Pollen tube tubes. The presence of multiple grains of pollen has been observed to stimulate quicker pollen tube growth in some plants. The vegetative cell then produces the pollen tube, a tubular protrusion from the pollen grain, which carries the sperm cells within its cytoplasm. The sperm cells are the male gametes that will join with the egg cell and the central cell in double fertilization. The germinated pollen tube must then drill its way through the nutrient-rich style and curl to the bottom of the ovary to reach the ovule. Once the pollen tube reaches an ovule, it bursts to deliver
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