1. Department of Agriculture, Graduate School of Science and Technology, Shinshu University, Minami-minowa, Nagano, 399-4598, Japan
2. Jardin botanique de Montréal (CMMF), Montréal, Québec, H1X 2B2, Canada
3. Natural Resources Canada, Laurentian Forestry Centre, Quebec, G1V 4C7, Canada
4. Faculty of Agriculture, Shinshu University, Minami-minowa, Nagano, 399-4598, Japan
5. Institute for Mountain Science, Shinshu University, Minami-minowa, Nagano, 399-4598, Japan