Marker-assisted selection for yield-enhancing QTLs in the progeny of 9311 Oryza rufipogon and its effects in rice breeding

A weedy relative of cultivated rice,Oryza rufipogon from Malaysia,contains two favorable yield-enhancing QTLs(yld1.1 and yld2.1)on chromosomes 1 and 2,which are capable of improving the yield of rice by 18% and 17%,respectively.To transfer the two QTLs into cultivated rice,a restorer line of two-line hybrid rice,9311,was used as a recurrent parent,and Oryza rufipogon as a donor parent of yield-enhancing QTLs.Four molecular markers,RM166,RM208,RM9 and RM5,which linked to the two yield-enhancing QTLs(yld1.1 and yld2.1),were used to identify the individuals possessing the Oryza rufipogon markers and good agronomic characters in the advanced backcrossed population from and Oryza rufipogon based on the genotype and phenotype,and some improved 9311 lines containing the two yield-enhancing QTLs were developed.The yield potential of the improved 9311 lines with more numbers of effective panicles and total grains was higher than that of 9311.Some promising hybrid had been developed with super high-yielding potential.The results indicated that the two yield-enhancing QTLs were expressed well in genetic background of 9311 and its hybrids.