Study On The Dynamic Changes Of Different Maize Germplasm Materials After Artificial Inoculated RBSDV

Maize is important in the world that can be used for food, feed and industrial materials. In our country, the maize yield ranking only second to rice, occupies a very important position in the national economy. Maize dwarf rough disease is a worldwide disease, and is one of the important diseases of maize in Huang-Huai-Hai region of China. In China, the disease is caused by Rice Black-streaked Dwarf Virus (RBSDV), which transmission vector is Laodelphax striatellus Fallen. Susceptible plants are dwarf significantly, no tassel, no grains, yield losses, and even have no harvest. In order to control disease epidemics, and reduce yield loss, breeding and genetic improvement is the most economic and effective ways of controlling the disease.This study makes a systematic introduction on pathogen of MRDD, host, spread way, symptoms, occurrence regularity, and resistance identification method, build technology platform of indoor artificial propagate Laodelphax striatellus Fallen, and artificial inoculation of virus. And then conduct the following three researches:1.Explore the technology conditions of indoor artificial propagate Laodelphax striatellus Fallen. Study the influence of survival rate and oviposition amount of Laodelphax striatellus Fallen in different temperature (21℃, and23℃, and25℃, and27℃,and29℃). The results indicate that high survival rate of laodelphax striatellus at23℃, the eggs hatch volume increment within21℃-29℃. Finally,25℃±2℃is choosed as the optimum temperature of indoor propagation of laodelphax striatellus.2. Choose3different area (Lianyungang, and Yuan yang and Baoding) diseased maize, rice and wheat plant,5samples for RBSDV virus nucleic acid extraction, sequence its S9measuring and blast in NCBI. Results show that5samples of homologous is97.92%,2of27bases mutations cause amino acids physic-chemical nature changed and are located in the first ORF. The nucleic acid sequence homology of RBSDV samples in Yuan yang and Lianyungang over samples in Hebei Baoding.3. In order to study the virus development in infected maize plant,8different maize materials(Zheng58, and C7-2, and Mo17, and478, and Dan340, and P138, and Zhengdan958and XH6) were detected after artificial inoculation by laodelphax striatelluswith different carrier rate. Three virus-acquisition time of laodelphax striatellus were settled as12h,24h,48h,72h,120h respectively, and the carrier rate were10%,13.3%,23.3%,30%,30%.Using Real-time fluorescence quantitative RT-PCR to detect virus content of diseased plant. Results show that, the higher virus-carried in laodelphax striatellus, the more rich virus in plant, the earlier and the more serious disease occurred. When the virus-carried rate is23.3%, all the experimental maize material can be identified more certainty out of others. In this group, virus content between the maximum and minimum is largest.Levels of resistance of the various materials are:P138is moderate resistance, C7-2and Dan340is resistance, other materials are high susceptibility which virus-content order of magnitude is as high as106copy/μl. In the virus-carried rate of10%, some material content modicum amounts of virus, but have no incidence.The virus in disease-resistant materials have little proliferation, virus’s peak is significantly smaller than the high susceptibility of material. Susceptible materials following the linear multiplication of the virus in the body, and virus content have high peak.