1. Bechtel Consulting, Manhattan, Kansas, U.S.A.
2. L'Institut National de la Recherche Agronomique—Unité Mixte de Recherche, Montpellier, France
3. Centre for Crop Genetic Improvement, Rothamsted Research, Harpenden, Hertfordshire, U.K.
4. Ascus Ltd., Markyate, Hertfordshire, U.K.