[QTL analysis of sheath blight resistance in rice (Oryza sativa L.)]

In this study, an indica variety Zhai Ye Qing 8 (ZYQ8) and a japonica variety Jing Xi 17(JX17) and their double haploid (DH) population were used. Sheath blight resistance of the DH population and their parents was investigated using a syringe inoculation method. Quantitative trait loci (QTL) analysis was undertaken based on a constructed molecular linkage map of this population in Hangzhou and Hainandao respectively. A total of four sheath blight resistant QTLs (qSBR-2, qSBR-3, qSBR-7 and qSBR-11) were identified, and located on chromosome 2, 3, 7 and 11, respectively. Resistant alleles of qSBR-2, qSBR-3, and qSBR-7 were derived from the resistant parent ZYQ8, whereas resistant allele of qSBR-11 from susceptible parent JX17. qSBR-2, qSBR-3 and qSBR-7 were detected both in Hangzhou and Hainandao, whereas qSBR-11 was detected only in Hangzhou. Sheath blight response was significantly correlated with culm length and heading date in Hangzhou's test. Among the QTLs for culm length and heading date, only qCL-3 for culm length, was in the same chromosome region of qSBR-3, the other QTLs were not linked to the QTLs for sheath blight resistance.