刺茄中分离的中国番茄黄化曲叶病毒及伴随的卫星DNA分子的全基因组结构

Genomic characterization of DNA-A and associated satellite DNA molecule of an isolate of Tomato yellow leaf curl China virus in Solanum aculeatissimum

从云南砚山刺茄(Solanum aculeatissimum)上分离到病毒分离物Y322,全序列测定表明,Y322DNA-A全长2730个核苷酸,共编码6个ORF。基因组比较发现,Y322DNA-A与中国番茄黄化曲叶病毒(TYLCCNV)各分离物的同源性最高(88.3%～99.2%),而与其它双生病毒的同源性均在79.6%以下,表明Y322是TYLCCNV的一个分离物。利用DNAβ的特异性引物在Y322中扩增到DNAβ分子(Y322β),序列分析表明,其全长1331个核苷酸,与TYLCCNV伴随的DNAβ的同源性最高,达75.1%～93.1%,而与已报道的其它种类的DNAβ的同源性均低于55.4%。这是首次在刺茄中检测到中国番茄黄化曲叶病毒。

The virus isolate Y322 was obtained from Solarium aculeatissimum showing leaf curl and enation symptoms in Yanshan, Yunnan Province. Complete nucleotide sequence of the DNA-A like molecule of Y322 was determined to be 2 730 nucleotides. Y322 DNA-A was most closely related to isolates of Tomato yellow leaf curl China virus （ TYLCCNV ） with 88.3% - 99.2% nucleotide sequence identifies, while less than 79.6% nucleotide sequence identities were found in comparisons with other begomoviruses. Therefore, Y322 was taxonomically considered as an isolate of TYLCCNV. Further studies showed that Y322 was associated with a DNAβ molecule. The DNAβ of Y322 contained 1 331 nucleotides having the highest nucleotide sequence identity （75.1%-93.1%） with DNAβ associated with TYLCCNV, while less than 55.4% nucleotide sequence identities were found in comparisons with other DNAβ molecules. This is the first report of TYLCCNV in S. aculeatissimum.