Identification of QTLs Associated with Heat Tolerance of Yuanjiang Common Wild Rice (Oryza rufipogon Griff.) at Flowering Stage

Using an introgression line population of Chinese common wild rice(Oryza rufipogon Griff.) from Yuanjiang, Yunnan Province, with the background of Teqing (O. sativa ssp. indica), four quantitative trait loci (QTLs) for heat tolerance at the flowering stage were identified by the method of single-point regression analysis. Two QTLs (qHT1and qHT3) mapped on chromosome 1 and 3, explained 12% and 6% of the phenotypic variance, respectively, and the O. rufipogon-derived alleles contributed desired effects on Teqing background, which could increase 9.13% and 6.71% seed set. The other two QTLs (qHT8 and qHT10) detected on chromosome 8 and 10, explained 6% and 6% of the phenotypic variance, respectively, and the O. rufipogon-derived alleles could decrease percent seed set on Teqing background. The results may be helpful for improvement of heat tolerance by marker-assisted selection in rice. It is also suggested that there is enormous potential for improving the tolerance to abiotic stress of cultivated rice utilizing the favorable genes of wild species in rice breeding program.