Charlock mustard (Sinapis arvensis): a weed reservoir for begomoviruses and associated betasatellite in Jordan

Four crop-infecting begomoviruses were found naturally affecting Charlock mustard (Sinapis arvensis L.) plants in Jordan and characterized at the molecular level. Symptoms included leaf curling and stunting. PCR analysis showed the presence of Tomato yellow leaf curl virus (TYLCV), Tomato yellow leaf curl Sardinia virus (TYLCSV), Squash leaf curl virus (SLCV) and Watermelon chlorotic stunt virus (WmCSV). These viruses were associated with Cotton leaf curl Gezira betasatellite (CLCuGβ). Sequence analysis revealed that TYLCV and TYLCSV had 98.5% and 99.3% nucleotide (nt) sequence identities with a previously described TYLCV strain from Florida and TYLCSV from Sardinia, respectively. The other two viruses, SLCV and WmCSV, shared 99.7% and 99.5% nt identities with previously described strains from Jordan. Sequence analysis also showed that CLCuGβ had 98.8% nt identity with a strain from Israel. To our knowledge, this is the first report of S. arvensis as a natural host of SLCV, WmCSV, TYLCSV and CLCuGβ.

本研究在约旦地区自然感病的野芥菜（Sinapis arvensis L.，俗称Charlock mustard）植株中检出4种侵染作物的菜豆金色花叶病毒属（Begomovirus）病毒，并完成了分子水平的特征鉴定。该寄主植株表现出叶片卷曲与植株矮化症状。PCR分析显示，样本中存在番茄黄化曲叶病毒（Tomato yellow leaf curl virus, TYLCV）、番茄黄化曲叶撒丁岛病毒（Tomato yellow leaf curl Sardinia virus, TYLCSV）、南瓜曲叶病毒（Squash leaf curl virus, SLCV）以及西瓜褪绿矮缩病毒（Watermelon chlorotic stunt virus, WmCSV）。上述病毒均与棉花曲叶吉齐拉贝塔卫星（Cotton leaf curl Gezira betasatellite, CLCuGβ）伴随发生。序列分析结果表明，TYLCV与此前报道的佛罗里达地区TYLCV毒株的核苷酸（nt）序列同源性达98.5%，TYLCSV与撒丁岛地区TYLCSV毒株的核苷酸同源性达99.3%；SLCV与WmCSV则分别与约旦地区此前报道的对应毒株共享99.7%和99.5%的核苷酸序列同源性。序列分析同时显示，CLCuGβ与以色列地区的对应毒株的核苷酸同源性为98.8%。据我们所知，本研究首次报道了野芥菜（Sinapis arvensis L.）作为SLCV、WmCSV、TYLCV及CLCuGβ的自然寄主。