1. Institute of Upland Food CropsGuiyangGuizhou550006PRC
2. USDA‐ARS and Dep. of Soil and Crop SciencesTexas A & M UniversityCollege StationTX77843
3. Dep. of Biological SciencesPurdue Univ.West LafayetteIN47907‐1392
4. Dep. of AgricultureThe University of QueenslandBrisbaneQld 4072Australia