title: A major QTL controlling deep rooting on rice chromosome 4.
abstract: Drought is the most serious abiotic stress that hinders rice production under rainfed conditions. Breeding for deep rooting is a promising strategy to improve the root system architecture in shallow-rooting rice cultivars to avoid drought stress. We analysed the quantitative trait loci (QTLs) for the ratio of deep rooting (RDR) in three F₂ mapping populations derived from crosses between each of three shallow-rooting varieties ('ARC5955', 'Pinulupot1', and 'Tupa729') and a deep-rooting variety, 'Kinandang Patong'. In total, we detected five RDR QTLs on chromosomes 2, 4, and 6. In all three populations, QTLs on chromosome 4 were found to be located at similar positions; they explained from 32.0% to 56.6% of the total RDR phenotypic variance. This suggests that one or more key genetic factors controlling the root growth angle in rice is located in this region of chromosome 4.
authors.affiliation: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Uga
authors.forename: Eiji
authors.initials: E
authors.lastname: Yamamoto
authors.forename: Noriko
authors.initials: N
authors.lastname: Kanno
authors.forename: Sawako
authors.initials: S
authors.lastname: Kawai
authors.forename: Tatsumi
authors.initials: T
authors.lastname: Mizubayashi
authors.forename: Shuichi
authors.initials: S
authors.lastname: Fukuoka
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D008126:Lod Score; D012275:Oryza / Q000235:genetics* / Q000254:growth & development*; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development*; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci