水蜡A病毒在呼和浩特市和哈尔滨市紫丁香上的发生及其基因组分子特征分析  

Surveys and molecular characterization of Ligustrum virus A isolated from Syringa oblata in Hohhot and Harbin

作　　者：宋爽 张磊[2] 孙平平 李正男 Song Shuang;Zhang Lei;Sun Pingping;Li Zhengnan(College of Agriculture,Northeast Agricultural University,Harbin 150030,Heilongjiang Province,China;College of Horticulture and Plant Protection,Inner Mongolia Agricultural University,Hohhot 010018,Inner Mongolia Autonomous Region,China)

机构地区：[1]东北农业大学农学院,哈尔滨150030 [2]内蒙古农业大学园艺与植物保护学院,呼和浩特010018

出　　处：《植物保护学报》2021年第3期645-651,共7页Journal of Plant Protection

基　　金：黑龙江省自然科学基金联合引导项目(LH2019C024);内蒙古自然科学基金(2019MS03021)。

摘　　要：为明确侵染紫丁香Syringa oblata并引起褪绿花叶症状的病毒种类及其基因组分子特征,利用透射电子显微镜对分离自呼和浩特市和哈尔滨市的紫丁香病样中的病毒粒子进行观察,并通过小RNA高通量测序和RT-PCR技术对其进行检测分析。结果表明,在紫丁香显症叶片的病毒粗提液中观察到长约600 nm、宽约13 nm的线状病毒粒子。利用小RNA高通量测序和RT-PCR技术从病样中检测到水蜡A病毒(Ligustrum virus A,LVA),发病率为3.7%。呼和浩特市紫丁香分离物LVA-Sob的基因组序列全长8 525 nt,包含6个开放阅读框,分别编码Rep(1 968 aa)、TGB1(229 aa)、TGB2(107 aa)、TGB3(60 aa)、CP(294 aa)和NABP(119 aa)共6个蛋白。序列一致性分析表明,分离物LVA-Sob与韩国水蜡树分离物LVA-SK的基因组序列一致率高达97.9%,而与我国辽宁省暴马丁香分离物LVA-DX的基因组序列一致率仅为73.6%。在这3个LVA分离物基因组中没有检测到重组事件;基于基因组和cp基因序列的系统发育树显示这3个LVA分离物形成一个分支,并与瑞香S病毒(daphne virus S,DVS)有较近的亲缘关系。To determine the species and genome characterization of the virus causing symptoms of chlorotic mosaic on Syringa oblata plants, viral particles isolated from infected S. oblata plants in Hohhot and Harbin were observed under a transmission electron microscope and their genomes were analyzed via high-throughput sequencing of small RNAs and RT-PCR. Flexuous filamentous particles with a length of about 600 nm and a width of about 13 nm were observed in crude sap of symptomatic S. oblata leaves. Through high-throughput sequencing of small RNAs and RT-PCR, Ligustrum virus A(LVA)was detected with incidence rate of 3.7%. The genome of LVA-Sob, a LVA isolate of S. oblata from Hohhot was 8 525 nt in length and contained six open reading frames(ORFs) which encoded Rep(1 968 aa),TGB1(229 aa), TGB2(107 aa), TGB3(60 aa), CP(294 aa) and NABP(119 aa) proteins. Sequence comparison analysis showed that LVA-Sob isolate shared a high genome identity of 97.9% with the Ligustrum obtusifolium isolate LVA-SK from Korea, but only 73.6% with the S. reticulata var. mandshurica isolate LVA-DX from Liaoning Province of China. No recombination event was detected among the three LVA isolates. Phylogenetic analysis based on genome and cp gene sequences showed that the three LVA isolates clustered into a single clade, which was closely related to daphne virus S(DVS).

关 键 词：水蜡A病毒 紫丁香 基因组 小RNA 

分 类 号：S436.8[农业科学—农业昆虫与害虫防治]