Rapid Mapping of Quantitative Trait Loci in Rice by Whole Genome Resequencing

The majority of agnoromically important crop traits are controlled by multiple genes each with a minor effect (quantitative trait loci: QTL).  However, QTL analysis has been time consuming and labor intensive mainly because it requires DNA marker development for linkage analysis.  Here we propose a new method for the identification of QTL by next-generation whole genome sequencing of two bulked DNAs of progeny showing extreme phenotypic values.  Since it does not involve DNA marker development, the most time-consuming and costly procedure required in the conventional QTL analysis, our new method allows rapid identification of QTL.  We applied this method to rice recombinant inbred lines and successfully identified QTL for partial resistance to rice blast, which is the most destructive and widespread disease of rice.