Population structure and diversity of citrus tristeza virus (CTV) isolates in Hunan province, China
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- 作者：Cui Xiao ; Run-Xian Yao ; Fang Li ; Su-Ming Dai ; Grazia Licciardello…
- 刊名：Archives of Virology
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：162
- 期：2
- 页码：409-423
- 全文大小：
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Virology; Medical Microbiology; Infectious Diseases;
- 出版者：Springer Vienna
- ISSN：1432-8798
- 卷排序：162
文摘
Stem-pitting (SP) is the main type of citrus tristeza virus (CTV) that causes severe damage to citrus trees, especially those of sweet orange, in Hunan province, China. Understanding the local CTV population structure should provide clues for effective mild strain cross-protection (MSCP) of the SP strain of CTV. In this study, markers for the p23 gene, multiple molecular markers (MMMs), and sequence analysis of the three silencing suppressor genes (p20, p23 and p25) were employed to analyze the genetic diversity and genotype composition of the CTV population based on 51 CTV-positive samples collected from 14 citrus orchards scattered around six major citrus-growing areas of Hunan. The results indicated that the CTV population structure was extremely complex and that infection was highly mixed. In total, p23 gene markers resulted in six profiles, and MMMs demonstrated 25 profiles. The severe VT and T3 types appeared to be predominantly associated with SP, while the mild T30 and RB types were related to asymptomatic samples. Based on phylogenetic analysis of the amino acid sequences of p20, p23 and p25, 19 representative CTV samples were classified into seven recently established CTV groups and a potentially novel one. A high level of genetic diversity, as well as potential recombination, was revealed among different CTV isolates. Five pure SP severe and two pure mild strains were identified by genotype composition analysis. Taken together, the results update the genetic diversity of CTV in Hunan with the detection of one possible novel strain, and this information might be applicable for the selection of appropriate mild CTV strains for controlling citrus SP disease through cross-protection.