title: Map-based cloning proves qGC-6, a major QTL for gel consistency of japonica/indica cross, responds by Waxy in rice (Oryza sativa L.).
abstract: In this study, one major QTL affecting gel consistency (GC) of japonica/indica cross was identified on chromosome 6 using a DH population. To understand the molecular mechanism that regulates GC in rice grains, the major QTL (qGC-6) was isolated through a map-based cloning approach utilizing chromosome segment substitution lines (CSSLs). Using 64 plants with extremely soft GC that were selected on recombinant break points between two SSR markers, RM540 and RM8200 in a BC4F2 population, qGC-6 was mapped to a 60-kb DNA region between two STS markers, S26 and S27. These two markers were then used to further identify recombination break points. Finally, qGC-6 was delimited in an interval of a 11-kb region. Gene prediction analysis of the 11-kb DNA sequence containing qGC-6 identified only one putative ORF, which encodes granule-bound starch synthesis protein (Wx protein). Results of sequencing analysis and complementation experiment confirmed that this candidate ORF is responsible for rice GC. Genetic evidences revealed that Wx might contribute equally to the grain amylose content-controlling gene as well as gel consistency. This new information is important to breed rice varieties with improved grain quality.
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, 31006, Hangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Su
authors.forename: Yuchun
authors.initials: Y
authors.lastname: Rao
authors.forename: Shikai
authors.initials: S
authors.lastname: Hu
authors.forename: Yaolong
authors.initials: Y
authors.lastname: Yang
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Gao
authors.forename: Guanghen
authors.initials: G
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Jiang
authors.initials: J
authors.lastname: Hu
authors.forename: Meixian
authors.initials: M
authors.lastname: Yan
authors.forename: Guojun
authors.initials: G
authors.lastname: Dong
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Longbiao
authors.initials: L
authors.lastname: Guo
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Dali
authors.initials: D
authors.lastname: Zeng
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D056726:Genetic Association Studies; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D040641:Quantitative Trait Loci