辽宁沈阳甜椒曲叶病的病原鉴定

Pathogen identification of sweet pepper leaf curl disease in Shenyang,Liaoning Province

从辽宁省沈阳市采集到具有严重曲叶症状的甜椒叶片,负染色试验显示病叶中存在300 nm×18 nm的杆状病毒粒子.RT-PCR检测、克隆和测序显示9个样本中存在辣椒轻斑驳病毒(PMMoV).基于外壳蛋白(cp)基因进行同源性分析,显示PMMoV沈阳分离物与已报道PMMoV核苷酸同源性为93.7%~99.8%,氨基酸同源性为96.8%~100.0%.系统进化树分析表明,PMMoV沈阳分离物与PMMoV P_(1,2)致病型的各个分离物聚在一个分支上.摩擦接种试验显示,PMMoV局部侵染心叶烟并诱导其产生坏死枯斑,但可系统侵染辣椒并诱导曲叶症状的发生.

Samples were collected from sweet pepper （ Capsicum annuurn var. grossum） plants showing severe leaf curling disease in Shenyang,Liaoning Province,China. Virions in the diameter of 300 nmX 18 nm were observed from the affected plants by negative staining under scanning electron microscopes,and were identified as pepper mild mottle virus （PMMoV） by RT-PCR from 9 symp-tomatic leaf samples. The coat protein （cp） of Shenyang isolates shared identities of 93.7%-99.8% and 96.8%-100.0% in nucleo-tide sequence and amino acid with the published PMMoV. Phylogenetic trees showed that Shenyang isolates clustered with those be-long to the P, 2 pathotype. By juice friction,the PMMoV was transmitted to healthy Nicotiana glutinosa and Capsicum annuum,cau-sing only local lesions in N.glutinosa,but systemic infection in C.annuum.