1. Department of Forest Sciences and Research Institute for Agriculture and Life Sciences , Seoul National University .
2. National Instrumentation Center for Environmental Management , Genomics Laboratory , Seoul National University , Gwanak-gu, Seoul , 151-921 , Korea .
3. USDA, ARS, US National Arboretum , Floral and Nursery Plants Research Unit , Beltsville , MD 20705 , United States of America .