大气CO_2不同浓度对灰飞虱获毒与传毒的影响研究

The impact of different CO_2 concentrations on the acquisition and transmission of viruses in Laodelphax striatellus (Fallén)

本世纪初,由灰飞虱Laodelphax striatellus传播的条纹病毒(RSV)引起的条纹叶枯病在长江中下游广大稻区肆虐,给这些地区的水稻生产带来了灾难性影响。本文采用模拟气室法,研究了大气CO_23个浓度(370μL/L(CK)、470μL/L和570μL/L)对媒介害虫灰飞虱获毒与传毒的影响。结果表明,灰飞虱获毒个体数与灰飞虱的取食时间成正比,在有毒稻株上取食时间越长,获毒的灰飞虱个体数越多。不同CO_2浓度间,取食相同时间后的灰飞虱获毒个体数虽有差异,但没有达到显著水平。鉴于稻株获得RSV与病毒病的症状显现之间存在较长的时间差,本文通过提取水稻植株体内的RNA并借助RT-PCR技术,研究判定被害稻株是否已经获得了RSV,从而间接证明灰飞虱的传毒力。研究结果显示,CO_2浓度对灰飞虱的传毒力有影响:470μL/L CO_2浓度条件下灰飞虱的传毒力最强。研究还发现,在处理的3个CO_2浓度范围内,灰飞虱只要取食为害稻苗1 h,水稻中就能检测到条纹病毒(RSV)。说明灰飞虱的传毒速率还是较快的。

In this early century, stripe virus disease which was caused by rice stripe virus （ RSV ） transmitted by the small brown planthopper Laodelphax striatellus （ Fall＆#233;n） , had brought great damages to rice production in Yangtze River region. Effects of CO2 concentration in the atmosphere （ 370 μL/L （ the current concentration）, 470 μL/L and 570 μL/L） on the acquisition and transmission of viruses in L. striatellus were studied using a simulation chamber method. The results showed that the number of L. striatellus that acquired viruses was proportional to their feeding time, that is, the longer they fed on infected rice plants, the more L. striatellus acquired viruses. Although there was a difference in the number of infected L. striatellus after identical feeding times under different CO2 concentrations, this difference was not statistically significant. Due to a long lag between RSV acquisition of rice and symptom occurrence, the RNA of rice plants was extracted to analyze the transmission of viruses in L. striatellus using RT-PCR technique. The results showed that CO2 concentration had some influence on the transmissibility of viruses in L. striatellus and that the transmissibility of viruses in L. striatellus was highest under 470 μL/L CO2 .Furthermore, as long as L. striatellus fed on the rice plants for 1 h, RSV could be detected in the plants under the three concentrations of CO2 , which indicates that the transmission of viruses by L. striatellus is very rapid.