Fluorescent microscopy of pollen tube germination within the style of the pistil of onion (aniline blue-stained germinated pollen tube).

(a) Pollination with dry pollen grains; (b) pollination with pollen suspension without removal of pollenkitt; (c) pollination with pollen suspension after removal of pollenkitt. Numerous pollen tubes are observed along the style (a,b). Only one pollen tube is observed along the style after the removal of pollenkitt (c).