中国南部地区蜘蛛兰上朱顶红褪绿环斑病毒RNA L序列分析

L RNA Analysis of Hippeastrum Chlorotic Ringspot Virus on Spider Lily in Southern China

朱顶红褪绿环斑病毒(Hippeastrum chlorotic ringspot virus, HCRV)流行和扩张速度极快,严重危害多种蔬菜和花卉产业,造成严重的经济损失,已上升成为中国南部地区正番茄斑萎病毒属(Orthotospovirus)优势种。对不同地区HCRV分离株进行克隆,研究其在不同地区快速扩张和进化的机制对农业发展具有重要意义。本研究对2013-2015年在云南、广东、广西、福建和海南等5个中国南部地区采集的疑似感染Orthotospovirus属病毒的蜘蛛兰样本,采用RT-PCR技术鉴定、分离,得到10份HCRV新分离株,对其L序列进行克隆、测序。结合现有分离株,利用DNAMAN 7.0和MEGA 7.0进行分子多样性、系统发育和重组分析。结果显示,本研究的10份HCRV L分离株,包括1个最早报道的HCRV HLS1-2 L分离株,可分为2个不同来源的类群。结合10份分离株采集地的环境信息,对比可看出其气候、温度、降水等差异很大,推测HCRV在中国南部地区的广泛分布与不同地区多态的气候类型有关,在它们的进化过程中,突变和重组发挥作用。RdRp是参与HCRV在细胞内的复制和转录的重要蛋白,对RdRp序列的分析,可为后续研究HCRV RdRp的遗传变异对HCRV侵染能力的影响提供理论基础,也为HCRV的防治提供思路。

The epidemic and expansion of Hippeastrum chlorotic ringspot virus(HCRV) is extremely fast, which has seriously harmed a variety of vegetable and flower industries and caused severe economic losses. It has risen to become the dominant species of Orthotospovirus in Southern China. It is of great significance for agricultural development to clone HCRV isolates from different regions and study their rapid expansion and evolution mechanism in different regions. In this study, ten new strains of HCRV were identified and isolated by RT-PCR from spider orchids suspected to be infected with Orthotospovirus in Yunnan, Guangdong, Guangxi, Fujian, and Hainan from 2013 to 2015, and their L sequences were cloned and sequenced. According to the existing isolates, DNAMAN 7.0 and MEGA 7.0 were used for molecular diversity, phylogeny and recombination analysis. The results showed that the ten HCRV L isolates in this study, including one of the earliest reported HCRV HLS1-2 L isolates,can be divided into two groups of different origins. Combining the environmental information of the ten isolates collected, the comparison showed that the climate, temperature, and precipitation were very different. It was speculated that the widespread distribution of HCRV in various provinces in Southern China played related to the different types of climate in different regions. During their evolution, mutation and recombination played a role. RdRp was an important protein involved in the replication and transcription of HCRV in cells. The analysis of the RdRp sequence provided a theoretical basis for the subsequent study of the impact of genetic variation of HCRV RdRp on HCRV infection ability, and also ideas for the prevention and treatment of HCRV.