title: Fine mapping of the grain chalkiness QTL qPGWC-7 in rice (Oryza sativa L.).
abstract: Chalkiness of rice grain is an important quality component of rice, as it has a profound influence on eating and milling qualities. We has determined the inheritance of percentage of grain with chalkiness (PGWC) using a set of chromosome segment substitution lines, made from a cross between cv. PA64s and cv. 9311. Two loci controlling PGWC, designated as qPGWC-6 and qPGWC-7, were located on, respectively, chromosomes 6 and 7. Comparisons were made between C-51 (a CSSL harbouring qPGWC-7 and having a chalky endosperm) and the recurrent parent 9311 (translucent endosperm) to characterize the physical and chemical differences between translucent and chalky endosperm. Unlike the translucent endosperm, the chalky endosperm contains loosely packed starch granules, and there were significant difference between C-51 and 9311 for amylopectin structure and degree of crystallinity, but not for either amylose content or starch viscosity. Segregation analysis of the F2 population from the cross between C-51 and 9311 showed PGWC is a semi-dominant trait, controlled by single nuclear gene. A large F2 population was constructed from the cross C51x9311, and used for the fine mapping of qPGWC-7, which was located to a 44-kb DNA fragment, containing thirteen predicted genes. This result provides a springboard for the map-based cloning of qPGWC-7 and allowed for marker-assisted selection for endosperm texture.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Provincial Center of Plant Gene Engineering, Nanjing Agricultural University, 210095, Nanjing, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Zhou
authors.forename: Liangming
authors.initials: L
authors.lastname: Chen
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.forename: Wenwei
authors.initials: W
authors.lastname: Zhang
authors.forename: Linglong
authors.initials: L
authors.lastname: Liu
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Shijia
authors.initials: S
authors.lastname: Liu
authors.forename: Lujun
authors.initials: L
authors.lastname: Zhang
authors.forename: Jiankang
authors.initials: J
authors.lastname: Wang
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wan
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D017343:Genes, Plant; D005819:Genetic Markers; D006824:Hybridization, Genetic; D018895:Microsatellite Repeats; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology; D040641:Quantitative Trait Loci
chemical_list: D005819:Genetic Markers