Yield Trait Variation and QTL Mapping in a DH Population of Rice under Phosphorus Deficiency

Abstract

To study the difference of QTLs for rice yield and its component traits under different phosphorus applications, a DH (doubled haploid) population including 116 lines, derived from a cross between phosphorus deficiency tolerant rice IRAT109 and phosphorus deficiency sensitive rice Yuefu, was evaluated for yield per plant (YP) and its components including 1000-grain weight (GW), seed-setting percentage (SP), panicle number per plant (PN), and grain number per panicle (GN) under phosphorus deficiency and normal conditions. No significant differences were found in GW and GN but significant differ-ences were found in SP, PN, and YP for the DH population between the two conditions. This result indicted that SP, PN, and YP were more easily influenced by phosphorus deficiency than GW and GN. A total of seventeen QTLs were detected for plant yield and its components under phosphorus deficiency using the constructed molecular linkage map (including 94 RFLP and 71 SSR markers and covering 1 535 cM). Among them, there were twelve QTLs with general contributions of over 10% to pheno-typic variation. Three tightly linked QTL regions on chromosomes 3, 6, and 7 were identified. These QTLs with high general con-tribution and tightly linked QTL regions might be useful for phosphorus deficiency tolerant and high yielding rice breeding by molecular marker assisted selection.