Mapping of QTLs for eating quality and physicochemical properties of the japonica rice 'Koshihikari'

Abstract

To reveal the genetic regions controlling eating quality of japonica rice and to establish a system for markerassisted selection (MAS), we conducted a QTL analysis for eating quality of Koshihikari, a leading cultivar in Japan. We used a recombinant inbred population consisting of 92 lines derived from a cross between two closely related japonica cultivars, Moritawase (low eating quality) and Koshihikari. We evaluated overall eating quality (OE), glossiness (GL), taste (TA), stickiness (ST), and hardness (HD) of the lines over 3 years by sensory tests. QTL analysis revealed 43 QTLs on 16 regions across all chromosomes except chromosome 5. QTLs on chromosomes 1, 3, 6, 7, and 10 were detected in multiple years. The Koshihikari alleles at 37 QTLs increased the eating quality. Further QTL analysis revealed 8 QTLs for textural characteristics of cooked rice and 3 for the amino acid ratio of polished rice. Those on chromosomes 1, 3, 6, and 7 were located near the QTLs for eating quality.

Identification of Quantitative Trait Loci Associated with Rice Eating Quality Traits Using a Population of Recombinant Inbred Lines Derived from a Cross between Two Temperate japonica Cultivars

“…Two QTLs qAC11 and qADV11 identified on chromosome 11 appear to be affected by heading date as other QTLs for this trait have been detected previously in the same region. A QTL for glossiness has also been reported by Wada et al (2008).…”

“…Of these, three QTL blocks on chromosomes 6, 7 and 8 were detected in which several QTLs for eating quality components were found to be clustered together. These QTLs were consistently detected in two RILs derived from the crosses of Moritawase/Koshihikari (Wada et al, 2008) and Sakihikari/ Nipponbare (Kobayash and Tomita, 2008) over two years, sug-gesting that they are stably expressed under different environmental conditions. Three QTLs, qADV6, qAC6.1 and qGCR6 mapped to the terminal region of the short arm of chromosome 6, corresponding to the wx locus (Harushima et al, 1998;Tan et al, 1999;Wan et al, 2004).…”

“…Five stable QTLs and 21 additional QTLs associated with eating quality were previously identified using chromosome segment substitution lines (CSSLs) derived from a cross of Asominori (japonica) and IR24 (indica), and by using backcross inbred lines (BILs) derived from a cross of Koshihikari/Kasalath (indica)//Koshihikari and CSSLs, respectively (Ebitani et al, 2005;Wan et al, 2004). A few studies have also identified QTLs for eating quality in doubled haploid (DH)lines or RILs derived from crosses between different japonica strains (Kobayashi and Tomita, 2008;Suh et al, 2006;Takeuchi et al, 2008;Tanaka et al, 2006;Wada et al, 2008). DNA markers closely linked to these QTLs have made it possible to more efficiently develop rice cultivars with a higher eating quality (Lestari et al, 2009).…”

Q-TARO: QTL Annotation Rice Online Database

“…These analyses have identified several unique QTLs for heading date (Matsubara et al 2008), culm length (Hori et al 2009), pre-harvest sprouting resistance (Hori et al 2010), and eating quality (Takeuchi et al 2008;Kobayashi and Tomita 2008;Wada et al 2008). The success of this approach implies that the use of a wide range of cross combinations might increase the opportunity to detect unique QTLs.…”

Identification of QTLs controlling heading date on the short arm of chromosome 3 in rice (Oryza sativa L.)

“…The results of this study revealed that a QTL for heading date, qDTH3, was linked to qLTG3-1. Furthermore, QTLs for agronomically important traits, eating quality (Kobayashi et al 2008, Takeuchi et al 2008, Wada et al 2008) and pre-harvest sprouting resistance (Hori et al 2010), have been identified in this chromosomal region. For the manipulation of these traits, targeted recombination within this chromosomal region should be useful for creating novel genotypes, which may provide novel advantages for adaptation for local environmental conditions.…”