01509naa a2200157 a 450000100080000000500110000800800410001902400300006010000180009024500680010826000090017652010780018565000140126365000110127777300630128818361212019-01-28       1965    bl ---       0--  u    #d7 aDOI: 10.2307/24402292DOI1 aLARSON, D. A.  aFine-structural changes in the cytoplasm of germinating pollen.  c1965  aQuiescent and germinated pollen grainis of Parkinsonia aculeata, Hymenocallis occidentalis, Hippeastrum belladonna, and Ranunculus macranthus were studied electron microscopically following KMnO4-fixation, and comparisons between the 2 developmental stages were made. In the process of germination, mitochondrial structure characteristically remains unchanged from the quiescent stage form, while other organelles undergo significant modifications. In all 4 species, the Golgi apparatus becomes secretory, producing large vesicles which migrate to the cell surface and contribute substrate(s) to the forming pollen tube wall. In Hymnenocallis and Hippeastruin, plastids initiate starch storage only after germination begins; this appears to involve an increase in plastid lamellae. Vacuoles arise in germinating pollen of P. aculeata from elements of the ER, while in the other 3 species vacuoles develop from "prevacuolar bodies." Generative cell structure, vegetative nuclear structure and a unique plasma nmembrane-ER relationship in H. belladonna are briefly described.  aCitologia  aPólen  tAmerican Journal of Botanygv. 52, n. 2, p. 139-154, 1965.