This supplement to Crop Science includes 22 of the 28 papers presented during the 2006 International Plant Breeding Symposium, held on 21-26 August 2006 in Mexico City (One of the 28 papers has been previously published in Crop Science [Löffler et al. (2005), Crop Sci. 45:1708-1716]). The symposium served as a global forum for current plant breeding research in major row-crop species and honored Professor John W. Dudley of the University of Illinois for his 49 years of research, teaching, and service in plant breeding and genetics. A total of 356 scientists and students from 60 different countries participated in the symposium. Participation by many scientists from developing countries was made possible by generous financial support primarily from CIMMYT, Generation Challenge Program, HarvestPlus, Iowa State University, Monsanto, Pioneer Hi-Bred, Renessen, Syngenta Seeds, USDA, and the University of Illinois.