title: Phosphorus deficiency-induced root elongation and its QTL in rice (Oryza sativa L.).
abstract: A significant level of root elongation was induced in rice (Oryza sativa) grown under phosphorus-deficient conditions. The root elongation clearly varied among a total of 62 varieties screened under two different phosphorus levels. Two contrasting varieties, 'Gimbozu', with a low elongating response and 'Kasalath', with a high elongating response, were chosen and crossed to produce a hybrid population for QTL analyses. QTLs for the phosphorus deficiency-induced root elongation were detected by two linkage maps, i.e., one with 82 F3 families constructed by 97 simple sequence repeat (SSR) and sequence-tag site markers and another with 97 F8 lines by 790 amplified fragment length polymorphism and SSR markers. A single QTL for the elongation response was detected on chromosome 6, with a LOD score of 4.5 in both maps and explained about 20% of total phenotypic variance. In addition, this QTL itself, or a region tightly linked with it, partly explained an ability to reduce accumulation of excess iron in the shoots. The identified QTL will be useful to improve rice varieties against a complex nutritional disorder caused by phosphorus deficiency and iron toxicity.
authors.affiliation: Laboratory of Plant Genetics and Breeding, College of Bioresource Sciences, Nihon University, Kameino Fujisawa, Kanagawa, 252-8501, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Shimizu
authors.forename: Seiji
authors.initials: S
authors.lastname: Yanagihara
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikehashi
mesh_terms: D012275:Oryza / Q000235:genetics*; D010758:Phosphorus / Q000172:deficiency*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development*; D040641:Quantitative Trait Loci; D015203:Reproducibility of Results; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D013045:Species Specificity
chemical_list: D010758:Phosphorus