, Volume 107, Issue 3, pp 205–215 | Cite as

The rôle of the tapetum in the formation of sporopollenin-containing structures during microsporogenesis in Pinus banksiana

  • H. G. Dickinson
  • P. R. Bell


In the microsporangium of Pinus the outer layer of the peritapetal membrane and the pro-orbicular cores are not only formed in a similar manner, but are composed of apparently identical materials. Precursors for this lipoidal material are produced by the tapetal protoplasts, as are the precursors of sporopollenin. Production the precursors is sequential and appears to involve different cytoplasmic structures.

The sporopollenin synthesised by the tapetum condenses upon the pro-orbicular cores, the peritapetal membrane, the exine initials and, on fragmentation of the tapetum, parts of the disintegrating cytoplasm. The evident unpolarised nature of the tapetal protoplasts, and the sequential nature of the synthesis of the lipoid and the sporopollenin by them, may point to orbicule formation in gymnosperms being a necessary by-product of the development of the peritapetal membrane.


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  1. Avetissian, N. M.: Method simplifiée d'acetolyse dans la préparation des pollens. J. Bot. U.R.S.S.T. 35, 385–386. (1950).Google Scholar
  2. Dickinson, H. G.: The fine structure of a peritapetal membrane investing the microsporangium of Pinus banksiana. New Phytol. 69, 1065–1068 (1970a).Google Scholar
  3. Dickinson, H. G.: The role played by sporopollenin in the development of pollen in Pinus banksiana. In: Sporopollenin, ed. J. Brooks, P. R. Grant, M. D. Muir, P. van Gijzel and G. Shaw, p. 31–67. London: Academic Press 1970b.Google Scholar
  4. Echlin, P., Godwin, H.: The ultrastructure and ontogeny of pollen in Helleborus foetidus L. I. The development of the tapetum and Ubisch bodies. J. Cel Sci. 3, 161–174 (1968).Google Scholar
  5. Heslop Harrison, J.: An acetolysis resistant membrane investing tapetum and sporogenous tissue in the anthers of certain Compositae. Canad. J. Bot. 47, 541–542 (1969).Google Scholar
  6. Heslop Harrison, J., Dickinson, H. G.: Time relationships of sporopollenin synthesis associated with tapetum and microspores in Lilium. Planta (Berl.) 84, 199–214 (1969).Google Scholar
  7. Martino, C. de, Natali, P., Bruni, C., Accinni, L.: Influence of plastic embedding on staining and morphology of lipid bodies. Histochemie 16, 350–360 (1968).Google Scholar
  8. Pettitt, J. M.: A new interpretation of the structure of the megaspore membrane in some gymnospermous ovules. J. Linn. Soc. (Bot.) 59, 253–262 (1966).Google Scholar
  9. Reynolds, E. S.: The use of lead citrate at a high pH as an electron opaque stain in electron microscopy. J. Cell Biol. 17 p. 208–212 (1963).Google Scholar

Copyright information

© Springer-Verlag 1972

Authors and Affiliations

  • H. G. Dickinson
    • 1
  • P. R. Bell
    • 1
  1. 1.Dept. Botany and MicrobiologyUniversity CollegeLondonUK

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