1. Biometrics and Statistics Unit of the Crop Informatics Laboratory (CRIL)International Maize and Wheat Improvement Center (CIMMYT) Apdo. Postal 6-641 México D.F. México
2. Dep. of Plant and Soil Sciences and Dep. of StatisticsUniv. of Kentucky Lexington KY 40546-0312 USA
3. Plant Breeding InstituteUniversity of Sydney PMB 11 Camden NSW 2570 Australia
4. Biometrics and Bioinformatics Unit of the Crop Informatics Laboratory (CRIL)International Rice Research Institute (IRRI) DAPO Box 7777 Manila the Philippines