The Studies On Molecular Marker Related With Affinity To RSV In SBPH And Effect On SBPH Infected With RSV In Viability

Rice stripe virus (RSV), a typical member of Tenuivirus, is an important rice virus in Easten Asian. The virus is transmitted by small brown plant-hopper (Laodelphax striatellus Fallén, SBPH) in a persistant manner through ovum. In order to parse the cause of the virus occurrence and find the way to control its epidemics, the affinity between RSV and small brown plant-hopper was studied in this dissertation.After continual several generations' artificial selective breeding, here we constructed successfully high affinity virus transmitter groups and non-affinity virus transmitter groups, which is collected from Haian, Jingjiang, Gaoyou and Yandu in Jiangsu province, China. Incidence of the high affinity transmitter could keep about 90.0% although without artificial selecting pressure for four generations. High affinity transmitter group is significant for the research of virus transmission mechanism, variability of RSV pathogenicity and variety resistance.In order to understand the molecular mechanism of RSV transmission, the differential expressed bands between the high affinity virus transmitter group and the non-affinity virus transmitter group was detected with the technique of RAPD PCR (random amplified polymorphic DNA, RAPD) and SPAR PCR(single primer amplified reactions, SPAR). The results showed that polymorphic bands could be amplified commendably with three in thirty-seven random primers and two in three SPAR primers, of which one could amplified differentially expressed bands, and the effect of amplified differentially expressed bands was relatively singularity. They could amplified respectively a 1 200 bp band and a 900 bp band from the high affinity virus transmitter group. It is speculated that two differentially bands be likely to molecular markers related with affinity RSV in SBPH.Applying infected and uninfected SBPHs by RSV from the high affinity virus transmitter group, the parents of SBPHs assemble four crosses: cross 1, infected female×infected male; cross 2, infected female×healthy male; cross 3, healthy female×infected male; cross 4, healthy female×healthy male as CK. The infection of F₁ larvae was observed to only relate with infected female, and infected female decided infection of its offspring by RSV. No significant difference of fecundity was detected between infected and uninfected SBPHs. Effect of hatchability, the order of number of 1st-instar larvae was cross 4> cross 2 >cross 1 and cross 3, suggested that parents of infected SBPHs weaken hatchability, especially in infected male parent. It simultaneity indicated that incubation period of infected SBPHs was protracted, and survive rate of F₁ larvae and adults was increased.