[Mapping of QTLs of Cd2+ content in brown rice under Cd2+ stress in rice]

A population of F8 recombinant inbred lines (RILs), derived from a cross between IR26 (Oryza sativa L. spp. indica) and Jiucaiqing (japonica), were used to identify the quantitative trait loci (QTLs) for Cd2+ content in brown rice under 5 mg/kg Cd2+ stress. Two QTLs, qCCBR-11a and qCCBR-11b, associated with the Cd2+ content in brown rice, were detected on chromosome 11. qCCBR-11a was located at the position between markers RM6288 and RM6544, accounting for 11.17% of the phenotypic variance with an additive effect value of 0.089. qCCBR-11b at the interval between markers RM167 and RM5704 explained 7.66% of the phenotypic variance with an additive effect value of 0.075. In addition, the correlation coefficients between Cd2+ content of brown rice and plant height, spikelets per panicle, filled grains per panicle, seed setting rate, and 1 000-grain weight were not significant. This suggested that the Cd2+ content in brown rice under Cd2+ stress was an independent genetic trait.