1. Biometrics and Statistics Unit, Crop Research Informatics Laboratory (CRIL); International Maize and Wheat Improvement Center (CIMMYT); Apdo. Postal 6-641 06600 Mexico D.F. Mexico
2. Biometrics and Statistics Unit; CRIL, CIMMYT, and Colegio de Postgraduados; Km. 36.5, CarreteraMéxico-Texcoco Montecillos Estado de México 56230 México
3. Departamento de Ciencias Agronómicas, Facultad de Ciencias Agropecuarias; Universidad Nacional de Colombia
4. Department of Statistics; University of Kentucky; Lexington KY 40546-03121
5. Auxilium Pharmaceuticals, Inc.; PA
6. Department of Plant and Soil Sciences and Department of Statistics; University of Kentucky; Lexington KY 40546-03121