[QTL analysis for rice stripe disease resistance gene using recombinant inbred lines (RILs) derived from crossing of Kinmaze and DV85].

Rice stripe disease transmitted by small brown planthopper (Laodelphax striatellus Fall.) is one of the most serious viral diseases in East Asia. The disease is severely epidemic in most rice growing areas where the main cultivars are susceptible or moderately susceptible to rice stripe virus. In this research, a recombinant inbred lines (RILs) population of 81 lines derived from a cross of Kinmaze (japonica)/DV85(indica) by the single seed descent method was used to detect quantitative trait loci (QTL) conferring resistance to rice stripe virus(RSV). The response of the two parents and 81 RILs to RSV were investigated by inoculating seedlings with viruliferous small brown planthopper insects, and scored by the disease rate index. The quantitative trait loci for rice stripe disease resistance were analyzed by QTL Cartographer software. Three QTL controlling RSV resistance were detected on chromosomes 1, 7 and 11, respectively. Individual QTL accounted for 19.8%-30.9% of the phenotypic variance in the RILs population. The direction of the additive gene effects at two loci qStv7 and qStv11 coincided with that predicted by phenotypes of the parents. At these two loci, the DV85 alleles increased the resistance to RSV, while at qStv1, the Kinmaze alleles increased the resistance to RSV.