ABSTRACT
The term fungi is used for describing a life style rather than as a systematic category. In this phenomenological, ecological sense, fungi are nonphotosynthetic organisms that propagate via spores. Most of them are chemo-osmotrophs with the exception of slime moulds that are phagotrophs. Fungi are primary heterotrophs with the possible exception of oomycetes, which at the sequence level form a common clade with algae. In this classical broader sense fungi are certainly polyphyletic and range somewhere between algal heritage (Oomycota), protozoa (Myxomycota, Acrasiomycota), and the Mycota sensu strictu (Chytridiomycota, Zygomycota, Ascomycota, and Basidiomycota). Only this latter group, Mycota or Eumycota is monophyletic and has been recognized in recent years as the natural sister group of Metazoa. In this sense the terms fungi and (Eu) Mycota are not synonymous. Due to their polyphyletic origin, fungal biological diversity is necessarily very high; consequently their genome organization and the concepts and procedures for genetic handling and manipulation are not easily comparable. The wealth of physiological diversity in fungal organisms becomes evident from their basal position in the tree of life.
