Advances on rice QTL analysis

Most of the important agronomic traits of rice are quantitative in nature, which are controlled by polygenes. In conventional quantitative genetics, QTL analysis was only executed as a whole. In recent years, the construction of highly dense molecular linkage map and the development of effective biostatistical methods have revolutionized the genetic studies of quantitative traits. The joint analysis of molecular marker genotype and phenotype values of individuals or lines in different populations enabled the detection and location of quantitative trait loci (QTL). In the present paper, the principles and methods of QTL mapping were introduced, recent progresses in the studies of QTL analysis in rice were reviewed, including QTL numbers and effects, epistasis effect, interaction between QTL and environment, QTLs of related characters, developmental QTL and so on. The rice genome sequencing project has been finished, therefore in this paper, the strategy for fine mapping and cloning of QTLs in the genome era was also discussed. Application prospect of QTL analysis in rice breeding was forecasted.