Effects Of Aposymbiosis In Sitobion Avenae On Reducing The Damage Of Wheat Yellow Dwarf Disease

Sitobion avenae(Fabricius)is a pest that seriously affects the yield in wheat production,It not only sucks the juice of wheat leaves,stems and ears,but also secretes honeydew to hinder photosynthesis and respiration of wheat.The most important thing is that the S.avenae is the medium of BYDV-GAV transmission.Barley yellow dwarf virus(BYDV)is extremely harmful to wheat,and when the disease is prevalent,it will cause a sharp drop in wheat output.Secondary symbionts in the S.avenae share a common position with the virus and have a complex mutual relationship.To explore the symbiotic bacteria-vector aphid-plant virus interaction theory,we can understand the influencing factors of virus disease epidemic,and provide a theoretical basis for the prevention and control of S.avenae and Barley yellow dwarf virus.In this study,we tested the infection of Secondary symbionts in the monoclonal system of different S.avenae,and selected one or two Secondary symbionts monoclonal strains to eliminate Secondary symbionts by adding antibiotics to artificial diet.The strain obtained the monoclonal line of the S.avenae which is consistent with the genetic background of the Secondary symbionts and has no infection and Secondary symbionts,and comparative study on the ability to acquire and transmit the mainstream strain of virus BYDV-GAV.The results are as follows:1.Collecting adult S.avenae from a Yangling wheat field,and raising 22 monoclonal lines in a single head.The 16 S rDNA specific primers were used to detect five Secondary symbionts: H.defensa,R.insecticola,Rickettsia,Wolbachia and Arsenophonus.Infection,the results showed that the monoclonal lines C3 and Y4 were not infected with any Secondary symbionts,the monoclonal line F3 was only infected with H.defensa,the monoclonal lines C6 and F2 were only infected with R.insecticola,and the monoclonal lines C9 and F5 were infected with H.defensa and R.insecticola.The remaining monoclonal lines infect three or more Secondary symbionts.2.Improve the artificial feed formula of the former S.avenae,compared with the control artificial feed formula,under the improved artificial feed formula conditions,the survival rate of S.avenae increased significantly from 46.00% ± 7.48% to 90.00% ± 4.47%,and the daily average body weight growth rate increased significantly from 0.2646 ± 0.0139 to 0.3336 ± 0.0139.After adding different concentrations of ampicillin,cefotaxime and gentamycin to the improved artificial diet formula,the 2 day old F3,C6,F2,C9 and F5 monoclonal strains were reared for 7 days.The single head was transplanted into wheat plants,and the elimination of Secondary symbionts in the larvae of the larvae was detected after 3 generations,and Successful elimination of F3 in vivo H.defensa,C9 and F5 in vivo R.insecticola.3.After the monoclonal strain C9 eliminated the R.insecticola,its obtain BYDV-GAV did not change significantly,but the ability to transmit was significantly reduced from 90.00% ± 5.774% to 53.33% ± 6.667%;while F5 eliminated R.insecticola and F3 eliminated H.defensa.There was no significant change in the ability to obtain BYDV-GAV and the ability to transmit BYDV-GAV.In summary,some Secondary symbionts can be successfully eliminated by adding antibiotics to artificial diet.Elimination of Secondary symbionts R.insecticola can reduce the ability of the S.avenae to transmit BYDV-GAV.Therefore,it is feasible to reduce the damage of wheat yellow dwarf by eliminating the Secondary symbionts.