Plant Systematics and Evolution

, Volume 158, Issue 2–4, pp 87–96

“Self-tanning”—a new and important source of stoichiometric error in cytophotometric determination of nuclear DNA content in plants

  • Johann Greilhuber
Article

DOI: 10.1007/BF00936335

Cite this article as:
Greilhuber, J. Pl Syst Evol (1988) 158: 87. doi:10.1007/BF00936335

Abstract

A Feulgen-densitometric comparison of nuclear DNA contents (C-values) was performed in various plant species (a fern, four gymnosperms, 16 woody and herbaceous angiosperms) after two types of fixation, additive (neutral formaldehyde) and non-additive (methanol-acetic acid, 3:1, MAA). Nuclei from tissues containing a significant amount of polyphenols (of the hydrolysable and non-hydrolysable tannin type) always showed reduced stainability and distorted spectral absorbance curves after MAA-fixation, while after formaldehyde-fixation no evidence for distorted staining was found. No fixation-dependent differences in Feulgen-DNA contents were stated in nuclei from tissues having no polyphenols. Distorted Feulgen-staining is a consequence of cellular self-tanning during fixation. Tanning is impaired by formaldehyde which binds to tannins and inactivates them. The rationale for using formaldehyde as a fixative in Feulgen-cytophotometry can be mainly seen in its capability of eliminating the “self-tanning error”. Standardization in plant DNA cytophotometry, and recent reports on unorthodox nuclear DNA variation in conifers are critically discussed.

Key words

Feulgen cytophotometry DNA contents genome size tannins 

Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • Johann Greilhuber
    • 1
  1. 1.Institute of Botany of the University of ViennaWienAustria

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