为探究赣南地区柑桔黄龙病菌的遗传多样性,从赣南16个县(市、区)采集32份具典型柑桔黄龙病症状的脐橙叶片样品,运用PCR-RFLP(聚合酶链式反应-限制性长度多态性分析)技术研究柑桔黄龙病菌16SrDNA序列、16S/23SrDNA间隔区序列和核糖体蛋白基因的多态性,并对3个基因片段进行测序,分析序列的碱基含量、碱基转换率与颠换率、相似性、核苷酸遗传距离和系统进化特征。结果表明,供试赣南柑桔黄龙病菌样品在3个基因片段上的RFLP指纹图谱均一致,未表现出多态性,且序列相似性均在98%~100%;序列碱基中的GC含量以16SrDNA最大,序列碱基的转换率/颠换率以16SrDNA最小;赣南柑桔黄龙病菌样品与亚洲种Candidatus Liberibacter asiaticus之间的序列相似性最大、核苷酸遗传距离最小,在系统进化中归属亚洲种。 To explore the genetic diversity of Citrus Huanglongbing in Gannan area, 32 samples of navel orange leaves with typical symptoms of citrus Huanglongbing were collected from 16 counties (cities and districts) in Gannan. PCR-RFLP (polymerase chain reaction) - restriction fragment length polymorphism (RFLP)) technique was used to study the 16SrDNA sequence, 16S / 23SrDNA spacer region and ribosomal protein gene polymorphism of Citrus Huanglongsheng. The three gene fragments were sequenced to analyze the base content, Base turnover rate and transversion rate, similarity, nucleotide genetic distance and phylogenetic characteristics. The results showed that the RFLP fingerprints of three samples of Citrus Huanglongbing in Gannan were the same, showing no polymorphism, and the sequence similarity was 98% -100%. The GC The highest content of 16SrDNA, the base conversion rate / transversion rate of 16SrDNA minimum; Gannan Citrus Huanglong germplasm samples and Asian species Candidatus Liberibacter asiaticus sequence similarity between the smallest, the genetic distance of nucleotide minimum in the system evolution In the Asian species.