中国农业科学2025，Vol.58Issue(19)：3890-3904,15.DOI:10.3864/j.issn.0578-1752.2025.19.007
ToLCNDV广东冬瓜分离物的分子特征及其遗传演化规律
Molecular Characterization and Evolutionary Dynamics of Tomato Leaf Curl New Delhi Virus Isolate from Wax Gourd(Benincasa hispida)in Guangdong
摘要
Abstract
[Objective]Tomato leaf curl New Delhi virus(ToLCNDV)is one of the most severe viral pathogens affecting cucurbit crops in recent years.Reports on the genome sequences of ToLCNDV isolates from China remain limited.ToLCNDV infection in wax gourd(Benincasa hispida)has not been reported in China.The objective of this study is to investigate the occurrence patterns of ToLCNDV in B.hispida in Guangdong Province,analyze sequence characteristics,pathogenicity,genetic diversity,and spatiotemporal dynamics of ToLCNDV isolates from China,and to provide a theoretical basis for the prevention and control of ToLCNDV.[Method]The complete genome of ToLCNDV was amplified using high-throughput sequencing and PCR.PCR assays were performed to detect ToLCNDV in 79 B.hispida samples.The obtained full-length genome sequences were subjected to phylogenetic analysis,sequence identity assessment,genetic diversity evaluation,Bayesian phylogenetics,and phylogeographic analysis.Pathogenicity was tested on 12 potential host species using mechanical sap-inoculation.[Result]High-throughput sequencing revealed that ToLCNDV was present in the collected B.hispida samples.PCR assays confirmed ToLCNDV infection in 58 of 79 suspected virus samples,representing a detection rate of 73.4%.The B.hispida isolate of ToLCNDV was mechanically transmissible through sap-inoculation to eight plant species.These included Citrullus lanatus,Luffa aegyptiaca,Cucurbita pepo,Phaseolus vulgaris,Cucumis sativus,Lagenaria siceraria,Nicotiana clevelandii,and N.benthamiana.All sap-inoculated plants developed characteristic symptoms.The complete nucleotide sequences of the DNA A and B components of the B.hispida isolate 23GD_BeHi1 were 2 739 and 2 693 bp,respectively.Pairwise sequence comparison showed 98.7%-99.7%identity for DNA A and 98.7%-99.3%for DNA B compared to representative Chinese ToLCNDV isolates.Phylogenetic trees based on complete DNA A and DNA B sequences of Chinese ToLCNDV isolates revealed two distinct clades.All isolates obtained in this study clustered within Clade I.No recombination events were detected among these isolates.Genetic diversity analyses indicated that the Chinese ToLCNDV population exhibited relatively low genetic diversity.The adequate population size remained stable,and no evidence of recombination was observed.However,significant genetic differentiation was detected between isolates from Jiangsu and Shanghai.Bayesian maximum clade credibility(MCC)trees constructed from DNA A and DNA B datasets placed Zhejiang isolates at the basal position.The estimated emergence times were April 25,2020,for DNA A and November 30,2020,for DNA B.Phylogeographic reconstruction suggested that Zhejiang served as the origin center of ToLCNDV in China,and the population expansion occurred in Guangdong.[Conclusion]The complete genome sequence of ToLCNDV isolate from B.hispida in China was obtained.The DNA A and B components comprise 2 739 and 2 693 bp,respectively.Mechanical sap-inoculation demonstrates that this isolate can infect C.pepo,C.lanatus,L.aegyptiaca,C.sativus,P.vulgaris,N.clevelandii,L.siceraria,and N.benthamiana.Infected plants develop leaf curling,chlorosis,and other typical symptoms.关键词
新德里番茄曲叶病毒/冬瓜/全基因组序列/遗传多样性/谱系地理分析Key words
tomato leaf curl New Delhi virus(ToLCNDV)/wax gourd(Benincasa hispida)/complete genome sequence/genetic diversity/phylogeographic analysis引用本文复制引用
郭孟泽,张磊,孙平平,江彪,闫晋强,李正男..ToLCNDV广东冬瓜分离物的分子特征及其遗传演化规律[J].中国农业科学,2025,58(19):3890-3904,15.基金项目
内蒙古自治区自然科学基金(2023LHMS03020,2022QN03018)、内蒙古自治区高等学校青年科技英才项目(NJYT23079) （2023LHMS03020,2022QN03018）
