江西胜红蓟黄脉病病原的分子鉴定

Molecular Identification of the Pathogen Inducing Ageratum Yellow Vein Disease in Jiangxi

为明确引起江西赣州地区胜红蓟上黄脉症状的病原,利用PCR技术,从3个样品上均扩增到双生病毒的约500 bp特异片段,并选择病毒分离物JX01进行全序列测定。结果表明,JX01 DNA-A全长2 754 nts,符合双生病毒DNA-A的结构特征,与中国番木瓜曲叶病毒(Papaya leaf curl China virus,Pa LCCNV)分离物Pa LCCNVFz10同源性最高,达99.7%。利用特异性引物对JX01样品进行卫星分子的扩增,得到大约1 300 bp的片段(JX-Gz01β)。序列分析表明,JX-Gz01β全长1 314 nts,与伴随中国胜红蓟黄脉病毒的卫星分子(Ageratum yellow vein China betasatellite,AYVCNB)Hn9分离物的同源性最高,为94.3%。系统关系树分析表明,JX01与Pa LCCNV各分离物聚类为一个大分支,而与其他病毒亲缘关系较远。这是江西首次报道Pa LCCNV侵染胜红蓟。

To determine the virus species infecting Ageratum conyzoides in Ganzhou,Jiangxi Province,weed samples showing typical geminivirus-like symptoms were tested by PCR technique.A fragment of 500 bp was consistently amplified from total DNA extracts of 3 samples with a pair of specific primer.Comparison of sequences of the 500 bp fragment revealed that these samples were infected by a same virus and thus an isolate denoted JX01 was selected for further sequence analysis.The complete sequence of JX01 comprised 2 754 nucleotides with typical genomic organization of geminiviral DNA-A.JX01 was most closely related to Papaya leaf curl China virus isolate Fz10（ Pa LCCNV-Fz10）,with 99.7% nucleotide sequence identity.By using the specific primers for the full length of betasatellite,a fragment of about 1 300 bp was amplified.The complete sequence of betasatellite（ JX-Gz01β） was determined to be 1 314 nucleotides.Sequence analysis showed that JX-Gz01β was most closely related to Ageratum yellow vein China betasatellite isolate Hn9（ AYVCNB-Hn9）,with 94.3% nucleotide sequence identity.Phylogenetic analysis showed that JX01 clustered together with isolates of Pa LCCNV.This is the first report of Pa LCCNV infecting Ageratum conyzoides in Jiangxi Province.