1. National Beet Medium-Term Gene Bank, Heilongjiang University, Harbin 150080, P. R. China
2. Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin 150080, P. R. China
3. Key Laboratory of Molecular Biology, School of Life Sciences, Heilongjiang University, Harbin 150080, P. R. China