Funding for this research was provided by:
National Natural Science Foundation of China (ID0ESNAI8701)
National Natural Science Foundation of China (ID0E1TAI8702)
the Fundamental Research Funds for the Central Universities (ID0EC1AI8703)
China Agriculture Research System (ID0EIABI8704)
Article History
Received: 2 October 2015
Accepted: 25 February 2016
First Online: 5 March 2016