This work was financially supported by the National Science Foundation of China (31530009, 31500476), the Research Foundation of the Education Bureau of Hunan Province (15K151), the Young Elite Scientists Sponsorship Program by CAST (2016QNRC001), the Outstanding Innovative Youth Training Program of Changsha (KQ1707019), the Hunan Provincial Technical Innovation Platform and Talent Program in Science and Technology (2016RS2010, 2016TP1013), the Hunan Provincial Innovation Foundation for Postgraduate (CX2017B396) and the Scientific Innovation Fund for Graduate of Central South University of Forestry and Technology (CX2017A01).