国家自然科学基金面上项目31271818;沈阳市科技创新农业科技攻关专项F13-143-3-00;中国博士后科学基金项目2012M510836,2013T60299Supported by the National Natural Science Foundation of China 31271818,by the Special Fund Project for Technology Innovation of Shenyang City F13-143-3-00,and by the Postdoctoral Science Foundation of China 2012M510836,2013T60299