Electron micrographs of wheat microspores after pretreatment using transmission electron microscopy.

<p>Figures a-c show differences in thickness of intine, number of cytoplasmic organelles and amount of starch accumulated in amyloplasts. (A) represents type I developmental pathway, (B) represents type II developmental pathway, and (C) represents type III developmental pathway. am = amyloplast, ex = exine wall, in = intine layer, mt = mitochondria, gl = Golgi apparatus, p = proplastid, rer = rough endoplasmic reticulum, st = starch.