Asci and Ascospores in Ascomycete Systematics

  • A. Bellemère
Part of the NATO ASI Series book series (NSSA, volume 269)


Ascus characters are only of secondary importance in ascomycete systematics. This results in part from rather difficult technical problems in interpreting observations made only by light microscopy. The contribution to ascomycete systematics from ascus characters are illustrated in different groups, highlighting recent progress. Difficulties resulting from superficial or imperfect use of these criteria are also mentioned.

The proper systematic value of different ascus characters is considered in several groups of ascomycetes lichenized and including ascus formation, morphological characters and their variations during ascus development, structure of the epiplasm, ascus wall structure, apical wall structure, ascus dehiscence, ascosporogenesis, and the fine structure of the ascospore wall.

The systematic consequences resulting from a more important and more coherent utilization of ascus characteristics are considered. The relative constancy in several types of ascus seems to indicate that they can be used to define taxa of a rather high level. Conversely, ascospore wall structure is probably more dependent on external variations and has to be used only to define lower systematic levels.

Data relating to ascus characters are frequently insufficient in the systematic literature. If asci are precisely described, and if their variations during ascus development are carefully reported, important progress will be made in systematics and in our appreciation of evolution in ascomycete fungi.


Apical Structure Apical Wall Axial Canal Ocular Chamber Ascogenous Hypha 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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© Springer Science+Business Media New York 1994

Authors and Affiliations

  • A. Bellemère
    • 1
  1. 1.PuteauxFrance

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