The three important traits for cooking and eating quality of rice grains are controlled by a single locus in an elite rice hybrid, Shanyou 63

The cooking and eating quality of the rice grain is one of the most serious problems in many rice-producing areas of the world. In this study, we cond ucted a molecular marker-based genetic analysis of three traits, amylose co ntent (AC), gel consistency (GC)and gelatinization temperature (GT), that a re the most important constituents of the cooking and earing quality of ric e grains. The materials used in the analysis included F-2 seeds, an F-2:3 p opulation, and an F-9 recombinant inbred-line population from a cross betwe en the parents of 'Shanyou 63', the most widely grown hybrid in rice produc tion in China. Segregation analyses of these three generations showed that each of the three traits was controlled by a single Mendelian locus. Molecu lar marker-based QTL (quantitative trait locus) analyses, both by one-way a nalysis of variance using single marker genotypes and by whole-genome scann ing with MAPMAKER/QTL, revealed a single locus that: controls the expressio n of all three traits. This locus coincided with the Wx region on the short arm of chromosome 6, indicating that all three traits were either controll ed by the Wx locus or by a genomic region tightly linked to this locus. Thi s finding has provided clues to resolving the molecular bases of GC and GT in future studies. The results also have direct implications for the qualit y improvement of rice varieties.