تعیین خصوصیات مولکولی جدایه های ایرانی ویروس پیچیدگی برگ زرد گوجه فرنگی

‭Tomato yellow leaf curl virus (TYLCV), (genus: Begomovirus; Family: Geminiviridae) is one of the most important viral agents that caused high yield losses in tomato fields, worldwide. Genomic sequence analyses have revealed that recombination has played an important role in begomovirus genetic diversity and evolution. Intergenic region (IR) is a known hot spot region for recombination in begomoviruses. A survey was conducted from 2003 to 2005 and 83 tomato leaf samples with yellowing and leaf curling symptoms were collected in seven provinces, comprising the major tomato growing areas of the country. TYLCV was detected in 65 samples of seven provinces, using DAS-ELISA and PCR with one primer pairs (TY1 (+)/TY2 (-) corresponding to TYLCV coat protein (CP). DAS-ELISA and PCR results showed that TYLCV introduced to new provinces of Iran. To our knowledge, this is the first report of occurrence of TYLCV in Yazd (Ashkzar), Markazi(Delijan), Khorasan( Dargaz and Mashad), and Bushehr(Baghan). To study of genetic diversity among Iranian TYLCV isolates, PCR with one primer pairs TY-Ir(F)/TY-Ir(R)) corresponding to TYLCV intergenic region, amplified the expected 750-bp fragment(s), from positive samples. The nucleotide sequences of the intergenic region of eight representative Iranian isolates from seven provinces were determined and compared with each other and other TYLCVs. 202028 The nucleotide sequences of the intergenic regions of Iranian isolates showed 93 100% similarity among the seven sequenced isolates. The jiroft isolate showed 75-76% similarity with seven Iranian isolates. Maximum nucleotide sequence similarity was observed between all Iranian isolates with TYLCV-IR (75-79%), and TLCIRV (59-62%). The Iranian isolates represented in this study showed 92-93% similarity with TYLCV, except Jiroft isolate (75%). Based on IR sequence analyses, two major groups among Iranian TYLCV isolates are evident. ‬4 ‭The first major group (indicated as group A) consists of seven virus isolates (Behbahan, Baghan, Dargaz, Delijan, Ashkzar, Sarkhon, and Mashad) originating from northern, central, and southern provinces of Iran. The second group (indicated as group B) consists of Jiroft isolate originating mainly from southern province of Iran (Kerman province). Within the major group (group A), two main clusters of isolates could be defined: cluster 1 and 2. Cluster1: The nucleotide sequences of isolates (Behbahan, Baghan, and Dargaz) of this cluster were 100%. Cluster2: The nucleotide sequences of isolates (Delijan, Ashkzar, Sarkhon, and Mashad) of this cluster were 93-94%. Sequence data suggest that the seven Iranian TYLCV isolates (group A) were probably originated from TYLCV and highly divergent from TYLCV-IR and TLCIRV. Jiroft isolate (group B) was highly divergent from TYLCV-IR, TLCIRV and TYLCV. 212128‬

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گوجه فرنگی ، خراسان ، یزد ، کرمان ، بوشهر (باغان) ، بگوموویروس ، نو ترکیبی ، جمینی ویروس پیچش برگ زرد