Effects Of Hybrid Rice Varieties On Population Growth Of Sogatella Furcifera And Comparative Analysis Of Mitochondrial Genome Of Laodelphax Striatellus Populations

Along with the increase of hybrid rice and the reform of cultivation system, the damage caused by Sogatella furcifera and Laodelphax striatellus becomes more and more severe recently. S. furcifera and L. striatellus, instead of Nilaparvata lugens, have been dominant pests in local area. We try to seek for the reason of the high incidence of S. furcifera by the relationship between hybrid rice and S. furcifera, and clarify the specific migration pathways by comparative analysis of mitochondrial DNA of L. striatellua populations.The primary results are as follows:1. The indica hybrid rice combinations, like IIY023,SY63,JY987, IIY838etc, favored S. furcifera development and adult emergence and suffered insignificantly on height, chlorophyll and biomass because of their strong tolerance, which is main reason of rapid increase of initial immigrant population.2. S. furcifera prefers IR64, IR60, ARC10550, TN1to PTB33, Babawee, Ndiang Marie, MO1under the sowing of rice variety mixtures. So the former four varieties are considered high sensitive to S. furcifera and the latter four varieties are considered suitable to field.3. The indica rice RHT and the japanca rice JH218, CJ06reduced S. furcifera nymphal survival or extended nymphal development, postponed adult emergence, which are high resistant varieties.4. There are2and5variable sites in469bp of nad3and in681bp between nad5and nad4respectively, which divide L. striatellus into four groups; The base sequences of cox2, between nad4and nad4l could not be molecular markers of population genetics for similar degree more than99.9%; Due to fluky sequences, it is indistinct currently that whether variable sites between nadl and lrRNA, between lrRNA and srRNA, between A+T and nad2can be molecular markers.