Clarification of the infection pattern of Xanthomonas citri subsp. citri on citrus fruit by artificial inoculation od Lian Liu, Xin Liu, Lingyi Liu, Tao Zhu, Rongchun Ye, Hao Chen, Linglei Zhou, Guang Wu, Limei Tan, Jian Han, Ronghua Li, Xianfeng Ma, Ziniu Deng