The ongoing global spread of Tomato yellow leaf curl virus (TYLCV) poses an endemic threat to tomato production in all tropical and sub-tropical regions of the world. In Oman, TYLCV evolved into the new species Tomato leaf curl Oman virus (ToLCOMV) by recombination with Papaya leaf curl virus (PaLCuV). In March 2017, during a field survey of Sindh province of Pakistan, tomato (Solanum lycopersicum L.) plants showing typical symptoms of Tomato leaf curl disease (ToLCD); such as leaf curling, yellowing and stunted plant growth were observed. For identification and characterization of the causative agent, leaf samples were collected and tested for the presence of begomoviruses and associated DNA satellites. We have recently reported the presence of ToLCOMV-PK (previously known as TYLCV-PK strain) on Cyamopsis tetragonoloba in the same province of Pakistan. The tomato samples were analyzed for the presence of ToLCOMV-PK using specific primers. Approx. 2.8 kb and 1.4 kb PCR products were obtained which were cloned and sequenced; the results indicated the presence of ToLCOMV-PK and Tomato leaf curl betasatellite (ToLCB). We were also able to identify defective molecules of ToLCOMV-PK which were about half the size of the complete virus. Phylogenetic analysis and the sequence demarcation tool (SDT) showed that these are new isolates of ToLCOMV-PK (ToLCOMV-Pakistan strain) associated with ToLCB. Recombination analysis detected a strong recombination event in ToLCOMV-PK in which TYLCV (JQ928346) and PaLCuV (LT009400) were major and minor parents, respectively. We also corrected the classification of the previously identified distinct strain i.e. TYLCV-PK (TYLCV-Pakistan strain) into ToLCOMV-PK strain, based on our current analysis and classification. Biolistic inoculation of ToLCOMV-PK and associated ToLCB in Nicotiana benthamiana plants showed that coinfection with ToLCB resulted in enhanced symptoms and virus accumulation. This report of ToLCOMV-PK associated with ToLCB infecting tomato in Pakistan represents the widespread and vast host range of ToLCOMV and which poses serious threat to tomato production in Pakistan.

番茄黄叶卷曲病毒（TYLCV）的全球扩散正在威胁着世界所有热带和亚热带地区的番茄生产。在阿曼，TYLCV通过与木瓜叶卷曲病毒（PaLCuV）重组而进化为新物种番茄叶卷曲阿曼病毒（ToLCOMV）。在2017年三月，巴基斯坦信德省的实地调查过程中，番茄（番茄L.）表现出番茄叶片卷曲病（ToLCD）的典型症状的植物；如叶片卷曲，发黄和植物生长受阻。为了鉴定和表征病原体，收集了叶片样品，并测试了是否存在Begomoviruses和相关的DNA卫星。我们最近报道ToLCOMV-PK对存在（以前称为TYLCV-PK株）瓜尔豆在巴基斯坦的同一省。使用特异性引物分析番茄样品中是否存在ToLCOMV-PK。约 获得了2.8 kb和1.4 kb PCR产物，对其进行了克隆和测序。结果表明存在ToLCOMV-PK和番茄叶片卷曲β卫星（ToLCB）。我们还能够鉴定出ToLCOMV-PK的缺陷分子，它们大约是完整病毒大小的一半。系统发育分析和序列划分工具（SDT）表明，这些是与ToLCB相关的ToLCOMV-PK（ToLCOMV-巴基斯坦毒株）的新分离株。重组分析在ToLCOMV-PK中检测到强重组事件，其中TYLCV（JQ928346）和PaLCuV（LT009400）分别是主要父母和未成年人父母。我们还纠正了先前确定的不同菌株的分类，即 根据我们目前的分析和分类，将TYLCV-PK（TYLCV-巴基斯坦菌株）转化为ToLCOMV-PK菌株。ToLCOMV-PK及其相关ToLCB的生物射弹接种烟草（Nicotiana benthamiana）植物显示与ToLCB共同感染导致症状增强和病毒积累。这份与ToLCB感染巴基斯坦番茄相关的ToLCOMV-PK报告代表了ToLCOMV的宿主范围广泛而广泛，对巴基斯坦的番茄生产构成了严重威胁。