1. Swedish University of Agricultural Sciences Umeå Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, , 901 83 Umeå , Sweden
2. Umeå University Umeå Plant Science Centre (UPSC), Department of Plant Physiology, , 901 87 Umeå , Sweden
3. Swedish University of Agricultural Sciences Department of Forest Ecology and Management, , 901 83 Umeå , Sweden