1. Plant Pathology Department, University of California, Davis, CA, U.S.A.
2. The John Innes Centre, Norwich Research Park, Norwich, U.K.
3. Rijk Zwaan Breeding B.V, Burgemeester Crezéelaan 40, De Lier, 2678 KX, The Netherlands
4. School of Integrative Plant Science, Plant-Microbe Biology and Plant Pathology Section, Cornell University, Ithaca, NY, U.S.A.