title: Genetic factors responsible for eating and cooking qualities of rice grains in a recombinant inbred population of an inter-subspecific cross.
abstract: The eating and cooking qualities of rice grains are the major determinants of consumer preference and, consequently, the economic value of a specific rice variety. These two qualities are largely determined by the physicochemical properties of the starch, i.e. the starch composition, of the rice grain. In our study, we determined the genetic factors responsible for the physicochemical properties of starch in recombinant inbred lines (RILs) ofjaponicacv. Tainung 78 ×indicacv. Taichung Sen 17 (TCS 17) cultivated over two crop seasons by examining palatability characteristics and several Rapid Viscosity Analyzer (RVA) parameters. Thirty-four quantitative trait loci (QTLs), each explaining between 1.2 and 78.1 % phenotypic variation, were mapped in clusters on eight chromosomes in 190 RILs genotyped with 139 markers. Ten pairs of QTLs were detected in the two environments, of which seven were in agreement with previous findings, suggesting that these QTLs may express stable experimental populations across various environments. Waxy (Wx), which controls amylose synthesis, was determined to be a primary gene regulating the physicochemical properties of cooked rice grains, as indicated by the presence of a major QTL cluster on chromosome 6 and by marker regression analysis. Six starch synthesis-related genes (SSRGs) which were located in the QTL intervals significantly differed in terms of gene expression between the two parents during grain-filling and were important genetic factors affecting physicochemical properties. The expression of four genes,PUL,ISA2,GBSSI, andSSII-3, was significantly upregulated in TCS 17, and this expression was positively correlated with six traits. The effects of the six SSRGs and gene interaction depended on genetic background and environment; grain quality may be fine tuned by selecting forSBE4forjaponicaandPULforindica. We provide valuable information for application in the breeding of new rice varieties as daily staple food and for use in industrial manufacturing by marker-assisted selection.
authors: Department of Agronomy, Chiayi Agricultural Experiment Station, Taiwan Agricultural Research Institute, Chiayi, Taiwan.
authors: Yu-Chia
authors: YC
authors: Hsu
authors: Department of Agronomy, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan.
authors: Meng-Chun
authors: MC
authors: Tseng
authors: Department of Agronomy, Chiayi Agricultural Experiment Station, Taiwan Agricultural Research Institute, Chiayi, Taiwan.
authors: Yong-Pei
authors: YP
authors: Wu
authors: Department of Agronomy, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan.
authors: Meng-Ying
authors: MY
authors: Lin
authors: Department of Agronomy, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan ; Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
authors: Fu-Jin
authors: FJ
authors: Wei
authors: Department of Agronomy, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan.
authors: Kae-Kang
authors: KK
authors: Hwu
authors: Department of Agronomy, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan ; Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
authors: Yue-Ie
authors: YI
authors: Hsing
authors: Department of Agronomy, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan.
authors: Yann-Rong
authors: YR
authors: Lin
keywords: Grain quality; Palatability; RVA parameters; Starch synthesis-related gene; Viscosity