1. Institute of Crop Breeding and CultivationChinese Academy of Agricultural Sciences Zhongguancun South Street 12 100081 Beijing China
2. Inst. of Plant Breeding, Seed Science and Population GeneticsUniv. of Hohenheim 70593 Stuttgart Germany
3. ICRISAT Patancheru Hyderabad 502‐324 Andhra Pradesh India
4. CIMMYT Apdo. Postal 6‐641 06600 Mexico D.F. Mexico