Affiliation: | (1) AFRC-IPSR Nitrogen Fixation Laboratory, University of Sussex, BN1 9RQ Brighton, Sussex, UK;(2) AFRC-IPSR John Innes Centre for Plant Science Research, Colney Lane, NR4 7UH Norwich, UK;(3) Department of Virology, Scottish Crop Research Institute, DD2 5DA Dundee, Tayside, UK |