This book records the contributions presented at the XIIth Interna tional Congress of Microbiology, Mycology Section, held in Munich on 3-8 September 1978. All the papers given at the Symposium (no. 33) on Fungal Viruses, and at the Round Table Discussion (RTD 1) are reported in full, and the paper on fungi as vectors of plant viruses by R.N. Campbell (who was unfortunately unable to attend the Congress) has also been included (Part A). Much of the current work with viruses in fungi involves genetic studies and virus-host gene interactions; for this reason, the Sympo sium (no. 32) on Extrachromosomal Vectors in fungi has also been reported, in the form of abstracts from all those contributors who gave permission for this (part B). Authors' abstracts of posters relating to fungal viruses have simi larlyleen given (part C). Fungal viruses, or mycoviruses, can be defined as viruses that repli cate in fungi, and since their discovery in 1962, considerable progress has been made towards an understanding of their biological and par ticularly their physico-chemical properties. Present knowledge sug gests that mycoviruses are usually latent in nature, and their biological manifestations can often be more readily studied as cytoplasmically inherited determinants than as viruses. An attempt has therefore been made in this book to bring together the most recent advances, not only in mycovirus research, but also in extrachromosomal determi nants in fungi.

A Symposium and Round Table Discussion on Fungal Viruses

Evolution
Coevolution of Fungi and Their Viruses
Fungi as Vectors and Hosts of Viruses
Fungal Vectors of Plant Viruses
Fungal Viruses in Edible Fungi
Infectivity and Transmission of Fungal Viruses
Characterization of Fungal Viruses and Their Effect on the Host
Physicochemical Properties of Mycoviruses: An Overview
Virion-Associated RNA Polymerases of Double-Stranded RNA Mycoviruses
Some Morphological Changes in Fungi Induced by Fungal Viruses
Interactions of Fungal Viruses and Secondary Metabolites
Fungal Viruses and Killer Factors (Saccharomyces cerevisiae)
Fungal Viruses and Killer Factors - Ustilago maydis Killer Proteins
Methods
Screening for Viruses in Human Pathogenic Fungi
Immunochemical Detection of Viruslike Particles and Double-Stranded RNA from Agaricus bisporus
Serological Screening for Fungal Viruses
Taxonomy
Taxonomy of Fungal Viruses
B Symposium on Extrachromosomal Vectors in Fungi - Abstracts
Introductory Remarks of the Chairman
Recent Developments on the Genetics of the URE 3 Cytoplasmic Factor
The Organization of the Mitochondrial Genome of Saccharomyces cerevisiae and Its Implications on the Phenomenon of Suppressiveness
Sequence Organization and Expression of a Plasmid DNA Molecule Found in Yeast
Structure and Function of Saccharomyces cerevisiae 2-?m DNA
Elements of Infectious Heredity in Fungi
C Posters on Fungal Viruses - Abstracts
Mycoviruses in Helminthosporium
Viruses of Aspergillus awamori and the Production of Glucoamylase
Sporulation and dsRNA Viral Molecules in Penicillium citrinum.