苹果锈果类病毒(ASSVd)的种群及遗传变异分析  

Analysis of population structure and genetic variation of apple scar skin viroid(ASSVd)

作　　者：杜亚杰 张煜泓 李世访[2] 朱英波 张志想[2] DU Yajie;ZHANG Yuhong;LI Shifang;ZHU Yingbo;ZHANG Zhixiang(College of Agronomy and Biotechnology,Hebei Normal University of Science&Technology,Hebei Key Laboratory of Crop Stress Biology(in Preparation),Qinhuangdao 066004,China;State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing 100193,China)

机构地区：[1]河北科技师范学院农学与生物科技学院,河北科技师范学院河北省作物逆境生物学重点实验室(筹),秦皇岛066004 [2]中国农业科学院植物保护研究所,植物病虫害综合治理全国重点实验室,北京100193

出　　处：《植物保护》2023年第2期103-110,共8页Plant Protection

基　　金：国家重点研发计划(2019YFD1001800)。

摘　　要：苹果锈果类病毒apple scar skin viroid(ASSVd)引起苹果锈果病,是限制我国苹果生产的重要因素之一。然而,目前对ASSVd全球种群的组成及遗传变异仍缺乏足够的了解。为此,本研究对GenBank中登录的212条基因组序列进行了比较、变异分析以及系统发育分析。确认ASSVd的种群符合准种模式,由165种序列相似但不相同的变体组成。以来自我国苹果的MW315909和MW302328为代表的两种变体的数量最多,是主流变体。依据参考序列(NC001340)分析碱基变异,发现碱基变异偏好于某种碱基,并且偏好于基因组上的一些特定位点。变异不仅发生在基因组二级结构的左末端区、致病区、中央区,也发生在可变区和右末端区。值得指出的是,基因组上有4个区域极少发生变异,为保守区。其中的两个保守区(末端保守区和中央保守区)是已知的,而在可变区与右末端区交界处的两个保守区是新发现的,它们对ASSVd的复制和移动可能具有重要作用。这些结果不仅有助于掌握ASSVd的发生及流行,而且为研发RT-PCR/qPCR检测技术提供了参考,为研究ASSVd与寄主的相互作用提供了线索。Apple scar skin viroid(ASSVd)is the causal agent of apple scar skin disease and is a major pathogen limiting apple production in China.However,the composition and genetic variation of the global population of ASSVd remain unclear.Here,we aligned 212 genome sequences of ASSVd retrieved from GenBank and analyzed their genetic variation and phylogenetic relationships.The global population of ASSVd fitted the model of quasispecies.It consisted of 165 highly related but nonidentical variants with two master variants represented by MW315909 and MW302328 from apple in China.In addition,genetic variation analysis based on the reference sequence(NC001340)showed obvious bias towards certain bases for mutation types and towards several certain positions for the distribution of mutations on the genome.Mutations occurred not only in terminal left(T_(L)),pathogenicity(P),and central(C)regions in the secondary structure of ASSVd,but also in variant(V)and terminal right(T_(R))regions.It should be noted that there were four conserved regions in the secondary structure of ASSVd,two of which,terminal conserved region(TCR)and central conserved region(CCR),are known and the other two located in the junction of V and T_(R) regions are new.The two new conserved regions may play important roles in ASSVd replication and movement.Together,these results are helpful for understanding the occurrence and epidemic of ASSVd,and provides a reference for developing detection technology of RT-PCR/qPCR and new clues for studying the interactions between ASSVd and its hosts.

关 键 词：苹果 类病毒 种群 遗传变异 变异 

分 类 号：S436.611.1[农业科学—农业昆虫与害虫防治]