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Genetic and Biochemical Analysis of Iron Bioavailability in Maize
Author(s) -
Mwaniki Angela Muthoni,
Cheng Zhiqiang,
Hoekenga Owen,
Buckler Edward,
Kochian Leon,
Glahn Raymond
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a623-d
Subject(s) - quantitative trait locus , bioavailability , biofortification , population , interaction , biology , inbred strain , food science , chemistry , agronomy , genetics , gene , zinc , bioinformatics , demography , organic chemistry , sociology
The average iron deficiency prevalence in Sub‐Saharan Africa is 40 percent. The high consumption of maize in the region makes it an ideal crop for Fe biofortification. The objective of this study was to utilize an in vitro digestion/Caco‐2 cell model to identify molecular markers that correlate with iron bioavailability. We employed 145 recombinant inbred (RI) varieties from the highly genetically characterized Intermated B73 x Mo17 (IBM) RI maize population. Total Fe and phytate content in ground seeds ranged from: 13.3 to 32.3 mg/g and 6.3 to 12 mmoles/g respectively. Total Fe content did not correlate with Caco‐2 cell Fe uptake. ANOVA on Caco‐2 cell Fe uptake data confirmed differences in Fe availability between genotypes (p<0.01). Composite interval mapping analysis identified quantitative trait loci (QTL) on chromosome 6 for Fe availability (p < 0.01). QTL were identified between molecular genetic markers php20528 and uck1. Using marker regression analysis additional minor QTL were identified on chromosome 3 (between umc2117 and mmp144) and chromosome 9 (between ufg24 and umc2134). Multivariate regression analysis was performed with Fe, Ca, P and Zn concentration as continuous variables, QTL associated markers as categorical variables and ferritin formation as the dependent variable. This statistical model obtained explained 30% of the variance observed. Our results indicate that Fe bioavailability has a genetic component and is unrelated to total Fe levels. Further characterization of these QTL should provide valuable tools to the maize breeder seeking to develop maize with improved Fe bioavailability.