Funding for this research was provided by:
China Agriculture Research System (CARS-42-16)
Received: 15 January 2019
Accepted: 9 May 2019
First Online: 17 May 2019
Ethics approval and consent to participate
: Experiments involving animals were conducted following the guidance and under approval of the Animal Welfare and Ethical Censor Committee at China Agricultural University and Beijing Administration Committee of Laboratory Animals (Approval ID: CAU20170617–2).
: Not applicable.
: The authors declare that they have no competing interests.
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