Genetic Dissection of Silicon Content in Different Organs of Rice

Abstract

Quantitative trait loci (QTLs) analysis for Si content in rice (Oryza sativa L.) was performed to study the inheritance of Si content in rice. A recombinant inbred line (RIL) population of 244 lines derived from the indica rice cross ‘Zhenshan 97B’ (ZS97B)/‘Milyang 46’ (MY46) were grown in 2003 with two replications. Silicon content in the hull (HUS), flag leaf (FLS), and stem (STS) were measured. On the basis of a linkage map consisting of 207 DNA marker loci, a total of 10 QTLs showing significant additive effects and 14 digenic interactions having significant additive‐by‐additive (AA) epistatic effects were detected. The number of QTLs and AA interactions for individual traits were four and four for HUS, four and four for FLS, and two and six for STS, respectively. General contributions to the phenotype variance due to additive effects and AA effects were 29.3 and 18.6% for HUS, 14.8 and 13.6% for FLS, and 8.6 and 28.6% for STS, respectively. This indicates that gene actions at both the one‐ and two‐locus levels play an important role to genetically control Si content in rice. In addition, it was shown that the detection of QTLs at the one‐locus level, as well as magnitude and direction of the additive effect, might be influenced greatly by digenic interactions involving loci linked to the given QTL. By comparing these results with other reports, genetic association between QTLs for Si content and QTLs for yield component traits and lodging‐tolerance related traits were evident.