Development of Near-isogenic Lines with Yield-enhancing Genes from O.rufipogon by MAS in 9311

Using 9311,a restorer line of two-line super-hybrid rice,as the recipient and recurrent parent and Oryza rufipogon as the donor of two yield-enhancing QTL alleles,yld1.1 and yld2.1 on chromosomes 1 and 2, respectively,three types of near-isogenic lines(NILs) containing yld1.1 and yld2.1 or yld1.1 or yld2.1 were developed by successive backcrossing and molecular marker-assisted selection(MAS).The genetic background of the near-isogenic lines was similar to that of the original parent 9311 at a degree of 93.9%.The NILs with the yield-enhancing QTLs had a higher grain yield than 9311 in the field experiments,which indicates that transferring the yield-enhancing QTLs into the restorer line of hybrid rice can increase its yielding ability.Furthermore,the yield-increasing effect of the NILs with both yld1.1 and yld2.1 was greater than that of the NILs with only a single QTL allele yld1.1 or yld2.1.