Commentary A Proposal for a Uniform Genetic Nomenclature for Avirulence Genes in Phytopathogenic Pseudomonads. Alan Vivian. Biological Sciences Department, University of the West of England, Frenchay Campus, Coldharbour Lane, Bristol, BS16 1QY, U.K.. John Mansfield(2). (2)Department of Biochemistry and Biological Sciences, Wye College, Ashford, Kent, TN25 5AH, U.K.. MPMI 6:9-10. . Copyright 1993 The American Phytopathological Society.