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为明确中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus,TYLCCNV)伴随的卫星DNAβ分子在寄主体内的遗传结构特点及种群变异水平,将TYLCCNV分离物Y10(Y10)和伴随的DNAβ(Y10β)的全长侵染性克隆经农杆菌介导共同接种心叶烟,从Y10β的分子克隆出发,对心叶烟中Y10β的种群结构、变异水平、突变分布及碱基变异类型进行分析。结果表明,Y10β种群具有丰富的遗传多样性及较高的变异水平,所获得的43个Y10β全长克隆在核苷酸水平均发生不同程度的变异,接种后60天的Y10β种群60-1和种群60-2的突变频率分别为2.7×10-3和3.0×10-3,另一个接种后120天的种群120-1的突变频率为3.0×10-3;此卫星DNAβ的变异位点在整个基因组内均有分布,但在A-rich区碱基变异位点数最多,且主要为碱基A的缺失和插入,特别是在889～901核苷酸位点,所得43个克隆中有19个克隆在这一区段发生碱基A的缺失或插入;此外,Y10β的碱基替换突变类型以A突变为G及T突变为C的比例较高。
In order to elucidate the genetic structure and population variation of satellite DNAβ molecules in Tomato yellow leaf curl China virus (TYLCCNV), TYLCCNV isolate Y10 (Y10) and its associated DNAβ (Y10β ) Of the full-length invasive clones mediated by Agrobacterium tumefaciens co-vaccinated leaf-leaf tobacco, Y10β molecular cloning starting from the leaf center tobacco Y10β population structure, mutation level, mutation distribution and base mutation types were analyzed. The results showed that the Y10β population was rich in genetic diversity and high level of variation. The 43 Y10β full-length clones obtained at different nucleotide levels all had different degrees of variation. After 60 days of inoculation, Y10β population 60-1 and The frequency of mutation in population 60-2 was 2.7 × 10-3 and 3.0 × 10-3, respectively. The mutation frequency of population 120-1 was 3.0 × 10-3 in 120 days after inoculation. The mutation site of DNAβ in this satellite was The distribution of the entire genome, but in the A-rich region, the largest number of base mutation sites, and mainly the deletion and insertion of base A, especially in the 889 ~ 901 nucleotide positions, 43 of the resulting clone 19 In this region, the clones lost or inserted base A; in addition, the type of the base substitution mutation of Y10β was higher in the mutation of A to G and the mutation of T to C.