Gene Pyramiding Assisted Breeding of New Hybrid Rice Combination Zhongyou 161 with High Yield and High Grain Quality

Beneficial genes carried by rice lines Teqing and IRBB51 were determined through literature reading and gene based marker detection. While Teqing carries resistance alleles at the Pib and Pita loci for blast resistance and at the Xa4 locus for bacterial blight resistance,IRBB51 carries resistance alleles at the Pib,Xa4 and xa13 loci and high-grain-quality allele at the wx locus. Zhonghui 161,a new restorer line which carries beneficial alleles at all of the above-mentioned five target loci,was developed from a recombinant inbred population of Teqing/IRBB51. Zhongyou 161,a new hybrid rice combination with good grain quality and high yield derived from Zhong 9A and Zhonghui 161,was released commercially nationwide in 2009. This study suggests that adding beneficial genes which are carried by either parental lines of a rice population to those carried by both parental lines might be a feasible way of gene pyramiding in the breeding of commercial rice varieties.