1. International Maize and Wheat Improvement Center (CIMMYT)Apdo. Postal 6‐641MéxicoD.F.México
2. Colegio de PostgraduadosKm. 36.5 Carretera México, Texcoco, MontecilloEstado de México56230México
3. Section on Statistical Genetics, BiostatisticsUniv. of Alabama at Birmingham1665 University Blvd., Ryals Public Health Building 414BirminghamAL35294
4. Univ. of Wisconsin‐Madison1675 Observatory Dr.MadisonWI53706