An Xing-Kui, Hou Mao-Lin, Liu Yu-Di
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuan Ming Yuan Road, Beijing 100193, China.
J Econ Entomol. 2015 Jun;108(3):917-24. doi: 10.1093/jee/tov065. Epub 2015 Apr 3.
The white-backed planthopper, Sogatella furcifera (Horvath), is currently the only confirmed vector of Southern rice black-streaked dwarf virus (SRBSDV), which causes severe rice production losses in China. In this study, an absolute quantification qPCR method was used to detect viral gene mRNA expression levels at different developmental stages of white-backed planthoppers fed SRBSDV-infected rice plants. A comparison of viral copy numbers of the SRBSDV S10 gene at the same developmental stage indicated that the white-backed planthopper had higher viral copy numbers when the virus was acquired at the earlier developmental stages. The adult-stage white-backed planthoppers that had acquired the virus at the first-second nymphal stage displayed significantly higher viral titers than white-backed planthoppers that acquired the virus at the third-fourth nymphal stage, at the fifth nymphal stage, and at the adult stage. The fifth nymphal stage white-backed planthoppers that acquired the virus at the first-second nymphal stage displayed higher viral copy numbers than fifth nymphal stage white-backed planthoppers that acquired the virus at the third-fourth nymphal stage and at the fifth nymphal stage. The highest viral load value appeared in the middle adult stage. The annual immigration characteristics of white-backed planthoppers would be beneficial for the dispersal of SRBSDV because this virus could be transmitted far away following the migration of vigorous planthoppers. Therefore, investigating the change in the viral load at different life stages of SRBSDV-positive individuals is required to develop more effective control of the spread of SRBSDV in the field.
白背飞虱，即灰飞虱（Sogatella furcifera (Horvath)），是目前已确认的南方水稻黑条矮缩病毒（SRBSDV）的唯一传播媒介，该病毒在中国导致水稻产量严重损失。在本研究中，采用绝对定量qPCR方法检测取食感染SRBSDV水稻植株的白背飞虱不同发育阶段的病毒基因mRNA表达水平。对同一发育阶段SRBSDV S10基因的病毒拷贝数进行比较表明，当在较早发育阶段获取病毒时，白背飞虱的病毒拷贝数更高。在若虫第一至二龄期获取病毒的成虫期白背飞虱，其病毒滴度显著高于在若虫第三至四龄期、第五龄期及成虫期获取病毒的白背飞虱。在若虫第一至二龄期获取病毒的第五龄期白背飞虱，其病毒拷贝数高于在若虫第三至四龄期及第五龄期获取病毒的第五龄期白背飞虱。最高病毒载量值出现在成虫中期。白背飞虱的年度迁飞特性有利于SRBSDV的传播，因为这种病毒可随着活跃飞虱的迁飞被传播到很远的地方。因此，需要研究SRBSDV阳性个体不同生命阶段病毒载量的变化，以制定更有效的田间SRBSDV传播控制措施。
