title: A major quantitative trait locus for increasing cadmium-specific concentration in rice grain is located on the short arm of chromosome 7.
abstract: Large phenotypic variations in the cadmium (Cd) concentration of rice grains and shoots have been observed. However, the genetic control of Cd accumulation remains poorly understood. Quantitative trait loci (QTLs) determining the grain Cd concentration of rice grown in a Cd-polluted paddy field were identified. Using a mapping population consisting of 85 backcross inbred lines derived from a cross between the low-Cd-accumulating cultivar Sasanishiki (japonica) and high-Cd-accumulating cultivar Habataki (indica), two QTLs for increasing grain Cd concentration were found on chromosomes 2 and 7. A major-effect QTL, qGCd7 (QTL for grain Cd on chromosome 7), was detected on the short arm of chromosome 7. It accounted for 35.5% of all phenotypic variance in backcross inbred lines. qGCd7 was not genetically related to any QTLs for concentrations of essential trace metals (Cu, Fe, Mn, and Zn) or those for agronomic traits such as heading date, suggesting that this QTL is specific to Cd. Furthermore, the existence of qGCd7 was confirmed using chromosome segment substitution lines (CSSLs) and an F(2) population from a cross between the target CSSL and Sasanishiki grown in a Cd-polluted paddy soil. To our knowledge, qGCd7 is a novel QTL with major effects for increasing grain Cd concentrations.
authors.affiliation: Soil Environment Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan. isatoru@affrc.go.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Tadashi
authors.initials: T
authors.lastname: Abe
authors.forename: Masato
authors.initials: M
authors.lastname: Kuramata
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Tsuyu
authors.initials: T
authors.lastname: Ando
authors.forename: Toshio
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yano
mesh_terms: D002104:Cadmium / Q000378:metabolism*; D032461:Chromosomes, Plant / Q000235:genetics*; D003433:Crosses, Genetic; D007178:Inbreeding; D008126:Lod Score; D012275:Oryza / Q000235:genetics* / Q000378:metabolism*; D010641:Phenotype; D020161:Physical Chromosome Mapping; D012150:Polymorphism, Restriction Fragment Length; D040641:Quantitative Trait Loci / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D015203:Reproducibility of Results; D012639:Seeds / Q000235:genetics*; D014131:Trace Elements / Q000378:metabolism
chemical_list: D014131:Trace Elements; D002104:Cadmium