title: Examining Two Sets of Introgression Lines in Rice (Oryza sativa L.) Reveals Favorable Alleles that Improve Grain Zn and Fe Concentrations.
abstract: In the modern world, the grain mineral concentration (GMC) in rice (Oryza sativa L.) not only includes important micronutrient elements such as iron (Fe) and zinc (Zn), but it also includes toxic heavy metal elements, especially cadmium (Cd) and lead (Pb). To date, the genetic mechanisms underlying the regulation of GMC, especially the genetic background and G × E effects of GMC, remain largely unknown. In this study, we adopted two sets of backcross introgression lines (BILs) derived from IR75862 (a Zn-dense rice variety) as the donor parent and two elite indica varieties, Ce258 and Zhongguangxiang1, as recurrent parents to detect QTL affecting GMC traits including Fe, Zn, Cd and Pb concentrations in two environments. We detected a total of 22 loci responsible for GMC traits, which are distributed on all 12 rice chromosomes except 5, 9 and 10. Six genetic overlap (GO) regions affecting multiple elements were found, in which most donor alleles had synergistic effects on GMC. Some toxic heavy metal-independent loci (such as qFe1, qFe2 and qZn12) and some regions that have opposite genetic effects on micronutrient (Fe and Zn) and heavy metal element (Pb) concentrations (such as GO-IV) may be useful for marker-assisted biofortification breeding in rice. We discuss three important points affecting biofortification breeding efforts in rice, including correlations between different GMC traits, the genetic background effect and the G × E effect.
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun Street, Beijing, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun Street, Beijing, China.
authors.forename: Tian-Qing
authors.initials: TQ
authors.lastname: Zheng
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun Street, Beijing, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Hu
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun Street, Beijing, China.
authors.forename: Li-Rui
authors.initials: LR
authors.lastname: Cheng
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun Street, Beijing, China; Institute of Agricultural Genomics at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
authors.forename: Jian-Long
authors.initials: JL
authors.lastname: Xu
authors.affiliation: Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, China.
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Shi
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan-Cun Street, Beijing, China; Institute of Agricultural Genomics at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
authors.forename: Zhi-Kang
authors.initials: ZK
authors.lastname: Li
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D002523:Edible Grain / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D007501:Iron / Q000378:metabolism*; D018895:Microsatellite Repeats; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D040641:Quantitative Trait Loci; D015032:Zinc / Q000378:metabolism*
chemical_list: D007501:Iron; D015032:Zinc