1. Program in Agricultural Chemistry, Faculty of Agricultural Production, Maejo University, Chiang Mai, Thailand
2. Plant Genetic Resource and Nutrition Laboratory, Chiang Mai University, Chiang Mai, Thailand
3. Agronomy Division, Department of Plant and Soil Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, Thailand
4. Lanna Rice Research Centre, Chiang Mai University, Chiang Mai, Thailand