南疆温室番茄黄化曲叶病病毒种类的分子鉴定

为明确南疆温室番茄黄化曲叶病的病毒种类,利用双生病毒的兼并引物通过PCR扩增,对采集的20个番茄病株进行了分子检测.从20个病株中均扩增到约500 bp的目标片段,对其中4株进行克隆和测序,其相互间序列同源性为97.1％ ～99.3％,与番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的同源性较高,为98.6％ ～ 99.5％.随机选取莎车分离物KS2-5进行全基因组的克隆和测序,KS2-5 DNA全长为2781 nt(序列号:JQ807735),具有典型的双生病毒基因组特征,与TYLCV其它分离物同源性达到98.9％～99.5％,而与其它粉虱传双生病毒的序列同源性较低,为68.3％ ～75.5％,表明危害南疆温室番茄的病毒种类为番茄黄化曲叶病毒TYLCV.

Molecular identification of begomovirus species of tomato yellow leaf curl disease from greenhouse in southern Xinjiang

In order to ascertain the virus species of tomato yellow leaf curl disease occurring in greenhouse in southern Xinjiang, 20 greenhouse-grown tomato plants with yellow leaf curl symptoms were subjected to PCR-based diagnosis of begomovirus infection. Using universal primers of begomoviruses, fragments of about 500 bp were amplified from all samples and 4 fragments were chosen to clone and sequence. The sequences of the 4 fragments shared 97.1%-99.3% nucleotide sequence identities each other and had high nucleotide sequence identities (98.6%-99.5%) with DNA of Tomato yellow leaf curl virus (TYLCV). Isolate KS2-5 from Shache was chosen to determine complete sequence of DNA. The results showed that it was comprised of 2 781 nucleotides and had typical genomic organization of begomoviruses(JQ807735). DNA of KS2-5 had 98.9%-99.5% sequence identities with those of TYLCV isolates, while less than 75.5% identities with other whitefly-transmitted begomoviruses. It was concluded that tomato plants with viral symptoms were caused by TYLCV in southern Xinjiang.