基于不同位点的广东省柑橘黄龙病菌种群分子多样性分析  

Population diversity of “Candidatus Liberibacter asiaticus” in Guangdong Province based on different gene loci

作　　者：黄洪霞 郑正 邓晓玲 许美容 HUANG Hongxia;ZHENG Zheng;DENG Xiaoling;XU Meirong(College of Agriculture,South China Agricultural University/Guangdong Province Key Laboratory of Microbial Signals and Disease Control,Guangzhou 510642,China)

机构地区：[1]华南农业大学农学院/广东省微生物信号与作物病害防控重点实验室

出　　处：《华南农业大学学报》2020年第2期66-75,共10页Journal of South China Agricultural University

基　　金：国家重点研发计划(2018YFD0201506);广东省科技计划项目(2017A0303030066)

摘　　要：【目的】探究广东省不同地区柑橘黄龙病菌“Candidatus Liberibacter asiaticus”(CLas)的种内遗传结构及遗传多样性情况;评价用多基因位点分析柑橘黄龙病菌遗传多样性的科学性。【方法】基于原噬菌体区域(SC1、SC2和PJXGC)、转座子位点(CLIBASIA_05620~CLIBASIA_05625)和短串联重复序列STR1(CLIBASIA_03080)、STR12(CLIBASIA_01215)6个基因位点的多态性,对来自广东省10个市(县)的176个黄龙病样品进行病原菌遗传多样性分析。【结果】基于噬菌体类型鉴定出6组菌株,其中携带Type II类型原噬菌体的菌株为优势种群(85.23%);基于转座子位点鉴定出4种类型菌株,含有缺失MCLas-A类型转座子的B350片段的菌株为优势种群(76.70%);基于短串联重复序列STR1和STR12分别鉴定出9和10类菌株,且STR1位点上含有3个“CAGT”串联重复的菌株为优势种群(56.82%);STR12位点上多态性条带分布不集中,没有优势条带类型。聚类分析结果表明湛江、茂名和深圳的种群与其他地区种群的差异较大,而清远和梅州的黄龙病菌种群关系较近。【结论】基于不同位点和基于所有位点所得的聚类结果不尽相同,说明利用单个或单种基因位点对黄龙病菌进行种群遗传结构分析具有较大的局限性。【Objective】To explore the intraspecific genetic structure and genetic diversity of“Candidatus Liberibacter asiaticus”(CLas)in different regions of Guangdong Province,and evaluate the feasibility of using multiple loci in studying genetic diversity of CLas.【Method】Six polymorphic gene loci,including three phage regions(SC1,SC2 and PJXGC),transposon region(CLIBASIA_05620−CLIBASIA_05625)and short tandem repeat(STR)genes,STR1(CLIBASIA_03080)and STR12(CLIBASIA_01215),were used to evaluate genetic diversity of 176 CLas samples from 10 cities in Guangdong Province.【Result】Based on the prophage types,the CLas isolates were classified into six groups,among which the strains with Type II prophage were predominate,accounting for 85.23%of the population.Four types of isolates were identified based on transposon sites,and the Clas strains containing the B350 fragment(non-MCLas-A type)were the dominant group,accounting for 76.70%of the population.Based on the two STR loci,nine and ten band types were identified respectively,and the isolates with three CAGT tandem repeats at the STR1 locus were predominate accounting for 56.82%of the population.The distribution of polymorphic bands at the STR12 locus was scattered,and no predominate band type was identified.Cluster analysis showed that CLas populations from Zhanjiang,Maoming and Shenzhen were different from populations of other regions,while the CLas populations collected from Qingyuan and Meizhou were similar.【Conclusion】Cluster results based on individual locus and based on all six loci are different,indicating the limitation of using single gene locus to analyze the genetic structure of CLas population.

关 键 词：柑橘黄龙病 韧皮部杆菌 种内遗传结构 遗传多样性 多态基因位点 

分 类 号：S436.661[农业科学—农业昆虫与害虫防治]