Mapping QTLs conferring resistance to rice black-streaked dwarf disease in rice (Oryza sativa L)

Rice black-streaked dwarf disease, caused by the rice black-streaked dwarf virus (RBSDV), can lead to severe yield losses in rice. The deployment of resistant cultivars is an effective disease control measure, but few studies related to the genetics and breeding of RBSDV resistance have been reported in rice. Here, we identified 'IR36' (indica) and 'L5494' (japonica) as resistant and susceptible parents, respectively, using a field test, and 208 recombinant inbred lines were derived from their cross. A genetic analysis indicated that the resistance of rice materials to RBSDV was controlled by quantitative trait loci (QTLs). A total of 12 QTLs for RBSDV resistance on chromosomes 1, 6, 8 and 9 were identified in three environments (2013-2015), and QTLs in two marker intervals, RM19234-CHR6-2 and RM3700-RM160 on chromosomes 6 and 9, respectively, were consistently detected. These QTLs explained 6.19-29.00 % of the total phenotypic variation for rice black-streaked dwarf disease incidence. The alleles enhancing resistance on chromosomes 6 and 8 originated from 'IR36', whereas the alleles on chromosomes 1 and 9 originated from 'L5494'. The materials and identified resistance QTLs in this study are expected to be useful resources for efficiently breeding rice cultivars resistant to RBSDV.