In countries with rice as staple, rice contributes a major portion
of food energy and nutrient (Juliano, 1993), in which energy yield is
determined by grain yield, and the nutrient supply by both the
grain yield and nutrient content. In breeding for improved nutritional
quality of rice, it is essential to take into account the relationship
between grain yield and nutrient content. Simultaneous
analysis of the genomic positions and genetic effects of the QTLs
underlying grain yield and the two major nutrient components of
rice, protein and fat, could facilitate the application of markerassisted
selection for the nutritional improvement of rice. In the
present study, a total of 22 QTLs for brown rice recovery, the
contents of crude protein and crude fat in brown rice, and the yields
of grain, brown rice, crude protein and crude fat, were detected
using the XQZ/MY46 RIL population whichwas derived from a cross
between parental lines of a commercial three-line hybrid rice. This
might be the first report in which QTLs for the content and yield of
rice nutrient content are simultaneously analyzed.