1 Tropical Crop Improvement Laboratory, Biosystems Department, KU Leuven, Belgium; Plant Genetics and Rhizosphere Processes Laboratory, TERRA Teaching and Research Center, University of Liège, Gembloux Agro-Bio Tech, Gembloux, Belgium. Electronic address: herve.vanderschuren@kuleuven.be.
2 IBMCP, Departament de Producció Vegetal, Universitat Politècnica de València, Valencia, Spain. Electronic address: jagusti@ibmcp.upv.es.