Funding for this research was provided by:
Minstry of Science and Technology of the People's Republic of China (2013AA102504, 2011BAD28B02, 2014ZX08009-053B)
Natural Science Foundation of Beijing Municipality (31072016, 31472065, 6152013)
Ministry of Education of the People's Republic of China (IRT1191)
Beijing Municipal Bureau of Agriculture (BAIC06-2016)