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

Abstract

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 conducted a molecular marker-based genetic analysis of three traits, amylose content (AC), gel consistency (GC) and gelatinization temperature (GT), that are the most important constituents of the cooking and eating quality of rice grains. The materials used in the analysis included F(2) seeds, an F(2:3) population, and an F(9) recombinant inbred-line population from a cross between the parents of 'Shanyou 63', the most widely grown hybrid in rice production in China. Segregation analyses of these three generations showed that each of the three traits was controlled by a single Mendelian locus. Molecular marker-based QTL (quantitative trait locus) analyses, both by one-way analysis of variance using single marker genotypes and by whole-genome scanning with MAPMAKER/QTL, revealed a single locus that controls the expression 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 controlled by the Wx locus or by a genomic region tightly linked to this locus. This finding has provided clues to resolving the molecular bases of GC and GT in future studies. The results also have direct implications for the quality improvement of rice varieties.

Mapping quantitative trait loci underlying triploid endosperm traits

“…However, these traditional methods were not designed for QTL mapping; rather they were developed for analyzing the overall contribution of the genetic variance to the phenotypic variance. Traditional QTL mapping methods for diploid traits have been applied to mapping endosperm traits (Tan et al, 1999;). The assumption was that the genetic variance of an endosperm trait is controlled by the segregation of QTL in the diploid maternal plants.…”

“…Improving grain quality is one of the important objectives in cereal breeding (Sadimantara et al, 1997;Mazur et al, 1999;Tan et al, 1999;. Many grain quality traits, such as amylose content and gel consistency in rice, protein and amino-acid content in wheat, starch and gum content in barley, and sugar content in sweet corn, are endosperm traits.…”

Genetic Control of a Transition from Black to Straw-White Seed Hull in Rice Domestication

“…Amylose content, gel consistency, and gelatinization temperature were measured according to methods reported by Tan et al (1999). Gelatinization temperature was evaluated as the alkali spreading value.…”

Verification of quantitative trait locus for stickiness of cooked rice and amylose content by developing near-isogenic lines

“…On the other hand, in introgression breeding with more distantly related lines (such as indica cultivars or wild relatives), many studies have focused on the introgression of genes related to disease and insect resistance or environmental stress tolerance, while less attention has been paid to eating quality. Several major QTLs associated with eating quality, for example, the Wx gene (Takeuchi et al 2007, Li et al 2003, Tan et al 1999) and alk region (Li et al 2003), have been reported using populations derived from crosses between a Japanese cultivar and a distantly related line or cultivar. However, it seems rather difficult to retain eating quality in introgression breeding.…”