引起番茄植株坏死病的病毒研究

 2004~2005年,在上海郊区夏番茄上连续发生严重的植株坏死病。表现为番茄植株矮化、顶端坏死、果实畸形和整株枯萎症状,并在叶柄和茎干上出现不规则坏死条斑,具有典型的病毒病特征。通过采集典型病叶、病果,进行病毒分离、dsRNA分析、寄主生物学研究、病毒纯化、病毒蛋白分析、组织病理学与形态学观察和ELISA检测,初步确定是由番茄花叶病毒(Tomato mosaic virus,ToMV)和黄瓜花叶病毒(Cucumber mosaic virus,CMV)侵染。经5次心叶烟单斑分离,获得N5分离物,对CP基因克隆测序的结果确定该分离物为ToMV。寄主反应测定显示,N5的寄主反应与常规ToMV株系存在明显区别,主要表现为常规番茄品种上出现严重坏死。进一步接种GCR品系番茄鉴定N5与ToMV-1株系相似。因此,作者认为,在上海地区番茄上流行并引起坏死病的主要病原可能是ToMV-1株系的1个变异株。

Characterization of viruses causing necrosis disease on tomato

A severe necrosis disease was found occurring at suburban Minghang-districts,Shanghai,during summer of 2004 and developed more widely in 2005.The typical symptoms of the disease occurred at fruiting stage were top necrosis,plant stunt,fruit distortion,foliage yellowing and slight-mosaic,combined with brown necrosis strikes on stems and leaf stalks,and developed into death of the whole plant.Virus isolates were obtained by mechanical inoculation,and characterized by double stranded-RNA analysis,morphological and cytopathological alteration tests,virus purification,protein analysis,ELISA,and CP sequence analysis.The virus causing top necrosis on tomato was identified as Tomato mosaic virus(ToMV)with some mutation.A typical isolate N5 was obtained after five cycles of single-spot isolation on Nicotiana glutinosa.The results of biological characterization tests for ToMV-N5 showed that it is similar to ToMV-1 strain.A necrosis strain of ToMV was thought out as the principal virus causing necrosis disease on tomato at Shanghai.