Comparison of the Composition of Three Mahonia Plants Based on GC-MS Analysis Haitao Guo, Xiaoming Xue, Chenghui Nan, Xi Liu, Zehui Wang and Bin Dao E3S Web Conf., 131 (2019) 01125 Published online: 19 November 2019 DOI: 10.1051/e3sconf/201913101125