wind, water or pollinators. The last step before fertilization is the growth of the pollen tube to transfer non-motile sperm to the protected egg. Pollen tubes are unique to plants and their structure had evolved over plant history. The pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists. Pollen is produced by the stamen, the male reproductive organ of the flower. Each pollen grain contains a vegetative cell, and a generative cell that divides to form two sperm cells. The pollen is delivered by the opening of anthers for
Spore (agricultural publication) publisher, CTA. Recent Special Issues have covered Climate Change (2015), Family Farming (2014), Structured Grain Trading (2013); Agricultural Value Chains (2012); Modernizing Farms (2011) and Population and Agriculture (2010). Issues from September 1997 (No. 72) to the present are available at the magazine's website . Issues 1-69 are available from . Spore (agricultural publication) Spore is a magazine published by the Technical Centre for Agricultural and Rural Cooperation ACP-EU (CTA) in English and French. It covers a wide range of agricultural topics and is extensively distributed and widely reproduced throughout African, Caribbean and Pacific (ACP) countries and elsewhere. Originally known