title: Fine mapping of stable QTLs related to eating quality in rice (Oryza sativa L.) by CSSLs harboring small target chromosomal segments.
abstract: Amylose content (AC) and viscosity profile are primary indices for evaluating eating and cooking qualities of rice grain. Using chromosome segment substitution lines (CSSLs), previous studies identified a QTL cluster of genes for rice eating and cooking quality in the interval R727-G1149 on chromosome 8. In this study we report two QTLs for viscosity parameters, respectively controlling setback viscosity (SBV) and consistency viscosity (CSV), located in the same interval using rapid viscosity analyzer (RVA) profile as an indicator of eating quality. Previously reported QTL for AC was dissected into two components with opposite genetic effects. Of four QTLs, qCSV-8 and qAC-8-2 had stable genetic effects across three and four environments, respectively. qSBV-8, qCSV-8 and qAC-8-1 partly overlapped, but were separated from qAC-8-2. Based on data from an Affymetrix rice GeneChip, two genes related to starch biosynthesis at the qAC-8-2 locus were chosen for further quantitative expression analysis. Both genes showed enhanced expression in sub-CSSLs carrying the target qAC-8-2 allele, but not in sub-CSSLs without the target qAC-8-2 allele, indicating their possible role in rice quality determination. Molecular markers closely linked to the two stable QTL provide the opportunity for marker-assisted selection (MAS) in breeding high quality rice.
authors.affiliation: Key Laboratory of Crop Genetics and Germplasm Enhancement/Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University , Nanjing 210095, Jiangsu, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.forename: Wenwei
authors.initials: W
authors.lastname: Zhang
authors.forename: Hongkai
authors.initials: H
authors.lastname: Wu
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Liu
authors.forename: Xiangyuan
authors.initials: X
authors.lastname: Wan
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Jin
authors.forename: Than Thi Thu
authors.initials: TT
authors.lastname: Hanh
authors.forename: Nguyen Thi Nhu
authors.initials: NT
authors.lastname: Thoa
authors.forename: Mingjiang
authors.initials: M
authors.lastname: Chen
authors.forename: Shijia
authors.initials: S
authors.lastname: Liu
authors.forename: Liangming
authors.initials: L
authors.lastname: Chen
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.forename: Jiankang
authors.initials: J
authors.lastname: Wang
authors.forename: Huqu
authors.initials: H
authors.lastname: Zhai
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wan
keywords: Chromosome segment sub-situtution lines; Eating and cooking quality; QTL; Rapid viscosity analyzer profiles