摘 要：柑橘黄龙病（HLB）是世界柑橘产业的一种毁灭性病害，主要由韧皮部杆菌（Candidatus Liberibacter）引起。该属细菌包括亚洲种（CLas）、非洲种（CLaf）和美洲种（CLam），其中，我国主要流行的是CLas。本研究对湖南省、广西壮族自治区、江西省及广东省的183份携带CLas的柑橘叶片样本进行噬菌体及转座子基因序列差异分析，并对来自湖南省4个市区的19份样本的外膜蛋白（OMP）的基因序列进行差异分析。研究结果表明，CLas的转座子组合有3种，噬菌体的组合有7种，4个省（区）的CLas群体出现次数最多的是缺失了MCLas-A类型转座子且单一携带T2型噬菌体的病菌，分辨指数（DI）为0.534 0。基于噬菌体和转座子类型进行聚类分析，遗传距离为0.15时，所有样本被分成三类：江西省吉安市、赣州市被聚成一类；湖南省郴州市与永州市聚在一起并与广东省肇庆市组成此类的一个分支，作为第二类；来自印度尼西亚、越南、日本和泰国等国家的样本为第三类。每个样本OMP上的突变核苷酸位点个数为0～4，一共发现了18个不同的核苷酸突变位点，表明OMP基因具有较高的遗传多样性。聚类结果显示，国内的CLas大多数被聚在了一类，而来自印度尼西亚、越南、日本和泰国等国家的样本聚在另一类。这一格局清晰地表明了不同地理种群间存在一定程度的遗传距离，为理解CLas的种群进化与传播路径提供了关键遗传学证据。

关键词：韧皮部杆菌亚洲种；外膜蛋白基因；噬菌体转座子；遗传多样性；群体结构分析
中图分类号：Q933         文献标志码：A      DOI：10.3969/j.issn.1007-7146.2026.03.005

Abstract: Citrus Huanglongbing is a devastating disease in the global citrus industry, primarily caused by bacterium of the genus Candidatus Liberibacter, which comprises three species: asiaticus (CLas), africanus (CLaf) and americanus (CLam). Among them, CLas is the predominant species in China. This study conducted phage and transposon gene sequence differential analyses on 183 citrus leaf samples carrying CLas from Hunan Province, Guangxi Zhuang Autonomous Region, Jiangxi and Guangdong Province, and additionally performed outer membrane protein (OMP) gene sequence differential analysis on 19 samples from four cities in Hunan Province. It was found that CLas had three transposon combinations and seven phage combinations. The most frequent CLas population in the four regions was characterized by the absence of the MCLas-A type transposon and the presence of a single T2 phage, with a discrimination index (DI) of 0.534 0. Cluster analysis based on phage and transposon types divided all samples into three clusters at a genetic distance of 0.15: Ji’an and Ganzhou in Jiangxi formed the first cluster; Chenzhou and Yongzhou in Hunan clustered together and branched with Zhaoqing of Guangdong, forming the second cluster; samples from other countries such as Indonesia, Vietnam, Japan, and Thailand formed the third cluster. The number of mutated nucleotide sites in the OMP gene of each sample ranged from 0 to 4, with a total of 18 different nucleotide mutation sites, indicating a high genetic diversity in OMP. The clustering results showed that most domestic CLas samples clustered together, while samples from Indonesia, Vietnam, Japan, and Thailand formed another cluster. This pattern clearly indicates a certain degree of genetic isolation among different geographical populations, providing critical genetic evidence for understanding the population evolution and transmission routes of the CLas.
Keywords: Candidatus Liberibacter asiaticus; outer membrane protein gene; bacteriophage transposon; genetic diversity; population structure analysis
（Acta Laser Biology Sinica, 2026, 35(3): 233-240）