This work was supported by Funding of agricultural science and technology innovation of Jiangsu Province, China (CX(15)1030), National Natural Science Foundation of China (31501795, 31400600), the China Postdoctoral Science Foundation funded project (2014M560432, 2015T80563), the Natural Science Foundation of Jiangsu Province in China (BK20151229, BK20140695), and the fundamental research funds for the central universities (KJQN201659).