灰飞虱地理种群的标记研究

Laodelphax striatellus (Fallén) was an important vector for the transmission of plant viruses in agricultural production.In recent years, the rice stripe virus (RSV) and rice black-streaked dwarf virus (RBSDV) which carried and transmitted by L.striatellus outbreaked and damaged in the rice and maize crops production region of eastern China, leaded to severe yield losses. L.striatellus was the residence insect which could overwinter in local, mainly dispersed nearby. The last study finded that L.striatellus also had the possibility of long-distance migration, but there was no report about the systematic study. This project intended to seize the opportunity of RSV and RBSDV which were outbreaking in some areas, through comparing the differences of virulence ratio, genetic diversity and hotspot of molecular variability of RSV and RBSDV carried by L.striatellus populations from different areas, supplemented by comparing the differences of insecticide resistance and content of chemical elements in body, in order to obtain the combinated lable of L.striatellus which could effectively distinguish the geographic populations.This study provided the technical support for the study of L.striatellus long distance migration, and further providing the scientific basis for the management against L.striatellus, the study of viral origin and evolution, and the control of viral disease.

灰飞虱是农业生产上一种重要的传毒媒介，近年来其携带并传播的水稻条纹病毒（RSV）和水稻黑条矮缩病毒（RBSDV）在中国东部沿海地区的水稻和玉米上流行危害，造成粮食产量严重损失。灰飞虱可本地越冬为居留型昆虫，以近距离迁移扩散为主，最新研究发现灰飞虱也存在远距离迁移传毒的现象，但尚未有系统研究的报道。本项目拟抓住灰飞虱传播的RSV和RBSDV正在局部地区流行的契机，通过比较不同地区灰飞虱种群所携带病毒的带毒状况、遗传多样性及其分子变异热点，辅以分析灰飞虱抗药性和虫体化学元素含量差异，获得可有效区分灰飞虱地理种群的组合型标记，为灰飞虱远距离迁飞研究提供技术支撑，进一步为灰飞虱的治理及其传播病毒的起源进化研究与病害控制提供科学依据。

灰飞虱（Laodelphax striatellus Fallén, SBPH）是一种重要的农业昆虫，其传播的病毒病多次在我国暴发成灾，目前灰飞虱传播的水稻条纹病毒（Rice stripe virus，RSV）和水稻黑条矮缩病毒（Rice black-streaked dwarf virus，RBSDV）在中国沿海地区的水稻和玉米上流行，造成粮食产量严重损失。灰飞虱可本地越冬为居留型昆虫，以近距离迁移扩散为主。本研究连续两年对采自江苏、云南、山东、河北、浙江等13个地点的灰飞虱种群进行标记研究。采用ELISA法、RT-PCR法、稻苗浸渍法等对不同地理来源的灰飞虱种群进行带毒率、遗传多样性及分子变异、抗药性等的标记，最终形成组合标记。研究结果显示：带毒率标记将RSV和RBSDV各自分布地区进行标记，可有效划分几大生态区域；遗传多样性和分子变异标记中RSV的cp, sp, NS2和NS3 4个基因氨基酸变异热点标记可作为云南种群的特征标签，可将云南种群与其他地区种群有效区分。RBSDV的S10和S5-ORF2基因氨基酸变异热点的组合标记可将河北保定、江西南昌和安徽庐州3个种群有效区分；抗药性标记筛选到5种不同类型的杀虫剂，其中毒死蜱和吡虫啉的组合可对浙江和江苏种群分别标记，异丙威可对山东和河南种群联合标记而高效氯氰菊酯和噻嗪酮的组合又可对山东种群单独标记，高效氯氰菊酯可对辽宁种群单独标记，最后5种药剂形成抗药性的组合标记，可有效标记浙江、江苏、山东、河南和辽宁种群。综合以上结果，已获得了有效区分灰飞虱不同地理种群的组合标记，结果显示同一生态区域（江苏和云南等）具相似的标记，表明其灰飞虱种群交流较频繁；而不同地理种群的标记都不尽相同，所以应有针对性地对不同地理种群的灰飞虱采取不同的治理措施。本研究为灰飞虱远距离迁移扩散与传毒危害提供科学推断，也为灰飞虱的治理及其传播病毒起源进化与病害控制提供科学依据。