The Resistance Research Of24Rice Varieties To Southern Black-streaked Dwarf Disease Of Rice

Southern rice black-streaked dwarf virus(SRBSDV)is the member of the family ofFijivirus,Reoviridae. It is the pathogen for southern black-streaked dwarf diseases of rice.The viruswas found by Guohui Zhou in Guangdong Province in2001and was named in2008after identifingin biology and molecular.The new rice virus disease have the similar symptom with riceblack-streaked dwarf virus(RBSDV).Since it was discoveried,which had a rapid expansion inmajority of rice production areas in southern China and northern Vietnam in a few short years,it hascaused serious yield losses in China and Vietnam.The most economical and effective ways forcontrolling the disease are to culture resistant variety,which has already been verified by lots ofpractice.Now there hasn't still found the effective resistant variety.So,searching the resistant varietywhich we have disintering the resistant resource is very necessary.Under artificial inoculation of the virus, the incidence of24rice varieties were determinatedand repeated three times in Biology. The anova analysis showed that the varieties had significanteffect on the incidence.The resistant grade were divided into according to the incidence. Among the24varieties stud ied,3varieties were moderately resistant to SRBSDV, accounting for12.5%;10varieties were moderately susceptible, accounting for41.67%;11varieties varieties were highlysusceptible, accounting for45.83%. The susceptible varieties was up to87.5%,which accord withthe situation that varieties were general susceptible in practical production. Furthermore,LSDmultiple comparison was performed to analysis the resistant difference of24rice varieties.Combinating the incidence,the inhibition rate of plant height and syptoms, the resistance of24ricevarieties had been evaluated in the biological. Shandong variety,Yueyou036, Yueyou137were allidentified the moderately resistant varieties,which may be fine materials for SRBSDV resistancebreeding.The rice leaves were snapped respectively on20days and40days after the planting of riceseedlings,for the first and second sampling.SRBSDV p-10gene of24rice varieties weredeterminated on twice sampling using Real-time PCR.Two sampling both showed that there was ahighly significant correlation between the incidence and the amount of virus gene relative expression.Under normal circumstances, the higher the incidence of varieties, the virus content wascorrespondingly higher; lower the incidence of species, the virus content was correspondinglylower,which verified the correctness on the evaluation of variety resistance on gene level.Shandong variety,Yueyou036,Yueyou137were all identified as the moderately resistant variety.On the basis of two samples quantitative results, the virus gene relative expression of3varities wereall very low,suggesting that the three varieties may contain the resistance gene.Therefore, making the genetic analysis of resistance to the3varieties and studying whether the resistance (tolerance)gene is contained is very necessary, and then the research lay a good foundation for resistancebreeding.