1. Department of Agrosystems, The Swedish University of Agricultural Sciences, Box 104, SE-23053 Alnarp, Sweden.
2. Corresponding author. E-mail: eva.johansson@slu.se
3. Present address: Department of Plant Breeding, The Swedish University of Agricultural Sciences, Box 101, SE-23053 Alnarp, Sweden.
4. Present address: Syngenta Seeds AB, Box 302, 26123 Landskrona, Sweden.
5. Present address: Department of Biosciences, COMSATS Institute of Information Technology, Sahiwal Campus, COMSATS Road, P. Code 57000 Sahiwal, Pakistan.
6. MAX-lab, Lund University, SE-221 00 Lund, Sweden.
7. Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
8. Innventia, Box 5604, SE-11486 Stockholm, Sweden.