This volume contains a series of contributions from established European researchers which consider aspects of molecular variability in fungal pathogens. Chapters are derived from a workshop held in Evian, France, in September 1997, supported by the EU Concerned Action Air 3-CT94-2448. The volume is divided into three sections. The first includes contributions which consider and review the major mechanisms involved, the second details specific studies on variability in populations of different fungal pathogens, and the third includes contributions on methods for interpreting such variability. The workshop was intended to bring together methods and understanding from a wide range of fungal pathogens, and this is reflected in the volume where individual contributions include case studies and reviews of populations of fungi pathogenic on insects and nematodes as well as plant and human pathogens. The combination of mechanisms, characterisation and interpretation across a wide range of applied mycology should make this a general text for those working on molecular characterization. The broad spectrum of topics provides a multidisciplinary reference source within mycology and the book should be suitable for postgraduate students and research scientists in applied mycology, including plant pathology, medical mycology and biological control.